Muscle function and age are associated with loss of bone mineral density in Duchenne muscular dystrophy.

INTRODUCTION: Patients with Duchenne muscular dystrophy (DMD) demonstrate decreased bone mineral density (BD). It is not clear which factors exert the greatest impact on BD loss in these patients. METHODS: In 63 patients with DMD, serum cytokines (interleukin [IL]-1, IL-6, and tumor necrosis factor-beta [TNF-ß]), C-reactive protein (CRP), creatine kinase (CK), muscle function (by Vignos scale), body composition, and total BD (the latter 2 measured by dual-energy X-ray absorptiometry, or DEXA) were determined. RESULTS: The main factors associated with BD loss were muscle function (34.0%; ß = -0.139; P < 0.023) and age (36.7%; ß = -0.151; P = 0.004). Cytokines, CRP, body fat mass, and CK did not contribute to BD loss. DISCUSSION: Muscle function and age contribute to BD loss in DMD. We propose that a cut-off of at least 6 points for the Vignos scale and at least 10.5 years of age predict a Z-score of less than or equal to -2.0. Muscle Nerve 59:417-421, 2019.

Evidence of muscle loss delay and improvement of hyperinsulinemia and insulin resistance in Duchenne muscular dystrophy supplemented with omega-3 fatty acids: A randomized study.

BACKGROUND & AIMS: Duchenne Muscular Dystrophy (DMD) is the most prevalent dystrophy of childhood and is characterized by generalized motor delays due to progressive muscular weakness, leading to loss of muscle mass. Additionally, patients with DMD develop obesity, hyperinsulinemia, and Insulin Resistance (IR). Omega-3 Long-Chain PolyUnsaturated Fatty Acids (Ω-3LCPUFA) increase fat mass, decrease lean mass, and decrease hyperinsulinemia and IR. The aim of this study was to analyze the impact of Ω-3LCPUFA consumption on lean mass, fat mass, hyperinsulinemia, and IR in children with DMD. METHODS: This placebo-controlled, double-blind, randomized study was carried out in 28 patients with DMD supplemented with 2.9 g/d of Ω-3LCPUFA (n = 14) or sunflower oil (placebo, n = 14) during 6 months. Serum glucose and insulin were measured at baseline and thereafter at months 3 and 6 of the intervention to estimate IR by HOmeostasis Model Assessment. Body composition was assessed by Dual Energy X-ray Absorptiometry. RESULTS: The percentage of change in EicosaPentaenoic Acid (EPA) and DocosaHexaenoic Acid (DHA) in erythrocytes was significantly (p < 0.05) higher in boys who consumed Ω-3LCPUFA than in the placebo group. Lean mass and fat mass (both in g/kg of Body Weight [BW]) had a trend toward being higher (p = 0.07 at month 3 and p = 0.085 at month 6) and lower (p = 0.05 at month 3 and p = 0.085 at month 6) respectively, in boys with DMD supplemented with Ω-3LCPUFA compared with the placebo group. The loss of lean mass was delayed in the Ω-3LCPUFA group; it started at month 6 but, in placebo, it started at month 3 of supplementation in comparison with the baseline of each group. Fasting insulin, percentage of boys with hyperinsulinemia, and IR were similar between the placebo and Ω-3LCPUFA groups during the 6 months of supplementation. The percentage of boys with IR was significantly (p = 0.045) lower at month 6 of supplementation in the Ω-3LCPUFA group than in the placebo group. CONCLUSION: This study suggests that Ω-3LCPUFA (2.9 g/day) intake during 6 months likely slows the progression of muscle loss, decreases the fat mass, and reduces IR in boys with DMD. The findings of this study provide scientific background for conducting a randomized trial focused of confirming the possible beneficial role of Ω-3LCPUFA on the previously mentioned alterations mentioned in boys with early muscle damage (without fibrosis) DMD. This research was registered at clinicaltrials.gov (NCT018264229).