For many people, the workday does not begin until the sun has gone down. Although shift work is common in many companies, the results might be unsafe. A study published in Circulation, the journal of the American Heart Association, reveals that night shift workers have a higher risk of developing cardiovascular disease.

The human body seems to run on a 24-hour pattern, regardless of the changes in sleep habits. People do not adapt easily to shift work, because it is difficult for the body’s "internal clock" to change with varied work schedules. The study suggests that the forced change in sleep routines could explain why shift workers are at a higher risk for diseases and accidents.

According to the researchers, night shift workers have alterations in the nerve systems that control the heartbeat. The functions that work best during the day seem to subside at night. For example, the heart rate and digestive system best operate during the day, because the blood levels of the hormone cortisol kick in. However, the blood levels drop during the night. For the employees who work on the night shift, these cortisol levels did not "shift" to meet the demand. Mary Jo Wakeman, M.D., advises, "If a person must work the night shift, my advice is to try to handle shift work gradually," she said. "It is also important to get plenty of sleep." Dr. Wakeman is medical director of OccNet, the occupational health service of the Health Alliance.

The study also examined the function of certain nerves that control the heart’s activity. Researchers measured 24-hour changes throughout three different work shifts and performed 24-hour electrocardiograms. The findings reveal the nerve activity that accelerates the heart was lower during the overnight shift compared to morning or afternoon work periods. The lower nerve activity at night might cause a person to be in poor biochemical condition, which may lead to more errors and accidents in the workplace.

To learn more about how your company can reduce the risk of illness and accidents among night shift workers, contact OccNet at 513-585-9400.

The occupational health specialists of Alliance Health for Business, working with other Health Alliance network providers, place a strong emphasis on prompt and appropriate return-to-work. To find out more about Alliance Health for Business services, call 513-585-9400.