Male Sex and Anemia Are the Most Pivotal Risk Factors for Progression of Kidney Dysfunction and All-Cause Mortality, Especially in Elderly Patients with CKD

Background: Two decades have been passed since the definition of chronic kidney disease(CKD) was advocated in 2003. Hypertension and the diabetes have been recognized as the most important risk factors for progression of CKD, cardio-vascular events, and mortality. However, the recent therapeutic strategies and managements might change those risks. This study analyzed about the renal survival and all-cause mortality and risk factors for them in elderly patients and non-elderly patients in recent data. Methods: The 311 out-patients with CKD on January 2017 were divided into two groups according to their age over and under 65 [elderly patient group (EPG: ≥ 65 years old, n=193), non-elderly patient group (NEPG: < 65 years old, n=118)]. The clinical and laboratory findings, treatments, and the survival rate until progression to end stage kidney disease (ESKD) and all-cause mortality were compared between both groups. The risk factors were analyzed by Cox regression analysis in each group. Results: The mean arterial pressure (MAP) was significantly lower and the diabetes patients were significantly higher in EPG (EPG vs. NEPG; MAP:92.0 vs. 96.4 mmHg, p=0.006, diabetes: 42.0 vs. 26.3 %, p=0.005).The hemoglobin (Hb) (12.1 vs. 13.2 g/dL, p<0.001), and eGFR(31.2 VS.38.0mL/min/1.73m', p<0.001) were significantly lower, and the blood urea nitrogen (27.7 vs. 22.4 mg/dL, p<0.001) and uric acid (6.66 vs. 6.27 mg/dL, p=0.01) were significantly higher in EPG. The survival rates were similar between both groups (EPG vs. NEPG:58.1 vs. 66.7 %, p=0.093). The univariate and multivariate analysis indicated that CKD stage and amount of proteinuria were significant risk factors in both groups. Moreover, the male and lower Hb were significant risk factors in EPG [male: hazard ratio (HR) 2.56, 95% confidence interest (CI) 1.27-5.17, p=0.009, Hb: HR 1.46, 95% CI 1.27-5.17, p=0.009], but not in NEPG. Conclusion: CKD stage and proteinuria were the significant risk factors for progression of CKD and all-cause mortality in both elderly and non-elderly CKD patients rather than hypertension and diabetes. Moreover, the male and anemia were also the significant risk factors in especially elderly CKD patients. These results indicated that the risk factors of CKD and all-cause mortality have changed in these two decades.