Background: Huntington disease (HD) is a genetic neurologic disorder. Weight loss is common in HD and is related to progression of the disease, but the cause of weight loss remains unclear.
Objective: The study objective was to compare 24-h energy expenditure (EE) and energy intake in persons with early midstage HD with those of matched control subjects to determine how HD affects energy balance.
Design: EE was assessed in 13 subjects with early-stage HD and in 9 control subjects via indirect calorimetry in a human respiratory chamber. Energy intake was determined by weighing all food provided and all leftovers from an ad libitum diet. Body composition was measured via air-displacement plethysmography. Stage of disease was estimated on the basis of the Unified Huntington's Disease Rating Scale and modified Mini-Mental Status examinations. Regression analysis included all 13 HD subjects; t tests were used for the comparisons between matched HD and control subjects.
Results: 24-h EE was 11% higher in the HD subjects than in the control subjects (NS). This difference was due to a higher (P = 0.043) waking metabolic rate, which was related to a significantly greater displacement of the center of mass by HD subjects than by control subjects (P = 0.028). On average, both groups were in positive energy balance and exceeded their energy expenditure by 2510-2929 kJ.
Conclusions: Higher 24-h EE in persons with early midstage HD is due to increased physical activity, both voluntary and involuntary. However, HD subjects are able to maintain positive energy balance when offered adequate amounts of food in a controlled setting.