Night Shift Work Affects Cardiovascular Health And Brain Functions

Similarly to other bodily functions, cardiovascular function exhibits circadian oscillation. The severity and incidence of cardiovascular infarcts vary across time of day. The relationship between circadian disruption and increased incidence of cardiovascular events has also been reported.

These effects do not appear to be mediated by circadian deregulation alone, but rather are the product of a lack of coherence between the individual’s innate circadian timing system and the world around them.

As one would have thought, shift work has a significant negative impact on the functions of our brain, and particularly on the working memory. An investigation conducted in 90 healthcare workers, of whom 45 were night shift workers, showed that shift workers achieved significantly lower scores on verbal memory, attention–concentration, and the digit span forward sub-scales of the Wechsler Memory Scale-Revised (WMS-R), as well as on the immediate memory and total learning sub-scales of the Auditory Verbal Learning Test (AVLT). 

Diverse range of health problems is associated with night shift work

Circadian rhythm disruption also negatively impacts reproduction by altering our hormone profiles, reproductive timing, and fertility. Research is beginning to show the deleterious effects of circadian disruption during pregnancy on the offspring. Several studies have reported increased rates of preterm births and lower birth weights among women employed on shift work schedules; though there is still some debate regarding whether circadian disruption is the actual mediating factor.

Deregulation of clock gene expression has truly diverse consequences.

See Also: Prolonged Nighttime Driving Can Be Just As Hazardous As Driving Drunk

What is behind the night shift effects?

A study conducted by researchers from the University of Surrey demonstrated that working night shifts completely alters the synchronized working of certain genes. About 6% of our genes are more or less active at very specific times of the day. Working through the night eliminates this time-precise genetic expression, with obvious negative side effects and health consequences.

The bundle of scientific evidence available leaves little doubt about the problematic impacts of circadian rhythm disruption in shift workers. From cancer to cardiovascular diseases, the risks exist and are well documented. It is important to bring these issues to the attention of government agencies and business owners, as well as to raise awareness among workers for the practice of health behaviors for the risk reduction of some of those conditions.

Many professionals who work nightshifts form the backbone of society — including doctors, nurses, and other medical professionals, first-responders, and police officers. They are at our service, and our world would quickly collapse without them. Let's recognize all the ways in which they sacrifice themselves for the good of society, including through the impact of shift work.