Aging is associated with slower renal progression in patients with chronic kidney disease

OBJECTIVES: Chronic kidney disease (CKD) is prevalent among the elderly. However, little is known about how the clinical course of CKD vary with age. The purpose of this study was to examine the impact of aging on the risk of end-stage kidney disease (ESKD) in patients with moderate to advanced CKD. MATERIALS AND METHODS: A total of 454 patients with stages 3–5 CKD were prospectively followed for a median of 5.1 years. The primary outcome was ESKD needing chronic dialysis therapy or preemptive kidney transplantation. The secondary outcome was a composite of ESKD or all-cause mortality. RESULTS: The mean age of the patients was 65 ± 13 years. 65.4% were men, 44.9% had diabetes mellitus, and 22.7% had cardiovascular disease. Overall, 142 participants progressed to ESKD and 63 participants died. Compared with young patients (age <65 years, n = 205), elderly patients (age ≥65 years, n = 249) were associated with a significantly decreased risk of ESKD in Cox proportional hazards models adjusted for sex, smoking history, diabetes mellitus, cardiovascular disease, systolic blood pressure, estimated glomerular filtration rate, urine protein: Creatinine ratio, use of renin-angiotensin-aldosterone blocker, hemoglobin, phosphate, interleukin-6, body mass index, and N-terminal pro-brain natriuretic peptide (hazard ratio [HR]: 0.66; 95% confidence interval [CI]: 0.45, 0.96; P = 0.028). The results remained statistically significant when death as a competing risk was taken into account (subdistribution HR: 0.65; 95% CI: 0.45, 0.95, P = 0.026). Notably, elderly did not predict a higher risk for the composite outcome (HR: 0.94; 95% CI: 0.67, 1.32; P = 0.723). CONCLUSION: Elderly confers a decreased risk of ESKD in Taiwanese patients with moderate to advanced CKD. Our findings suggest that age is an important effect modifier for CKD progression.