A US cohort study suggested that metformin cessation was associated with increased dementia incidence. The cohort consisted of 12 220 early terminators and 29 126 routine users, respectively (women 46.2% and 46.6%, respectively; mean age at start of first metformin prescription 59.4 and 61.1 years, respectively). Early terminators had 1.21 times the hazard of dementia diagnosis compared with routine users (hazard ratio, 1.21). Mediation analysis indicated that the association was not mediated by insulin use 1 or 5 years after metformin cessation, and minimally mediated by HbA1c level at 1 year after metformin cessation, suggesting that the association was largely independent of changes in HbA1c level and insulin usage. The findings are in line with other observational studies showing an association between metformin use and lower dementia incidence, with potential implications for diabetes treatment in late life. Source: https://jamanetwork.com/