Diabetes and Parkinson's - a simple solution?

Researchers are taking a closer look at whether the diabetes medication metformin might convey benefit in patients with both Parkinson's disease (PD) and diabetes - and are finding some positive signals.

A small retrospective study showed that patients with PD and diabetes who took the antihyperglycemic agent performed significantly better on tests of motor and nonmotor function than their counterparts who did not.

The findings were presented at the Congress of the European Academy of Neurology (EAN) 2020.

Emerging evidence points to a link between PD and diabetes, and highlights the many shared pathological mechanisms, such as neuroinflammation and neurogenesis.

Observational studies have shown that individuals with diabetes are at increased risk of developing PD; and when they do, they experience more severe motor and nonmotor symptoms such as cognitive impairment compared with nondiabetic patients with PD.

The observed link between diabetes and PD has generated the research hypothesis that antidiabetic drugs such as metformin might be neuroprotective and even disease modifying in PD.

The current retrospective cohort study included 19 de novo PD patients (85% men; mean age, 65 years) with diabetes mellitus from the Parkinson's Progression Markers Initiative (PPMI) cohort.

Results showed that compared with the patients not taking metformin, those taking the drug had a significantly better Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) total score (P = .04) and Benton Judgement of Line Orientation score, which assesses visuospatial function (P = .04).

These patients also did significantly better on certain measures of cognitive impairment, including the Symbol Digit Modalities Test score (P = .03) and the Semantic Fluency total score (P = .003). A higher metformin cumulative dose was associated with the MDS-UPDRS rigidity score.