The association between dietary factors and body weight and composition in boys with Duchenne muscular dystrophy.

Abstract

Duchenne muscular dystrophy (DMD) is a X-linked neuromuscular disorder. Boys with DMD have high rates of obesity, although little is known about dietary factors that may contribute to weight gain in this population. The present study aimed to explore the relationship between dietary factors, body mass index (BMI) z-score, body composition and motor function and to describe dietary intake in boys with DMD. A cross-sectional analysis of 3-day food diaries from ambulant and steroid treated boys with DMD aged 5-13 years was conducted. Correlation analysis explored the relationship between dietary factors, BMI z-score, fat mass percentage (FM%) and lean mass percentage (LM%). The median age was 8.5 years (interquartile range [IQR] = 7.2-10.5years). Median energykg-1 day-1 in those within a healthy weight range (n = 11) was 316 kJkg-1 day-1 (IQR=276-355kJkg-1 day-1 ) and greater than estimated requirements and, for those above a healthy weight (n = 26), energy intake was 185 kJkg-1 day-1 (IQR=143-214kJkg-1 day-1 ) and lower than estimated requirements. Energykg-1 day-1 was negatively associated with BMI z-score (r = -0. 650) and FM% (r = -0.817) but positively associated with LM% (r = 0.805; all analyses p = <0.01). Younger age was associated (r = -0.609 p = <0.01) with a higher energykg-1 day-1 . For all participants, vegetable, grains, meat/alternatives and dairy intakes were sub-optimal. Younger boys with DMD within a healthy weight range are overconsuming energy dense nutrient poor foods. A focus on improving diet quality during early childhood may prove to be a useful strategy for reducing excess weight gain and supporting healthier eating habits in this vulnerable clinical population.