Sleep disordered breathing, asthma and socio-economic status in children: How do they interact?

Background: Sleep disordered breathing (SDB) and asthma have been closely linked. Both conditions are affected by socio-economic status (SES). Aim: To study the rate of asthma and SDB by SES in children. Methods: This cross sectional study was performed in 6 primary schools; 3 with low and 3 with high SES. These schools were determined by a previous study which evaluated the SES of students. All children in the 1st to the 4th grades were included. ISAAC questionnaire for asthma, pediatric sleep questionnaire for SDB and a standardized SES questionnaire were completed by the parents. Results: 1383 children (51% female) were included. Mean age was 8.7±1.1 years. Rates of ever and current wheezing were 25.8% (95%CI: 23.5-28.2%) and 19.8% (95%CI:17.7-21.9), respectively. 11.4% (95%CI:9.8-13.2%) children had doctor diagnosed asthma and 7.1% (95%CI:5.8-8.5) had SDB. Children attending schools in poor neighbourhoods tended to have higher rates of SDB (p=0.05). Although children in both groups had similar rates of ever and current wheezing, those with lower SES had less doctor diagnosed asthma (p=0.03). Children with SDB had increased risk of ever and current wheezing and risk increased in children with lower SES. Presence of SDB increased the risk of ever wheezing among children with low and high socieconomic status with an OR of 4.4 and 3.2, respectively (p<0.05). Conclusion: SDB is more common in children with lower SES. Children with SDB have higher rates wheezing and risk increases in children with lower SES.