Working in rotating shifts can increase the risk of developing type-2 diabetes, a new study states.

According to the researchers, risk of type-2 diabetes is the highest in men, especially those working in rotating shifts. The study shows that police officers, medics, firefighters and truckers are at an increased risk of developing the chronic health complication.

Previous research has shown that people who work in shifts have increased risk of cancers and digestive problems. These workers are also at a higher risk of becoming obese and developing heart problems due to lack of proper sleep-wake cycle, unhealthy eating habits and poor physical activity levels.

The present study was based on data from 12 studies, which involved around 226,500 participants. More than 14,000 people in the study had type-2 diabetes, according to a news release.

Researchers found that people who worked in shifts had a nine percent higher risk of developing diabetes than people who had day-jobs.

The risk of developing diabetes due to shift work was 37 percent higher in men. Researchers aren't sure why men are at a higher risk of diabetes, but say that shift-workers ought to be more careful about their diet and physical activity levels.

"These findings suggest that shift workers need to be aware of their personal risk of developing type-2 diabetes. They can do this by taking a type-2 diabetes risk assessment, either online or in their local pharmacy," Dr Alasdair Rankin, from the charity Diabetes UK, told BBC. "The best way to reduce your risk of type 2 is to maintain a healthy weight through regular physical activity and by eating a healthy balanced diet."

Researchers said that fluctuating levels of male hormone in men, due to disrupted sleep-wake cycle, might be increasing their diabetes risk.

The study is published in the journal Occupational & Environmental Medicine.