Rationale and design of a nationwide prospective cohort study in type 2 diabetic kidney disease: the Korean Diabetic Kidney Disease (K-DKD) Cohort.

BACKGROUND: Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease (ESKD) worldwide. In South Korea, DKD accounts for nearly half of all ESKD cases, yet prospective data reflecting the clinical characteristics of Korean patients remain limited. This study aims to investigate the clinical and biological features of DKD in Koreans and identify long-term prognostic indicators. METHODS: The Korean Diabetic Kidney Disease (K-DKD) Cohort is a nationwide prospective multicenter study investigating the clinical, biochemical, and molecular determinants of DKD progression in Korean adults with type 2 diabetes mellitus. Approximately 1,300 participants will be enrolled from 15 university-affiliated hospitals in South Korea. Demographic, clinical, laboratory data and outcome data are collected using a standardized electronic case report form at baseline and annually for up to 10 years. Blood and urine biospecimens are obtained at baseline and every 2 years thereafter for centralized storage and biospecimen analyses. Clustering analyses will identify the distinct clinical phenotypes of DKD, and long-term prognostic models will be developed on the basis of renal and cardiovascular outcomes using traditional and artificial intelligence-based approaches. Additionally, treatment patterns and management behaviors will be evaluated to understand the real-world clinical practices in Korean DKD. DISCUSSION: The K-DKD Cohort will expand Korea's national big data and biobank platform into a DKD-focused prospective study that integrates standardized clinical and biospecimen data. It aims to facilitate biomarker discovery, data-driven risk prediction, and precision research in Korean patients with DKD.