Metformin may ‘substantially lower’ dementia risk in older blacks
African Americans within the Veterans Affairs health system who were older than 50 years and treated with metformin for their diabetes had a much lower risk for dementia vs. similar patients treated with sulfonylureas, according to findings recently published in Annals of Family Medicine.
Evidence is growing that metformin has limited neurological benefits in some patients with diabetes, Jeffrey F. Scherrer, PhD, of the department of family and community medicine at the Saint Louis University School of Medicine, and colleagues wrote.
“The protective effects of metformin might be observed in younger patients not included in existing research,” researchers added.
Scherrer and colleagues reviewed medical records of 73,761 patients — 10,559 of whom were African American — treated at VA hospitals from 2000 to 2015 who had not received diabetes medications or a dementia diagnosis before fiscal year 2002. The mean age of the African Americans was 58.2 years; in whites it was 61.3 years.
Researchers found that among all patients, and after controlling for confounding, metformin use was associated with a significantly lower risk for dementia vs. sulfonylureas in African American patients (HR = 0.73; 95% CI, 0.6-0.89) but not white patients (HR = 0.96; 95% CI, 0.9-1.03).
The strongest association was found in African American patients aged 50 to 64 years (HR = 0.6; 95% CI, 0.45-0.81). In patients aged 65 to 74 years, metformin was significantly associated with lower risk for dementia in both races. No such association was found in patients older than 75 years.
Scherrer provided possible reasons for the links in an interview with Healio Primary Care.
“African Americans suffer more diabetes-related cognitive decline than whites,” he said. “African Americans are more likely to have cardiovascular disease before dementia, general inflammation and are at higher risk for vascular dementia. Metformin appears to reduce risk for cardiovascular disease and has anti-inflammatory effects. Therefore, these additional metformin effects may be particularly beneficial for African Americans.”
Until additional research can take a closer look at the associations found, Scherrer suggested ways the current study’s findings should change clinical practice, regardless of where patients are treated.
“Providers may want to start metformin earlier for patients with type 2 diabetes who are less than 75 years of age. This does not mean patients should receive metformin if they are diabetes-free, but it is possible that metformin in pre-diabetes and immediate starts of the medication in nearly-diagnosed diabetes might result in reducing risk for dementia in African Americans.” - by Janel Miller
Disclosures: The authors report no relevant financial disclosures.