HbA1c is associated with severity of obstructive sleep apnea hypopnea syndrome in nondiabetic men

Abstract

The aim of this study was to examine the potential correlation of sleep characteristics with glucose metabolism in nondiabetic men with obstructive sleep apnea syndrome (OSAS). Included were 31 male patients (mean age 46.7 ± 11 years), recently diagnosed with OSAS by full polysomnography. There was a significant correlation of fasting glucose and glycosylated hemoglobin (HbA1c) levels with arousal index (P = 0.047 and P = 0.014, respectively). Moreover, HbA1c levels were correlated with apnea hypopnea index (P = 0.009), a widely accepted marker of the severity of OSAS, and with percentage of sleep time with saturation of hemoglobin with oxygen as measured by pulse oximetry (SpO2) <90% (t < 90%) (P = 0.010). Finally, glucose and HbA1c levels showed a significant negative correlation with average SpO2 (P = 0.013 and P = 0.012, respectively) and, additionally, glucose levels with minimum SpO2 (P = 0.027) during sleep. In conclusion, severity of OSAS among nondiabetic men is associated with increased HbA1c levels and increased fasting glucose. Thus, severity of OSAS may be an additional marker of cardiovascular risk, as well as of future diabetes, in these subjects. However, further work is needed to confirm the clinical significance of these observations. © 2009 Papanas et al, publisher and licensee Dove Medical Press Ltd.