Objective: To compare the anthropometric and polysomnographic data between obese and non-obese subjects with obstructive sleep apnea (OSA).

Materials and Methods: A prospective parallel group comparative study was conducted by analyzing the anthropometric and polysomnographic data in 50 subjects with suspected OSA who underwent a sleep study from October 2013 to September 2015. Of these, 25 patients were obese (body mass index [BMI] ≥30 kg/m²) and 25 were not (BMI <30 kg/m²). The anthropometric and polysomnographic data were evaluated and compared between the two groups using either chi-squared tests or unpaired t-tests.

Results: After study completion, 39 subjects (78%; 17 non-obese and 22 obese) were diagnosed with OSA (apnea-hypopnea index [AHI] ≥5). The mean AHI per hour was significantly higher in obese than in non-obese subjects (67.6 ± 28.6 vs. 16.7 ± 5.99, P value 0.000). Anthropometric measurements were significantly higher in obese than in non-obese subjects with OSA. Moreover, the Epworth Sleepiness Scale, arousal index, and snoring index scores were significantly higher in obese than in non-obese subjects with OSA. The oxygen desaturation parameters, total sleep time, sleep efficiency, and N3 and rapid-eye movement stages of sleep were significantly decreased in obese subjects compared to in non-obese subjects with OSA. Overall, the OSA in obese subjects was more severe compared to that in non-obese subjects.

Conclusion: OSA was more common in obese than in non-obese subjects; however, some non-obese subjects also had OSA. This finding contrasts with theories suggesting OSA is confined only to obese subjects. Therefore, when a non-obese person presents with the clinical characteristics of OSA, the diagnostic possibility should not be underestimated and should be evaluated thoroughly.

Keywords: body mass index, obesity, obstructive sleep apnea, apnea-hypopnea index.

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Dr K.Surendar Reddy

Associate Professor, Dept of Pulmonary Medicine SVS Medical College &Hospital, Mahabubnagar, Telangana

Contact number: 9949316154, Email: This email address is being protected from spambots. You need JavaScript enabled to view it.