Integrative Analysis of Oxidative Stress and Cellular Senescence Pathways in Chronic Obstructive Pulmonary Disease

Background/Objectives: Chronic obstructive pulmonary disease (COPD) is increasingly viewed as a disorder of impaired cellular adaptation to chronic stress, involving oxidative injury, mitochondrial dysfunction, and accelerated cellular senescence. We investigated whether genetic variation in these pathways contributes to disease susceptibility, lung function impairment, and polygenic risk prediction. Methods: Thirty-three single-nucleotide variants were analysed in 747 patients with COPD and 703 controls. Associations with disease susceptibility and lung function parameters were assessed using regression models with correction for multiple testing. Weighted and unweighted polygenic scores were constructed from associated variants and evaluated using receiver operating characteristic and net reclassification improvement analyses. Results: Significant associations were identified in genes involved in antioxidant defence (NFE2L2, HMOX1, GSR), PI3K/AKT/mTOR signalling (PIK3R1, PTEN), mitochondrial function (TOMM40), cellular stress responses (FOXO3A), and long non-coding RNA regulation (MEG3, CDKN2B-AS1). The strongest association was observed for PIK3R1 rs831125 (OR = 2.31, p = 2.53 × 10^-10). Variants in NFE2L2, PIK3R1, MEG3, MALAT1, and SIRT3 were additionally associated with pulmonary function parameters. The weighted polygenic score demonstrated good discriminative ability (AUC 68.8%, 95% CI 65.9-71.7%) and substantially improved prediction when combined with age, sex, and smoking exposure (AUC 88.1%, 95% CI 86.3-89.8%; NRI = 0.62, p = 2.21 × 10^-28). Conclusions: The identified loci converge on interconnected pathways involved in cellular stress adaptation, mitochondrial homeostasis, and senescence, supporting their contribution to chronic obstructive pulmonary disease susceptibility and functional decline.