The risk for incident ischemic heart disease according to estimated glomerular filtration rate in a korean population

Aim: Chronic kidney disease, evaluated by the estimated glomerular filtration rate (eGFR), is an established risk factor for cardiovascular disease. However, the association between renal function stratified by the eGFR and the risk of incident ischemic heart disease (IHD) in a community-based Asian population is still inconclusive. Study design: Retrospective longitudinal observational study. Method: In data from 206,919 Korean patients registered in the National Health Insurance Corporation (NHIC), we analyzed the risk of incident IHD according to the quartiles (Q) of eGFR (ml/min/1.73 m²) (Q1＜ 71.07, Q2: 71.07–83.16, Q3: 83.17–95.49, Q4＞95.50). The identification of IHD was based on the International Classification of Diseases (ICD) for IHD (ICD code: I20–I25) registered in the NHIC. The Cox proportional hazards model was used to calculate the adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for IHD according to quartile groups of eGFR levels. Results: Q1 had the more unfavorable baseline metabolic conditions than the other quartile groups. Consider-ing Q4 as the reference, the unadjusted HRs (95% CIs) for IHD increased significantly in the order of Q3 (1.42 [1.29–1.56]), Q2 (1.51 [1.38–1.67]), and Q1 (2.11 [1.93–2.30]), and fully adjusted HRs (95% CIs) increased significantly from Q2 (1.15 [1.04–1.27]) to Q1 (1.31 [1.18–1.44]). Conclusion: The risk of IHD increased significantly from individuals with an eGFR ≤ 83.16. Mildly decreased renal function is a potential risk factor for IHD.