The role of oxygen saturation measurement and body mass index in distinguishing between non-apnoeic snorers and patients with obstructive sleep apnoea syndrome.

The aim of this study was to examine the role of oxygen saturation (SaO2) measurement in identifying apnoeic snorers from non-apnoeic snorers and in the assessment of the severity of obstructive sleep apnoea. Ninety-two patients with clinically suspected obstructive sleep apnoea syndrome (OSAS) were assessed, using overnight polysomnography. The patients were classified as follows: 14 patients were non-apnoeic snorers, 27 patients had mild OSAS, 31 patients had moderate OSAS and 20 patients had severe OSAS. Minimum SaO2 level, mean SaO2, time below 85% of SaO2, the ratio between the time SaO2 and total sleep time and body mass index (BMI) were assessed retrospectively. There was a statistically significant difference between the non-apnoeic group and OSAS patients in Min SaO2 (P = 0.03). Patients who had Min SaO2 above 85% could be evaluated as non-apnoeic snorers; however, SaO2 and BMI were not found to be useful in the assessment of the severity of OSAS.