Is the inverse relation between blood pressure and mortality normalized in 'low-risk' dialysis patients?

Background SBP is a potent predictor of mortality. However, in hemodialysis populations, the relation between SBP and mortality is a matter of debate. In hemodialysis patients, low SBP rather than high SBP has been related to mortality. It has been suggested that this inverse relationship is 'normalized' in dialysis patients with a low mortality risk and that short-term and long-term effects of SBP might differ. Design We analyzed the relationship of mortality and SBP in 1111 incident hemodialysis patients participating in the Netherlands Cooperative Study on the Adequacy of Dialysis (NECOSAD) cohort. Long-term and short-term effects were studied in patients with (n = 452) and without (n = 659) cardiovascular comorbidity. Results Maximal follow-up was 7.5 years; 477 patients died. Two-year mortality rate was 44 and 20% in the groups with and without cardiovascular comorbidity, respectively. Both in the whole group and in both subpopulations, low SBP was associated with an increased mortality. The increased mortality risk associated with low SBP was especially observed as a short-term effect (6 months). In neither group did we observe a significant long-term effect between SBP and mortality. Conclusion Our data do not support the hypothesis that the inverse relation between SBP and mortality is 'normalized' in a dialysis population with a low absolute mortality risk. Neither do our data support the hypothesis that elevated SBP increases mortality risk in the long-term. J Hypertens 28:439-445 (c) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.