Prevalence and Risk Factors of Obstructive Sleep Apnea Syndrome in a Population of Delhi, India

ObjectiveObstructive sleep apnea (OSA) has been recognized in the Western world as a public health burden, but there has been no community-based study performed to assess the prevalence of the condition in India. The study was performed to assess the prevalence and risk factors of OSA in a semi-urban Indian population.DesignA two-stage, cross-sectional, community-based prevalence study.SettingA semi-urban community in Delhi.DurationTwo years (2003 to 2005).Patients and participantsAll citizens residing in the community who were 30 to 60 years of age. Exclusion criteria included those patients with recent myocardial infarction, upper airway surgery, class III/IV congestive heart failure, pregnancy, hypothyroidism on treatment, acromegaly, chronic renal failure, systemic steroid treatment, and hormone replacement therapy.InterventionAn OSA assessment was performed in 2,400 subjects who were screened in stage 1 of the study by means of a sleep questionnaire. Subjects were then divided into habitual and nonhabitual snorers. Eighty-three randomly selected habitual snorers and 80 nonhabitual snorers were invited to participate in stage 2 of the study, which consisted of in-hospital polysomnography studies.Observations and resultsA total of 2,150 subjects returned questionnaires (response rate, 90%). Of 550 habitual snorers and 1,596 nonhabitual snorers, 77 habitual snorers and 73 nonhabitual snorers underwent polysomnography. A total of 36 habitual snorers (46.75%) and 2 nonhabitual snorers (2.73%) were found to have OSA, giving prevalence rates of 13.74% and 3.57%, respectively, for OSA and OSA syndrome (OSAS) on extrapolation. Multivariate analysis revealed that male gender, age, obesity (defined by a high body mass index), and waist/hip ratio as significant risk factors for OSAS.ConclusionsThis study demonstrated that the risk factors and prevalence for OSA in India are similar to those in the West, which is contrary to the findings of some previous reports, which had a strong inclusion bias.