Results from the Nurses' Health Study found a positive association between rotating night shift work and the risk of developing type 2 diabetes.

Frank Hu, MD, PhD, and colleagues with the Harvard School of Public Health in Boston, used data from the Nurses' Health Study I (established in 1976 with a total of 121,704 women) and the Nurses' Health Study II (established in 1989 with 116,677 women), and found that 6,165 women in NHS I and 3,961 women in NHS II developed type 2 diabetes.

Using statistical models, the authors found that the duration of rotating night shift work was strongly associated with an increased risk of type 2 diabetes in both cohorts and that the risk of developing type 2 diabetes increased with the numbers of years working rotating shifts.

When compared to women with no experience in rotating night shift work, women had a 5% higher risk of developing type 2 diabetes after one to two years of shift work, a 20% higher risk after three to nine years, a 40% higher risk after 10 to 19 years and a 58% higher risk after 20 or more years.

"Recognizing that rotating night shift workers are at a higher risk of type 2 diabetes should prompt additional strategies into preventive strategies in this group," the authors wrote in their report, which appears in PLOS Medicine. To read the study, visit http://bit.ly/rRhnx6.