Shift Work-Induced Sleep Problems May Raise Risk for Heart Health Problems

Sleep can impact heart health in many ways. Research shows greater cardiovascular risk when a person’s natural body clock is upset or deviated from. This was the information shared at this year’s online scientific congress of the European Society of Cardiology (ESC).

Research relayed that at least 20% of European employees work evening or night shifts, which could be responsible for a high number of cardiovascular outcomes in this group.

This study focused on the role of circadian misalignment, which is the difference between the “social clock” and the individual’s “biological clock.” In this case, the social clock referred to the participant’s work schedules.

Study author Dr. Sara Gamboa Madeira explained, “We all have an internal biological clock which ranges from morning types (larks), who feel alert and productive in the early morning and sleepy in the evening, to late types (owls), for whom the opposite is true — with most of the population falling in between. Circadian misalignment occurs when there is a mismatch between what your body wants (e.g., to fall asleep at 10pm) and what your social obligations impose on you (e.g., work until midnight).”

In the study, researchers included 301 blue-collar workers from Portugal. Participants either worked early mornings (6am – 3pm) or late evening (3pm to midnight). All participants were required to complete a questionnaire about their work schedule, work seniority, and lifestyle factors. Questions about their blood pressure and cholesterol were also recorded.

The average age of participants was 33 years, and 56% were men. Approximately half were smokers, almost half had high cholesterol, and 10% had hypertension. Overall, one in five were classified as high cardiovascular risk.

Social Jetlag

Social jetlag, (the mismatch between an individual’s biological clock and working hours), was used to record findings. In the participants, the average social jetlag was 2 hours. In most workers (59%), social jetlag was 2 hours or less, while for 33% of staff, it was 2-4 hours, and in 8%, it was 4 hours or more.

The study found that those who worked hours outside of a typical workday had more adverse health events. By interfering with the body’s circadian clock, the health risks were greater. For each hour the work schedule was out of sync with an employee’s body clock, the risk of heart disease would increase.

This research adds to the mounting evidence that circadian misalignment may explain the link between people who work night shifts and detrimental health outcomes. Experts agree that those who work in such conditions should be monitored closely for heart health. By understanding the relationship between sleep patterns and disease, health care providers provide better treatment plans to those who are at a higher risk.