A review of nutrition in Duchenne muscular dystrophy
Duchenne muscular dystrophy (DMD) is a recessive X linked genetic disorder characterised by progressive muscle weakness and reduced muscle tone. Affecting only boys, it limits life expectancy to approximately 20 years. A literature review was conducted using MEDLINE and the Cochrane Library, employing the term ‘Duchenne muscular dystrophy’. A total of 1491 articles in English were recovered. These papers were searched thematically under the headings: body composition (n = 10), energy expenditure (n = 10), nutrition (n = 6), corticosteroid therapy (n = 55) and gene therapy (n = 199). Key dietetic practice points were identified relevant to nutritional management. Papers supporting these key themes were assigned a level of evidence and grade of recommendation. There is limited high-quality evidence to guide the nutritional management of boys with DMD. Currently, the majority of evidence is based on expert opinion and clinical expertise. Delayed growth, short stature, muscle wasting and increased fat mass are characteristics of DMD and impact on nutritional status and energy requirements. The early introduction of steroids has altered the natural history of the disease, but can exacerbate weight gain in a population already susceptible to obesity. Prior to commencing steroids, anticipatory guidance for weight management should be provided. Malnutrition is a feature of end stage disease requiring a multidisciplinary approach, such as texture modification and supplemental feeding. Micronutrient requirements are yet to be determined but, as a result of corticosteroid treatment, vitamin D and calcium should be supplemented. Some evidence exists supporting supplementation with creatine monohydrate to improve muscle strength. More research is needed to provide a higher quality of evidence for dietitians working within this area.