Associations of body size with metabolic syndrome and mortality in moderate chronic kidney disease

Background and Objectives: Obesity is associated with metabolic syndrome and poor outcomes in those with normal kidney function but better survival in dialysis patients. We examined whether chronic kidney disease (CKD) modifies the association of obesity with metabolic syndrome and mortality. Design, Setting, Participants, & Measurements: Analyses of 15,355 participants in limited access, public use Atherosclerosis Risk in Communities Study database. Results: The prevalence of metabolic syndrome in (BMI) groups < 20, 20 to 24.9, 25 to 29.9, 30 to 34.9, and >= 35 kg/m(2) were 1, 6, 17, 28, and 35% and 9, 15, 32, 46, and 58% in participants without (n = 14,894) and with CKD (n = 461), respectively. Using BMI 20 to 24.9 kg/m(2) as the reference, there was a U-shaped association of BMI with mortality in a parametric survival model of death. An interaction term of BMI and CKD added to the model was significant. In participants with (BMI) 2:25 kg/m(2), each 1-kg/m(2) increase in BMI was associated with increased hazard of death only in those without CKD. Adjustment for components of metabolic syndrome, markers of inflammation, and cardiovascular conditions abolished these associations in participants without CKD but became protective in participants with CKD. Conclusions: The prevalence of obesity parallels metabolic syndrome in popultions with and without CKD. However, the presence of CKD modifies the associations of obesity with mortality.