Hypertension as a determinant of survival for patients treated with home dialysis

Abstract

Previous studies of the risks of hypertension for dialysis patients have yielded conflicting results. The aim of this study was to investigate, in a home dialysis population with low rates of diabetes and antihypertensive drug use, whether blood pressure (BP) was an independent risk factor for survival. The outcome of 168 consecutive patients (94 male, 88% Caucasian), aged 48 years (SD 16), who began home hemodialysis (HD; N = 124) or home continuous ambulatory peritoneal dialysis (CAPD; N = 44) between January 1, 1985 and December 31, 1994 were analyzed retrospectively. Only 4.7% of patients took antihypertensive drugs while on dialysis. The patients were followed to December 31, 1998 with the primary outcome being all-cause mortality. Censoring events were transplantation, transfer to another center and treatment modality change. The Cox proportional hazard model was used with baseline predictors. Seventy-one patients died and the median overall survival was 4.2 years (5.6 on HD, 2.2 on CAPD, P < 0.0001). Mean BP at start of dialysis predicted survival on its own (P = 0.0009) and in the joint Cox model (P = 0.047). Other significant predictors in the joint model were age [10 year increase, relative hazard (RH) = 1.55, P = 0.0008], albumin (10 g/L decrease, RH = 2.05, P = 0.007), diabetes (RH = 3.42, P = 0.015) and peripheral vascular disease (RH = 2.19, P = 0.02) but not dialysis modality (RH = 1.63, P = 0.13). High and low mean blood pressure (BP) values at the start of dialysis were associated with the highest mortality. Among the home dialysis patients, most of whom did not require antihypertensive drugs, hypertension was a risk factor for survival and patients with mid-range BP values survived the longest.