Shorter telomeres in non-smoking patients with airflow limitation

Abstract

Background: Cross-sectional and longitudinal studies describe shorter telomeres in patients with chronic obstructive pulmonary disease (COPD) compared to matched non-COPD controls, but the relationship is confounded by tobacco consumption. We hypothesized that telomere shortening would be similar between non-smoking and smoking individuals with airflow limitation and shorter than non-obstructed controls.

Methods: Telomere length (T/S) was measured by qPCR in blood leukocytes of 80 non-smoking patients and 80 age-matched smokers with airflow limitation. Forty non-smoker healthy individuals served as controls. Anthropometrics, lung function, previous and current comorbidities were recorded in all individuals. Relationship between telomere length and clinical and functional variables were explored in the three groups.

Results: Telomeres length was similar in non-smokers and smoker individuals with airflow limitation (T/S = 0.61 ± 0.19 vs. 0.60 ± 0.23, p > 0.05) respectively. Telomere length was significantly shorter in both groups compared to healthy controls (T/S 0.79 ± 0.40; p = 0.01) independent from age and sex. No significant association was found between the telomere length and clinical or lung function parameters.

Conclusions: Telomere shortening is associated with airflow limitation independent of smoking status. Weather premature ageing or biologically determined shorter telomeres are responsible for this finding remain to be determined.

Keywords: Ageing; Asthma; COPD; Non-tobacco smoking; Telomeres.