(HealthDay News) — Increased sleep duration is associated with increased risk of incident type 2 diabetes, according to a study published online in Diabetes Care.

Jane E. Ferrie, Ph.D., from the University of Bristol in the United Kingdom, and colleagues examined whether a change in sleep duration is associated with incident diabetes using data waves spanning more than 20 years. Sleep duration was reported at the beginning and end of 4 5-year cycles from 1985-1988 to 2007-2009.

The researchers found that after adjustment for age, sex, employment grade, and ethnic group, an increase of at least 2 hours of sleep per night correlated with an increased risk of incident diabetes compared with a reference group of persistent 7-hour sleepers (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.15 to 2.37). 

Continue Reading

After adjustment for body mass index (BMI) and change in weight, the correlation was partially attenuated (OR, 1.50; 95% CI, 1.04 to 2.16). Persistent short sleepers (average ≤5.5 hours/night) had an increased risk of incident diabetes (OR, 1.35; 95% CI, 1.04 to 1.76), but the correlation was no longer significant after adjustment for BMI and change in weight (OR, 1.25; 95% CI, 0.96 to 1.63).

“This study suggests that individuals whose sleep duration increases are at an increased risk of type 2 diabetes,” the authors write. “Greater weight and weight gain in this group partly explain the association.”


  1. Ferrie, JE, et al. Diabetes Care, published online before print June 11, 2015; doi: 10.2337/dc15-0186.