Night shift work may impair vascular function in healthy adults

Adults who constantly work the night shift are at greater risk of impaired endothelial function, driven potentially by disrupted sleep and reduced physical activity, reveals a study.

Forty healthy adults (20 day workers and 20 night shift workers) participated in this cross-sectional study and underwent assessments of flow-mediated dilation (FMD), brachial‒ankle pulse wave velocity (baPWV), and ankle‒brachial index (ABI).

The researchers measured physical activity and sleep status using triaxial accelerometery for 7 consecutive days. They also explored the effects of night shift work and its association with lifestyle factors via group comparisons and correlation analyses.

Adults in the night shift group had significantly lower FMD than those in the day shift group (4.0 percent vs 7.0 percent; p<0.01), with no significant between-group differences in ABI and baPWV.

FMD was positively associated with time in bed, total sleep time, and sleep efficiency and negatively associated with nocturnal awakening in the overall cohort. In subgroup analysis, FMD correlated with sleep quality in day workers and with physical activity patters in night shift workers.

“This study shows that healthy adults who regularly work night shifts have poorer blood vessel function than people who only work daytime hours, and that sleep and physical activity patterns may help explain this difference,” the researchers said.

“Early assessment using FMD and targeted behavioural interventions may help preserve vascular health among shift workers,” they said.