For the minority of patients who may not already have hypertension diagnosed prior to starting dialysis, we recommend using ABPM as gold-standard to diagnose hypertension. Fagugli et al. compared 48-hour ABPM that included a dialysis day and found that 24-hour APBM either on interdialytic period or dialysis day is not different from 48-hour ABPM. Prevalence of hypertension diagnosed in this study (SBP >140 mmHg) was 80% compared to 61.7% diagnosed by predialysis SBP of >140 mmHg (10).
For people on haemodialysis, BP measured outside the dialysis unit has more prognostic value (4, 11) and both studies suggest ambulatory BP is more closely associated with the risk of all-cause mortality than home BP. Alborzi et al. studied this in a cohort of 150 people on haemodialysis and found that every increase in SBP by 22.3 or DBP by 13.8 mmHg was associated with 50% increase in mortality, whereas home BP was associated with 35-40% elevation in risk (11). There was no association seen with dialysis unit SBP or DBP. Agarwal et al. report similar findings in a larger cohort of a similar population and demonstrated an increased risk of all-cause mortality with increasing SBP using both ABPM and HBPM but not with dialysis unit BP (4).
There is very limited data on using HBPM to diagnose hypertension in dialysis patients. Agarwal found one week averaged systolic BP of 150 mmHg or post-dialysis standardized BP of 122 mmHg has both high sensitivity and specificity to predict hypertension diagnosed by ABPM (12).