Weight Loss May Signal Cognitive Decline in Early Parkinson Disease

In patients with Parkinson disease, early weight loss was associated with a faster progression of global cognitive decline compared with weight maintenance, and early weight gain with a slower decline in processing speed. Researchers published their findings online ahead of print in Neurology.

“Early weight loss is a common symptom in people with Parkinson’s disease,” said study author Jin-Sun Jun, MD, of Kangnam Sacred Heart Hospital in Seoul, Republic of Korea. “It could serve as a sign that people are at risk of cognitive decline.”

The study included 358 patients with early Parkinson disease, diagnosed an average 2 years earlier, who had not yet started medication treatment. During the first year of the study, 98 of the patients experienced weight loss (a weight decrease of more than 3%), 201 maintained their weight (a change of no more than 3%), and 59 experienced weight gain (a weight increase of more than 3%). Participants underwent the Montreal Cognitive Assessment (MoCA) as well as neuropsychological testing every year for up to 8 years.

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Participants who lost weight during the first year showed a notably quicker rate of decline in their overall MoCA scores compared with participants who maintained their weight, according to the study. From an average 27, scores for patients who lost weight declined 0.19 points faster per year than scores for those who maintained their weight. The steepest declines were in verbal fluency.

In contrast, participants who gained weight demonstrated a slower decline in processing speed on the Symbol-Digit Modalities Test compared with those who maintained their weight.

Researchers found no association between weight change and any other nonmotor symptoms in patients with Parkinson disease. Further, in a comparison involving 174 people without Parkinson disease, they found no relationship between weight change and cognitive test scores.

“These findings highlight the potential importance of weight management in the early stages of Parkinson’s disease,” said Dr Jun. “Further studies are needed to determine whether taking steps to prevent weight loss could slow cognitive decline in people with Parkinson’s.”

References

Kim R, Choi S, Byun K, et al. Association of early weight change with cognitive decline in patients with Parkinson disease. Neurology. Published online October 19, 2022. doi: 10.1212/WNL.0000000000201404

Weight change in early Parkinson’s may be tied to changes in thinking skills. News release. American Academy of Neurology; October 14, 2022. Accessed October 24, 2022.