Association of obesity with inflammation in occult chronic kidney disease

Background: There are few studies concerning the development of chronic kidney disease (CKD) in obese patients independent of its relation with other risk factors. Also, the role of inflammation in this relationship is unclear. In this study we aimed to test the hypothesis that obesity is associated with risk for CKD and whether this risk is associated with serum C-reactive protein (CRP) levels in an apparently healthy obese population. Methods: Biochemical parameters and urinary protein excretion were determined in 110 patients with body mass index (BMI) >30.0 (calculated as kg/m(2)) and 50 age-matched healthy controls. Glomerular filtration rate was estimated by calculation of creatinine clearance. Results: Of the patients, 17.3% had CKD. They had higher CRP levels than controls (6.52 +/- 0.58 mg/L and 4.48 +/- 1.26 mg/L, respectively, p=0.001). Furthermore, CRP levels were positively correlated with BMI, waist circumference, waist to hip ratio and proteinuria, and negatively correlated with glomerular filtration rate (GFR). When GFR was considered as the dependent variable in a multiple regression analysis, CRP maintained its significant correlation with GFR. Conclusion: Our study of apparently healthy obese individuals, has shown a significant association between BMI and CKD independent of other potential mediators. Furthermore, our findings suggest that inflammation may be the pathogenic mechanism of obesity-related CKD.