Predictors of weight loss in Parkinson's disease.

The objective of this study was to examine the change of body weight (BW) among Parkinson's disease (PD) patients and controls over years and determine the predictors of weight loss among PD patients. Studies on weight loss in PD studies are cross-sectional, have a short follow-up, or lack in clinical detail. We examined the percentage of BW change over years among 49 PD patients and 78 controls. The controls were from another study on longitudinal evolution of BW and body composition in the elderly. We determined the BW, Hoehn and Yahr (HY) stage, and dyskinesia status of 49 consecutive nondemented PD patients with symptom duration of 6.1 +/- 0.7 years (mean +/- SEM) and ascertained their BW at the time of diagnosis and 2.4 +/- 0.2 years before the diagnosis from medical records. We collected data again 7.2 +/- 0.5 years after the first visit. The PD group lost 7.7% +/- 1.5% of BW over the entire symptomatic period (13.1 +/- 0.8 years), while the control group lost only 0.2% +/- 0.7% of BW over 9.9 +/- 0.1 years; weight loss was clinically significant (>5%) in 55.6% of PD patients vs. 20.5% of the controls (both P values < 0.001, adjusted for sex, baseline age, and observation period duration). PD patients lost weight in both the early and advanced phases. While worsening of parkinsonism was the most important factor, age at diagnosis, emergence of visual hallucinations, and possibly dementia were also associated with weight loss. We demonstrated significant weight loss in PD patients compared to controls over approximately 1 decade. Neurodegeneration involving both motor and nonmotor systems may be associated with weight loss in PD.