Changes in waist circumference and incidence of chronic kidney disease.

BACKGROUND: Many studies have evaluated the association of anthropometric indices with chronic kidney disease (CKD), but the association of waist circumference(WC) changes with CKD incidence is less clear. We evaluated the effect of WC changes on CKD incidence in participants of the Tehran Lipid and Glucose Study (TLGS).

STUDY DESIGN: The risk of CKD incidence was evaluated in three serial phases with interval censoring. A group of 8,183 (46·5% men) participants, mean age 47·4 years, free of previous CKD, were followed. Waist changes were divided into four groups: (i)decrease in WC; (ii) reference group; (iii)mild to moderate increase in WC and (iv)severe increase in WC. Glomerular filtration rate(GFR) was estimated using the MDRD equation.

RESULTS: In 8,183 participants, mean GFR was higher in men (77·1 vs. 74·4 mL/min/1·73 m2, P<0·001). During the 9 years of follow-up, 1477 new cases of CKD occurred(1026 in women). WC changes were not associated with the development of CKD in women. In men, decrease in WC was not related to lower risk of CKD (HR: 0·90, 95% CI 0·6-1·4), whereas a mild to moderate increase in WC was associated with a 70% (HR: 1·7, 95% CI 1·3-2·2) higher risk of CKD even after adjusting for covariates (HR: 1·6, 95% CI 1·2-2·2). Severe increase in WC was associated with a fourfold risk of CKD in comparison with reference group (HR: 3·7, 95% CI 2·7-5·1).

CONCLUSION: Changes in WC are not independent risk factors for CKD development in women, whereas waist gain can adversely influence the development of CKD in men.