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

BACKGROUND: Obstructive sleep apnea (OSA) occurs in both obese and nonobese individuals. This study was designed to compare clinical, metabolic profile, and polysomnographic parameters among obese and nonobese OSA patients. MATERIAL AND METHODS: This cross-sectional retro-prospective study involved 148 OSA patients. OSA patients were classified as nonobese (body mass index [BMI] <27.5 kg/m(2)) and obese (BMI ≥27.5 kg/m(2)) to determine the influence of BMI on its risks, clinical, metabolic, and polysomnographic parameters. For statistical comparisons, continuous variables were analyzed by Student’s t-test and categorical variables by Chi-square. RESULTS: Of 148 patients, 106 patients were of a retrospective group and 42 in the prospective group. 116 patients were obese and 32 were nonobese with a mean BMI of 33.66 ± 5.3 versus. 25.17 ± 2.2 kg/m(2) respectively. Female sex (70.7% vs. 43.4%), larger neck circumference (37.99 ± 3.93 vs. 33.67 ± 5.5 cm), loud snoring (94.8% vs. 81.3%), excessive daytime sleepiness (53.4% vs. 9.4%), fatigability (94.8% vs. 75%), high Epworth Sleepiness Scale score (16% vs. 8%), and hypertension (77.6% vs. 46.9%) were significantly (P < 0.05) more common among obese OSA patients while as smoking and sedative use was more prevalent among nonobese OSA group. However, no significant difference in median apnea-hypopnea index and severity of OSA between obese and nonobese group was observed. At the same time, the median oxygen desaturation index was significantly higher in obese patients (26.1 vs. 12.7, P = 0.005). CONCLUSION: Nonobese OSA patients depicted less severe disease symptoms and thus require high index of suspicion for early identification due to associated cardiovascular risk.