A Faster Residual Renal Function Decline In The First Year As A Risk Predictor For All-Cause Mortality In Peritoneal Dialysis

Background:Preservation of residual renal function has been reported to be very important to patients in dialysis.Factors associated with residual renal function remain inconsistencies among studies.Little is known about the relationship of residual renal function decline in the earlier period with patient survival in peritoneal dialysis.Methods:A total of 911 incident patients who began peritoneal dialysis therapy at our hospital between January 1,2005,and June 30,2015,with residual renal function decline in the first year of peritoneal dialysis period was investigated.The rate of decline of residual renal function was determined by the "slope of the trend equation" of serial residual renal function.The association of residual renal function decline in the first year with all-cause mortality was assessed.Results:The mean age of the cohort was 49.4 ± 13.9 years,55.5%of the patients were male,and the median of "the slope of residual renal function decline equation" was 0.308(0.190-0.475)mL/month/1.73 m2.Seventy-nine(8.7%)patients died during the study period.Multivariate linear regression analysis indicated that male,without diabetes mellitus,higher baseline residual renal function,low serum albumin,low uric acid,high calcium and high parathyroid hormone levels were independently associated with the rate of residual renal function decline in the first year of peritoneal dialysis.Multivariable Cox proportional hazards models revealed that the high residual renal function decline group was associated with significantly higher all-cause mortality(HR,2.97,95%CI,1.53 to 5.77,P = 0.001)compared with the low residual renal function decline group even after adjusting for various covariates.Using the rate of residual renal function decline as a continuous variable,the hazard ratio(HR)for all-cause mortality associated with a 1 mL/month/1.73 m2 deterioration of residual renal function decline in the first year was 6.19(95%CI,2.97 to 12.9,P<0.001).But the rate of residual renal function decline did not correlate with cardiovascular mortality(HR,3.33,95%CI,0.84 to 13.1,P = 0.086).Conclusions:A faster residual renal function decline in the early peritoneal dialysis period is independently associated with higher risks of all-cause mortality in peritoneal dialysis patients.