Metabolic syndrome and smoking are associated with future development of advanced chronic kidney disease in older adults

Introduction: Metabolic syndrome (MetS) and smoking have been identified as risk factors for chronic kidney disease (CKD) in cross-sectional studies in various age groups, but longitudinal data on progression of CKD in older adults are limited. Our objectives were to examine whether MetS and its components and smoking predict the onset of CKD stage 3b (CKD-3b) in older adults. Methods: A subset of participants of the Einstein Aging Study who were free of diabetes, dementia, and CKD-3b at enrollment were included in this analysis. CKD-3b was defined as an estimated glomerular filtration rate <45 ml/min/1.73 m². Cox proportional hazards models were used in these analyses. Results: In total, 413 ≥70-year-old individuals were eligible for this study. 65.4% were female and 26.6% were black. 22.3% of the participants had MetS at baseline, 4.4% were active smokers, and 6.1% developed CKD-3b over a mean of 4 years of follow-up. MetS and smoking independently predicted incident CKD in our fully adjusted model (hazard ratio 3.65, 95% CI 1.20-10.60, p = 0.022; hazard ratio 29.69, 95% CI 4.47-197.23, p = 0.000). Conclusion: MetS and smoking are associated with an increased incidence of CKD-3b. These risk factors are modifiable, easily identified and prevented through better health care practice and early diagnosis.