Characteristics and Risk of Incident Diabetic Nephropathy between Early-onset versus Late-onset Type 2 Diabetics of Nigerian Origin

Background: Diabetic nephropathy (DN), the most common complication of type 2 diabetes (T2DM), has been reported to occur more often among the early-onset type 2 diabetes (ET2DM) compared to the late-onset type 2 diabetes (LT2DM) in the Western populations with no previous data on this subject in Nigeria. Hence, the current study evaluated the incidence and risk of DN between ET2DM versus LT2DM. Methods: This was a retrospectively designed cross-sectional observational study conducted at the Rivers State University Teaching Hospital, Southern Nigeria. Socio-demographic, anthropometric, clinical, and laboratory data for 10 years (2014–2023) were obtained from medical records of T2DM patients with similar DM duration and analyzed using descriptive/inferential statistics. Results: During the studied period, 3,111 adults were diagnosed with T2DM of which 352 (11.3%) presented with incident DN. T2DM cohorts with incident DN were mostly those with ET2DM diagnosis (n = 218; 61.9%) compared to the LT2DM. The ET2DM cohorts were relatively younger with higher proportions of positive DM family history, overweight/obesity status, blood pressure, plasma creatinine/glucose, urine albumin-to-creatinine ratio, and HbA1c but lower eGFR at presentation than the LT2DM cohorts. The ET2DM was significantly associated with incident DN following crude (HR: 6.986; 95%CI: 3.476–9.518; p < 0.001) and confounder-adjusted (HR: 4.684; 95%CI: 2.270–7.114; p < 0.001) Cox proportional regression models compared to the LT2DM cohorts. Conclusion: DN is common among patients with T2DM and more particularly prevalent among younger patients with metabolic condition. Hence, aggressive exploration of renal status should be made mandatory during the initial evaluation of T2DM among younger patients.