Prevalence and Risk Factors of Altered Control of Bp During the Night in a Large Hemodialysis Population Investigated by 48 Hours Abpm

Objective: Altered BP control during the night (non-dipping, reverse dipping and nocturnal hypertension) is recognised as a powerful risk factor for death and CV events in the hemodialysis (HD) population. However, these alterations have been described in relatively small studies, and the epidemiology and risk factors for the subtypes of non-dipping and nocturnal hypertension are still poorly characterised in the current literature. We investigated the problem in the large EURECAM registry, the sole that has adopted state-of-the-art 48h ABPM recording in the HD population. Design and method: We included in this analysis 534 HD patients enrolled in 7 centres, led by members of the EURECA-m working group in 3 European countries. 48h ABPM was measured using validated instruments (AAMI/ESH/ISO). As the European Society of Hypertension guidelines recommended, recordings were made at 15-minute intervals during the day and 30 minutes at night. Hypertension was defined as 48h blood pressure (BP)>130/80, nocturnal hypertension as a nighttime BP>120/70 mmHg, non-dipping as a night/day systolic BP fall 1. Results: Among 534 HD patients, 317 were hypertensive and. 217 normotensive. As many as 274 patients were non-dippers (51%), 32% were reverse dippers, and 381 (71%) had nocturnal hypertension. Of note, forty-one per cent of non-dippers, 37% of reverse dippers and 19% of patients with nocturnal hypertension were normotensives. As expected, most reverse dippers (87%) had frank nocturnal hypertension. In a combined analysis of non-dippers and reverse dippers, as compared to dippers, these patients more frequently exhibited atrial fibrillation and had lower Heart Rate both pre-dialysis (72±11 vs 77±13 bpm, P=0.004) and post-dialysis (74±13 vs 78±14 bpm, P=0.03) and lower serum albumin (3.9±0.4 vs 4.0±0.3 g/dL, P=0.02) but did not differ for age and gender. Conclusions: In a large cohort of HD patients investigated by the state-of-the-art technique, 48hABPM alterations in the nocturnal BP profile were almost universal, and nocturnal hypertension was the more prevalent alteration, followed by non-dipping and reverse dipping. These alterations were independent of age and gender. Long-term, granular follow-up analyses are warranted to identify the prognostic value of these alterations.