Factors Associated with Low Body Mass Index in Huntington's Disease: A Spanish Multicenter Study of the European Huntington's Disease Registry

Background: Patients with Huntington's disease (HD) are at risk for body weight loss and increased risk for institutionalization, morbidity, and mortality. The aim of this study was to determine the factors associated with low body mass index (BMI) in patients with HD. Methods: In this national, observational, cross-sectional study of the European Huntington's Disease Network, the frequency of food consumption, calories, and nutrient intake in patients with HD was assessed using questionnaires validated for the Spanish population and were calculated using the software package Alimentacion and Salud (Diet and Health), version 2.0. Nutritional status was estimated using the BMI, and disease severity was assessed using the Unified Huntington's Disease Rating Scale and a total functional capacity (TFC) score. Linear regression models were performed using BMI as the dependent variable and using energy balance (energy caloric intake - energy expenditure); the TFC score; the presence of a caregiver; dysphagia; cytosine, adenine, guanine (CAG) repeats; comorbidities; intake of supplements; pharmacologic treatments; age; gender; education; and physical activity as the independent variables. Results: Two hundred twenty-four patients with HD were included (59% women), and their mean age was 47.41 ± 14.26 years, a median TFC score of 9 (range, 3-13), normal BMI in 124 patients (55.4%), and low BMI in 13 patients (6.7%). In the linear regression model, older age (β = 0.003; P = 0.01), male gender (β = 0.13; P = 0.003), and lower energy balance (β = -0.0001; P = 0.0003) were associated with a higher log-transformed BMI. Conclusions: Younger female HD patients are at risk for low BMI. To counteract the influence of the HD gene mutation on decreased BMI, an increase in kilocalories per day should be encouraged.