Prevalence and association analysis of obstructive sleep apnea in India: Results from BLESS cohort

Background: Despite having the largest population in the world with 1.4 billion inhabitants, there is only scarce data on the prevalence of OSA from India.

Research question: This study aimed to find the prevalence of Obstructive Sleep Apnea (OSA) using Polysomnography (PSG) and current scoring rules (AASM 2012) in population and investigate OSA associations for cardiovascular and metabolic comorbidities.

Study design: and Methods: Participants were randomly selected among the accompanying attendants of patients admitted to a hospital in Bhopal, India and underwent level I PSG. Anthropometric measurements, blood investigations were taken. The primary outcome was prevalence of OSA, assessed by the Apnoea-Hypopnoea Index (AHI).

Results: Level I PSG was performed on 1015 adult participants from December 2019 to February 2023; after excluding 57 participants with sleep time <240 min, 958 participants (age range 18-80 years) were finally included in this study. Median (IQR) age was 40.0 years (31.0, 49.0) while median (IQR) BMI was 23.5 (20.7, 26.8) Kg/m². Prevalence (95 % CI) of moderate-to-severe OSA (AHI ≥15) and severe OSA (AHI≥30) was 30.5 % (28-34 %) and 10.1 % (8.3-12), respectively. The upper quartile of the AHI (Q4 ≥17) was independently associated with the presence of Diabetes Mellitus [OR 2.14 (95 % CI 1.07-4.44)], Hypertension [OR1.98 (95 % CI 1.20-3.28)] and Metabolic Syndrome [OR 2.36 (95 % CI 1.37-4.09)] compared to the first quartile AHI.

Interpretation: OSA prevalence was found to be significantly higher than previously estimated in Indian population. Association of OSA with diabetes, hypertension, and metabolic syndrome was observed.