The association of obstructive sleep apnea (OSA) and nocturnal hypoxemia with the development of abnormal HbA1c in a population cohort of men without diabetes

Abstract

Aim: To examine the relationship between indices of undiagnosed OSA and the development of abnormal glycaemic control in community-dwelling men free of diabetes.

Methods: The Men, Androgens, Inflammation, Lifestyle, Environment, and Stress (MAILES) Study is a population-based cohort study in Adelaide, South Australia. Clinic visits at baseline (2002-06) and follow-up (2007-10) identified abnormal glycaemic metabolism [HbA1c 6.0 to <6.5% (42 to <48mmol/mol)] in men without diabetes. At follow-up (2010-11), n=837 underwent assessment of OSA by full in-home unattended polysomnography (Embletta X100).

Results: Development of abnormal glycaemic metabolism over 4-6 years (n=103 "incident" cases, 17.0%) showed adjusted associations [odds ratio (95% CI)] with the 1st [1.7 (0.8-3.8)], 2nd [2.4 (1.1-4.9)], and 3rd [2.3 (1.1-4.8)] quartiles of mean oxygen saturation (SaO2) compared to the highest quartile. Prevalent abnormal glycaemic metabolism (n=140, 20.8%) was independently associated with the third and fourth quartiles of percentage of sleep time with oxygen saturation <90% and lowest quartile of mean SaO2. Linear regression analysis showed a significant reduction in HbA1c [unstandardized B, 95% CI: -0.02 (-0.04, -0.002), p=0.034] per percentage point increase in mean SaO2. OSA as measured by the apnea-hypopnea index showed no adjusted relationship with abnormal glycaemic metabolism.

Conclusions: Development of abnormal glycaemic metabolism was associated with nocturnal hypoxemia. Improved management of OSA and glycaemic control may occur if patients presenting with one abnormality are assessed for the other.

Keywords: Cohort study; Glycaemic control; Men; Nocturnal hypoxemia; Obstructive sleep apnea.