NEUROLOGY 2009;73:385-392
© 2009 American Academy of Neurology
Dietary intake in adults at risk for Huntington disease
Analysis of PHAROS Research Participants
K. Marder, MD, MPH,
H. Zhao, ScD,
S. Eberly, MS,
C. M. Tanner, MD, PhD,
D. Oakes, PhD,
I. Shoulson, MD On behalf of the Huntington Study Group*
From the Departments of Neurology and Psychiatry, Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Gertrude H. Sergievsky Center (K.M.), Columbia University, New York, NY; Department of Epidemiology and Biostatistics (H.Z.), Texas A&M Health Science Center, College Station; Departments of Biostatistics (S.E., D.O.) and Neurology (I.S.), University of Rochester, NY; and Parkinson’s Institute (C.M.T.), Sunnyvale, CA.
Address correspondence and reprint requests to Dr. Karen Marder, 630 W. 168th St. Unit 16, Columbia University College of Physicians and Surgeons, New York, NY 10032 ksm1{at}columbia.edu
Objective: To examine caloric intake, dietary composition, and body mass index (BMI) in participants in the Prospective Huntington At Risk Observational Study (PHAROS).
Methods: Caloric intake and macronutrient composition were measured using the National Cancer Institute Food Frequency Questionnaire (FFQ) in 652 participants at risk for Huntington disease (HD) who did not meet clinical criteria for HD. Logistic regression was used to examine the relationship between macronutrients, BMI, caloric intake, and genetic status (CAG <37 vs CAG 
37), adjusting for age, gender, and education. Linear regression was used to determine the relationship between caloric intake, BMI, and CAG repeat length.
Results: A total of 435 participants with CAG <37 and 217 with CAG 37 completed the FFQ. Individuals in the CAG 37 group had a twofold odds of being represented in the second, third, or fourth quartile of caloric intake compared to the lowest quartile adjusted for age, gender, education, and BMI. This relationship was attenuated in the highest quartile when additionally adjusted for total motor score. In subjects with CAG 37, higher caloric intake, but not BMI, was associated with both higher CAG repeat length (adjusted regression coefficient = 0.26, p = 0.032) and 5-year probability of onset of HD (adjusted regression coefficient = 0.024; p = 0.013). Adjusted analyses showed no differences in macronutrient composition between groups.
Conclusions: Increased caloric intake may be necessary to maintain body mass index in clinically unaffected individuals with CAG repeat length 37. This may be related to increased energy expenditure due to subtle motor impairment or a hypermetabolic state.
Abbreviations: BEE = basal energy expenditure; BMI = body mass index; FFQ = Food Frequency Questionnaire; HD = Huntington disease; OR = odds ratio; PD = Parkinson disease; PHAROS = Prospective Huntington At Risk Observational Study; TEE = total energy expenditure; UHDRS = Unified Huntington’s Disease Rating Scale.
*PHAROS co-investigators are listed in the appendix.
Disclosure: Author disclosures are provided at the end of the article.
Received September 2, 2008. Accepted in final form May 1, 2009.
