Effects of statins on glycemic control and cardiovascular events in patients with new-onset type 2 diabetes: a retrospective cohort study.

Background: Cardiovascular disease is the leading cause of morbidity and mortality in patients with type 2 diabetes (T2D). While statin therapy is universally recommended for cardiovascular disease prevention, its potential adverse effects on glycemic progression remain controversial, particularly in patients with newly diagnosed disease. This study aimed to evaluate the dual effects of statin initiation on glycemic control and major adverse cardiovascular events (MACEs) in a retrospective cohort of patients with new-onset T2D. Methods: We conducted a retrospective cohort study in which patients who were newly diagnosed with T2D between January 2018 and December 2020 were screened. The primary outcome was the change in the glycated hemoglobin (HbA1c) levels. Secondary outcomes included fasting plasma glucose (FPG) levels, 2-hour post-prandial glucose (2hPG) levels, diabetes therapy intensification, insulin initiation, hyperglycemic crisis, and MACEs. Longitudinal glycemic trajectories were assessed using two-way repeated-measures ANOVA. The MACE risk was evaluated with a Kaplan-Meier analysis and multivariable Cox regression model. Results: A total of 604 eligible patients were classified into a statin group (n = 458) and a nonstatin group (n = 146). At the 6-month follow-up, both groups exhibited improved glycemic indices, but this improvement was significantly attenuated in the statin group. Similar attenuated improvements were observed in the FPG and 2hPG levels at 6 months. Group × time interaction effects were significant for FPG, 2hPG, and HbA1c levels at 6 months. By 60 months, between-group differences in HbA1c levels were no longer significant. During the median (interquartile range) follow-up of 73 (68-80) months, statin therapy was associated with higher frequencies of diabetes therapy intensification (33.3% vs. 22.6%, p = 0.016), insulin initiation (21.5% vs. 12.3%, p = 0.015), and hyperglycemic crisis (8.5% vs. 3.4%, p = 0.039). Despite these metabolic disadvantages, statin therapy was independently associated with a lower MACE risk according to the multivariable Cox regression analysis (HR 0.41, 95% CI 0.21-0.83; p = 0.013). Conclusions: In patients with new-onset T2D, early statin initiation is associated with worse short-term glycemic improvement and a greater need for escalating glucose-lowering therapy; however, it is also associated with a substantial reduction in the long-term MACE risk.