D3.479 - Association between Mitochondrial DNA Copy Number and Lung Function in Schoolchildren

Mitochondrial DNA copy number, an indicator of mitochondrial function and cellular health, has been linked to several inflammatory diseases, but the role of mitochondrial DNA copy number playing in respiratory health is unclear. The present study aimed to investigate the association between mitochondrial DNA copy number and lung function in a population of Asian schoolchildren.

A total of 1,338 singleton-born children who participated in the Longitudinal Investigation of Global Health in Taiwanese Schoolchildren (LIGHTS) cohort were included in this study. Genomic DNA was extracted from peripheral blood samples. Mitochondrial DNA copy number was quantified using a quantitative real-time polymerase chain reaction (qPCR) method. Lung function was measured using spirometry (Spirolab II, Medical International Research, Italy). Multiple linear regression models were applied to estimate the association between mitochondrial DNA copy number and lung function, after adjusting for covariates including age, sex, body mass index, environmental tobacco smoke exposure, and parental allergic diseases.

A total of 1,338 singleton-born children (756 boys, 56.5%; mean age ± standard deviation: 6.47 ± 0.52 years) participating in the LIGHTS cohort were included in this study. Mitochondrial DNA copy number was significantly associated with forced vital capacity (FVC) (β: 0.01, p=0.040), forced expiratory volume in 1 second (FEV₁) (β: 0.01, p=0.011), FEV₁/FVC ratio (β: 0.31, p=0.071), peak expiratory flow (PEF) (β: 0.03, p=0.049), and forced expiratory flow at 25–75% of FVC (FEF_25–75) (β: 0.02, p=0.021) after controlling for pertinent covariates.

This study provides suggestive evidence of an association between mitochondrial DNA copy number and various lung-function parameters (FVC, FEV₁, PEF, and FEF_25–75) in schoolchildren, indicating that mitochondrial DNA copy number may impact on the health of general respiratory system. Further investigation is needed to validate mitochondrial DNA copy number as a potential biomarker for lung function