The prevalence and risk factors of obstructive sleep apnea in patients with stroke in a tertiary care hospital in India

Abstract

<b>Background:</b> Secondary prevention of stroke involves the treatment of modifiable risk factors. Obstructive sleep apnea(OSA), a risk factor for stroke, has a very effective treatment in the form of positive airway pressure therapy. Untreated OSA is also a risk factor for recurrent stroke. <b>Aims &amp; Objectives:</b> To determine the prevalence and risk factors of OSA in patients with stroke in a tertiary care hospital in India <b>Methods:</b> This is a cross-sectional study conducted between April 2019 to April 2020 in Christian Medical College, Vellore. Acute stroke patients or stroke in the last 6 months were recruited from ward and outpatient stroke clinic. Level 3 polysomnography was done and OSA was diagnosed in patients with an apnea-hypopnea index(AHI) of &gt;5 events/hour. The OSA group and non-OSA group were compared for demographic factors, stroke characteristics, and co-morbidities. <b>Results:</b> A total of 50 patients were recruited and all were asymptomatic for OSA. The mean AHI was 17 events/hour and the prevalence of OSA was 76%(95% CI: 61.8 – 86.9). Overall 14% had severe OSA(AHI ≥ 30), 32% had moderate OSA (AHI ≥15 &lt; 30), and 30% had mild OSA(AHI ≥5 to &lt;15). We observed a gradual increase in the trend of mean body mass index(BMI) from mild to severe OSA and all severe OSA patients were obese(BMI ≥25). The adjusted odds ratio for BMI≥25 as a risk factor for AHI ≥ 15 events/hour was 34.8(p=0.003;95%CI:2.8 - 431) <b>Conclusion:</b> OSA is highly prevalent in the stroke population with subtle clinical symptoms. BMI was found to be an independent risk factor associated with moderate to severe OSA. A diagnostic sleep study is warranted in stroke patients, particularly with obesity.