Shift work linked to increased risk of heart attack and stroke

Shift work is associated with an increased risk of major vascular problems, such as heart attacks and strokes, concludes a study published on bmj.com today.

This is the largest analysis of shift work and vascular risk to date and has implications for public policy and , say the authors.

Shift work has long been known to disrupt the (circadian rhythm) and is associated with an increased risk of high blood pressure, and diabetes, but its association with vascular disease is controversial.

So a team of international researchers analysed the results of 34 studies involving over two million individuals to investigate the association between shift work and major vascular events. Shift work was defined as evening shifts, irregular or unspecified shifts, mixed schedules, night shifts and rotating shifts. Control groups were non-shift (day) workers or the general population.

Differences in study design and quality were taken into account to minimise bias.

Among the 2,011,935 people in the studies more than 17,359 had some kind of coronary event, 6,598 had myocardial infarctions (heart attacks), and 1,854 had ischaemic strokes caused by lack of blood to the brain. These events were more common among shift workers than other people: shift work was associated with an increased risk of heart attack (23%), (24%) and stroke (5%). These risks remained consistent even after adjusting for factors such as study quality, socioeconomic status and unhealthy behaviours in shift workers.

were associated with the steepest increase in risk for coronary events (41%). However, shift work was not associated with increased death rates from any cause.

Although the relative risks were modest, the authors point out that the frequency of shift work in the general population mean that the overall risks are high. For Canada - where some of the study's authors are based and where 32.8% of workers were on shifts during 2008-9 - 7.0% of myocardial infarctions, 7.3% of all coronary events, and 1.6% of ischaemic strokes could be attributed to .

The authors say their findings have several implications. For example, they suggest screening programmes could help identify and treat risk factors, such as high blood pressure and cholesterol levels. Shift workers could also be educated about symptoms that could indicate early heart problems.

Finally, they say more work is needed to identify the most vulnerable groups of shift workers and the effects of modifying shift patterns on overall vascular health.

add to favorites email to friend print save as pdf

Related Stories

Rotating shift workers have lower levels of serotonin

Aug 01, 2007

People who work rotating shifts have significantly lower levels of serotonin, a hormone and neurotransmitter in the central nervous system believed to play an important role in the regulation of sleep, according to a study ...

Recommended for you

High-calorie and low-nutrient foods in kids' TV

6 hours ago

Fruits and vegetables are often displayed in the popular Swedish children's TV show Bolibompa, but there are also plenty of high-sugar foods. A new study from the University of Gothenburg explores how food is portrayed in ...

Chemical companies shore up supplement science

6 hours ago

As evidence mounts showing the potential health benefits of probiotics, antioxidants and other nutritional compounds, more and more people are taking supplements. And the chemical industry is getting in on the action. But ...

More Americans in their golden years are going hungry

6 hours ago

In a country as wealthy as the United States, it may come as a surprise that one in 12 seniors do not have access to adequate food due to lack of money or other financial resources. They are food insecure.

User comments