Background

Patients with normoalbuminuria and a reduced estimated glomerular filtration rate (eGFR) account for a considerable proportion of type 2 diabetes (T2DM) patients. The aim of the research was to investigate the epidemiological and clinical characteristics of normoalbuminuric kidney disease in Chinese population.

Methods

We included 8131 diabetic patients from a multicenter prospective study in China. Based on eGFR and urinary albumin/creatinine ratio (UACR), participants were stratified into four groups—normal albuminuria, albuminuria, normoalbumunuria with eGFR<60 mL/min/1.73 m2, and albuminuria with eGFR<60 mL/min/1.73 m2. Clinical parameters and characteristics of patients with normoalbumunuria and eGFR<60 mL/min/1.73 m2 were retrospectively analyzed.

Results

A total of 1060 of 8131 individuals with diabetes had decreased eGFR (<60 mL/min/1.73 m2). Normoalbuminuria accounted for 63.3% of participants with eGFR<60 mL/min/1.73 m2, and microalbuminuria and macroalbuminuria accounted for 30.1% and 6.3%, respectively. Patients with normoalbuminuria and reduced eGFR were more frequently male, older and had higher levels of triglycerides than patients with normal albuminuria and eGFR. We also detected a correlation between lower extremity arterial disease, newly diagnosed diabetes and normoalbuminuria-reduced eGFR. Compared with participants with both albuminuria and eGFR decline, those with normoalbuminuria had better metabolic indicators, including systolic blood pressure and glycated hemoglobin A1c, and shorter diabetes duration. Even in the normal range, UACR has a significant correlation with the risk of eGFR insufficiency.

Conclusions

Normoalbuminuric renal insufficiency, characterized by male, older age, a higher level of triglycerides and a higher risk of lower extremity arterial disease, accounted for a dominant proportion of diabetic patients with eGFR decline.