Association Between Metformin Initiation and Incident Dementia


Posted Oct 17 , 2019 04:27 AM

Association Between Metformin Initiation and Incident Dementia Among African American and White Veterans Health Administration Patients.
Scherrer JF, et al. Annals of Family Medicine 2019;17:352-362

Institute Summary (excerpted from the abstract)

African American patients are more likely to experience cognitive decline after type 2 diabetes mellitus onset than white patients. Metformin use has been associated with a lower risk of dementia compared with sulfonylureas. Evidence for whether this association differs by race is sparse. Veterans Health Administration (VHA) medical record data were obtained for 73,761 African American and white patients aged ≥50 years who used the VHA from fiscal years 2000 to 2015. Patients were free of dementia and diabetes medications during fiscal years 2000 and 2001 and subsequently initiated metformin or sulfonylurea monotherapy. For race and age subgroups, Cox proportional hazards models using propensity scores and inverse probability of treatment weighting to control for confounding were computed to measure the association between metformin vs sulfonylurea initiation and incident dementia. After controlling for confounding, among patients aged ≥50 years, metformin vs sulfonylurea use was associated with a significantly lower risk of dementia in African American patients (hazard ratio [HR] = 0.73; but not white patients (HR = 0.96). The strongest magnitude of association between metformin and dementia was observed among African American patients aged 50 to 64 years (HR = 0.6). Among those aged 65 to 74 years, metformin was significantly associated with lower risk of dementia in both races. Metformin was not associated with dementia in patients aged ≥75 years.

Why is this important?

Diabetes is a risk factor for dementia, and African Americans with T2DM have nearly twice the incidence of dementia as whites. This disparity is greater in patients aged 55 to 65 years compared with older patients. Results from the Atherosclerosis Risk in Communities study indicate that African American participants with T2DM had a 41% decrease in cognitive test scores over a period of 14 years, whereas white participants experienced no decrease. There are no existing medications to prevent dementia. The 29% decreased risk of dementia associated with metformin use in African American patients aged 65 to 74 years and the 40% decreased risk in those aged 50 to 64 years suggest that this inexpensive, widely available treatment if more broadly prescribed could substantially reduce the risk of dementia in younger African American patients with T2DM.Do you start newly diagnosed African Americans on metformin? Will you do so now?

Concluding Thought “Curious is a good thing to be, it seems to pay some unexpected dividends.” -Iggy Pop

Read the Article: