ABSTRACT
OBJECTIVES: Higher 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. METHODS: Participants 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%. RESULTS: Of 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. CONCLUSIONS: During 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.
Subject(s)
Blood Pressure/physiology , Emergency Medical Technicians , Nurses , Shift Work Schedule , Sleep/physiology , Actigraphy , Adult , Blood Pressure Monitoring, Ambulatory , Emergency Medical Services , Female , Humans , MaleABSTRACT
BACKGROUND: Compared to day workers, shift workers face an elevated risk of cardiovascular disease. We reviewed the evidence to address the research question: Does acute exposure to shift work impact (blunt) the natural drop (dip) in Blood Pressure (BP) occurring during sleep and/or nighttime hours? (PROSPERO CRD42018110847). METHODS: We performed a systematic review of five databases. We compared pooled estimates of mean BP stratified by periods of shift work, rest/leisure, and sleep, and evaluated the quality of evidence with the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework. RESULTS: Our search covered 1/1/1980-10/24/2018 and yielded 1,636 records. Inter-rater agreement during screening was high (Kappa=0.87). We retained 44 studies described in 50 publications. We identified wide variation in shift worker type, shift schedules, and regularity of BP measurements. Most studies examined BP during one shift workday and one rest/leisure day. No study examined the impact of repeated exposure to shift work on the sleep-related dip in BP. Eighteen studies examined night shifts and one reported on BP during sleep post night shift. Compared to BP measured during shift work, BP measured during any sleep period separate from shift work was lower by 17.5 mmHg Systolic BP (95%CI 15.75, 19.27) and 15.4 mmHg lower for Diastolic BP (95%CI 14.38, 16.42) (p < 0.05). CONCLUSIONS: There is limited research exploring the acute and long-term impact of shift work on BP during sleep. The available evidence is heterogenous, low quality, and suggests that the mean dip in BP during sleep separate from shift work is not blunted.
