Rotating shift patterns could increase one's chances of developing type 2 diabetes.

The correlation between rotating shifts and type 2 diabetes seemed to be highest among men, British Medical Journal (BMJ) reported. The findings were published in Occupational & Environmental Medicine.

Past research has suggested a link between working shifts and an elevated risk of health problems including digestive disorders, cardiovascular disease, and certain cancers. This new research suggests diabetes could be an addition to that list.

To make their findings the researchers looked at 12 international studies encompassing 226,500 participants, 14,600 of whom had diabetes. When the data was pooled together it revealed a nine percent increase in the risk of developing diabetes in shift workers when compared with individuals working normal office hours. The risk rose 37 percent for men when other factors such as "gender, study design, study location, job, shift schedule, body mass index (BMI), family history of diabetes and physical activity levels," were taken into account.

The reason for the elevate risk is still unclear, but it could be due to a disruption in male hormones that are regulated by an internal body clock. Low male hormone levels have been linked to reduced insulin resistance and diabetes.

Most shift patterns, excluding mixed and evening shifts, were associated with an increased diabetes rate. Rotating shifts (when people work different parts of a 24 hour shift) were linked to the highest risk at 42 percent.

Rotating shifts often keep people who work them from adjusting to a regular sleep-wake cycle; in the past studies have also shown poor sleep habits increase the risk of diabetes. Shift work is associated with weight gain and an increase in appetite, which is associated with type 2 diabetes as well.

About 380 million people are predicted to have type 2 diabetes by the year 2025; adjusting lifestyle factors such as shift work could help cut this number down.