Studies Shift work leads to deadly heart disease

Constantly changing working hours disturb our circadian rhythm
Many people in Germany work as shiftworkers. The constant change of working hours disturbs the daily rhythm. This often causes sleep problems and other health problems. Researchers have now found that shiftworkers are even at increased risk for heart disease due to their irregular working hours.

Scientists from Northwestern University in Chicago have now discovered in their research that abnormal sleep patterns of shiftworkers disrupt the body's natural rhythm. As a result, sufferers have an increased risk of developing heart disease. The physicians published the results of their study in the journal "Hypertension".

Shift workers suffer from the constant change of their working hours. This process also greatly affects their sleep. The consequences of this are an increased risk of heart disease. (Image: i-picture / fotolia.com)

Shift work puts a strain on our health and social life
Shift work poses an increased health risk compared to working with regular working hours. This risk continues to increase when night work is involved, say the experts. For this reason, in many countries at night workers even medical checks are required. Continuous shift work is physically very stressful and also hinders our social activities, such as sports and dealing with friends and family. Often, in addition, our rest periods are affected. For example, sleep after a night shift is usually shorter and worse than a normal night's sleep, explain the doctors. The new study has now shown that an abnormal sleep cycle increases the risk of heart disease, especially for shift workers.

Through shift work, a so-called circadian misalignment can occur
Almost all physiological and behavioral processes that are regulated by an internal clock in our brain, in particular the sleep-wake cycle, are influenced by the so-called circadian rhythm, explains the main author. Daniela Grimaldi. If our sleep-wake and nutritional cycle is not in line with the rhythm of our internal clock, a circadian misalignment may occur. Grimaldi added.

Study among people with too little sleep or delayed sleep
The results of the new study suggest that shift workers are chronically exposed to circadian miscarriage. With the rotation of shift work, the regenerative cardiovascular effects of nocturnal sleep can not be optimally exploited, experts from Northwestern University in Chicago explain. The small study included 26 healthy people aged 20 to 39 years. All subjects either achieved only five hours of sleep daily for a period of eight days, or experienced a shift in sleep times of eight or five hours over four nights out of eight, the researchers say.

Over-tired people produce larger amounts of the stress hormone norepinephrine
Both groups showed an increased heart rate during the day. This increased even further at night, when sleep deprivation was combined with delayed sleep, the researchers warn. There was also an increase in the stress hormone norepinephrine in the fatigued group with delayed bedtime. The norepinephrine can constrict the blood vessels in the body, increase blood pressure and expand the trachea, explain the researchers.

Reduced bedtime reduces the activity of the vagus cranial nerve
Sleep deprivation and delayed bedtime were associated with reduced heart rate variability at night, the experts explain. In addition, a reduction in the activity of the so-called vagus cranial nerve was found, if those affected were in deeper sleep phases. These deep sleep phases usually have a strengthening effect on our heart functions. The main effect of the vagus nerve on our heart, is the lowering of the heart rate, explain the authors of the study. Shift workers should be encouraged to look for a healthy diet, and those affected need to exercise regularly and try to get extra sleep to better protect their heart, the researchers add. (As)