Metformin in elderly type 2 diabetes mellitus: dose-dependent dementia risk reduction

This study aimed to investigate the controversial association between metformin use and diabetes-associated dementia in elderly patients with type 2 diabetes mellitus (T2DM) and evaluate the potential protective effects of metformin, as well as its intensity of use and dose-dependency, against dementia in this population. The study used a time-dependent Cox hazards model to evaluate the effect of metformin use on the incidence of dementia. The case group included elderly patients with T2DM (≥60 years old) who received metformin, while the control group consisted of elderly patients with T2DM who did not receive metformin during the follow-up period. Our analysis revealed a significant reduction in the risk of dementia among elderly individuals using metformin, with an adjusted hazard ratio of 0.34 (95% confidence interval: 0.33 to 0.36). Notably, metformin users with a daily intensity of 1 defined daily dose (DDD) or higher had a lower risk of dementia, with an adjusted hazard ratio (95% confidence interval) of 0.46 (0.22 to 0.6), compared to those with a daily intensity of <1 DDD. Additionally, the analysis of cumulative DDDs of metformin showed a dose-response relationship, with progressively lower adjusted hazard ratio across quartiles (0.15, 0.21, 0.28, and 0.53 for quartiles 4, 3, 2 and 1, respectively), compared to never metformin users (P for trend < 0.0001). Metformin use in elderly patients with T2DM is significantly associated with a substantial reduction in the risk of dementia. Notably, the protective effect of metformin demonstrates a dose-dependent relationship, with higher daily and cumulative dosages of metformin showing a greater risk reduction.

Long-term outcomes of statin dose, class, and use intensity on primary prevention of cardiovascular mortality: a national T2DM cohort study

PURPOSE

To investigate how statins reduce cardiovascular mortality in patients with type 2 diabetes (T2DM) in a dose-, class-, and use intensity-dependent manner.

METHODS

We used an inverse probability of treatment-weighted Cox hazards model, with statin use status as a time-dependent variable, to estimate the effects of statin use on cardiovascular mortality.

RESULTS

Adjusted hazard ratio [aHR; 95% confidence interval (CI)] for cardiovascular mortality was 0.41 (0.39-0.42). Compared with nonusers, pitavastatin, pravastatin, simvastatin, rosuvastatin, atorvastatin, fluvastatin, and lovastatin users demonstrated significant reductions in cardiovascular mortality [aHRs (95% CIs) = 0.11 (0.06, 0.22), 0.35 (0.32, 0.39), 0.36 (0.34, 0.38), 0.39 (0.36, 0.41), 0.42 (0.40, 0.44), 0.46 (0.43, 0.49), and 0.52 (0.48, 0.56), respectively]. In Q1, Q2, Q3, and Q4 of cDDD-year, our multivariate analysis demonstrated significant reductions in cardiovascular mortality [aHRs (95% CIs) = 0.63 (0.6, 0.65), 0.44 (0.42, 0.46), 0.33 (0.31, 0.35), and 0.17 (0.16, 0.19), respectively; P for trend < 0.0001]. The optimal statin dose daily was 0.86 DDD, with the lowest aHR for cardiovascular mortality of 0.43.

CONCLUSIONS

Persistent statin use can reduce cardiovascular mortality in patients with T2DM; in particular, the higher is the cDDD-year of statin, the lower is the cardiovascular mortality. The optimal statin dose daily was 0.86 DDD. The priority of protective effects on mortality are pitavastatin, rosuvastatin, pravastatin, simvastatin, atorvastatin, fluvastatin, and lovastatin for the statin users compared with non-statin users.