Clinical characteristics and prognosis of non-albuminuric diabetic kidney disease: a single-center retrospective cohort study

To investigate the clinical characteristics and prognosis of non-albuminuric diabetic kidney disease (NADKD), evaluate the association between macrovascular disease and composite renal outcomes, and develop a risk prediction model. In this single-center retrospective cohort study, patients with diabetic kidney disease (DKD) with a baseline eGFR of 15 to < 60 mL/min/1.73 m² enrolled between June 1, 2008, and April 1, 2024 were classified as having NADKD or albuminuric DKD according to the urine albumin-to-creatinine ratio. Propensity score matching (1:1) was used to compare clinical characteristics, composite renal outcomes, all-cause mortality, and annual eGFR decline between the two groups. A total of 905 patients with DKD were included, comprising 176 with NADKD and 729 with albuminuric DKD. After matching, 151 patients remained in each group, and the median age of the matched population was 73 years (IQR, 64–79 years). Compared with the albuminuric DKD group, patients with NADKD had higher albumin levels, lower fasting blood glucose, total cholesterol, HbA1c, and TyG index, and a higher prevalence of macrovascular disease (59.6% vs. 39.7%, P = 0.001). Kaplan-Meier analysis showed significantly better renal survival in the NADKD group ( P < 0.001), whereas all-cause mortality did not differ significantly between groups ( P = 0.054). The annual eGFR decline rate was significantly lower in the NADKD group than in the albuminuric DKD group (0.747 vs. 3.224 mL/min/1.73 m², P < 0.001). Multivariable Cox analysis identified macrovascular disease as an independent risk factor for composite renal outcomes (HR = 4.19, 95% CI: 1.45–12.09, P = 0.008). The final model included age, sex, baseline eGFR, and macrovascular disease. Its apparent C-index was 0.762, and the optimism-corrected C-index after 1,000 bootstrap resamples was 0.744, with 3- and 5-year AUCs of 0.828 and 0.745, respectively. NADKD may represent a distinct DKD subtype characterized by a heavier macrovascular burden and slower renal function decline. Macrovascular disease was independently associated with adverse renal outcomes, and the proposed model may help identify high-risk patients early. Not applicable.