Mitochondrial disorders in children: Co-enzyme Q10

Co-enzyme Q10 2 mg per kg daily

Analysis

N ^a

44

Selected outcomes

Global MRC muscle scale score (%)^b

Results presented graphically. No absolute values reported

Statistically significant increase from baseline after 6 months treatment (from approximately 89% to 91%^cp<0.01)

Mean serum lactate levels 5 minutes after exercise (mg %)

Results presented graphically. No absolute values reported

Statistically significant decrease from baseline after 6 months treatment (from approximately 68 to 52 mg %^c p<0.0001)

^a Fifty-nine participants entered study. However, 15 participants did not complete the study and results were only reported for the 44 remaining participants.

^b MRC muscle scale grades muscle power on a scale of 0 to 5 in relation to the maximum expected for that muscle. Study results were presented as a percentage. It is unclear from the information provided in the paper what these percentages represent and the clinical significance of any reported improvements. Five muscle groups were assessed and a global score was presented for all muscle groups.

^c Figures estimated from inspection of graph.

Abbreviations: MRC, Medical Research Council.

Co-enzyme Q10 2 mg per kg daily ^a

Placebo ^a

Analysis

N

8

8

Selected outcomes

Global MRC muscle scale score (%)^b

Results presented graphically. No absolute values reported

No significant change in either group after entering comparative phase

Mean serum lactate levels 5 minutes after exercise (mg %)

Results presented graphically. No absolute values reported

All participants showed a statistically significant decrease from baseline after 6 months treatment with co-enzyme Q10. In the group treated with a further 3 months of co-enzyme Q10, the decrease from baseline to 9 months was statistically significant (p<0.01). In the group switched to placebo for 3 months, the decrease from baseline to 9 months was not statistically significant (p value not stated)

^a Participants had all completed open-label phase so had all received 6 months of co-enzyme Q10. Co-enzyme Q10 group therefore had 9 months of co-enzyme Q10 and placebo group had 6 months of co-enzyme Q10 and 3 months of placebo.

^b MRC muscle scale grades muscle power on a scale of 0 to 5 in relation to the maximum expected for that muscle. Study results were presented as a percentage. It is unclear from the information provided in the paper what these percentages represent and the clinical significance of any reported improvements. Five muscle groups were assessed and a global score was presented for all muscle groups.

Abbreviations: MRC, Medical Research Council.

Co-enzyme Q10 160 mg daily

Placebo

Analysis

N

8

8

Selected outcomes

Fatigability in ADL^a

Results presented graphically. No absolute values reported

No statistical significant difference between co-enzyme Q10 and placebo

Score on MRC muscle scale (%)^b

Results presented graphically. No absolute values reported

After 3 months treatment with co-enzyme Q10 there was no statistically significant change in the score for the 4 individual muscle groups assessed. There was a statistically significant increase in the global score from all muscle groups combined (from approximately 83% to 87%)^b,c

Sustained endurance strength (mean time taken in seconds to perform specified activities)

Results presented graphically. No absolute values reported

No statistical significant difference between co-enzyme Q10 and placebo

^a Scored on a 6 point scale from 1 (minimal or no fatigue) to 6 (severe impairment of activities of daily living and use of walking assistance or in wheelchair).

^b MRC muscle scale grades muscle power on a scale of 0 to 5 in relation to the maximum expected for that muscle. Study results were presented as a percentage. It is unclear from the information provided in the paper what these percentages represent and the clinical significance of any reported improvements. Four muscle group were assessed: upper extremity distal and proximal muscles and lower extremity distal and proximal muscles. A global score was presented for all muscle groups.

^c Figures estimated from inspection of graph.

Abbreviations: ADL, activities of daily living; MRC, Medical Research Council.

Co-enzyme Q10 600 mg twice daily

Placebo

Analysis

N ^a

30

30

Selected outcomes ^b

Mean (SEM) mitochondrial disease specific ADL questionnaire score^c

5.14 (0.19)

4.73 (0.19)

No statistical significant difference between co-enzyme Q10 and placebo (p=0.26)

Mean (SEM) mitochondrial disease specific QOL questionnaire score^c

5.06 (0.16)

4.66 (0.27)

No statistical significant difference between co-enzyme Q10 and placebo (p=0.09)

Mean (SEM) maximal isometric forearm strength (Nm)^d

23.8 (1.8)

24.6 (1.6)

No statistical significant difference between co-enzyme Q10 and placebo (p=0.27)

^a Not all participants completed all outcomes. Complete data for the ADL and QOL questionnaires was available for 22 participants.

^b All outcomes assessed after 60 days taking co-enzyme Q10 and after 60 days taking placebo.

^c These consisted of a series of questions that assessed the participants' capacity to perform tasks such as cooking and housework and perceived health and well-being measured on a visual-analogue scale from 0 to 100 mm.

^d Ninety second (9 second contraction and 1 second rest) isometric handgrip fatigue test.

Abbreviations: ADL, activities of daily living; HR, heart rate (beats per minute); Nm, maximal isometric grip strength in newton; QOL, quality of life; RER; respiratory exchange rate (VCO₂/VO₂); SEM, standard error of the mean; VE, minute ventilation (litre/minute); VO₂; oxygen uptake (ml/kg lean body mass).