Implications
Obesity is a potent predictor of OSA in children with asthma as indicated by our findings. The BMI z-score with or without reported loud snoring and morning dry mouth may be used for OSA screening with several implications for health systems, global public health and our understanding of the impact of OSA on asthma disease management. First, the questionnaire-based approach has been the mainstay for initial OSA screening. In the past two decades, however, electronic medical records and health informatics systems have reshaped healthcare delivery. Given that anthropometric measures such as BMI and BMI z-scores are available on such platforms, OSA risk stratification may be implemented in an automated fashion on a wide scale. Second, in low to middle income countries were such databases may not exist, OSA screening may be deployed via mobile applications that have a BMI z-score calculator or the MOP algorithm incorporated. Thus, the BMI z-score or MOP algorithm may serve as low-cost OSA screening methods for children with asthma in these locations where sleep study facilities may also be non-existent. Finally, the impact of OSA on asthma and vice-versa may be tracked by examining retrospective and prospective trends in BMI z-scores, as a biomarker of OSA, along with metrics of asthma control, which may reveal disease management practices most likely to decrease the future burden of OSA and asthma.
In conclusion, we recommend that children with asthma who have BMI z-scores of 2.07 or greater be referred for in-laboratory polysomnography and OSA evaluation. Future efforts should refine OSA screening tools that are specific to children with asthma.
ACKNOWLEDGEMENT: The authors wish to thank the sleep technologists and staff of the Johns Hopkins Pediatric Sleep Center, study coordinators, patients as well as caregivers who committed to participation.