The impact of metformin on mortality in patients with type 2 diabetes mellitus: a prospective cohort study.

Abstract

Metformin, a widely used antihyperglycemic drug, has shown efficacy in treating type 2 diabetes mellitus (T2DM) and is associated with potential benefits beyond glycemic control. This study investigates the impact of metformin on mortality in T2DM patients using a prospective cohort design utilizing data from the National Health and Nutrition Examination Survey (NHANES). In NHANES 1999-2014, a total of 5813 representative participants aged 20 and above with T2DM were included in the analysis. We utilized Kaplan-Meier survival curves and multivariate Cox regression analysis to investigate the impact of metformin on both all-cause mortality and cause-specific mortality among patients with T2DM. Kaplan-Meier analysis showed a significant reduction in all-cause and cause-specific mortality in metformin users compared to non-users (p < 0.05). Multivariate Cox regression confirmed these findings, indicating that metformin use was associated with a 18% reduction in all-cause mortality (HR = 0.82, 95% CI = 0.73-0.92, p < 0.001) and 25% reduction in cardiovascular mortality (HR = 0.75, 95% CI = 0.60-0.94, p = 0.01). Our results suggest that metformin significantly reduces all-cause and cardiovascular mortality in T2DM patients, highlighting its potential benefits beyond glycemic control. These results contribute to the existing literature by providing robust evidence from a large prospective cohort study. However, further research is needed to validate these findings and elucidate the underlying mechanisms controlling the effects of metformin on mortality outcomes in individuals with T2DM.