Is childhood asthma associated with biological aging markers?

Background: Asthma, the most common chronic disease in childhood, is an inflammatory disease of the airways. The presence of chronic inflammation in the organism causes production of ROS; this suggests that asthma could be associated to an accelerated biological aging. Objective: To explore if there is an association between asthma in school-age children from the population-based birth cohort study HELIX (n = 1623) and three proposed aging markers: telomere length, mitochondrial DNA, and DNA methylation age. Methods: Information on wheezing and asthma was obtained from parental questionnaires administered at 6-11 years. We defined "active wheezing" as either by wheezing or by having taken medication in the last year and "asthma" as children ever diagnosed with asthma by a doctor. Leukocyte TL and mtDNA content were measured in the children at 6-11 years employing real time polymerase chain reaction (qPCR). DNAm was measured on blood samples using the Horvath (Illumina HumanMethylation27 Bead Chip) and Hannum (Illumina HumanMethylation 450 BeadChip) algorithms. Results: Prevalence of active wheezing and asthma was 10% and 17%, respectively. Ever asthma was borderline statistically significantly associated with a decrease of 2.21% (95% CI: 6.21%;1.94%) in mtDNA. mtDNA also decreased in children with active wheezing compared to children with no wheezing. Active wheezing was non-statistically significantly associated with an increase in HOma (0,20 (95% CI: -0,03;0,44) and HAma (0,28 (95% CI: -0.13;0.68), in relation to children without active wheezing. Ever asthma was non-statistically significantly associated with an increase in HAma compared with children without asthma. Associations did not substantially change after considering air pollution as confounder. Conclusion: This study, the first one to assess whether asthma is related to biological aging in children, finds little evidence of associations of active wheezing and ever asthma with three different biological ageing markers. Further studies are needed to confirm these results