Association of residual renal function at initiation of dialysis with prognosis in maintenance dialysis patients / 中华肾脏病杂志

ABSTRACT

Objective To examine the association between residual renal function at initiation of dialysis and prognosis in maintenance dialysis patients.Methods Incident patients with end-stage renal diseases initiating dialysis between 1 January 2005 and 30 September 2009,followed up to 31 March 2010 were enrolled in this study.Residual renal function was evaluated using eGFR estimated by the abbreviated MDRD equation.Patients were classified into four groups according to eGFR of ≥10.5,8 to ＜10.5,6 to ＜8,＜6 ml·min-1·(1.73 m2)-1.The outcome was all-cause and cardiocerebral vascular mortality.Results (1) A total of 562 patients were included.The median eGFR at initiation of dialysis was 5.60 (2.26-12.62) ml·min-1·(1.73 m2)-1.The median follow-up time was 17 (0-58) months from initiation of dialysis and 141 patients died within this period.The median survival time was 45.48 (43.05-47.90) months.With eGFR declined,Scr,BUN,serum uric acid,serum prealbumin,phosphorus,calcium and phosphate product,iPTH,mean arterial pressure (MAP) at initiation of dialysis increased (P＜0.05),and hemoglobin,proportion of male,proportion of diabetes comorbidity,proportion of the Charlson comorbidity index ≥5 decreased (P＜0.05).Though there was no significant difference among the four groups,the proportion of left ventricular hypertrophy comorbidity increased when eGFR declined.(2) There was no significant difference of all-cause mortality among four groups using Kaplan-Meire survival curve.Cox regression model indicated no significant difference of all-cause mortality in levels of eGFR (HR=1.012,95％CI 0.961-1.065,P=0.654).Without patients died in the first 3 months,the multivariate Cox regression model indicated eGFR at initiation of dialysis was the protective factor to 1 year survival (HR=0.791,95％CI 0.669-0.935,P＜0.01).(3) The multivariate Cox regression model indicated the risk of overall and 1 year cardiocerebral vascular death decreased with eGFR at initiation of dialysis increased (HR=0.868,95％CI 0.777-0.971,P＜0.05; HR=0.937,95％CI 0.851-0.992,P＜0.05,respectively).(4) The multivariate Cox regression model indicated eGFR at initiation of dialysis was benefit to survival of patients treated by peritoneal dialysis,with all-cause death risk decreased by 10％ when eGFR increased by 1 ml·min-1·(1.73 m2)-1 (HR=0.90,95％CI 0.81-0.99,P＜0.05).In hemodialysis patients,Kaplan-Meire survival curve was significantly different among the four groups (Log-rank test,P=0.047); the survival of the group of 8 to ＜10.5 ml·min-1·(1.73 m2)-1 was lower as compared to the groups of 6 to ＜8 (Log-rank test,P=0.033) and ＜6 ml·min-1(1.73 m2)-1 (Log-rank test,P=0.005); but the multivariate Cox regression model indicated no relationship between survival and eGFR.In the subgroup of chronic glomerulonephritis as primary renal disease,the eGFR at initiation of dialysis was the benefit factor,with all-cause death risk decreased by 16.6％ (HR=0.834,95％CI 0.736-0.946,P＜0.01) and cardiocerebral vascular death risk decreased by 18.2％ (HR=0.818,95％CI 0.669-0.999,P＜0.05) when eGFR increased by 1 ml ·min-1 ·(1.73 m2)-1.In the subgroup of chronic glomerulonephritis treated by peritoneal dialysis,the all-cause death risk decreased by 32.1％ with eGFR increased by 1 ml·min 1·(1.73 m2)-1 (HR=0.679,95％CI 0.535-0.862,P＜0.01).Conclusions Early initiation of dialysis may not be associated with improved overall survival,but may reduce cardiocerebral vascular and 1 year all-cause mortality,improve the survival of chronic glomerulonephritis patients and peritoneal dialysis patients.