3 Clinical need and practice
3.1 The purpose of this assessment is to evaluate the clinical and cost effectiveness of the MiniMed Paradigm Veo system and the Vibe and G4 PLATINUM CGM system for managing blood glucose levels in people with type 1 diabetes.
3.2 Using these integrated sensor‑augmented pump therapy systems may improve glucose control and consequently may reduce the number of diabetes‑related complications and improve the quality of life for people with type 1 diabetes. They may also make it easier for people to adhere to treatment. The ability of the MiniMed Paradigm Veo system to automatically suspend insulin delivery may help to reduce the incidence of severe and nocturnal hypoglycaemia, and its associated anxiety. Both systems may also offer benefits to the NHS through cost and resource savings by reducing the number of hospital admissions and consultations for diabetes‑related complications, and by achieving optimum blood glucose control more quickly.
3.3 Type 1 diabetes is a chronic metabolic disorder caused by the destruction of insulin‑producing cells in the pancreas that leads to an absolute lack of the hormone and subsequent loss of blood glucose control. As a result, blood glucose levels become too high and lifelong treatment with insulin is needed. Type 1 diabetes typically develops in children and young adults. It is estimated that about 370,000 adults and 24,000 children and young people in the UK have type 1 diabetes.
3.4 Achieving good control of blood glucose levels with insulin can reduce the risk of developing both short‑ and long‑term diabetes‑related complications. Short‑term complications of diabetes include diabetic ketoacidosis, a life‑threatening acute metabolic emergency caused by high blood glucose levels (hyperglycaemia), and hypoglycaemia, which happens when blood sugar levels become too low as a result of insulin therapy.
3.5 Hypoglycaemia can be mild, which is corrected by eating or drinking sugar, or severe, which is defined by the need for help from another person for recovery. The main symptoms of hypoglycaemia are blurred vision, dizziness, fatigue, hunger and sweating. More severe symptoms include confusion, convulsions, coma and death. Severe symptoms may be associated with disabling hypoglycaemia, which can happen often and without warning for some people with type 1 diabetes. In children, especially those younger than 5 years, severe hypoglycaemia can cause long‑term cognitive impairment. Hypoglycaemia can also occur during sleep (nocturnal hypoglycaemia) and is particularly serious because the person cannot detect its symptoms while sleeping and may not awake during an episode. Although death from nocturnal hypoglycaemia is rare, it can occur in extreme cases. Repeated hypoglycaemia can also lead to an impaired awareness of hypoglycaemia, in which people with type 1 diabetes are often less able to notice when they have hypoglycaemia. Fear of recurrent hypoglycaemia not only decreases quality of life in the short‑term but can also hinder treatment adherence and good glycaemic control.
3.6 Long‑term complications of chronically elevated blood glucose levels include retinopathy and blindness, peripheral and autonomic nephropathy, renal failure, ischaemic heart disease, stroke, neuropathy, and foot ulceration.
3.7 Diabetes that complicates pregnancy is also becoming more common, and it is estimated that up to 5% of about 700,000 women who give birth in England and Wales each year have pre‑existing or gestational diabetes. Maternal risks of pre‑existing diabetes include recurrent hypoglycaemia, progression of retinopathy, nephropathy, and increased incidence of pre‑eclampsia (especially in women with microvascular disease) and operative delivery. Fetal risks of pre‑existing maternal diabetes include structural congenital abnormality and intrauterine death. Neonatal complications include excessive birth weight (macrosomia), premature delivery and associated complications, birth trauma resulting from conditions such as shoulder dystocia, hypoglycaemia, and neonatal death.
3.8 Treatment of type 1 diabetes is by insulin therapy to achieve blood glucose control. Blood glucose levels are monitored to determine the type and amount of insulin needed to regulate blood glucose levels. These interventions are described in more detail in sections 3.9, 3.10 and 3.11.
3.9 There are various types of insulin, distinguished by their rate of onset and duration of action, that can be combined into different regimens depending on a person's individual needs. Insulin therapy can be delivered by multiple daily insulin injections or by continuous subcutaneous insulin infusion using an insulin pump. The care pathways for insulin therapy for adults and children are outlined in NICE's guidelines on type 1 diabetes in adults, diabetes in children and young people, and diabetes in pregnancy and in NICE's technology appraisal guidance on continuous subcutaneous insulin infusion.
3.10 Blood glucose concentrations vary widely during a 24‑hour period and from day to day in diabetes. Blood glucose measurements are taken after several hours of fasting, usually in the morning before breakfast (fasting blood glucose level), and before and after each meal to measure the change in glucose concentration (postprandial blood glucose level). Levels of blood glucose can be measured by testing a drop of blood using a glucose meter (capillary blood testing), or by a continuous glucose monitor that does frequent automated testing of interstitial tissue glucose and is calibrated to reflect blood glucose. The care pathways for measuring blood glucose for children and adults are outlined in NICE's guideline on type 1 diabetes in adults, diabetes in children and young people, and diabetes in pregnancy.
3.11 Long‑term monitoring of blood glucose control is achieved by measuring glycated haemoglobin (HbA1c levels), which reflect average blood glucose levels over the preceding 3 months. People with type 1 diabetes should aim for a target HbA1c level of 48 mmol/mol (6.5%) or lower, as recommended in NICE guidelines on type 1 diabetes in adults and diabetes (type 1 and type 2) in children and young people. The assessment for this guidance was based on a target HbA1c value of 58.5 mmol/mol (7.5%) or less. This was informed by the NICE guideline on diagnosis and management of type 1 diabetes in children, young people and adults, which was current at the time of the assessment. For people with diabetes, the higher the HbA1c value, the greater the risk of developing diabetes‑related complications. The care pathways for monitoring HbA1c levels for adults and children are outlined in NICE's guidelines on type 1 diabetes in adults, diabetes in children and young people, and diabetes in pregnancy.