Telomere shortening and oxidative stress in patients with COPD

Background: Chronic Obstructive Pulmonary Disease (COPD) may be associated with accelerated aging. No study has described telomere length shortening, as a biomarker of aging, and its relationship with COPD progression. Objectives: To investigate telomere trajectory over time and its relationship to inflammatory, repair and oxidative stress biomarkers and to clinical and lung function parameters in a COPD cohort. Method: We measured leukocytes relative telomere length (T/S) by qPCR; clinical and lung function parameters and serum biomarkers levels (IL-6, IL-8, IL-16, TNF-alpha, MMP9, VEGF, TAS, MDA) in 263 COPD patients at baseline and 136 of these individuals after 3 years. Results: T/S correlated with age (r=-0.173, p=0.005). Patients with shorter T/S showed decreased TAS (p=0.04) and increased MDA/TAS (p=0.03) levels. Non-significant associations were found between T/S and clinical or lung function parameters at baseline or the rest of biomarkers analyzed. The rate of change in T/S over 3-years inversely correlated with baseline telomere length (r=-0.506, p 2 ) (r=0.244; p=0.005) in COPD patients. Subjects that shorten greatly their telomeres in this period presented a significant decrease in lung function (FEV 1 ) and oxygenation (PaO 2 ) (GLIM, p= 0.04 and p=0.05, respectively). Conclusions: Telomere length was associated with oxidative stress in COPD patients. And its rate of shortening seems to be related with a decrease in lung function and oxygenation over the follow-up period. Further studies in cohorts with a larger follow-up period are needed to confirm these findings.