Prevalence of Nocturnal Oxygen Desaturation in Subjects with HIV Infection

Abstract

Background: Obstructive sleep apnea (OSA) is a common disorder that is linked to daytime fatigue and increased risk of cardiovascular disease. The general population prevalence of OSA is estimated to be 2-9%. The prevalence of OSA in people with HIV infection is unknown, although many patients with HIV report daytime fatigue. The diagnosis of OSA is typically established during an overnight study in a sleep laboratory. However, this testing is intrusive and costly. Simpler methods to select patients for definitive study have been previously validated including the Four-Variable Screening Tool and the STOP-BANG questionnaire. Nocturnal oxygen desaturation index (ODI) measurement has also been used to screen for reliably predicting over 85% of moderate to severe cases when the ODI >10. Methods: Patients with HIV infection presenting for routine medical care were invited to participate in this prospective OSA screening trial. Informed consent was obtained, subjects completed the Four-Variable Screening Tool, the STOP-BANG questionnaire, and were provided a fingertip oximeter for overnight use at home. Overnight oxygen saturation data was downloaded and analyzed. All subjects with ODI >10 were referred for a formal sleep study. Primary endpoint: to determine the percentage of patients with an ODI > 10. Secondary endpoint: to determine the correlation between the screening questionnaires and ODI results. Results: 108 subjects completed the study and 47 (43.5%) demonstrated an ODI greater than 10. The STOP-BANG questionnaire showed 91.5% sensitivity and specificity of 26.2%. The STOP-BANG positive and negative predictive values were 48.9% and 80.0% respectively. The Four-Variable screening tool showed a 31.9% sensitivity and specificity of 80.3%. The Four-Variable positive and negative predictive values were 55.6% and 60.5%, respectively. Conclusions: HIV-infected patients in our clinic demonstrated a high prevalence of nocturnal oxygen desaturation suggesting a high prevalence of OSA. Two commonly used screening tools did not reliably predict nocturnal desaturation in our population. The high prevalence of nocturnal oxygen desaturation in HIV patients indicates the need for additional HIV-related OSA research.