Johnson RF, et al. - By examining a cohort of obese adolescents with and without severe obstructive sleep apnea (OSA), researchers explored the potential connection between the velocity of weight gain and OSA severity. In this retrospective cohort study, they analyzed obese adolescents (aged 12 to 17 years) referred for full night polysomnography (PSG). The study sample consisted of 166 obese adolescents (105 with and 61 without severe OSA). According to the regression analysis, yearly change in weight among obese adolescents with severe OSA was significantly higher than those without. Weight increased by 6.5 kg each year before their PSG for the group with severe OSA, whereas weight increased by 5.1 kg per year for those without. A significant predictor of severe OSA in obese adolescents is the rate of weight gain over time.