Abstract
Cardiovascular disease (CVD) is the leading cause of adult death in the United States. Numerous studies show that night shift workers face a disproportionately higher risk of CVD compared to non-shift workers. Despite these data, the scientific and medical communities have not identified the physiological mechanisms that contribute to increased CVD risks for night shift workers. We propose that repetitive exposure to blunted blood pressure (BP) dipping associated with sleep loss during night shift work is an important, clinically meaningful, understudied, and modifiable contributor to increased risk of CVD. Blunted BP dipping occurs when BP fails to decrease or "dip" 10%-20% during nighttime hours (typically while sleeping) relative to daytime hours (typically while awake). Blunted BP dipping is widely considered a clinically meaningful indicator of poor cardiovascular health. Previous research suggests it is a common consequence of night shift work and occurs during sleep before and immediately after night shifts. Relatively few studies of shift work and CVD have focused on blunted BP dipping as a mechanism of CVD risk. Recent experimental research shows that restoration of normal BP patterns-during night shift work-is achievable with strategic napping and may reduce the risk of CVD. We present a series of important mechanistic-related questions and next steps for future research focused on blunted BP dipping and night shift work.