Comparison of clinical and polysomnographic parameters between obese and nonobese obstructive sleep apnea

Obstructive sleep apnea (OSA) is one of the most common sleep-disordered breathing characterized by repeated cessation or reduction in airflow during sleep. OSA occurs in both obese and nonobese individual. This study was designed to compare the clinical and polysomnographic data between obese and nonobese patients with OSA.

This was a retrospective study that included all the patients diagnosed as between November 2013 and December 2014. The patients were classified into nonobese (n = 23) and obese (n = 72) groups if their body mass index (BMI) was <27.5 and ≥27.5, respectively. Data were analyzed using Statistical Package for the Social Sciences (SPSS) software program, version 20.0 (SPSS, Chicago, Illinois). A value of P < 0.05 was considered statistically significant.

There were 95 patients of OSA, of which 23 (44.4%) were nonobese and 72 (75.78%) were obese with a mean BMI of 24.37 ± 3.09 and 34.27 ± 8.34 kg/m², respectively. Characteristics, such as male predominance, higher BMI, neck circumference, and loud snoring, were significantly higher in obese group (P < 0.05) as compared to nonobese. Mild OSA (AHI 5-15) was significantly higher in nonobese patients (39.13% vs. 5.55%, P < 0.00001), whereas severe OSA (AHI >30) was higher in obese patients as compared with nonobese (66.66% vs. 30.43%, P = 0.002). When comparing comorbidities, the hypertension was significantly higher in the obese (47.22% vs. 13.04%, P = 0.003) than the nonobese patients. The incidence of diabetes (37.50% vs. 17.39%) and hypothyroidism (16.66% vs. 4.34%) was also higher in obese group as compared with nonobese. No significant difference was found for mean age, racial origin (Asian/African), and ESS score between obese and nonobese patients.

Obstructive sleep apnoea is not restricted to only obese individual; rather it also occurs in nonobese. The severity of OSA in nonobese has generally less as compared with obese and its early identification required high index of suspicion.