Summary of findings for the main comparison. Strength training compared to no training for myotonic dystrophy.
| Strength training compared to no training for myotonic dystrophy | ||||||
| Patient or population: people with myotonic dystrophy Setting: hospital Intervention: strength training Comparison: without strength training | ||||||
| Outcomes | Mean (SD) without strength training | Mean (SD) with strength training | Difference (95% CI) | Certainty of the evidence (GRADE) | What happens | |
|
Muscle strength assessed with electronic dynamometer Follow‐up: mean 12 weeks 35 participants (1 RCT)a |
Hand grip force | The mean change in hand grip force without strength training was an increase of 3.0 N (17.0) | The mean change in hand grip force with strength training was an increase of 9.0 N (17.0) | MD 6.0 N higher (6.7 lower to 18.7 higher) | ⊕⊝⊝⊝ Very lowb | May have little or no effect on hand grip force |
| Pinch grip force | The mean change in pinch grip force without strength training was an increase of 3.0 N (7.0) | The mean change in pinch grip force with strength training was an increase of 4.0 N (6.0) | MD 1.0 N higher (3.3 lower to 5.3 higher) | ⊕⊝⊝⊝ Very lowb | May have little or no effect on pinch grip force | |
| Isometric wrist flexor force | The mean change in isometric wrist flexor force without strength training 0.0 N (17.0) | The mean change in isometric wrist flexor force with strength training was an increase of 7.0 N (14.0) | MD 7.0 N higher (3.3 lower to 17.4 higher) | ⊕⊝⊝⊝ Very lowb | May have little or no effect on isometric wrist flexor force | |
| Isometric wrist extensor force | The mean change in isometric wrist extensor force without strength training was 0.0 N (10.0) | The mean change in isometric wrist extensor force with strength training was an increase of 8.0 N (12.0) | MD 8.0 N higher (0.7 higher to 15.3 higher) | ⊕⊝⊝⊝ Very lowb | May slightly improve isometric wrist extensor force | |
| Aerobic capacity | No data were provided for this outcome | |||||
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Time‐scored functional assessments of muscle performance Follow‐up: 24 weeks 36 participants (1 RCT)a |
A study with a matched‐pair design presented data from multiple functional tests (see text). There were no statistically significant differences between the training and control groups. | ‐ | ⊕⊝⊝⊝ Very lowb | The effect on time‐scored functional assessments of muscle performance are uncertain | ||
| Quality of life | No data were provided for this outcome | |||||
| Pain | No data were provided for this outcome | |||||
| Experienced fatigue | No data were provided for this outcome | |||||
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Adverse effects requiring withdrawal Follow‐up: 24 weeks 71 participants (2 RCTs) |
1 participant in the training group withdrawn by GP from an exercise session because of back problems and did not complete final test session because of knee pain (relatedness to the exercise intervention unclear). In the other trial (36 participants), a few participants complained of muscle soreness and transient strength reduction after 8 weeks, but no signs of muscle damage were found after 24 weeks. |
⊕⊕⊝⊝ Very lowc | May have few or no adverse effects requiring withdrawal | |||
| CI: confidence interval; GP: General Practitioner; MD: mean difference RCT: randomised controlled trial; SD: standard deviation | ||||||
| GRADE Working Group grades of evidence High certainty: we are very confident that the true effect lies close to that of the estimate of the effect. Moderate certainty: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. Low certainty: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect. Very low certainty: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect. | ||||||
aData from a second myotonic dystrophy trial with 36 randomised participants was not suitable for inclusion in this analysis. bDowngraded three levels: two levels for imprecision and for study limitations. Quote: "The study sample was small and heterogeneous which lead to an underpowered study". Sample size of 35. Blinding of participants and personnel was not possible and the trial was also at a high risk of selective reporting bias. cDowngraded three levels: one level for imprecision and two levels for study limitations. The trial was unblinded and at a high risk of selective reporting and attrition bias.