Sleep duration as a risk factor for diabetes incidence in a large U.S. sample.

STUDY OBJECTIVES

To explore the relationship between sleep duration and diabetes incidence over an 8- to 10-year follow-up period in data from the First National Health and Nutrition Examination Survey (NHANES I). We hypothesized that prolonged short sleep duration is associated with diabetes and that obesity and hypertension act as partial mediators of this relationship. The increased load on the pancreas from insulin resistance induced by chronically short sleep durations can, over time, compromise beta-cell function and lead to type 2 diabetes. No plausible mechanism has been identified by which long sleep duration could lead to diabetes.

DESIGN

Multivariate longitudinal analyses of the NHANES I using logistic regression models.

SETTING

Probability sample (n=8992) of the noninstitutionalized population of the United States between 1982 and 1992.

PARTICIPANTS

Subjects between the ages of 32 and 86 years.

MEASUREMENTS AND RESULTS

Between 1982 and 1992, 4.8% of the sample (n=430) were determined by physician diagnosis, hospital record, or cause of death to be incident cases of diabetes. Subjects with sleep durations of 5 or fewer hours (odds ratio = 1.47, 95% confidence interval 1.03-2.09) and subjects with sleep durations of 9 or more hours (odds ratio = 1.52, 95% confidence interval 1.06-2.18) were significantly more likely to have incident diabetes over the follow-up period after controlling for covariates.

CONCLUSIONS

Short sleep duration could be a significant risk factor for diabetes. The association between long sleep duration and diabetes incidence is more likely to be due to some unmeasured confounder such as poor sleep quality.