By Nicholas Bakalar
Working long hours may increase the risk for Type 2 diabetes, a new review has found, but the risk is apparent only in workers of lower socioeconomic status.
Long working hours are associated with diabetes risk factors — work stress, sleep disturbances, depression and unhealthy lifestyle, and some studies have found long hours associated with increased risk for cardiovascular disease.
Researchers combined data from 19 published and unpublished studies on more than 222,000 men and women in several countries.
The analysis, published in The Lancet Diabetes & Endocrinology, found no effect of working hours in higher socioeconomic groups. But in workers of lower socioeconomic status, working more than 55 hours a week increased the risk for Type 2 diabetes by almost 30 percent. The association persisted after excluding shift workers and adjusting for age, sex, obesity and physical activity.
The study is observational, and the lead author, Mika Kivimäki, a professor of epidemiology at University College London, said there were no intervention studies that could establish cause and effect.
“My recommendation for people who wish to decrease the risk of Type 2 diabetes,” he said, “applies both to individuals who work long hours and those who work standard hours: Eat and drink healthfully, exercise, avoid overweight, keep blood glucose and lipid levels within the normal range, and do not smoke.”