Vascular inflammation and aortic stiffness: potential mechanisms of increased vascular risk in chronic obstructive pulmonary disease

Respir Res. 2018 May 24;19(1):100. doi: 10.1186/s12931-018-0792-1.

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is a complex inflammatory condition in which an important extra-pulmonary manifestation is cardiovascular disease. We hypothesized that COPD patients would have increased aortic inflammation and stiffness, as candidate mechanisms mediating increased cardiovascular risk, compared to two negative control groups: healthy never-smokers and smokers without COPD. We also studied patients with COPD due to alpha- 1 antitrypsin deficiency (α1ATD) as a comparator lung disease group.

Methods: Participants underwent 18F-Fluorodeoxyglucose (FDG) positron emission tomography imaging to quantify aortic inflammation as the tissue-to-blood-ratio (TBR) of FDG uptake. Aortic stiffness was measured by carotid-femoral aortic pulse wave velocity (aPWV).

Results: Eighty-five usual COPD (COPD due to smoking), 12 α1ATD-COPD patients and 12 each smokers and never-smokers were studied. There was no difference in pack years smoked between COPD patients and smokers (45 ± 25 vs 37 ± 19, p = 0.36), but α1ATD patients smoked significantly less (19 ± 11, p < 0.001 for both). By design, spirometry measures were lower in COPD and α1ATD-COPD patients compared to smokers and never-smokers. Aortic inflammation and stiffness were increased in COPD (TBR: 1.90 ± 0.38, aPWV: 9.9 ± 2.6 m/s) and α1ATD patients (TBR: 1.94 ± 0.43, aPWV: 9.5 ± 1.8 m/s) compared with smokers (TBR: 1.74 ± 0.30, aPWV: 7.8 ± 1.8 m/s, p < 0.05 all) and never-smokers (TBR: 1.71 ± 0.34, aPWV: 7.9 ± 1.7 m/s, p ≤ 0.05 all).

Conclusions: In this cross-sectional prospective study, novel findings were that both usual COPD and α1ATD-COPD patients have increased aortic inflammation and stiffness compared to smoking and never-smoking controls, regardless of smoking history. These findings suggest that the presence of COPD lung disease per se may be associated with adverse aortic wall changes, and aortic inflammation and stiffening are potential mechanisms mediating increased vascular risk observed in COPD patients.

Keywords: Aortic stiffness; Chronic obstructive pulmonary disease; Positron emission tomography; Vascular inflammation; α1 antitrypsin deficiency.

Publication types

  • Clinical Trial, Phase II
  • Observational Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aorta, Abdominal / diagnostic imaging*
  • Aorta, Abdominal / physiology
  • Aorta, Thoracic / diagnostic imaging*
  • Aorta, Thoracic / physiology
  • Cross-Sectional Studies
  • Female
  • Forced Expiratory Volume / physiology
  • Humans
  • Inflammation / diagnostic imaging
  • Inflammation / physiopathology
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Positron-Emission Tomography / trends
  • Prospective Studies
  • Pulmonary Disease, Chronic Obstructive / diagnostic imaging*
  • Pulmonary Disease, Chronic Obstructive / physiopathology
  • Risk Factors
  • Smoking / adverse effects
  • Smoking / physiopathology
  • Vascular Stiffness* / physiology