Introduction Determination of body composition is important in nutritional assessment and an indirect marker for skeletal muscle mass (SMM). Low SMM has been associated with morbidity and mortality. Animal models of HD exhibit muscle atrophy but the relevance of muscle wasting and its association with HD severity is unknown.

Objectives To analyse and to compare the body composition of patients with HD with healthy controls, and to analyse the association of SMM with HD severity, energy expenditure and the use of antidopaminergic drugs.

Methods Case-control, cross sectional study. Body composition was measured using bioimpedance, and energy expenditure with indirect calorimetry and actigraphy. Anthropometrics, biochemical and nutritional data were also collected. HD severity was measured using the UHDRS.

Results Twenty two patients with HD [36% males, mean age 50.2 + 15.6 years, motor UHDRS 27.9 + 23.7, TFC 10.4 (IR 6), cognitive UHDRS 155 (IQR 125), CAG 43 + 6.0, caloric food intake 1946.4 + 756.7 Kcal/day, BMI 24.4 + 3.0], and 17 controls (50% males, mean age 47.4 + 13.7, food caloric intake 2056.5 + 548.8, BMI 25.8 + 4.0) were included. Both groups were homogeneous in terms of age, gender and BMI. No significant differences were found in terms of SMM, fat mass, creatin kinase or proteic catabolism (urinary nitrogen), and similarly correlated with energy expenditure. In HD patients, body composition was similar in terms of antidopaminergic drugs use, and SMM was not correlated with UHDRS scores. In both groups BMI was only correlated with fat mass (not with SMM), and SMM was only moderately correlated with subscapular skinfold r=-0.53, p = 0.01).

Conclusions Compared to controls, patients with HD have similar body composition, SMM and proteic catabolism. In HD, BMI only estimates fat mass. Longitudinal studies are warranted to confirm these results.