Recommendations

People have the right to be involved in discussions and make informed decisions about their care, as described in NICE's information on making decisions about your care.

Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

Blood glucose and plasma glucose

'Blood glucose' is the more commonly used term. However, a lot of the evidence this guideline is based on uses 'plasma' rather than 'blood' glucose, and patient‑held glucose meters and monitoring systems are calibrated to plasma glucose equivalents. Because of this, in this guideline we use the term 'blood glucose', except when referring to specific concentration values.

1.1 Diagnosis and early care plan

Initial diagnosis

1.1.1 Make an initial diagnosis of type 1 diabetes on clinical grounds in adults presenting with hyperglycaemia. Bear in mind that people with type 1 diabetes typically (but not always) have 1 or more of:

  • ketosis

  • rapid weight loss

  • age of onset under 50 years

  • body mass index (BMI) below 25 kg/m2

  • personal and/or family history of autoimmune disease. [2015, amended 2022]

1.1.2 Do not use age or BMI alone to exclude or diagnose type 1 diabetes in adults. [2022]

1.1.3 Take into consideration the possibility of other diabetes subtypes and revisit the diagnosis at subsequent clinical reviews. Carry out further investigations if there is uncertainty (see recommendations 1.1.7 and 1.1.8). [2022]

1.1.4 Measure diabetes-specific autoantibodies in adults with an initial diagnosis of type 1 diabetes, taking into account that:

  • the false negative rate of diabetes-specific autoantibody tests is lowest at the time of diagnosis

  • the false negative rate can be reduced by carrying out quantitative tests for 2 different diabetes-specific autoantibodies (with at least 1 being positive). [2022]

1.1.5 Do not routinely measure serum C‑peptide to confirm type 1 diabetes in adults. [2022]

1.1.6 In people with a negative diabetes-specific autoantibody result, and if diabetes classification remains uncertain, consider measuring non-fasting serum C‑peptide (with a paired blood glucose). [2022]

Revisiting initial diagnosis

1.1.7 At subsequent clinical reviews, consider using serum C‑peptide to revisit the diabetes classification if there is doubt that type 1 diabetes is the correct diagnosis. [2022]

1.1.8 Take into account that the discriminative value of serum C‑peptide to diagnose type 1 diabetes increases the longer the test is done after initial diagnosis of diabetes. [2022]

1.1.9 For people aged 60 and over presenting with weight loss and new-onset diabetes, follow recommendations on assessing for pancreatic cancer in the section on pancreatic cancer in the NICE guideline on suspected cancer: recognition and referral. [2022]

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on diagnosis.

Full details of the evidence and the committee's discussion are in evidence review C: diagnosis of diabetes.

Early care plan

1.1.10 At diagnosis (or, if necessary, after managing critically decompensated metabolism), the diabetes professional team should work with adults with type 1 diabetes to develop a plan for their early care. This will generally require:

  • medical assessment to:

    • ensure the diagnosis is accurate (see recommendations 1.1.1 to 1.1.5)

    • ensure appropriate acute care is given when needed

    • review medicines and detect potentially associated disease

    • detect adverse vascular risk factors

  • environmental assessment to understand:

    • the social, home, work and recreational circumstances of the person and their carers

    • their lifestyle (including diet and physical activity)

    • other relevant factors, such as substance use

  • cultural and educational assessment to:

    • find out what they know about diabetes

    • help with tailoring advice, and with planning treatments and diabetes education programmes

  • assessment of their emotional wellbeing to decide how to pace diabetes education. [2004]

1.1.11 Use the results of the initial diabetes assessment to agree a future care plan. This assessment should include:

  • acute medical history

  • social, cultural and educational history, and lifestyle review

  • complications history and symptoms

  • diabetes history (recent and long term)

  • other medical history

  • family history of diabetes and cardiovascular disease

  • medication history

  • vascular risk factors

  • smoking

  • general examination

  • weight and BMI

  • foot, eye and vision examination

  • urine albumin:creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR)

  • psychological wellbeing

  • attitudes to medicine and self‑care

  • immediate family and social relationships, and availability of informal support. [2004, amended 2021]

1.1.12 Include the following in an individualised and culturally appropriate diabetes plan:

1.1.13 After the initial plan is agreed, implement it without inappropriate delay. Based on discussion with the adult with type 1 diabetes, modify the plan as needed over the following weeks. [2004]

1.2 Support and individualised care

1.2.1 Take account of any disabilities, including visual impairment, when planning and delivering care for adults with type 1 diabetes. [2015]

1.2.2 Advice to adults with type 1 diabetes should be provided by a range of professionals with skills in diabetes care, working together in a coordinated approach. [2004, amended 2021]

1.2.3 Provide adults with type 1 diabetes with:

  • access to services by different methods (including phone and email) during working hours

  • information about out-of-hours services staffed by people with diabetes expertise. [2004]

1.2.4 View each adult with type 1 diabetes as an individual, rather than as a member of any cultural, economic or health-affected group (also see recommendations 1.4.5 and 1.4.14 on cultural preferences in the section on dietary advice). [2004, amended 2015]

1.2.5 Jointly agree an individual care plan with the adult with type 1 diabetes. Review this plan annually and amend it as needed, taking into account changes in the person's wishes, circumstances and medical findings. [2004, amended 2015]

1.2.6 Individual care plans should include:

1.2.7 Use population, practice‑based and clinic diabetes registers (as specified by the Department of Health and Social Care's national service framework for diabetes) to assist programmed recall for annual reviews and assessments of complications and cardiovascular risk. [2004]

1.2.8 At diagnosis and periodically after this, give adults with type 1 diabetes up‑to‑date information about diabetes support groups (local and national), how to contact them and their benefits. [2004]

1.3 Education and information

1.3.1 Offer all adults with type 1 diabetes a structured education programme of proven benefit, for example, the DAFNE (dose adjustment for normal eating) programme. [2015]

1.3.2 Offer the structured education programme 6 to 12 months after diagnosis. For adults who have not had a structured education programme by 12 months, offer it at any time that is clinically appropriate and suitable for the person, regardless of how long they have had type 1 diabetes. [2015]

1.3.3 For adults with type 1 diabetes who are unable or prefer not to take part in group education, provide an alternative of equal standard. [2015]

1.3.4 Ensure that any structured education programme for adults with type 1 diabetes:

  • is evidence-based, and suits the needs of the person

  • has specific aims and learning objectives, and supports the person and their family members and carers in developing attitudes, beliefs, knowledge and skills to self‑manage diabetes

  • has a structured curriculum that is theory driven, evidence-based and resource effective and has supporting materials, and is written down

  • is delivered by trained educators who:

    • have an understanding of educational theory appropriate to the age and needs of the person and

    • are trained and competent to deliver the principles and content of the programme

  • is quality assured, and reviewed by trained, competent, independent assessors who measure it against criteria that ensure consistency

  • has outcomes that are audited regularly. [2015]

1.3.5 Explain to adults with type 1 diabetes that structured education is an integral part of diabetes care. [2015]

1.3.6 Provide information about type 1 diabetes and its management to adults with type 1 diabetes at all opportunities from diagnosis onwards. Follow the principles in NICE's guideline on patient experience in adult NHS services. [2015]

1.3.7 Consider the Blood Glucose Awareness Training (BGAT) programme for adults with type 1 diabetes who are having recurrent episodes of hypoglycaemia (see also the section on hypoglycaemia awareness and management). [2015]

1.3.8 Carry out an annual review of self‑care and needs for all adults with type 1 diabetes. Decide what to cover each year by agreeing priorities with the adult with type 1 diabetes. [2004, amended 2015]

1.4 Dietary management

Carbohydrate counting

1.4.1 Offer carbohydrate‑counting training to adults with type 1 diabetes as part of structured education programmes for self‑management (see the section on education and information). [2015]

1.4.2 Consider carbohydrate‑counting courses for adults with type 1 diabetes who are waiting for a more detailed structured education programme or who are unable to take part in a standalone structured education programme. [2015]

Glycaemic index diets

1.4.3 Do not advise adults with type 1 diabetes to follow a low glycaemic index diet for blood glucose control. [2015]

Dietary advice

1.4.4 Offer dietary advice to adults with type 1 diabetes about issues other than blood glucose control (such as managing weight and cardiovascular risk), as needed. [2015]

1.4.5 From diagnosis, provide nutritional information that is sensitive to the personal needs and culture of each adult with type 1 diabetes. [2004]

1.4.6 Provide nutritional information individually and as part of a structured education programme (see the section on education and information). Include advice from professionals who are trained and accredited to provide dietary advice to people with health conditions. [2004]

1.4.7 Offer opportunities to receive dietary advice at intervals agreed between adults with type 1 diabetes and their healthcare professionals. [2004]

1.4.8 Discuss the hyperglycaemic effects of the different foods the adult with type 1 diabetes wants to eat in the context of the insulin regimens chosen to match those food choices. [2004]

1.4.9 Provide education programmes for adults with type 1 diabetes to help them with:

  • healthy eating and a balanced diet

  • changing their insulin dosage to reduce glucose excursions when varying their diet. [2004, amended 2015]

1.4.10 Discuss snacks with the adult with type 1 diabetes:

  • Cover the choice of snack, the quantity, and when to eat them.

  • Explain the effects of eating different food types, and how long these effects last.

  • Explain which insulin regimens are available to match different food types.

  • Discuss changes in choice of snack if needed, based on the results of self‑monitoring tests. [2004]

1.4.11 Provide information on:

  • the effects of different alcohol‑containing drinks on blood glucose excursions and calorie intake

  • high‑calorie and high‑sugar 'treats'. [2004, amended 2015]

1.4.12 As part of dietary education after diagnosis (and as needed after this), provide information on how healthy eating can reduce cardiovascular risk. Include information about fruit and vegetables, types and amounts of fat, and how to make the appropriate dietary changes. [2004, amended 2015]

1.4.13 Modify nutritional recommendations to adults with type 1 diabetes to take account of associated features of diabetes, including:

  • excess weight and obesity

  • underweight

  • disordered eating

  • hypertension

  • renal failure. [2004, amended 2021]

1.4.14 Healthcare professionals giving dietary advice to adults with type 1 diabetes should be able to advise about common topics of concern and interest, and should seek advice from specialists when needed. Suggested common topics include:

  • body weight, energy balance and obesity management

  • cultural and religious diets, feasts and fasts

  • foods sold as 'diabetic'

  • sweeteners

  • dietary fibre intake

  • protein intake

  • vitamin and mineral supplements

  • alcohol

  • matching carbohydrate intake, insulin and physical activity

  • salt intake in hypertension

  • comorbidities, including nephropathy and renal failure, coeliac disease, cystic fibrosis or eating disorders

  • peer support groups. [2004, amended 2015]

1.5 Physical activity

1.5.1 Advise adults with type 1 diabetes that physical activity can reduce their enhanced cardiovascular risk in the medium and long term. [2004]

1.5.2 For adults with type 1 diabetes who choose to increase their level of physical activity as part of a healthier lifestyle, provide information about:

  • appropriate intensity and frequency of physical activity

  • self‑monitoring their changed insulin and or nutritional needs

  • the effect of physical activity on blood glucose levels (which are likely to fall) when insulin levels are adequate

  • the effect of physical activity on blood glucose levels when hyperglycaemic and hypoinsulinaemic (there is a risk of worsening hyperglycaemia and ketonaemia)

  • appropriate adjustments of insulin dosage and or nutritional intake for periods during and immediately after physical activity, and the 24 hours after this

  • interactions of physical activity and alcohol

  • further contacts and sources of information. [2004]

1.6 Blood glucose management

HbA1c measurement and targets

Measurement

1.6.1 Measure HbA1c levels every 3 to 6 months in adults with type 1 diabetes. [2015]

1.6.2 Consider measuring HbA1c levels more often in adults with type 1 diabetes if their blood glucose control is suspected to be changing rapidly; for example, if their HbA1c level has risen unexpectedly above a previously sustained target. [2015]

1.6.3 Measure HbA1c using methods calibrated according to International Federation of Clinical Chemistry (IFCC) standardisation. [2015]

1.6.4 Tell adults with type 1 diabetes their HbA1c results after each measurement and have their most recent result available at consultations. Follow the principles on communication in NICE's guideline on patient experience in adult NHS services. [2015]

1.6.5 If HbA1c monitoring is invalid because of disturbed erythrocyte turnover or abnormal haemoglobin type, estimate trends in blood glucose control using 1 of the following:

  • fructosamine estimation

  • quality-controlled blood glucose profiles

  • total glycated haemoglobin estimation (if abnormal haemoglobins). [2015]

Targets

1.6.6 Support adults with type 1 diabetes to aim for a target HbA1c level of 48 mmol/mol (6.5%) or lower, to minimise the risk of long‑term vascular complications. [2015]

1.6.7 Agree an individualised HbA1c target with each adult with type 1 diabetes. Take into account factors such as their daily activities, aspirations, likelihood of complications, comorbidities, occupation and history of hypoglycaemia. [2015]

1.6.8 Ensure that aiming for an HbA1c target is not accompanied by problematic hypoglycaemia in adults with type 1 diabetes. [2015]

1.6.9 Diabetes services should document the proportion of adults with type 1 diabetes who reach an HbA1c level of 53 mmol/mol (7%) or lower. [2015]

Continuous glucose monitoring

NICE's diagnostics guidance on integrated sensor-augmented pump therapy systems for managing blood glucose levels in type 1 diabetes is being updated. The guidance is being updated as a multiple technology appraisal and will assess hybrid closed loop systems.

1.6.10 Offer adults with type 1 diabetes a choice of real-time continuous glucose monitoring (rtCGM) or intermittently scanned continuous glucose monitoring (isCGM, commonly referred to as 'flash'), based on their individual preferences, needs, characteristics, and the functionality of the devices available. See box 1 for examples of factors to consider as part of this discussion. [2022]

1.6.11 When choosing a continuous glucose monitoring (CGM) device:

  • use shared decision making to identify the person's needs and preferences, and offer them an appropriate device

  • if multiple devices meet their needs and preferences, offer the device with the lowest cost. [2022]

Box 1 Factors to consider when choosing a continuous glucose monitoring device
  • Accuracy of the device

  • Whether the device provides predictive alerts or alarms and if these need to be shared with anyone else (for example, a carer)

  • Whether using the device requires access to particular technologies (such as a smartphone and up-to-date phone software)

  • How easy the device is to use and take readings from, including for people with limited dexterity

  • Fear, frequency, awareness and severity of hypoglycaemia

  • Psychosocial factors

  • The person's insulin regimen or type of insulin pump, if relevant (taking into account whether a particular device integrates with their pump as part of a hybrid closed loop or insulin suspend function)

  • Whether, how often, and how the device needs to be calibrated, and how easy it is for the person to do this themselves

  • How data can be collected, compatibility of the device with other technology, and whether data can be shared with the person's healthcare provider to help inform treatment

  • Whether the device will affect the person's ability to do their job

  • How unpredictable the person's activity and blood glucose levels are and whether erratic blood glucose is affecting their quality of life

  • Whether the person has situations when symptoms of hypoglycaemia cannot be communicated or can be confused (for example, during exercise)

  • Clinical factors that may make devices easier or harder to use

  • Frequency of sensor replacement

  • Sensitivities to the device, for example local skin reactions

  • Body image concerns

1.6.12 CGM should be provided by a team with expertise in its use, as part of supporting people to self-manage their diabetes. [2015, amended 2022]

1.6.13 Advise adults with type 1 diabetes who are using CGM that they will still need to take capillary blood glucose measurements (although they can do this less often). Explain that this is because:

  • they will need to use capillary blood glucose measurements to check the accuracy of their CGM device

  • they will need capillary blood glucose monitoring as a back-up (for example, when their blood glucose levels are changing quickly or if the device stops working).

    Provide them with enough test strips to take capillary blood glucose measurements as needed. [2022]

1.6.14 If a person cannot use or does not want rtCGM or isCGM, offer capillary blood glucose monitoring. [2022]

1.6.15 Include CGM in the structured education programme provided to all adults with type 1 diabetes (see the section on education and information), and ensure that people are empowered to use CGM devices (see the section on empowering people to self-monitor blood glucose). [2022]

1.6.16 Monitor and review the person's use of CGM as part of reviewing their diabetes care plan (see recommendations 1.1.7, 1.2.5 and 1.2.6 on what to consider when agreeing a care plan and what a care plan should cover). [2022]

1.6.17 If there are concerns about the way a person is using the CGM device:

  • ask if they are having problems using their device

  • look at ways to address any problems or concerns to improve their use of the device, including further education and emotional and psychological support. [2022]

    For guidance on CGM for pregnant women, see the NICE guideline on diabetes in pregnancy. [2022]

1.6.18 Commissioners, providers and healthcare professionals should address inequalities in CGM access and uptake by:

  • monitoring who is using CGM

  • identifying groups who are eligible but who have a lower uptake

  • making plans to engage with these groups to encourage them to consider CGM. [2022]

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on continuous glucose monitoring.

Full details of the evidence and the committee's discussion are in evidence review B: continuous glucose monitoring in adults with type 1 diabetes.

Self-monitoring of capillary blood glucose

Frequency of self-monitoring of blood glucose

1.6.19 Advise adults with type 1 diabetes who are using capillary blood glucose monitoring to routinely self‑monitor their blood glucose levels, and to measure at least 4 times a day (including before each meal and before bed). [2015, amended 2022]

1.6.20 Support adults with type 1 diabetes who are using capillary blood glucose monitoring to measure at least 4 times a day, and up to 10 times a day:

  • if their target for blood glucose control, measured by HbA1c level (see recommendation 1.6.6), is not reached

  • if they are having more frequent hypoglycaemic episodes

  • if there is a legal requirement to do so, such as before driving (see the Driver and Vehicle Licensing Agency [DVLA] guide for medical professionals)

  • during periods of illness

  • before, during and after sport

  • when planning pregnancy, during pregnancy and while breastfeeding (see NICE's guideline on diabetes in pregnancy)

  • if they need to know their blood glucose levels more than 4 times a day for other reasons (for example, impaired hypoglycaemia awareness, or they are undertaking high‑risk activities). [2015, amended 2022]

1.6.21 Enable additional blood glucose measurement (more than 10 times a day) for adults with type 1 diabetes who are using capillary blood glucose monitoring if this is necessary because of:

  • the person's lifestyle (for example, they drive for long periods of time, they undertake high‑risk activities or have a high‑risk occupation, or they are travelling) or

  • impaired hypoglycaemia awareness. [2015, amended 2022]

Blood glucose targets

1.6.22 Advise adults with type 1 diabetes to aim for:

  • a fasting plasma glucose level of 5 to 7 mmol/litre on waking and

  • a plasma glucose level of 4 to 7 mmol/litre before meals at other times of the day. [2015]

1.6.23 Advise adults with type 1 diabetes who choose to measure after meals to aim for a plasma glucose level of 5 to 9 mmol/litre at least 90 minutes after eating. (This timing may be different in pregnancy – for guidance on plasma glucose targets in pregnancy, see NICE's guideline on diabetes in pregnancy.) [2015]

1.6.24 Agree bedtime target plasma glucose levels with each adult with type 1 diabetes. Take into account the timing of their last meal of the day and the related insulin dose, and ensure the target is consistent with the recommended fasting level on waking (see recommendation 1.6.22). [2015]

Empowering people to self‑monitor blood glucose

1.6.25 Teach self‑monitoring skills at the time of diagnosis and the start of insulin therapy. [2004, amended 2015]

1.6.26 When choosing blood glucose meters:

  • take the needs of the adult with type 1 diabetes into account

  • ensure that meters meet current ISO standards. [2015]

1.6.27 Teach adults with type 1 diabetes how to measure their blood glucose level, interpret the results and take appropriate action. Review these skills at least annually. [2015]

1.6.28 Support adults with type 1 diabetes through structured education (see the section on education and information) to make the best use of data from self‑monitoring of blood glucose. [2015]

Sites for self-monitoring of blood glucose

1.6.29 Monitoring blood glucose using sites other than the fingertips cannot be recommended as a routine alternative to conventional self‑monitoring of blood glucose. [2004, amended 2015]

1.7 Insulin therapy

Insulin regimens

1.7.1 Offer multiple daily injection basal–bolus insulin regimens as the insulin injection regimen of choice for all adults with type 1 diabetes. Provide guidance on using this regimen. [2015]

1.7.2 Do not offer adults newly diagnosed with type 1 diabetes non‑basal–bolus insulin regimens (that is, twice‑daily mixed, basal only or bolus only). [2015]

Long-acting insulin

1.7.3 Offer twice‑daily insulin detemir as basal insulin therapy for adults with type 1 diabetes. [2021]

1.7.4 Consider 1 of the following as an alternative basal insulin therapy to twice-daily insulin detemir for adults with type 1 diabetes:

  • an insulin regimen that is already being used by the person if it is meeting their agreed treatment goals (such as meeting their HbA1c targets or time in target glucose range and minimising hypoglycaemia)

  • once-daily insulin glargine (100 units/ml) if insulin detemir is not tolerated or the person has a strong preference for once‑daily basal injections

  • once-daily insulin degludec (100 units/ml) if there is a particular concern about nocturnal hypoglycaemia

  • once-daily ultra-long-acting insulin such as degludec (100 units/ml) for people who need help from a carer or healthcare professional to administer injections.

    There is a risk of severe harm and death due to inappropriately withdrawing insulin from pen devices. See NHS England's patient safety alert for further information. [2021]

1.7.5 When starting an insulin for which a biosimilar is available, use the product with the lowest acquisition cost. [2021]

1.7.6 Ensure the risk of medication errors with insulins is minimised by following Medicines and Healthcare products Regulatory Agency (MHRA) guidance on minimising the risk of medication error with high strength, fixed combination and biosimilar insulin products, which includes advice for healthcare professionals when starting treatment with a biosimilar. [2021]

1.7.7 When people are already using an insulin for which a lower cost biosimilar is available, discuss the possibility of switching to the biosimilar. Make a shared decision with the person after discussing their preferences. [2021]

1.7.8 Consider other basal insulin regimens for adults with type 1 diabetes only if the regimens in recommendations 1.7.3 and 1.7.4 do not meet their agreed treatment goals. When choosing an alternative insulin regimen, take account of:

  • the person's preferences

  • comorbidities

  • risk of hypoglycaemia and diabetic ketoacidosis

  • any concerns around adherence

  • acquisition cost. [2021]

1.7.9 When prescribing, ensure that insulins are prescribed by brand name. [2021]

For a short explanation of why the committee made these recommendations and how they might affect practice, see the rationale and impact section on long-acting insulin.

Full details of the evidence and the committee's discussion are in evidence review A: long-acting insulins in type 1 diabetes.

Insulin pumps

1.7.10 For guidance on the use of insulin pumps for adults with type 1 diabetes, see NICE's technology appraisal guidance on continuous subcutaneous insulin infusion for the treatment of diabetes mellitus. [2015]

Rapid-acting insulin

1.7.11 Offer rapid‑acting insulin analogues that are injected before meals, rather than rapid‑acting soluble human or animal insulins, for mealtime insulin replacement for adults with type 1 diabetes. [2015]

1.7.12 Do not advise routine use of rapid‑acting insulin analogues after meals for adults with type 1 diabetes. [2015]

1.7.13 If an adult with type 1 diabetes has a strong preference for an alternative mealtime insulin, respect their wishes and offer the preferred insulin. [2015]

Mixed insulin

1.7.14 Consider a twice‑daily human mixed insulin regimen for adults with type 1 diabetes if a multiple daily injection basal–bolus insulin regimen is not possible and a twice‑daily mixed insulin regimen is used. [2015]

1.7.15 Consider a trial of a twice‑daily analogue mixed insulin regimen if an adult using a twice‑daily human mixed insulin regimen has hypoglycaemia that affects their quality of life. [2015]

Optimising insulin therapy

1.7.16 For adults with erratic and unpredictable blood glucose control (hyperglycaemia and hypoglycaemia at no consistent times), consider the following rather than changing a previously optimised insulin regimen:

  • injection technique

  • injection sites

  • self-monitoring skills

  • knowledge and self‑management skills

  • lifestyle

  • mental health and psychosocial problems

  • possible organic causes, such as gastroparesis. [2004, amended 2015]

1.7.17 Give clear guidelines and protocols ('sick‑day rules') to all adults with type 1 diabetes, to help them adjust insulin doses appropriately when they are ill. [2004]

Adjuncts

1.7.18 Consider adding metformin to insulin therapy for adults with type 1 diabetes if:

  • they have a BMI of 25 kg/m2 or above (23 kg/m2 or above for people from South Asian and related family backgrounds) and

  • they want to improve their blood glucose control while minimising their effective insulin dose.

    In August 2015, this was an off-label use of metformin. See NICE's information on prescribing medicines. [2015]

1.8 Insulin delivery

1.8.1 For adults with type 1 diabetes who inject insulin, provide their preferred insulin injection delivery device (this often means using one or more types of insulin injection pen). [2004]

1.8.2 For adults with type 1 diabetes and special visual or psychological needs, provide injection devices or needle‑free systems that they can use independently for accurate dosing. [2004]

1.8.3 Offer needles of different lengths to adults with type 1 diabetes who are having problems such as pain, local skin reactions and injection site leakages. [2015]

1.8.4 After taking clinical factors into account, choose needles with the lowest acquisition cost to use with pre‑filled and reusable insulin pen injectors. [2015]

1.8.5 Advise adults with type 1 diabetes to rotate insulin injection sites and avoid repeated injections at the same point within sites. [2015]

1.8.6 Provide adults with type 1 diabetes with:

1.8.7 Check injection site condition at least annually, and whenever new problems with blood glucose control occur. [2004, amended 2015]

1.9 Referral for islet or pancreas transplantation

1.9.1 For adults with type 1 diabetes who have recurrent severe hypoglycaemia that has not responded to other treatments (see the section on hypoglycaemia awareness and management), consider referral to a centre that assesses people for islet and/or pancreas transplantation. [2015]

1.9.2 Consider islet or pancreas transplantation for adults with type 1 diabetes with suboptimal diabetes control, if they have had a renal transplant and are currently on immunosuppressive therapy. [2015]

1.10 Hypoglycaemia awareness and management

Identifying and quantifying impaired hypoglycaemia awareness

1.10.1 Assess hypoglycaemia awareness in adults with type 1 diabetes at each annual review. [2015]

1.10.2 Use the Gold score or Clarke score to quantify hypoglycaemia awareness in adults with type 1 diabetes, checking that the questionnaire items have been answered correctly. [2015]

1.10.3 Explain to adults with type 1 diabetes that impaired awareness of the symptoms of plasma glucose levels below 3 mmol/litre is associated with a significantly increased risk of severe hypoglycaemia. [2015]

Managing impaired hypoglycaemia awareness

1.10.4 Ensure that adults with type 1 diabetes and impaired hypoglycaemia awareness have had structured education in flexible insulin therapy using basal–bolus regimens, and are following its principles correctly. [2015]

1.10.5 Offer additional education focusing on avoiding and treating hypoglycaemia to adults with type 1 diabetes who still have impaired hypoglycaemia awareness after structured education in flexible insulin therapy. [2015]

1.10.6 Avoid relaxing individualised blood glucose targets to address impaired hypoglycaemia awareness for adults with type 1 diabetes. [2015]

1.10.7 For adults with type 1 diabetes and impaired hypoglycaemia awareness who are using lower target blood glucose levels than recommended in this guideline, encourage them to use the recommended targets (see the recommendations on blood glucose targets). [2015]

1.10.8 Review insulin regimens and doses, and prioritise ways to avoid hypoglycaemia in adults with type 1 diabetes with impaired hypoglycaemia awareness, including:

  • reinforcing the principles of structured education

  • offering an insulin pump

  • offering real‑time continuous glucose monitoring. [2015]

1.10.9 If, despite these interventions, an adult with type 1 diabetes has impaired hypoglycaemia awareness that is associated with recurrent severe hypoglycaemia, consider referring them to a specialist centre. [2015]

Preventing and managing hypoglycaemia

1.10.10 Explain to adults with type 1 diabetes that a fast‑acting form of glucose is needed for managing hypoglycaemic symptoms or signs in people who can swallow. [2004, amended 2015]

1.10.11 Adults with type 1 diabetes who have a decreased level of consciousness because of hypoglycaemia and so cannot safely take oral treatment should be:

  • given intramuscular glucagon by a family member or friend who has been shown how to use it (intravenous glucose may be used by healthcare professionals skilled in getting intravenous access)

  • checked for response at 10 minutes, and then given intravenous glucose if their level of consciousness is not improving significantly

  • then given oral carbohydrate when it is safe to administer it, and put under continued observation by someone who has been warned about the risk of relapse. [2004, amended 2015]

1.10.12 Explain to adults with type 1 diabetes that:

  • it is very common to experience some hypoglycaemic episodes with any insulin regimen

  • they should use a regimen that avoids or reduces the frequency of hypoglycaemic episodes, while maintaining the most optimal blood glucose control possible. [2004]

1.10.13 Make hypoglycaemia advice available to all adults with type 1 diabetes, to help them find the best possible balance with any insulin regimen. (See the sections on insulin therapy and insulin delivery.) [2004]

1.10.14 If hypoglycaemia becomes unusually problematic or increases in frequency, review the following possible causes:

  • inappropriate insulin regimens (incorrect dose distributions and insulin types)

  • meal and activity patterns, including alcohol

  • injection technique and skills, including insulin resuspension if necessary

  • injection site problems

  • possible organic causes, including gastroparesis

  • changes in insulin sensitivity (including drugs affecting the renin–angiotensin system and renal failure)

  • mental health problems

  • previous physical activity

  • lack of appropriate knowledge and skills for self‑management. [2004]

1.10.15 Manage nocturnal hypoglycaemia (symptomatic or detected on monitoring) by:

  • reviewing knowledge and self‑management skills

  • reviewing current insulin regimen, evening eating habits and previous physical activity

  • choosing an insulin type and regimen that is less likely to cause low glucose levels at night. [2004, amended 2015]

1.10.16 If early cognitive decline occurs in adults on long‑term insulin therapy, then in addition to normal investigations consider possible brain damage from overt or covert hypoglycaemia, and the need to manage this. [2004]

1.11 Ketone monitoring and managing diabetic ketoacidosis

Ketone self-monitoring to prevent diabetic ketoacidosis

1.11.1 Consider ketone monitoring (blood or urine) as part of 'sick‑day rules' for adults with type 1 diabetes, to help with self‑management of hyperglycaemia. [2015]

Ketone monitoring in hospital

1.11.2 In adults with type 1 diabetes presenting to emergency services, consider capillary blood ketone testing if:

  • diabetic ketoacidosis (DKA) is suspected or

  • the person has uncontrolled diabetes during an illness, and urine ketone testing is positive. [2015]

1.11.3 Consider capillary blood ketone testing (incorporated into a formal protocol) for inpatient management of DKA in adults with type 1 diabetes. [2015]

Management of DKA

1.11.4 Professionals managing DKA in adults should have adequate and up-to-date training, and be familiar with all aspects of DKA management that are associated with mortality and morbidity. These topics should include:

  • fluid balance

  • acidosis

  • cerebral oedema

  • electrolyte imbalance

  • that DKA can affect the results of standard diagnostic tests (white cell count, body temperature, electrocardiogram [ECG])

  • respiratory distress syndrome

  • cardiac abnormalities

  • precipitating causes

  • infection management, including opportunistic infections

  • gastroparesis

  • use of high dependency and intensive care units

  • recommendations 1.11.5 to 1.11.12 in this guideline.

    Management of DKA in adults should be in line with local clinical governance. [2004]

1.11.5 Use isotonic saline for primary fluid replacement in adults with DKA, not given too rapidly except in cases of circulatory collapse. [2004]

1.11.6 Do not generally use bicarbonate for managing DKA in adults. [2004, amended 2015]

1.11.7 Give intravenous insulin by infusion to adults with DKA. [2004]

1.11.8 When the plasma glucose concentration has fallen to 10 to 15 mmol/litre in adults with DKA, give glucose‑containing fluids (not more than 2 litres in 24 hours) so that the insulin infusion can be continued at a sufficient rate to clear ketones (for example, 6 units/hour, monitored for effect). [2004, amended 2015]

1.11.9 Begin potassium replacement early in DKA in adults, with frequent monitoring for hypokalaemia. [2004]

1.11.10 Do not generally use phosphate replacement when managing DKA in adults. [2004, amended 2015]

1.11.11 In adults with DKA who have reduced consciousness, think about:

  • inserting a nasogastric tube and

  • monitoring urine output using a urinary catheter and

  • giving venous thromboembolism (VTE) prophylaxis. [2004, amended 2021]

1.11.12 To reduce the risk of catastrophic outcomes in adults with DKA, use continuous monitoring and frequent reviews that cover all aspects of clinical management. [2004, amended 2015]

1.12 Associated illness

1.12.1 In adults with type 1 diabetes who have unexplained weight loss, assess for coeliac disease. For guidance on testing for coeliac disease, see NICE's guideline on coeliac disease. [2004, amended 2015]

1.12.2 Be alert to the possibility of other autoimmune diseases in adults with type 1 diabetes (including Addison's disease and pernicious anaemia). For advice on monitoring for thyroid disease, see the recommendation on thyroid disease monitoring. [2004, amended 2015]

1.13 Control of cardiovascular risk

Aspirin

1.13.1 Do not offer aspirin for the primary prevention of cardiovascular disease in adults with type 1 diabetes. [2015]

Identifying cardiovascular risk

1.13.2 Assess cardiovascular risk factors annually, including:

  • estimated glomerular filtration rate (eGFR) and urine albumin:creatinine ratio (ACR)

  • smoking

  • blood glucose control

  • blood pressure

  • full lipid profile (including high-density lipoprotein [HDL] and low-density lipoprotein [LDL] cholesterol, and triglycerides)

  • age

  • family history of cardiovascular disease

  • abdominal adiposity. [2004, amended 2015 and 2021]

1.13.3 For guidance on tools for assessing risk of cardiovascular disease in adults with type 1 diabetes, see the recommendations on full formal risk assessment in NICE's guideline on lipid modification. [2015]

Interventions to reduce risk and manage cardiovascular disease

1.13.4 For guidance on the primary prevention of cardiovascular disease in adults with type 1 diabetes, see the section on primary prevention for people with type 1 diabetes in NICE's guideline on lipid modification. [2015]

1.13.5 Give adults with type 1 diabetes who smoke advice on stopping smoking and stop smoking services, including NICE guidance‑recommended therapies (see the NICE topic page on smoking and tobacco). Reinforce these messages annually for people who currently do not plan to stop smoking, and at all clinical contacts if there is a prospect of the person stopping. [2004]

1.13.6 Advise adults who do not smoke never to start smoking. [2004, amended 2021]

1.13.7 Provide intensive management for adults who have had myocardial infarction or stroke, according to relevant non‑diabetes guidelines. For angina or other ischaemic heart disease, beta-blockers should be considered (for insulin use in these circumstances, see the section on caring for adults with type 1 diabetes in hospital). For guidance on secondary prevention of myocardial infarction, see NICE's guideline on acute coronary syndromes. [2004, amended 2015]

Blood pressure management

1.13.8 Recommend blood pressure management at 135/85 mmHg for adults with type 1 diabetes. If they have albuminuria or 2 or more features of metabolic syndrome, recommend blood pressure management at 130/80 mmHg. See also the recommendations on diabetic kidney disease and NICE's guideline on hypertension in adults. [2004, amended 2021]

1.13.9 Discuss the following with adults with type 1 diabetes who have hypertension to help them make an informed choice:

  • reasons for the choice of intervention level

  • the substantial potential gains from small improvements in blood pressure control

  • any possible negative consequences of therapy. [2004, amended 2015]

1.13.10 Start a trial of a renin–angiotensin system blocking drug as first‑line therapy for hypertension in adults with type 1 diabetes. [2004, amended 2015]

1.13.11 Provide information to adults with type 1 diabetes on how lifestyle changes can improve their blood pressure control and associated outcomes, and offer help to achieve their aims in this area. [2004]

1.13.12 Do not allow concerns over potential side effects to inhibit advising and offering the necessary use of any class of drugs, unless side effects become symptomatic or otherwise clinically significant. In particular:

  • do not avoid selective beta-blockers for adults on insulin if these are indicated

  • low-dose thiazides may be combined with beta‑blockers

  • when prescribing calcium channel antagonists, only use long‑acting preparations

  • ask adults directly about potential side effects of erectile dysfunction, lethargy and orthostatic hypotension with different drug classes. [2004, amended 2015]

1.13.13 For guidance on blood pressure management in adults with type 1 diabetes and evidence of renal involvement, see the section on blood pressure control in NICE's guideline on chronic kidney disease. [2015]

1.14 Caring for adults with type 1 diabetes in hospital

Blood glucose control

1.14.1 Aim for a target plasma glucose level of 5 to 8 mmol/litre for adults with type 1 diabetes during surgery or acute illness. [2015]

1.14.2 Establish a local protocol for controlling blood glucose levels in adults with type 1 diabetes during surgery or acute illness to reach the target level. [2015]

1.14.3 Use intravenous rather than subcutaneous insulin regimens for adults with type 1 diabetes if:

  • they are unable to eat or are predicted to miss more than 1 meal or

  • an acute situation is expected to result in unpredictable blood glucose levels – for example, major surgery, high‑dose steroid treatment, inotrope treatment or sepsis or

  • insulin absorption is expected to be unpredictable, for example, because of circulatory compromise. [2015]

1.14.4 Consider continuing the person's existing basal insulin regimen (including basal rate if they are using insulin pump therapy) together with protocol‑driven insulin delivery for controlling blood glucose levels in adults with type 1 diabetes during surgery or acute illness. [2015]

1.14.5 Use subcutaneous insulin regimens (including rapid‑acting insulin before meals) if an adult with type 1 diabetes and acute illness is eating. [2015]

1.14.6 Enable adults with type 1 diabetes who are hospital inpatients to self‑administer subcutaneous insulin if they are willing and able and it is safe for them to do so. [2015]

Delivering care in hospital and other institutions

These recommendations are for care teams caring for adults with type 1 diabetes in hospital and in institutions such as nursing homes, residential homes and prisons.

1.14.7 From admission, provide ongoing advice to adults with type 1 diabetes and the team caring for them from a trained multidisciplinary team with expertise in diabetes. [2004]

1.14.8 Throughout inpatient admission, respect the personal expertise of adults with type 1 diabetes in managing their own diabetes and incorporate this into routine ward‑based blood glucose monitoring and insulin delivery. [2004, amended 2015]

1.14.9 Throughout inpatient admission, support adults with type 1 diabetes to make their own food choices based on their personal knowledge of their dietary needs, except when illness or medical or surgical intervention significantly disturbs those requirements. [2004]

1.14.10 Provide optimal insulin therapy, which can be achieved using intravenous insulin and glucose, to all adults with type 1 diabetes with threatened or actual stroke. Critical care and emergency departments should have a protocol for such management. [2004, amended 2011]

1.15 Managing complications

Periodontitis

1.15.1 Advise adults with type 1 diabetes at their annual review of self‑care and needs that:

  • they are at higher risk of periodontitis

  • if they get periodontitis, managing it can improve their blood glucose control and can reduce their risk of hyperglycaemia. [2022]

1.15.2 Advise adults with type 1 diabetes to have regular oral health reviews (their oral healthcare or dental team will tell them how often, in line with the NICE guideline on dental checks: intervals between oral health reviews). [2022]

1.15.3 For guidance for oral healthcare and dental teams on how to provide oral health advice, see the NICE guideline on oral health promotion.[2022]

1.15.4 For adults with type 1 diabetes who have been diagnosed with periodontitis by an oral healthcare or dental team, offer dental appointments to manage and treat their periodontitis (at a frequency based on their oral health needs). [2022]

For a short explanation of why the committee made these recommendations, see the rationale and impact section on periodontitis.

Full details of the evidence and the committee's discussion are in evidence review D: periodontitis.

Eye disease

1.15.5 When adults are diagnosed with type 1 diabetes, refer them immediately to the local eye screening service. [2004, amended 2020]

1.15.6 Encourage adults to attend eye screening, and explain that it will help them to keep their eyes healthy and help to prevent problems with their vision. Explain that the screening service is effective at identifying problems so that they can be treated early. [2004]

1.15.7 Arrange emergency review by an ophthalmologist for:

  • sudden loss of vision

  • rubeosis iridis

  • pre-retinal or vitreous haemorrhage

  • retinal detachment. [2004, amended 2015]

1.15.8 Refer to an ophthalmologist in accordance with the UK National Screening Committee criteria and timelines for any large sudden unexplained drop in visual acuity. [2004, amended 2020]

Diabetic kidney disease

1.15.9 For guidance on managing kidney disease in adults with type 1 diabetes, see NICE's guideline on chronic kidney disease. [2015]

1.15.10 Ask all adults with type 1 diabetes, with or without detected nephropathy, to bring in the first urine sample of the day ('early morning urine') once a year. Send this for estimation of albumin:creatinine ratio (estimating urine albumin concentration alone is a poor alternative) and measure eGFR at the same time. See NICE's guideline on chronic kidney disease. [2004, amended 2021]

1.15.11 Suspect other renal disease if:

  • progressive retinopathy is absent

  • blood pressure is particularly high

  • proteinuria develops suddenly

  • significant haematuria is present (see NICE's guideline on chronic kidney disease)

  • the person is systemically unwell. [2004]

1.15.12 If albuminuria is found, discuss with the person what this means. [2004, amended 2015]

1.15.14 Maintain the person's blood pressure below 130/80 mmHg by adding other anti‑hypertensive drugs if necessary. [2004]

1.15.15 Advise adults with type 1 diabetes and nephropathy about the advantages of avoiding a high‑protein diet. [2004]

1.15.16 Referral criteria for tertiary care should be agreed between local diabetes specialists and nephrologists. See NICE's guideline on chronic kidney disease. [2004]

Chronic painful diabetic neuropathy

1.15.17 For guidance on managing chronic painful diabetic neuropathy in adults with type 1 diabetes, see NICE's guideline on neuropathic pain in adults. [2015]

Autonomic neuropathy

1.15.18 Think about the possibility of autonomic neuropathy affecting the gut if adults with type 1 diabetes have unexplained diarrhoea, particularly at night. [2004]

1.15.19 When prescribing antihypertensive medicines, take care not to increase the risk of orthostatic hypotension from the combined effects of sympathetic autonomic neuropathy and blood pressure lowering medicines. [2004]

1.15.20 For adults with type 1 diabetes who have bladder emptying problems, investigate the possibility of autonomic neuropathy affecting the bladder, unless another explanation is found. [2004]

1.15.21 When managing the symptoms of autonomic neuropathy, include specific interventions for the manifestations encountered (for example, for abnormal sweating and postural hypotension). [2004, amended 2015]

1.15.22 Anaesthetists should be aware of the possibility of parasympathetic autonomic neuropathy affecting the heart in adults with type 1 diabetes who:

  • are listed for procedures under general anaesthetic and

  • have evidence of somatic neuropathy or other manifestations of autonomic neuropathy. [2004]

Gastroparesis

1.15.23 Advise adults with type 1 diabetes who have vomiting caused by gastroparesis to follow a small‑particle‑size diet (mashed or pureed food) to relieve their symptoms. [2015]

1.15.24 Be aware that gastroparesis needing specific therapy can only be diagnosed in the absence of hyperglycaemia at the time of testing, because hyperglycaemia delays gastric emptying. [2015]

1.15.25 Consider insulin pump therapy for adults with type 1 diabetes who have gastroparesis. [2015]

1.15.26 For adults with type 1 diabetes who have vomiting caused by gastroparesis, explain that:

1.15.27 To treat vomiting caused by gastroparesis in adults with type 1 diabetes:

1.15.28 Refer adults with type 1 diabetes who have gastroparesis for specialist advice if the interventions in this section have not helped or are not appropriate. [2015]

Acute painful neuropathy from rapid improvement of blood glucose control

1.15.29 Reassure adults with type 1 diabetes that acute painful neuropathy resulting from rapid improvement of blood glucose control is a self‑limiting condition and symptoms improve over time. [2015]

1.15.30 Explain to adults with type 1 diabetes that the specific treatments for acute painful neuropathy resulting from rapid improvement of blood glucose control:

  • aim to make symptoms tolerable until the condition resolves

  • may not relieve pain immediately and may need to be taken regularly for several weeks to be effective. [2015]

1.15.31 Use simple analgesics (paracetamol, aspirin) and local measures (bed cradles) as a first step to treat acute painful neuropathy, and if these do not help, try other measures. [2004, amended 2021]

1.15.32 Do not relax diabetes control to address acute painful neuropathy resulting from rapid improvement of blood glucose control in adults with type 1 diabetes. [2015]

1.15.33 If simple analgesia does not provide sufficient pain relief for adults with type 1 diabetes who have acute painful neuropathy resulting from rapid improvement of blood glucose control, offer treatment as described in NICE's guideline on neuropathic pain in adults. Simple analgesia may be continued until the effects of additional treatments have been established. [2015]

1.15.34 When offering medicines for managing acute painful neuropathy resulting from rapid improvement of blood glucose control to adults with type 1 diabetes, be aware of the risk of dependency associated with opioids. For more information, see NICE's guideline on medicines associated with dependence or withdrawal symptoms. [2015]

Diabetic foot problems

1.15.35 For guidance on preventing and managing foot problems in adults with type 1 diabetes, see NICE's guideline on diabetic foot problems. [2015]

Erectile dysfunction

1.15.36 Offer men with type 1 diabetes the opportunity to discuss erectile dysfunction as part of their regular review. [2015]

1.15.37 Offer a phosphodiesterase‑5 inhibitor to men with type 1 diabetes with isolated erectile dysfunction unless contraindicated. Choose the phosphodiesterase‑5 inhibitor with the lowest acquisition cost. [2015]

1.15.38 Consider referring men with type 1 diabetes to a service offering further assessment and other medical, surgical or psychological management of erectile dysfunction if phosphodiesterase‑5 inhibitor treatment is unsuccessful or contraindicated. [2015]

Thyroid disease monitoring

1.15.39 Measure blood thyroid‑stimulating hormone (TSH) levels in adults with type 1 diabetes at their annual review. [2015]

Mental health problems

1.15.40 Members of diabetes professional teams providing care or advice to adults with type 1 diabetes should be alert to possible clinical or subclinical depression and/or anxiety, particularly if someone reports or appears to be having difficulties with self‑management. [2004]

1.15.41 Diabetes professionals should:

Eating disorders and disordered eating

1.15.42 Members of diabetes professional teams should be alert to the possibility of bulimia nervosa, anorexia nervosa and disordered eating in adults with type 1 diabetes with:

1.15.43 Think about making an early (or if needed, urgent) referral to local eating disorder services for adults with type 1 diabetes with an eating disorder. [2004, amended 2021]

1.15.44 From diagnosis, the diabetes professional team should provide regular high-quality support and counselling about lifestyle and diet for all adults with type 1 diabetes (see the sections on education and information and dietary management). [2004]

Terms used in this guideline

This section defines terms that have been used in a particular way for this guideline.

Continuous glucose monitoring

This covers both real-time (rtCGM) and intermittently scanned (isCGM, commonly referred to as 'flash') continuous glucose monitoring.

A continuous glucose monitor is a device that measures blood glucose levels and sends the readings to a display device or smartphone.

Disordered eating

Disordered eating describes a range of irregular eating behaviours. These can include symptoms that reflect many but not all of the symptoms of eating disorders, such as anorexia nervosa, bulimia nervosa and binge eating disorder. Examples of disordered eating include fasting or chronic restrained eating, skipping meals, binge eating, self-induced vomiting, restrictive dieting, and laxative or diuretic misuse.

Periodontitis

A chronic inflammatory gum disease that destroys the supporting tissues of the teeth (the periodontium).

Gingivitis is a milder form of periodontal disease than periodontitis. However, gingivitis still causes inflammation in the gum, and if not treated it can lead to periodontitis.

Ultra-long-acting insulin

Insulin analogues that have a longer duration of action (beyond 24 hours) compared with standard long-acting insulins.

  • National Institute for Health and Care Excellence (NICE)