Studies have shown that people with Parkinson’s disease experience weight fluctuations, either losing or gaining weight, significantly more often than people without progressive neurodegenerative disease.
Weight loss in Parkinson’s disease patients was associated with faster progression of motor and cognitive decline over 5 years. Conversely, weight gain over the same period was associated with slower progression of motor symptoms.
Data showed that certain biomarkers such as amyloid load, blood uric acid (antioxidant) levels, and dopamine brain imaging may serve as predictors of future weight fluctuations.
“In this longitudinal study, we found that weight loss was associated with poor clinical outcomes … whereas more favorable progression of motor function was observed in patients who gained weight,” the researchers wrote. .
the study, “Clinical course and biomarkers of weight fluctuation in early Parkinson’s diseasewas published in Nature Portfolio Journal – Parkinson’s Disease.
Weight changes common in Parkinson’s disease
Weight fluctuations, including unintentional weight gain and loss, are a relatively common non-motor symptom of Parkinson’s disease and have been reported in all stages of the disease.
A variety of factors may contribute to such weight fluctuations. These include medications, loss of appetite, difficulty swallowing, gastrointestinal problems, changes in hormones involved in appetite, or changes in the brain that affect eating behavior.
However, the mechanisms underlying unintentional weight change in Parkinson’s disease are poorly understood, and the relationship between weight change and other clinical outcomes is also poorly understood.
“The lack of a clear pathophysiological understanding is accompanied by a paucity of biomarkers for this complex clinical condition,” the researchers wrote. ) makes it difficult for clinicians to determine a definite prognosis in patients with Parkinson’s disease.
In this study, researchers examined associations between weight variation and clinical course and disease biomarkers over five years in healthy volunteers with Parkinson’s disease and in the Parkinson’s Disease Progression Marker Initiative (PPMI). I was. His PPMI, initiated by the Michael J. Fox Foundation for Parkinson’s Disease Research in 2010, seeks to identify biomarkers of disease onset and progression.
There were 405 Parkinson’s patients included in the analysis, 64.7% of whom were male, with a mean age of 61.5 years. The study also included 187 healthy participants (65.4% male), whose mean age was 61.1 years. These individuals acted as controls.
The data showed that Parkinson’s disease patients had greater weight variability compared to healthy subjects. Of the patients, 203 were considered weight stable, 134 were ‘losing weight’ and 68 were ‘gaining weight’.
Patients in the weight loss group experienced more difficulty in activities of daily living at the beginning of the study (baseline) compared to weight-stable patients.
They also had higher levels of amyloid beta in their cerebrospinal fluid (the fluid that surrounds the brain and spinal cord). Amyloid beta is a biomarker for disease progression in Alzheimer’s disease, recently seen in Parkinson’s patients.
Over the course of follow-up, weight loss patients had more rapid progression in overall disease severity, as measured by the MDS-Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) total score. In comparison, there were also significant impairments in exercise experience of daily living, as measured by the MDS-UPDRS part II.
Activities of daily living and cognitive function also showed faster declines in the weight loss group.
In contrast, patients who gained weight had slower progression of motor symptoms, which was reflected in the MDS-UPDRS Part III score.
“We confirm that weight variability may have clinically significant implications. [Parkinson’s]weight loss is a factor in poor outcomes, and weight gain is associated with slower exercise progression in the long-term,” the researchers wrote.
Biomarkers of weight fluctuation
Binge eating, which is characterized by frequent and uncontrolled eating of abnormally large amounts of food, was more common in patients with weight gain. Treatment with agonists was associated with binge eating.
Blood levels of uric acid were also measured as a potential biomarker of weight fluctuation. Uric acid is an antioxidant and has been associated with reducing the risk of Parkinson’s disease and slowing disease progression.
Those who gained weight had higher uric acid levels compared to the stable group, and those who lost weight had lower levels.
An area of the brain called the striatum is involved in maintaining caloric requirements via dopamine, a neurochemical that is lost in Parkinson’s disease. The nerve cells that supply it degenerate.
Using brain imaging, the researchers investigated this surrogate measure of dopamine loss (denervation).
Results showed that striatal denervation on the right side of the brain at baseline was a predictor of body weight variation in both patients and healthy participants, but not the left side.
Based on these findings, the researchers proposed that ‘dopaminergic imaging and uric acid levels may serve as predictors of weight variation in patients.’ [Parkinson’s]”
Certain clinical variables, such as diet, bowel function, and exercise, which may have influenced the findings, were not available for analysis, the team noted.
Additional long-term studies will be needed to improve the characterization and identification of biomarkers for weight fluctuations [Parkinson’s],” they wrote.
Such studies should include nutritional assessments and measurements of body composition (such as fat and muscle), the researchers note.
