Ambulatory blood pressure monitoring among emergency medical services night shift workers

Abstract

ObjectivesHigher 24-hour blood pressure (BP) and blunted BP dipping during sleep and night-time hours are associated with adverse health outcomes. Night shift work may affect 24-hour BP and dipping patterns, but empirical data in emergency medical services (EMS) clinician shift workers are sparse. We implemented ambulatory blood pressure monitoring (ABPM) in EMS workers to characterise BP during night shift work versus a non-workday, and sleep versus wake.MethodsParticipants worked night shifts. Hourly ABPM and wrist actigraphy (to measure sleep) were collected during two 24-hour periods, one scheduled night shift and one non-workday. Blunted BP dipping was defined as a BP decrease of <10%.ResultsOf 56 participants, 53 (53.6% female, mean age 26.5 (SD 7.5) years) completed the study. During daytime sleep on a workday, 49.1% of participants had blunted systolic BP (SBP) or diastolic BP (DBP) dipping. During night-time sleep on a non-workday, 25% had blunted SBP dipping and 3.9% blunted DBP dipping. Blunted SBP or DBP dipping occurred among all participants who did not nap during the night shift or who napped <60 min. Blunted SBP dipping occurred in only 14.3% of participants who napped 60–120 min.ConclusionsDuring night shift work, the BP dipping of EMS shift workers is blunted; however, most who nap for 60 min or longer experience a healthy dip in BP. The potential health consequences of these observations in EMS clinicians warrant further study.

Guiding principles for determining work shift duration and addressing the effects of work shift duration on performance, safety, and health: guidance from the American Academy of Sleep Medicine and the Sleep Research Society

“…112,[154][155][156] Naps may facilitate adaptation to a shift work schedule and ease the return to daytime activity, 157,158 and may offer cardiovascular health benefits. 159,160 Split sleep schedules, in which a person takes a nap after a work shift and another nap before the next shift, have been associated with increased sleepiness, 161 but few differences in performance relative to a consolidated post-shift sleep bout. 162,163 For on-the-job napping to be implemented successfully as a countermeasure strategy, it is important that it be sanctioned 164 and that there is access to a safe and quiet place to rest while on break.…”

Sleep characteristics associated with nocturnal blood pressure nondipping in healthy individuals: a systematic review

“…The presence of BP nondipping in healthy individuals is, therefore, not only a risk factor for future CVD but also an important warning sign of future CVD risk. There is some evidence that sleep quality and sleep efficiency may be associated with nocturnal BP nondipping in otherwise healthy individuals, however, the studies reporting on this were limited and further studies are required [49,50,56].…”

“…As previously discussed, the implications of circadian misalignment between the biological clock and the sleep/wake cycle are well known [83] and it is well recognized that shift work has a negative impact on health, specifically that shift workers are already at a higher risk of developing hypertension [83–85]. Of the three studies reporting on shift workers [50,52,57] all showed that shift workers displayed BP nondipping during sleep on nonshift days. One might speculate that the fact that shift workers display BP nondipping during sleep on nonshift days may, at least in part, be related to chronic circadian misalignment.…”

“…Given the heterogeneity of the studies no definitive conclusions can be made, however, the accumulated evidence suggests that sleep duration (specifically short sleep) [46,48,54], sleep fragmentation (frequent awakenings) [43,44,45], a lack of sleep depth (low N3 time) [43,44,58] and increased variability in sleep timing (irregular sleep timing) [50][51][52]57] may be associated with nocturnal BP nondipping in otherwise healthy individuals. The direction of this relationship, however, is unclear (Figure 2).…”

“…In the five studies that did not fully meet the criteria, a lack of confounding factors identified was with the main factor contributing to their lower appraisal. Seven studies assessed sleep using polysomnography (PSG) [42][43][44][45][46][47][48], six used wrist actigraphy [44,45,[48][49][50][51], six used only self-report methods (e.g. sleep diaries and questionnaires) [52][53][54][55][56][57] and one used an EEG headband [58].…”