Prevalence of chronic kidney disease defined by using CKD-EPI equation and albumin-to-creatinine ratio in the Korean adult population

Background/Aims: An updated chronic kidney disease (CKD) definition and classification were proposed by Kidney Disease: Improving Global Outcomes (KDIGO), with adoption of a new equation to estimate glomerular filtration rate (GFR) and albuminuria to evaluate kidney structural damage. This study was performed to estimate the prevalence of CKD in the Korean adult population as defined and classified by the KDIGO guidelines. Methods: Cross-sectional samples of the fifth Korean National Health and Nutrition Examination Survey for 2011 to 2012 were examined for adults $aged{\geq}19years$. CKD prevalence was determined based on decreased GFR and albuminuria. The GFR was estimated using the CKD Epidemiology Collaboration creatinine equation, and albuminuria was evaluated using the albumin-to-creatinine ratio (ACR) in spot urine. Results: Of the 16,576 subjects participating in the survey, 10,636 (4,758 men, 5,878 women) were included in the present study. The prevalence of CKD was estimated as 7.9% (7.8% in 2011 and 8.0% in 2012, p = 0.770). The prevalence of low, moderately increased, high, and very high CKD risk prognosis was 92.0%, 6.3%, 1.1%, and 0.6%, respectively. The prevalence of albuminuria ($ACR{\geq}30mg/g$) in individuals with $GFR{\geq}60mL/min/1.73m^2$ has reached 5.7%. The odds ratios of hypertension and diabetes to CKD were 3.4 and 3.1 in men, and 2.9 and 2.0 in women (all p < 0.001), respectively. Conclusions: A large percentage of CKD patients had albuminuria prior to a decrease in GFR. Regular laboratory tests for albuminuria for the high-risk group, and especially for hypertensive or diabetic patients, might improve detection of CKD at an early stage.