The Long-Term Cardiovascular Effects of Metformin on Patients with Newly Diagnosed Type 2 Diabetes

Objective: Metformin is the first pharmacological option for preventing and treating type 2 diabetes. However, the use of this drug in preventing cardiovascular disease associated with the development of newly diagnosed type 2 diabetes is unclear. We aimed to examine whether the metformin reduced the incidence of major cardiovascular events over a 20-year follow-up of patients with newly diagnosed type 2 diabetes. Research Design and Methods: We conducted a retrospective observational cohort study of 48,338 patients with type 2 diabetes from Anhui Provincial Hospital between January 1, 2000, and June 30, 2021. Data were collected for patients with newly diagnosed T2D (within 6 months) who did not have prior cardiovascular disease and took metformin at baseline were compared with those who did not using. The primary outcome was the first occurrence of major cardiovascular events including coronary heart disease (CHD), stroke, and hospitalization due to heart failure (HF). The multivariate Cox proportional hazards regression with inverse probability of treatment weighting. Propensity score matching (PSM) was conducted for reducing the biases of baseline characteristics. Results: After matching, newly diagnosed T2D patients who used metformin, compared with those who did not use, had significantly lower risk of HF (HR 0.51, 95% CI 0.28 to 0.93) and CHD (HR 0.37, 95% CI 0.13 to 1.09). No difference in the risk incident stroke (HR 0.89, 95% CI 0.68 to 1.17) was observed. In both the original and PSM groups, use of metformin can reduce the risk of CHD events from newly diagnosed T2D patients (adjusted HR 0.74; 95% CI 0.69-0.87; P = 0.029). Conclusions: In the present retrospective study, metformin use may be beneficial for preventing CHD and HF in newly diagnosed T2D patients. Further randomized controlled trials are needed to confirm these findings. Disclosure T.Yue: None. X.Wang: None. M.Zhao: None. J.Weng: None. S.Luo: None. X.Zheng: None.