Workers also at greater risk of suffering stroke
Shift work could put workers at increased risk of heart attacks and strokes, according to a major piece of international research.
The studies, said to be the largest analysis of shift work and vascular problems to date, should prove controversial. While shift work has long been known to disrupt the body clock and is associated with an increased risk of high blood pressure, high cholesterol and diabetes, its association with vascular disease has been disputed.
The 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.
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%), coronary events (24%) and stroke (5%). The risks remained consistent even after adjusting for factors such as study quality, socioeconomic status and unhealthy behaviours in shift workers.
The authors say their findings, published on bmj.com, 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.
The research paper is available here.