PURPOSE: The objective of our study was to determine whether obstructive sleep apnea (OSA) is a risk factor for type 2 diabetes mellitus (DM) in a predominantly African-American and Hispanic population.
METHODS: We undertook a cross-sectional study in which we reviewed the records of 1008 consecutive patients who had polysomnography from June 2004 to February 2006. OSA was defined as an apnea-hypopnea index (AHI) of 5 or more and was determined by comprehensive nocturnal polysomnography with a focus on AHI during rapid eye movement (REM) sleep.
RESULTS: The prevalence of DM was 30.1% in the group with OSA compared to 18.6% in those without OSA. Subjects with OSA had significantly increased odds of type 2 diabetes compared with those without OSA (OR= 1.8, 95% CI: 1.2–2.6) but this association became of borderline significance when we controlled for confounding variables including age, body mass index (BMI), gender, race, oxygen nadir, and oxygen saturation (OR=1.3, 95% 0.9–2.0). The odds of being diagnosed with type 2 diabetes mellitus were 3.4 times higher in African-Americans with OSA than Caucasians or African-Americans without OSA even when we controlled for covariates. We also observed that the odds of type 2 DM were 2.8 times higher in the middle aged group with OSA than younger or middle aged without OSA suggesting that the duration of OSA contributes to the pathogenesis of type 2 diabetes mellitus. Finally, the odds of being diagnosed with type 2 diabetes mellitus were 2.0 times higher in patients who had a REM AHI of 10 per hour or more, (OR=2.0, 95% confidence interval 1.3–3.0) than their counterparts without a high REM AHI, independent of confounding variables. This may suggest that REM SDB may demonstrate pathophysiological specificity for diabetes.
CONCLUSION: These data are the first to show a relationship between AHI and type 2 diabetes mellitus in a cohort composed predominantly of African-American and Hispanics.
CLINICAL IMPLICATIONS: Sleep disordered breathing should be screened and treated in a population at risk for type 2 diabetes mellitus.
DISCLOSURE: Kamran Mahmood, No Financial Disclosure Information; No Product/Research Disclosure Information