Differential Profile of OSA in Obese Kashmiri Patients of Northern India

Abstract

Obstructive sleep apnea (OSA) and obesity are two interacting global epidemics both with high prevalence and morbidity. Both epidemiologic and clinical studies suggest that majority of patients with obesity also have OSA and untreated OSA in these patients results in significant cardiovascular and metabolic complications.
Objectives: To evaluate the profile of OSAin obese patients of Kashmir.
Methods: We performed polysomnography studies in obese patients that were referred from various sub-specialty clinics from July 2011 to August 2013.
Results: Out of 182 patients who underwent polysomnography (PSG), 11O (60.4%) were obese (BMI > 30 kg/m2). In 110 obese patients, 104 (94.5%) had OSA. Hypertension, diabetes and dyslipidemia were more prevalent among obese (p<0.05). The mean neck circumference and mean BMI of obese patients was significantly more than that of non-obese (33.9 kg/m2 vs. 26.8 kg/m2) (p <0.000). Presenting symptoms of obese were snoring (97.3%), daytime sleepiness (87.3%) with a mean ESS of 15.3, disturbed nocturnal sleep (70.0%), nocturia (62.7%) and witnessed apneas (45.5%). OSA was significantly (p=0.002) more common among obese compared to non-obese (93% vs 76%). Most were clinically suspected to have OSAby internists (29%), cardiologists (20%), endocrinologists (15%) and psychiatrists (13%). Sleep efficiency was significantly less (p< 0.03) in obese patients but sleep latency and REM sleep latency did not significantly differ between obese and non-obese. Unlike awake oxygen saturation the average nocturnal oxygen saturation of obese patients was significantly less [p=0.001] than that of nonobese patients (84.7% vs. 88.1%). The mean AHI of obese patients was significantly more than non-obese i.e 24.3 vs. 18.0 (p = 0.001) and so was the mean ODI i.e 24.6 vs. 17.2 (p = 0.001). Variables that significantly correlated with presence of OSA include age, gender, BMI, hypertension, diabetes and cardiovascular disease (p< 0.05), however on logistic regression only BMI, hypertension, and nocturia correlated with OSA. CPAPtherapy improved snoring, nocturia, nocturnal sleep and daytime sleepiness more in obese than non-obese OSApatients.
Conclusions: OSA which is highly prevalent among obese Kashmiri patients, is largely unrecognized in the primary care setting. It is associated with significant comorbidities and most of these improve with CPAPtherapy. JMS 2016; 19(2):65-74.