Losing weight may worsen symptoms of Parkinson’s disease (PD), according to a study published in JAMA Neurology. A trajectory of reduction in body mass index (BMI) was associated with higher measurements of disease progression, while the reverse was true for increasing BMI trajectory.
Weigh loss is common among people with PD, and corresponds with a worsening quality of life. The investigators looked at this pattern closely for direct correlations between changes in BMI in people diagnosed with PD, scoring on the Unified Parkinson’s Disease Rating Scale (UPDRS), and survival.
Longitudinal data (3-6 years) was collected from 1673 participants from the National Institute of Neurological Disorders and Stroke Exploratory Trials in PD Long-Term Study (NET-PD LS1) for secondary analysis of changes in BMI. All participants in the trial had been diagnosed early, and been treated with dopaminergic therapy. They were randomized to receive either creatine monohydrate 10 g/d or placebo.
Over the course of the trial, decreasing BMI was documented in 158 participants (9.4%), compared with increasing BMI in 233 (13.9%). The remaining 282 (76.6%) participants maintained stable weight, providing a basis for comparison.
A greater percentage of the participants in the decreasing BMI group were obese at baseline. They were also more likely to have received levodopa as their only treatment, and in higher daily doses than the other groups. “I suspect we may be looking at several subtypes of this disease,” explained lead author Anne-Marie Wills, MD, of the Massachusetts General Hospital Department of Neurology and Neurological Clinical Research Institute, and assistant professor of Neurology at Harvard Medical School. “The patients who experience early weight loss appear to have a more severe, systemic form of the disease, possibly due to involvement of the neuroendocrine system or the gastrointestinal nervous system, while those who gained weight may have a milder form of the disease.”
The investigators found increases in motor UPDRS mean (SE) scores of 1.48 (0.28) points and in total UPDRS of 2.40 (0.43) points greater than the mean increases in the weight-stable group (P < .001). Conversely, reductions in motor UPDRS and total UPDRS were reported in the increasing BMI group of -0.51 (0.24, P=.03) and -0.89 (0.36, P=.02), respectively.
These patterns were observed in patients with early PD, despite having had optimal dopaminergic therapy, suggesting that changes to BMI represent biomarkers for therapy. Although changes in BMI were also not associated with any differences in survival among the groups, the results were possibly influenced by the low death count in the NET-PD LS1 cohort.
“Since this is just the first observation of this association in Parkinson’s, we cannot recommend any changes to standard clinical care right now,” Dr Wills noted, adding that in her own practice she counsels PD patients to try to maintain stable weight. “I would recommend providers be attentive to weight changes in their patients, even early in the disease,” she said.
Wills AA, Perez A, Wang J, et al. Association Between Change in Body Mass Index, Unified Parkinson’s Disease Rating Scale Scores, and Survival Among Persons With Parkinson Disease Secondary Analysis of Longitudinal Data From NINDS Exploratory Trials in Parkinson Disease Long-term Study 1. JAMA Neurol. 2015; doi: 10.1001/jamaneurol.2015.4265.