Effect of hypertension before beginning dialysis on survival of hemodialysis patients

The role of hypertension as a predictor of mortality in hemodialysis patients is controversial. The purpose of this study is to investigate the effect of hypertension before starting hemodialysis therapy on survival of patients without diabetes during renal replacement therapy.

We reviewed 184 patients starting hemodialysis therapy. Variables studied were age, sex, renal disease, hypertension, comorbidity, vascular calcifications, left ventricular hypertrophy, body mass index, and albumin, cholesterol, and alkaline phosphatase levels. Regarding blood pressure control, three groups were considered: normotensive (NH), controlled hypertensive (c-HT), and uncontrolled hypertensive (uc-HT).

The Cox model was performed considering all-cause and cardiovascular mortality. The model was adjusted for age, sex, serum albumin level, vascular calcifications, history of hypertension, and comorbidity. Comorbidity included cardiovascular comorbidity. For all-cause mortality, comorbidity and history of uncontrolled hypertension were independent risk factors (comorbidity relative risk, 1.95; 95% confidence interval, 1.26 to 3.1; P = 0.003; uncontrolled hypertension relative risk, 1.79; 95% confidence interval, 1.15 to 2.8; P = 0.01). For cardiovascular mortality, uncontrolled hypertension was the main risk factor (relative risk, 2.93; 95% confidence interval, 1.68 to 5.12; P = 0.000). Mortality rates were 7.9/100 patient-years for NH, 8.7/100 patient-years for c-HT, and 14.1/100 patient-years for uc-HT patients.

This study suggests that uncontrolled hypertension in renal patients before starting dialysis therapy is a major risk factor for cardiovascular mortality during hemodialysis. Because hypertension usually starts in the initial stages of renal disease, we emphasize the importance of prompt and adequate control of blood pressure in this population.