Early glycaemic control helps lower dementia risk among new metformin users

A recent study provides evidence lending support to established recommendations for early glycaemic control in patients with type 2 diabetes to reduce their risk of developing dementia.

Researchers identified 46,332 metformin monotherapy initiators (median age 65 years) in Northern Denmark from 2000 to 2028 using national health registry data. They explored the association of early glycaemic control, HbA1c reduction magnitude, and their combination with incident dementia using standard hazard models and propensity score-based restricted and weighted models.

Of the metformin initiators, 83 percent achieved an HbA1c level <7 percent (<53 mmol/mol) within 1 year after metformin initiation, and 1,432 (3.2 percent) developed dementia over a median of 5.6 years of follow-up.

Both standard and propensity-score restricted/weighted analyses revealed an increased risk of dementia in individuals achieving HbA1c levels >7 percent (>53 mmol/mol) and little difference in dementia risk among those achieving tight (HbA1c, 6.5 percent to <7 percent/48 to <53 mmol/mol) or very tight glycaemic control (HbA1c, 6 percent to <6.5 percent/42 to <48 mmol/mol or <6 percent/<42 mmol/mol).

“While p-values for interaction were nonsignificant, point estimates suggesting benefits of early glycaemic control on dementia risk were limited to persons without established cardiovascular disease and take years to manifest,” the researchers said.