Abstract
BACKGROUND: Diabetic nephropathy is a common complication of diabetes. We investigated the risk factors for diabetic nephropathy in individuals newly diagnosed with type 2 diabetes. METHODS: Data from the Japanese Diagnosis Procedure Combination in-patient database (April 2008 to December 2018) were analyzed. The endpoint was subsequent diabetic nephropathy diagnosis or as the time when estimated glomerular filtration rate become <60 ml/min/1.73 m(2). Candidate risk factors included age, Hemoglobin A1c, log-transformed triglyceride, total cholesterol, and high-density lipoprotein cholesterol levels, body mass index, and estimated glomerular filtration rate. Eligible individuals with type 2 diabetes without complications who had pre- and post-diagnosis Hemoglobin A1c and serum creatinine measurements, and a history of hypertension or cardiovascular disease pre-diagnosis. Those with pre-existing kidney diseases, nephropathy onset pre-diagnosis, estimated glomerular filtration rate <60 ml/min/1.73 m(2) on or before diabetes diagnosis, or age <20 years at diabetes diagnosis were excluded. A multivariate Cox proportional hazards model (p = 0.2 backward selection) was employed. RESULTS: Of 2,664 eligible individuals (1,775 men, 889 women), 325 men and 175 women developed diabetic nephropathy during follow-up. Cumulative incidence within 5 years was 29.0% in men and 32.5% in women. Age and estimated glomerular filtration rate in both sexes, and total cholesterol in men were significant. CONCLUSIONS: Age, estimated glomerular filtration rate, and lipid pose potential risks for diabetic nephropathy onset within 5 years of diabetes diagnosis in individuals with hypertension. Collectively, our findings highlight the importance of early monitoring and intervention in this high-risk.