Ambulatory Blood Pressure Monitoring Does Not Reduce the Sleep of Off-Duty Firefighters

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Sleep Research Society

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Introduction Ambulatory blood pressure monitoring (ABPM) across 24 hours is recommended to confirm hypertension and, outside of a laboratory setting, is the only means to measure the extent of any nocturnal decrease in blood pressure (BP) i.e., nocturnal BP dipping. The ambulatory device is traditionally programmed to inflate every 20-30 minutes during awake and sleep. Despite diagnostic benefits, ABPM may disturb sleep and lead to reduced compliance in some individuals. Firefighters, an occupational group with a greater risk of developing cardiovascular disease, often note continued vigilance during sleep, possibly reflecting light sleep and/or frequent awakenings. This potential sleep disturbance may contribute to firefighters’ cardiovascular disease risk and may also impact ABPM data. Methods To assess the effect of ABPM on total sleep time (TST) and wake after sleep onset (WASO) in firefighters, we measured sleep using wrist actigraphy in 120 firefighters (91.3% male) from two different departments in Oregon. As part of a larger longitudinal study, participants’ sleep off-shift (as noted from daily survey) was recorded for up to 14 days at two different time points, two months apart. During two consecutive days off, participants completed 24-48 hours of ABPM with simultaneous actigraphy. Overall, there were 1273 measures of sleep, 206 with the cuff and 1067 without the cuff. Separate mixed models with cuff (on/off) as a fixed effect and participant as a random effect, were run for TST and WASO. Models were adjusted for total time in bed, department, and collection interval. Results Surprisingly, TST with the cuff on was significantly greater than nights without the cuff (marginal mean ± SE: 432.0±3.1 vs. 415.9±1.7 minutes respectively, p< 0.001). Increased TST was attributable to a lower WASO with the cuff than without the cuff (43.8±2.9 vs 59.8±1.7 minutes, respectively, p< 0.001). Conclusion Contrary to our expectations, ABPM was not associated with actigraphy measured disturbed sleep among firefighters. In fact, in these data, sleep appeared to be improved while wearing the cuff. Perhaps concerns around poor sleep when wearing the device may have led to improved sleep behaviors on those nights, but this hypothesis needs further investigation.


© The Author(s) 2023.


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Oxford University Press