Aging-Related Systemic Manifestations in COPD Patients and Cigarette Smokers

<div><p>Rationale</p><p>Chronic obstructive pulmonary disease (COPD) is often associated with age-related systemic abnormalities that adversely affect the prognosis. Whether these manifestations are linked to the lung alterations or are independent complications of smoking remains unclear.</p><p>Objectives</p><p>To look for aging-related systemic manifestations and telomere shortening in COPD patients and smokers with minor lung destruction responsible for a decline in the diffusing capacity for carbon monoxide (DL_CO) corrected for alveolar volume (K_CO).</p><p>Methods</p><p>Cross-sectional study in 301 individuals (100 with COPD, 100 smokers without COPD, and 101 nonsmokers without COPD).</p><p>Measurements and Main Results</p><p>Compared to control smokers, patients with COPD had higher aortic pulse-wave velocity (PWV), lower bone mineral density (BMD) and appendicular skeletal muscle mass index (ASMMI), and shorter telomere length (TL). Insulin resistance (HOMA-IR) and glomerular filtration rate (GFR) were similar between control smokers and COPD patients. Smokers did not differ from nonsmokers for any of these parameters. However, smokers with normal spirometry but low K_CO had lower ASMMI values compared to those with normal K_CO. Moreover, female smokers with low K_CO, had lower BMD and shorter TL compared to those with normal K_CO.</p><p>Conclusions</p><p>Aging-related abnormalities in patients with COPD are also found in smokers with minor lung dysfunction manifesting as a K_CO decrease. Decreased K_CO might be useful, particularly among women, for identifying smokers at high risk for aging-related systemic manifestations and telomere shortening.</p></div

Characteristics of the study patients.

<p><i>Definition of abbreviations</i>: COPD, chronic obstructive pulmonary disease; % predicted, percentage of the predicted value; BMI, body mass index; MAP, mean arterial pressure; K_CO, transfer factor coefficient of the lung for carbon monoxide; SpO₂, oxygen saturation by pulse oximetry.</p><p>Data are median [interquartile range] unless stated otherwise.</p><p>†<i>P</i> value by Chi-square test, Fisher exact test, or nonparametric Kruskal-Wallis test, as appropriate, comparing the three populations (COPD patients, control smokers, and nonsmokers).</p><p>Characteristics of the study patients.</p

Comparison of inflammatory mediators between smokers with low K_CO and those with normal K_CO.

<p>K_CO, transfer factor coefficient of the lung for carbon monoxide; IL, interleukin; MCP-1, monocyte chemotactic protein-1; TNF-α, tumor necrosis factor alpha</p><p>Data are median [interquartile range].</p><p>† <i>P</i> value by nonparametric Kruskal-Wallis test</p><p>Comparison of inflammatory mediators between smokers with low K_CO and those with normal K_CO.</p