OBJECTIVETo assess the value of blood glucose at different time points in oral glucose tolerance test (OGTT), particularly one?hour post load plasma glucose (1 hPG), in evaluating glucose metabolism in adult patients with obstructive sleep apnea (OSA).

METHODSEighty nine adultswith newly diagnosed OSA were analyzed retrospectively for sleep architecture assessed using polysomnography and glucose metabolism assessed by OGTT at different time points (0, 30, 60, 120, and 180 min). Pearson's correlatives and multiple linear regression models were established to investigate the correlations between glucose metabolism and other indices including sleep architecture, apnea hypopnea index (AHI), mean and lowest oxygen saturation (MSOand LSO) and obesity measurements.

RESULTSThe majority (67.4%) of the patients had abnormal 1 hPG, and 41.6% had abnormal 2 hPG. 1 hPG was positively correlated with neck circumference (r=0.245), abdomen circumference (r=0.231), systolic blood pressure (r=0.213), diastolic blood pressure (r=0.276) and AHI (r=0.324), and was negatively associated with MSO(r=-0.341) and LSO(r=-0.387) (all P<0.05). After controlling for age, BMI, neck and abdomen circumferences, 1 hPG was found to inversely correlated with MSO(r=-0.253, P=0.032) and LSO(r=-0.311, P=0.008). In non-obese OSA subgroup, 1 hPG was significantly associated with OSA-related indices, and regression models showed that LSOand N2 were the two most important contributors to 1 hPG (adjusted R=0.349, P<0.001); plasma glucose at other time points did not show such correlations.

CONCLUSIONS1 hPG abnormality occurs earlier than 2 hPG in OSA patients. 1 hPG is significantly associated with OSA independent of obesity and may serve as a better index for measuring OSA-related glucose disorder.