Few studies have investigated the association between COPD
and severity of airflow limitation and carotid wall thickening on
ultrasound (16–21). Consistent with our results, a study performedin vascular surgery patients detected an association between
COPD and carotid wall thickening (IMT >1.25 mm) independent
of age and smoking status (16). Frantz and coworkers (17)
recruited participants of a respiratory questionnaire survey and
observed a higher prevalence of COPD in subjects with than
without plaques (IMT >2 mm), although they could not confirm
that COPD was an independent predictor of carotid plaques. In
accordance with our lung function parameter results, an inverse
association between FEV1, FEV1/FVC, and internal carotid
IMT has been recently reported (18). Three other studies
also found that the severity of airflow limitation measured by
FEV1 was significantly associated with continuously increased
IMT (19–21). In line with these three studies, our populationbased
study performed in older subjects demonstrates a significant
association between severity of airflow limitation and carotid
wall thickening (IMT >2.5 mm). Although severity of airflow
limitation may not entirely reflect disease activity, it previously
correlated well with clinically important outcomes as hospitalizations
caused by exacerbations, cardiovascular comorbidity,
and mortality (22–25). Furthermore, our study adds to all previous
studies that the risk of carotid wall thickening further
increases when subjects with COPD have clinical symptoms of
dyspnea or chronic bronchitis, that plaques are more lipidrich
in subjects with COPD compared with control subjects,
and that lipid core plaques also relate to the severity of airflow
limitation