Clinical and polysomnographic predictors of severe obstructive sleep apnea in the South Indian population

Abstract

Background:With the emergence of lifestyle diseases in epidemic proportions, obstructive sleep apnea (OSA) is being increasingly recognized in less developed countries as well.Aim:We sought to study the demographic, clinical, and polysomnographic (PSG) predictors of OSA severity in a cohort of South Indian patients.Materials and Methods:Consecutive patients with PSG proven OSA [apnea hypopnea index (AHI) ≥5/h] were prospectively recruited. The study period was from January 2012 to December 2012. Demographic data, history of vascular risk factors, substance abuse, sleep quality, snoring, and witnessed apneas were collected using a structured pro forma. In addition, PSG variables such as AHI, sleep latency and efficiency, duration of slow wave and rapid eye movement (REM) sleep, and other parameters were collected. Correlations between AHI severity and clinical and PSG parameters were done.Results:There were 152 (119 males and 33 females) subjects with a mean age of 53.8 years and body mass index (BMI) of 29.31. Mean AHI was 36.2/h (range: 5.1-110) and 66 subjects had severe OSA. Around 12% had the presenting complaint as insomnia, mainly of sleep maintenance. Of the subjects, 35% had witnessed apneas and 67% had excessive daytime sleepiness (EDS); 40% of patients had ≥2 risk factors. PSG parameters showed short sleep onset latency with a high arousal index. Mean apnea duration was 24.92 s. We found that age >55 years, BMI >25 kg/m2, witnessed apneas, EDS, hypertension, dyslipidemia, reduced slow wave sleep duration, mean apnea duration >20 s, and desaturation index >10/h correlated well with OSA severity while the arousal index, sleep latency and efficiency, and exposure to smoking and alcohol showed no association.Conclusions:Older subjects with witnessed apneas are likely to have more severe OSA. Even though overall sleep architecture was similar between the groups, severe OSA had shorter slow wave sleep, longer apneas, and higher nocturnal hypoxemia.

Relation among obstructive sleep apnea, obesity, age and gender: A retrospective study

“…Our study supports these findings. However, Sreedharan et al showed that BMI did not have a statistically significant association with the severity of OSA [16]. In their study, the number of patients (n=152) is less than our patients and 12% of them had insomnia.…”

Prevalence of obstructive sleep apnoea in metabolic syndrome

“…Additionally, it is associated with an immense number of other comorbidities. 8,15 As the term syndrome implies, a single specific causative etiology to MetS is not clear. Nevertheless, abdominal adiposity and insulin resistance appear to be at the core of the pathophysiology of MetS and its individual components.…”

“…Although the incidence of metabolic syndrome in India is on the rise, there is paucity of Indian data on its correlation with obstructive sleep apnoea. 15 This study was primarily designed to study the clinical prevalence of in metabolic syndrome; and to find risk factors associated with obstructive sleep apnoea (OSA).…”

Sleep Apnea

“…These patients also showed symptoms of hypertension, dyslipidemia, duration of apnea >20 seconds and oxygen desaturation index >10/ h 9 . In another study conducted on a cohort from north India, OSA was found to be prevalent in 9.3% individuals, with high BMI and abdominal fat and the males having more propensities to acquire the disease.…”