Methods: This study was approved by the Allegheny Singer Research Institute-Allegheny Health Network Institutional Review Board. Informed consent/assent was obtained from all subjects prior to participation. Fifth grade students were recruited from twelve Pittsburgh schools. Physician diagnosed asthma was ascertained using a standardized, validated survey. Relationships between physician diagnosed asthma and environmental risk factors, including obesity (BMI), poverty (public health insurance), outdoor air pollution (NOx), psychological stress (salivary cortisol), and tobacco smoke exposure (salivary cotinine) were analyzed using logistic regression.
Results: 267 subjects were enrolled (37.5 % African American, 47.6% female). The prevalence of physician diagnosed asthma was 28.7%. Factors influencing odds of physician diagnosed asthma included elevated BMI (p=0.032) public vs private health insurance (p=0.002), NOx exposure (p=0.023), and salivary cortisol (p=0.34). A strong interaction was identified between poverty and psychological stress (p=0.004) such that the odds of physician diagnosed asthma was 6.88 times greater (p=0.002) in subjects with public health insurance and elevated salivary cortisol levels (>1 SD above mean). Conclusions: Results indicate a high estimated prevalence of physician diagnosed asthma among participants. Obesity, poverty, outdoor air pollution, and psychological stress were identified risk factors. Future efforts need to focus on improving asthma outcomes in this at-risk population.