Hypertension in the haemodialysis population: any relationship to 2-years survival?

Abstract

Background: Few studies have quantified the effect of hypertension on survival in the haemodialysis (HD) population. We have previously reported lack of adverse effect of hypertension on 1-year mortality in a cohort of 649 haemodialysis patients (Am J Kidney Dis 1996; 28: 737-744). We report here the effect of hypertension on 2-year survival in the same cohort of patients.

Methods: We reviewed the complete computerized files on 649 HD patients enrolled in 10 haemodialysis centres in the state of Mississippi, USA. One-month dialysis records for each patient from mid-October 1994 to mid-November 1994 were reviewed. Predialysis mean arterial pressure was calculated as immediate predialysis diastolic pressure plus one-third the difference between systolic and diastolic pressure. Patients were classified as hypertensive if their average pre-MAP was more than 114 mmHg or they were receiving antihypertensive drugs during the study period. Normotensives had a pre-MAP < 114 and were not receiving any antihypertensives. We followed these patients for 2 years to determine their survival and the effect of their BP status, as determined in October 1994, on 2-year mortality.

Results: In univariate analysis, hypertension was associated with improved 2-years survival (relative risk 0.64, P=0.08 compared to normotensives). Furthermore, among the hypertensives, good blood pressure control (less than 140/90) was associated with increased relative risk of death at 2 years (RR 1.86, P=0.004). In multivariate analysis, taking age, race, serum albumin, and diabetic status into consideration, there was a 27% reduction in mortality among hypertensives compared to normtensives (RR 0.73, P=0.06). Other factors of significance in multivariate analysis were age (RR 1.03/year, P=0.02), serum albumin (RR 0.36/g, P<0.0001), diabetes mellitus (RR 1.35, P=0.07), and race (RR 0.64, P=0.05).

Conclusions: Our study suggests that hypertension has no adverse effect on survival at 2 years in the haemodialysis population.