Ambulatory blood pressure monitoring and peri-hemodialysis blood pressures in a southeast US hemodialysis unit

Abstract

Aims: End-stage renal disease (ESRD) patients on dialysis are perceived to have difficult-to-control blood pressure (BP) and commonly treated with complex antihypertensive regimens. Our hypothesis was that peri-dialysis BP will overestimate the true burden of hypertension in these patients.

Subjects and methods: We performed 44-h ambulatory blood pressure monitoring (ABPM) in 43 patients recruited from the University of Mississippi outpatient dialysis unit. Data collected included routine peri-dialysis blood systolic blood pressure (SBP), diastolic blood pressure (DBP), weight gain, and demographic information. We investigated whether the pre-dialysis or post-dialysis blood pressure would better correspond to the ABPM results.

Results: The mean age of participants was 50.5 ± 12.05 years, 95% African-American, and 44% diabetic with an average dialysis vintage of 31.1 ± 30 months. The mean SBP and DBP were 164.6/87.9 mmHg ± 22.3/15 before dialysis, 151.5/81.3 mmHg ± 24.1/13 after dialysis and 136/80.6 mmHg ± 23.5/14.7 during ABPM. There were wide limits of agreements between peri-dialysis BP and ABPM, the largest with pre-dialysis SBP (28.5 ± 16.6 mmHg) and the least with post-dialysis DBP (0.7 ± 10 mmHg). With both peri-dialysis BP measurements as explanatory variables in a linear regression model, only the post-dialysis SBP (β 0.716; p < 0.001) but not pre-dialysis SBP (β 0.157; p = 0.276) had a significant independent association with ABPM systolic BP. For DBP, both pre-dialysis (β 0.543; p = 0.001) and post-dialysis (β 0.317; p = 0.037) values retained correlation with DBP on ABPM.

Conclusion: Peri-dialysis measurements overestimated true BP burden in this Southeastern U.S. cohort of ESRD patients. When BP readings from outside the dialysis unit are notavailable, assessment of BP control should focus pre-dialysis on DBP and post-dialysison both SBP and DBP.