More Than 55 Hours a Week of Manual Work Linked to Type-2 Diabetes Risk

People working for more than 55 hours per week or more doing manual work or low socioeconomic status jobs, have a 30 percent increased risk of developing type-2 diabetes.

The latest study led by researchers at University College London, United Kingdom, looked at the effects of long working hours on the risk of developing typ-2 diabetes. For this, they used the systematic review and meta-analysis of published studies and unpublished individual-level data.

Long working hours is known to have insidious effects on the health and wellbeing of a person. Studies have documented that long working hours put employees at the risk of heart attacks and strokes. The Centers for disease control and prevention reveal the 2004 data from the Bureau of Labor Statistics stating almost 15 million Americans work full time on evening shifts, night shifts, rotating shifts or other employer arranges irregular schedules.

The current study led by Mika Kivimaki, Professor of Epidemiology at the University College London, looked at data from 4 published studies and 19 studies with unpublished data that involved 222,120 men and women from the United States, Europe, Japan and Australia. The subjects were followed for an average of 7.6 years. 

They observed that people working for more than 55 hours a week had a higher risk of developing type-2 diabetes as compared to those working for less than 35 to 40 hours a week.

The risk of developing type-2 diabetes increased by 30 percent among those doing low socioeconomic status jobs who have been working 55 hours or more per week. The association between the two remained strong even after excluding shift work, which is known to up the risk of obesity and developing type-2 diabetes.

According to Professor Kivimaki, "The pooling of all available studies on this topic allowed us to investigate the association between working hours and diabetes risk with greater precision than has been previously possible. Although working long hours is unlikely to increase diabetes risk in everyone, health professionals should be aware that it is associated with a significantly increased risk in people doing low socioeconomic status jobs."

The finding was published in The Lancet Diabetes & Endocrinology.