Association of sleep apnea and type II diabetes: a population-based study

Cross-sectional association has been reported between sleep-disordered breathing (SDB) and insulin resistance, but no prospective studies have been performed to determine whether SDB is causal in the development of diabetes.

The purpose of our study was to investigate the prevalence and incidence of type II diabetes in subjects with SDB and whether an independent relationship exists between them.

A cross-sectional and longitudinal analysis was performed in 1,387 participants of the Wisconsin Sleep Cohort. Full polysomnography was used to characterize SDB. Diabetes was defined in two ways: (1) physician-diagnosis alone or (2) for those with glucose measurements, either fasting glucose > or = 126 mg/dl or physician diagnosis.

There was a greater prevalence of diabetes in subjects with increasing levels of SDB. A total of 14.7% of subjects with an apnea-hypopnea index (AHI) of 15 or more had a diagnosis of diabetes compared with 2.8% of subjects with an AHI of less than 5. The odds ratio for having a physician diagnoses of diabetes mellitus with an AHI of 15 or greater versus an AHI of less than 5 was 2.30 (95% confidence interval, 1.28-4.11; p = 0.005) after adjustment for age, sex, and body habitus. The odds ratio for developing diabetes mellitus within 4 yr with an AHI of 15 or more compared with an AHI of less than 5 was 1.62 (95% confidence interval, 0.67-3.65; p = 0.24) when adjusting for age, sex, and body habitus.

Diabetes is more prevalent in SDB and this relationship is independent of other risk factors. However, it is not clear that SDB is causal in the development of diabetes.