Shift work linked to increased risk of heart attack and stroke

July 26, 2012, British Medical Journal

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.

Explore further: Rotating night shift work linked to increased risk of Type 2 diabetes in women

Related Stories

Rotating night shift work linked to increased risk of Type 2 diabetes in women

December 6, 2011
Women who work a rotating (irregular) schedule that includes three or more night shifts per month, in addition to day and evening working hours in that month, may have an increased risk of developing type 2 diabetes when ...

Stress hormones may increase cardiovascular risks for shift workers

October 3, 2011
A recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM) found that shift work at a young age is associated with elevated long-term cortisol levels and increased ...

Modern shift work pattern potentially less harmful to health

September 27, 2011
Recent research suggests that the modern day-day-night-night shift pattern for shift workers may not be as disruptive or as potentially carcinogenic as older, more extreme shift patterns.

Recommended for you

Americans are getting more sleep

January 19, 2018
Although more than one in three Americans still don't get enough sleep, a new analysis shows first signs of success in the fight for more shut eye. According to data from 181,335 respondents aged 15 and older who participated ...

Wine is good for you—to a point

January 18, 2018
The Mediterranean diet has become synonymous with healthy eating, but there's one thing in it that stands out: It's cool to drink wine.

Sleep better, lose weight?

January 17, 2018
(HealthDay)—Sleeplessness could cost you when it's time to stand on your bathroom scale, a new British study suggests.

Who uses phone apps to track sleep habits? Mostly the healthy and wealthy in US

January 16, 2018
The profile of most Americans who use popular mobile phone apps that track sleep habits is that they are relatively affluent, claim to eat well, and say they are in good health, even if some of them tend to smoke.

Improvements in mortality rates are slowed by rise in obesity in the United States

January 15, 2018
With countless medical advances and efforts to curb smoking, one might expect that life expectancy in the United States would improve. Yet according to recent studies, there's been a reduction in the rate of improvement in ...

Can muesli help against arthritis?

January 15, 2018
It is well known that healthy eating increases a general sense of wellbeing. Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have now discovered that a fibre-rich diet can have a positive influence ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.