Prevalence of Obstructive Sleep Apnea Among Patients with Secondary Polycythemia: A Retrospective Cross-sectional Study

Objectives: Obstructive sleep apnea (OSA) and secondary polycythemia occasionally occur together, but their relationship remains unclear. This study aimed to explore the prevalence of OSA among patients with secondary polycythemia in our local population. Methods: In this retrospective cross-sectional study, we screened 524 adult patients with polycythemia who attended the hematology clinic at a major tertiary hospital in Muscat during 2013–2023. Our goal was to identify patients with OSA and secondary polycythemia who also underwent sleep studies and analyzed their data. Results: Out of 524 polycythemia patients, we identified N = 44 patients (8.4%) who had both OSA and secondary polycythemia. The vast majority were male (42/44; 95.5%). Participants’ mean age was 40.7 years, with a body mass index of 31.7 kg/m2, hemoglobin level of 16.5 g/dL, and hematocrit level of 0.5 L/L. The mean apnea/hypopnea index was 33.3, and the mean desaturation index was 20.3. More than half of the patients (23; 52.3%) had severe OSA (apnea/hypopnea index > 30). Conclusions: The majority of patients with secondary polycythemia had severe OSA. It is likely that OSA may contribute to secondary polycythemia, warranting further investigation.