Frequency of Positional Obstructive Sleep Apnea (POSA) in Patients with Obstructive Sleep Apnea and Differences in Demographic and Clinical Characteristics

The aim of this study was to evaluate the prevalence of positional obstructive apnea among the patients with obstructive sleep apnea (OSA) and its difference in terms of clinical and baseline factors in patients. This prospective cross-sectional study was conducted on 130 patients with OSA referred to Bamdad Respiratory and Sleep Research Center, Isfahan, Iran, during the years 2016-17. The demographics and clinical data and apnea type (positional or non-positional), as well as polysomnography test results were recorded using a checklist and statistically analyzed. Findings: From 130 patients with OSA, 70.8% had non-positional apnea, and 29.2% had positional apnea, 4 (1.3%) in subgroup 1, 12 (9.2%) in subgroup 2, and 22 ones (16.9%) in subgroup 3. Factors such as body mass index (BMI) (P = 0.026), supine and non-supine apnea hypopnea index (AHI) (P < 0.001), number of apnea during sleep (P = 033.03), and frequency of decrease in O2 saturation (P = 0.017) among the three subgroups of positional apnea were statistically different from the group with non-positional apnea. According to the results of this study, it can be concluded that total and supine and non-supine AHI were higher in patients with positional obstructive sleep apnea (POSA) rather than those with non-POSA. As patients with severe OSA were more likely to have POSA. Therefore, with early detection of the disease, it can be controlled and treated at an early stage with convenient and applicable treatments such as changing sleep position