Narayanan A, et al. - In this retrospective case-control analysis involving 367 children (aged 9 to 17 years) who had full-night polysomnography (PSG), the connection between asthma, obesity, and severe obstructive sleep apnea (sOSA) were analyzed. Data reported that asthma prevalence was 188 out of 367, obesity was 197 out of 367 (54%), and sOSA was 109 out of 367. The presence of asthma reduced the probability of sOSA in obese patients by an average of 14% and in nonobese patients by 9%. Even after controlling for age, sex, race, income, and tonsillar hypertrophy, these associations held. Among a large cohort of older children referred for PSG, asthma presence decreased while obesity increased the likelihood of sOSA. These associations have been additive.