Weight loss is usual in patients with Parkinson’s disease (PD), but these new findings indicate that weight loss early in the disease’s progression reflects a more serious form of the neurodegenerative disorder. The study is titled “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.”
“I suspect we may be looking at several subtypes of this disease,” Anne-Marie Wills, MD, from the Department of Neurology and Neurological Clinical Research Institute at Massachusetts General Hospital, said in a news release. “The patients who experience early weight loss appear to have a more severe, systemic form of the disease, possible 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.”
Evidence has shown that greater body mass index (BMI) is associated with improved survival in several neurodegenerative diseases, including Huntington’s disease and amyotrophic lateral sclerosis (ALS). However, the effect of weight on Parkinson’s disease progression and survival had not been previously examined.
To explore the association between changes in BMI and Unified Parkinson’s Disease Rating Scale (UPDRS) motor and total scores among PD patients, and to assess the association between BMI and survival, Dr. Wills — the study’s lead and corresponding author — and colleagues looked at data gathered in a clinical trial conducted between 2007 and 2013 to investigate the use of creatine to treat early stage disease. The trial, sponsored by the National Institutes of Health, included over 1,700 patients who were within five years of diagnosis and at 90 days to two years into treatment with dopamine-releasing drugs. The trial was stopped because creatine treatment was not found to be of benefit.
Researchers used data covering 1,673 patients, enrolled in the trial for three to five years, that included annual height and weight measurements as well as results from the Unified Parkinson’s Disease Rating Scale. Of the total sample in the analysis, 158 (9.4%) patients experienced weight loss, and 233 (13.9%) experienced weight gain. The majority held to a stable weight.
Those study patients who lost weight had a greater average increase in the UPDRS score — indicative of worsening disease — both in motor symptoms and overall symptoms compared with those whose weight remained stable. Patients who gained weight had the smallest annual increase in UPDRS scores. No significant difference in survival among the three groups was observed, which could be a consequence of participants having been in the disease’s early stages.
The researchers said it is too early to establish whether maintaining or increasing a patient’s weight might help to slow disease progression, although this hypothesis was suggested by a 2014 interventional ALS study also led by Dr. Wills. “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 said. “But in my own practice, I try to prevent weight loss in patients, and I would recommend providers to be attentive to weight changes in their patients, even early in the disease.”