A study to estimate prevalence and risk factors of Obstructive Sleep Apnoea Syndrome in a semi-urban Indian population

Abstract

Obstructive Sleep Apnea Syndrome (OSAS) has been recognised as a major cause of morbidity and mortality in developing countries like India. There is still a paucity of Indian studies regarding the prevalence of OSAS. The current single centre prospective cross-sectional study was undertaken to know prevalence estimates for key symptoms and features that can indicate the presence of OSAS in an Indian population. A survey was conducted on subjects with age groups ≥25 years at King George's Medical University, Lucknow, Uttar Pradesh, India from August 2009 to July 2011. Data was recorded during the interview on the basis of Berlin Questionnaire (BQ). Risk factors for OSAS were also evaluated. Risk group categorization for OSAS was done with the help of a questionnaire and overnight polysomnography was performed in each group to measure apnea and hypopnea index (AHI). Out of 1816 subjects, 1512 (response rate 83.3%) finally participated in the survey with mean age 42.6±11.2 years, males 67.9% and females 32.1%. Of them 6.2% were found to be at high-risk OSAS; 12.2% were obese (Body Mass Index ≥30 kg/m 2 ) and 33.5% of the obese population were at high-risk OSAS. Among high-risk patients with OSAS, 62.4% had hypertension. Statistically significant and independent risk factors found for OSAS were obesity, large neck size, alcoholism and use of sedatives/tranquillizers. Highrisk category predicted an AHI ≥5 with a sensitivity of 86.3% (95% CI 73.1-93.8), specificity of 93.1% (95% CI 89.1-95.7), positive and negative predictive values of 70.9% (95% CI 57.9-81.4) and 97.2% (95% CI 94.1-98.8) respectively. It can be concluded that BQ questionnaire can still be used as a pre-assessment tool for predicting persons at risk for OSAS in clinical practice. Further studies on estimation of prevalence of OSAS by applying BQ are warranted in near future from other regions of India.

Prevalence of Obstructive Sleep Apnea in an Indian Population: Using Stopbang Questionnaire

“…The prevalence of OSA in the Indian population is three-fold higher in men as compared to women (Reddy, 2009). According to a study by Singh et al, in North Indian population, it was found that 6.2% of the total populations were at high risk of OSAS whereas 33.5% of the obese population was at high-risk OSAS [1]. In our study, the prevalence of OSA was found to be 13.7% according to the STOP-Bang score which may be attributed to the higher BMI and presence of central obesity in this population ( Table 1).…”

“…The prevalence of OSAS based on the Wisconsin cohort study performed in the USA involving middle-aged adults 30-60 years of age, is 2% in females and 4% in males (Young, 1993). According to a survey conducted on a semiurban Indian population, it was found that around 6.2% among total sample were diagnosed with high-risk OSAS and 33.5% of the obese population were at high risk of OSAS [1].…”

Correlation between coronary artery disease and obstructive sleep apnea syndrome and analysis of risk factors

“…The main influencing mechanisms of OSAS ( 10 , 13 – 16 ), as a risk factor of CAD, are as follows: i) Hypoxemia in OSAS patients caused by repeated apnea can activate the chemical receptors and sympathetic nerve, resulting in vascular smooth muscle remodeling and hypertrophy, increasing oxygen consumption of heart and aggravating myocardial ischemia and hypoxia; ii) the platelet activity and aggregation capacity in OSAS patients are increased, leading to the occurrence of cardiovascular events; iii) the activity and content of tissue plasminogen activator inhibitor in OSAS patients are increased, inhibiting the fibrinolytic system in the body and leading to the hypercoagulable state, thrombosis and atherosclerosis development; iv) repeated apnea hypoxia activates the oxidative stress, which further leads to the lipid peroxidation, vascular endothelial cell injury and increased aggregation of inflammatory factors; v) nocturnal hypoxia may affect the activity of lipoprotein receptor, leading to the increased blood lipids and aggravating the development of atherosclerosis; and vi) accompanying factors: OSAS patients are mostly complicated by obesity, lipid metabolism disorders, hypertension, arrhythmia and other susceptibility factors of CAD. In order to reduce the incidence rate and improve the prognosis of CAD in OSAS patients, therefore, it is recommended to provide appropriate prevention and treatment for OSAS, as a risk factor.…”

The prevalence of symptoms and risk factors associated with obstructive sleep apnea among patients attending primary health centers in Erbil, Iraq

“…This was near to the result of an Indian study which found 62.4% of those with high risk were hypertensive, while only 5.3% of those with low risk had Discussion hypertension. 3 OSA was significantly higher in people who live in rural areas than those who live in urban areas, 50% and 22.4% respectively, (P = 0.024), but the small sample size of those in rural areas (only 14 persons) will reduce the importance of this difference. The socioeconomic status has a noticeable impact on OSAS, which was more prevalent among people with low and medium economic status than high socioeconomic class (27.0%, 28.8%, and 11.5% respectively), with a p-value less than 0.001.…”