Shift work can dramatically increase the risk of heart attacks and strokes, warn researchers.
A study of two million people found shift workers are almost 25 percent more likely to suffer, the Daily Mail reported Friday.
Night shift workers run the highest risk of 41 percent, says a study published on the British Medical Journal website bmj.com.
People working shifts also have higher levels of unhealthy behaviours such as eating junk food, sleeping badly and not exercising, which are linked to heart problems.
But researchers said they took this into account - and the excess risks remained.
The latest study is the biggest analysis of shift work and likelihood of vascular problems, including heart attacks, strokes and angina.
Shift work has long been known to disrupt the body clock and be linked to high blood pressure, high cholesterol and diabetes, but the overall impact on cardiovascular health has been unclear.
A team of international researchers analysed the results of 34 studies involving 2,011,935 people to investigate whether shift work was associated with major vascular events, the newspaper added.