Low-grade inflammation, metabolic syndrome and the risk of chronic kidney disease: The 2005 korean national health and nutrition examination survey

Either chronic inflammation or metabolic syndrome (MetS) is associated with renal impairment. This cross-sectional study was designed to investigate the relationship between elevated white blood cell (WBC) counts and chronic kidney disease (CKD) stage 3 or more according to the presence of MetS in adult Koreans. In total, 5,291 subjects (≥ 20 yr-old) participating in the 2005 Korean National Health and Nutrition Examination were included. CKD stage 3 or more was defined as having an estimated glomerular filtration rate below 60 mL/min/1.73 m ², as calculated using the formula from the Modification of Diet in Renal Disease study. The odds ratio (95% confidence interval) for CKD stage 3 or more in the highest WBC quartile (> 7,200 cells/μL) was 1.70 (1.17-2.39) after adjusting for MetS and other covariates, compared with the lowest WBC quartile (< 5,100 cells/μL). In subjects with MetS, the prevalence risk for CKD stage 3 or more in the highest WBC quartile was 2.25 (1.28-3.95) even after fully adjusting for confounding variables. In contrast, this positive association between WBC quartile and CKD stage 3 or more disappeared in subjects without MetS. Low-grade inflammation is significantly associated with CKD stage 3 or more in subjects with MetS but not in those without MetS.