Biological Age in COPD Patients Reveals an Accelerated Lung Aging

Abstract

Chronic obstructive pulmonary disease (COPD), the third leading cause of death worldwide, shows striking clinical aging-associated features of lung. We tested the hypothesis that lung biological aging in COPD is accelerated. Biological aging was assessed by mitotic telomere length (TL) and non-mitotic age-dependent methylation changes in specific CpGs (DNAmAge) of lung cells, obtained from induced sputum, and peripheral blood leucocytes in 18 COPD patients (72.4±7.7 years; 50% males), clinically appraised by lung function and blood parameters. DNAmAge (67.4±5.80 vs 61.6±5.40 years; p=0.0003), AgeAcc (-4.5±5.02 vs -10.8±3.50 years; p=0.0003) and TL attrition (1.05±0.35 vs 1.48±0.21 T/S; p=0.0341) are higher in lung than blood in the same patients. Blood DNAmAge (r=0.927245; p=0.0026) and AgeAcc (r=0.916445; p=0.0037), but not TL, highly correlate with that of lung. Therefore, blood can be a proxy indicator of lung biological age. Multiple regression analyses show that both blood DNAmAge and AgeAcc decrease (i.e., younger) in patients with combined inhaled corticosteroids (ICS) therapy (p=0.0494 and p=0.0553) and FEV1% enhancement (p=0.0254; p=0.0296). In conclusion, the new finding, that lung of COPD patients is remarkably biologically older than blood, opens new research challenge on novel therapeutic approaches to counteract this key aspect of the disease.