Obesity Paradox and Risk of Mortality Events in Chronic Kidney Disease Patients: A Decade of Follow-up in Tehran Lipid and Glucose Study

Objective: To evaluate the effect of different fat distribution measures on the risk of all-cause mortality events among chronic kidney disease (CKD) patients, which has not been previously evaluated. Methods: The present study consisted of 1,860 individuals with CKD, aged ≥30years who participated in Tehran Lipid and Glucose Study. The estimated glomerular filtration rate was estimated using the abbreviated prediction equation, provided by the Modification of Diet in Renal Disease formula, and CKD was defined as estimated glomerular filtration rate < 60mL/minute/1.73m². Cox proportional hazard regression was implemented to estimate the hazard ratios (HRs) of different anthropometric measures for predicting mortality events. Results: During 10.1 years of follow-up, 221 cases of all-cause mortality events occurred. In confounder-adjusted model (age, sex, creatinine, the history of cardiovascular disease, and smoking), none of the HRs of different anthropometric measures reached the significant level; however, when we also considered mediator variables (hypertension, diabetes, and hypercholesterolemia) in the model, there was significant interaction between sex and waist circumference for the risk prediction of mortality events. Among men, the HRs of mortality for 1 standard deviation increase in anthropometric measures were 0.73 (0.57-0.92) for weight, 0.67 (0.54-0.83) for waist circumference, 0.75 (0.58-0.97) for body mass index, and 0.71 (0.52-0.96) for hip circumference. However among women, none of the measures were associated with increased risk of all-cause mortality events. Conclusion: Among men with CKD, regardless of fat distribution in hip, waist, or in whole body, having more fat mass results in better survival.