Effects of Non-Albuminuric Type 2 Diabetes Mellitus on Renal Outcomes: A Nationwide Study

Abstract The specific impact of type 2 diabetes mellitus (T2D) on renal outcomes, independent of albuminuria, is not fully understood. This study aimed to investigate the renal outcomes in non-albuminuric T2D subjects compared to non-albuminuric non-T2D subjects. Data from the National Health Insurance Service-National Sample Cohort of Korea from 2009 to 2015 were analyzed. The non-albuminuric T2D group was compared with the non-albuminuric non-T2D group. The primary outcome was a composite renal outcome consisting of the initiation of renal replacement therapy and a decline of ≥ 40% in eGFR from baseline. Of 587,339 subjects, 77,267 were analyzed: 11,957 in the T2D group and 65,310 in the non-T2D group. The T2D group demonstrated a greater annual decline in eGFR of -0.113 ml/min/1.73 m2 (95% CI: -0.222 – -0.003, p = 0.044). The adjusted hazard ratio for the primary outcome was 1.57 (95% CI: 1.28¬–1.92, p < 0.001). The steeper decline in eGFR was particularly evident in patients with glomerular hyperfiltration (eGFR ≥ 120 ml/min/1.73 m2) and a duration of T2D exceeding 6 years. Non-albuminuric T2D was associated with a greater annual decline in renal function and had a 1.5-fold increased risk of adverse renal outcomes compared to non-albuminuric non-T2D.