Is childhood asthma associated with biological aging markers

Asthma is an inflammatory disease of the airways that can lead to the production of reactive oxygen species. Therefore, asthma could be associated with an accelerated biological aging. We explored whether wheezing and asthma in school-aged children could telomere length (TL), mitochondrial DNA content (mtDNA), and DNA methylation age. We used data from 1,623 children from six European birth cohorts. At 6-11 years of age, a blood sample was collected and parents reported the occurrence of wheezing and asthma. We defined active wheezing as having had any episode of wheezing or having taken medication for asthma in the last year. Asthma was defined as asthma ever diagnosed by a doctor. Relative TL and mtDNA were determined by quantitative real-time polymerase chain reaction and methylation age using 450k methylation data and the Horvath and Hannum algorithms. Prevalence of wheezing and asthma was 17% and 10%, respectively. Asthma was borderline statistically significantly associated with a decrease of 3.0% [95%CI: -6.5%; 0.5%] in mtDNA, compared with children without asthma. mtDNA also decreased in children with wheezing compared with no wheezers but results did not reach significance. Wheezing and asthma were associated with borderline increase in Hannum methylation age (β 0.28; -0.13, 0.68 for wheezing and β 0.18; -0.30, 0.67 for asthma). Neither wheezing nor asthma was associated with TL. We found little evidence of associations of school-age wheezing and asthma with three aging markers. The overall lack of molecular damage indicates that there is a chance for treatment and prevention for asthmatic children at school-age to avoid or diminish damages due to asthma related oxidative stress.