Effect of Glomerular Hyperfiltration on Incident Cardiovascular Disease in Patients with Type 2 Diabetes Mellitus

Background: The effects of glomerular hyperfiltration (GHF) on cardiovascular disease (CVD) risk in patients with type 2 diabetes mellitus (T2DM) were explored. Methods: This retrospective cohort study enrolled 1,952,053 patients with type 2 diabetes mellitus from the Korean National Health Insurance Service database between 2015 and 2016. Based on age- and sex-specific estimated glomerular filtration rate (eGFR) percentiles, patients were classified into five groups: <5 (low filtration), 5–40, 40–60, 60–95, and >95 (GHF). Patients with incident cardiovascular disease (CVD) (myocardial infarction [MI], stroke, and hospitalization for heart failure [HF]) were followed up until December 2022. Results: CVD occurred in 214,111 patients (11%). The incidence rates were 36.1, 20.8, 18.3, 18.7, and 19.3 per 1000 person-years for the eGFR groups, respectively. Low filtration (hazard ratio [HR] = 1.56, 95% confidence intervals [CI] 1.53–1.59) and GHF (HR = 1.13, 95% CI 1.10–1.15) were associated with higher CVD risk adjusted for covariates than that of the eGFR 40–60 percentile, showing an inverted J-shaped relationship. GHF was associated with a higher risk of MI (HR = 1.06, 95% CI 1.01–1.11) and HF (HR = 1.17, 95% CI 1.14–1.20) and with a higher risk of stroke. eGFR was associated with CVD risk across subgroups of age, sex, obesity, hypertension, and dyslipidemia. The impact of GHF on CVD may be greater in younger patients (HR = 1.30, 1.17, and 1.05 in <40, 40–60, and ≥65 years old, respectively). Conclusions: GHF was associated with CVD, particularly MI and HF. Screening for GHF in the early stages of T2DM may be beneficial.