The Relationship Between Hemoglobin Levels And Variation With Cardiovascular Prognosis In Peritoneal Dialysis Patients

Objective To explore the effect between hemoglobin levels and variation with cardiovascular prognosis in peritoneal dialysis( PD) patients.Method Retrospective cohort study was designed. We enrolled patients on PD treatment more than 1 year in PD center of General Hospital of Ningxia Medical University from May 2003 to October 2015. We collected information of the participants on their social-demographic condition, biochemical items, treatment of anemia, assessed the nutritional status(BMI), residual renal function(e GFR) and dialysis adequacy(Kt/V). All patients were divided into targeting groups(Hb≥110g/L) and non-targeting group(Hb<110g/L) according to mean hemoglobin level. The patients who did not reached hemoglobin target were divided into mild anemia group(90g/L ≤ Hb ≤ 110g/L) and moderate to severe anemia group(Hb<90 g/L) according to the anemia dividing standard. According to the hemoglobin variation which was calculated by the mean changes after dialysis for 1 month, 3 months, 6 months, 12 months over baseline hemoglobin, all patients were divided into low variation group(<10g/L), moderate variation group(10-20g/L) and high variation group(>20g/L). The end points are cardiovascular death and all-cause death. The relationship between hemoglobin level and hemoglobin variation with the cardiovascular prognosis were analyzed.Results(1)A total of 267 patients were enrolled. The rate of male was 59.93%( 160 cases), the average age was 52.66±13.72 years and the median dialysis age was 37(21, 61) months. As for the primary disease, 126 cases were chronic nephritis(47.19%), 64 cases(23.97%) were diabetes kidney disease and 56 cases were hypertension nephropathy(20.97%). Baseline hemoglobin is 80.16±14.89g/L. At the end of the study, the average hemoglobin is 105.34±22.08 g/L and 115(43.07%) cases reached the target.(2)The baseline comparisons: the non-targeting group had lower e GFR, Kt/V and the baseline hemoglobin level,while higher creatinine and parathyroid hormone level. They had longer dialysis age and used less erythropoietin and more iron compared with the hemoglobin target group(P<0.05). The high variation group had lower BMI and the baseline hemoglobin level and higher urea level and Kt/V, while the moderate variation group patients used less erythropoietin and the low volatility group patients had higher e GFR(all P<0.05).(3)The end point events: After median follow-up of 37(21, 61) months, 92 case of 267 patients died(34.46%), including 40(43.48%) cases of CVD death. The all-cause mortality of the non-targeting patients were significantly higher than the targeting patients(42.58% vs 23.21%, p=0.001). However, there were no statistically difference of the CVD death; Kaplan-Meier analysis showed that the CVD deaths and all-cause mortality showed no significant difference between the non-targeting patients and the targeting patients. Chi-square test and Kaplan-Meier method showed that there was no statistically differences in CVD death and all-cause mortality between different hemoglobin variation groups.(4)Univariate regression analysis showed that average hemoglobin level(all-cause mortality: OR=0.97, 95% CI(0.96-0.99), p=0.006) and hemoglobin variation(all-cause mortality : OR=0.98, 95% CI(0.96-1.00), p=0.02) were both risk factors for CVD death and all-cause mortality. After adjusted confounders, multivariable Logistic regression analysis showed low hemoglobin level was independently associated with cardiovascular death(OR=0.96, p=0.003) and all-cause death(OR=0.96, p=0.001). In addition, high BMI level and low phosphorus level were the risk factors of cardiovascular death;older, inadequate dialysis dose, hypoalbuminemia and hyperlipidemia were the risk factors of all-cause mortality.ConclusionThe general targeting rate of hemoglobin level in PD patients in our center was 43.07%. Both hemoglobin level and hemoglobin variation were associated with cardiovascular death and all-cause death of PD patients, however, hemoglobin levels was even more influencing. Low hemoglobin level is independent risk factor of cardiovascular mortality and all-cause mortality.