Central obesity, C-reactive protein and chronic kidney disease: a community-based cross-sectional study in southern China.

OBJECTIVE Previous studies have shown that central obesity is associated with chronic kidney disease (CKD). We hypothesized that the association of central obesity with CKD is modified by the presence of inflammation. To test this hypothesis, we performed this study. METHODS This was a cross-sectional study in southern China. Waist-to-height ratio (WHtR) was used as a central obesity index and C-reactive protein (CRP) was used as an index for inflammation. CKD was defined as estimated glomerular filtration rate(eGFR) <60 ml/min/1.73m(2) or albuminuria-to-creatinine ratio (ACR) >30mg/g. Multivariable logistic regressions were used and logistic regression models were adjusted for potential confounders and other components of metabolic syndrome. RESULTS 1834 subjects were included in the current study. WHtR, body mass index and waist circumference were significantly associated with the level of CRP. When adjustment for potential confounders, only central obesity with a higher CRP level was associated with CKD (Relavitve-risk Ratio, 95% CI: 1.68, 1.03 - 2.75, P = 0.04). In multivariate logistic models, WHtR was associated with CKD. The odd ratio for WHtR (every SD increment), was 1.38 (95% CI 1.15, 1.66, P < 0.001). Further adjustment for log-transformed CRP had an impact on the odd ratios. CONCLUSION Central obesity is associated with CKD, independently of other MetS components. Central obesity is also associated with inflammation and the presence of inflammation modifies the associations of central obesity and CKD. This study is based on a community-based chinese population, and the results may only be applicable for Chinese population.