Weight change in early Parkinson's linked to changes in thinking skills

Weight gain or loss was defined as a change of more than 3% of body weight during the first year of the study. Weight maintenance was defined as no change or change of no more than 3%. A total of 98 people had weight loss, 59 had weight gain and 201 maintained their weight.

Participants took tests of thinking skills at the beginning of the study and then every year for up to eight years. They also took tests for other non-motor symptoms that can occur in people with Parkinson's disease, such as depression, anxiety and sleep disorders.

The people with Parkinson's who lost weight had a faster decline in their overall thinking scores compared to those with Parkinson's who maintained their weight. Both groups started with average scores of 27 on the test. The scores of those who lost weight declined 0.19 points faster per year than those of those who maintained their weight. The thinking skills with the steepest declines were related to verbal fluency skills, which are a measure of executive function.

In contrast, the people with Parkinson's who gained weight had a slower decline in their scores on a test of processing speed compared to those who maintained their weight.

However, its to be noted that the study does not prove that weight change causes changes in thinking skills; it only shows an association.

Reference:

Jin-Sun Jun et al,JOURNAL:Neurology