title: Atherosclerotic plaques in the internal carotid artery and associations with lung function assessed by different methods.
abstract: BACKGROUND
  Previous studies on associations between reduced lung function and cardiovascular disease (CVD) have mainly been based on forced expiratory volume in 1-s (FEV(1) ) and vital capacity (VC). This study examined potential associations between five different lung function variables and plaques in the internal carotid artery (ICA).
  
  
  METHODS
  Subjects (n = 450) from a previous population-based respiratory questionnaire survey [current smokers without lower respiratory symptoms, subjects with a self-reported diagnosis of chronic obstructive pulmonary disease (COPD) and never-smokers without lower respiratory symptoms] were examined using spirometry, body plethysmography and measurements of diffusing capacity for CO (D(L,CO) ). Plaques in the ICA were assessed by ultrasonography.
  
  
  RESULTS
  Two hundred and twenty subjects were current smokers, 139 ex-smokers and 89 never-smokers. COPD was diagnosed in 130 subjects (GOLD criteria). Plaques in the ICA were present in 231 subjects (52%). General linear analysis with adjustment for established risk factors for atherosclerosis, including C-reactive protein, showed that D(L,CO) was lower [77.4% versus 83.7% of predicted normal (PN), P = 0.014] and residual volume (RV) was higher (110.3% versus 104.8% of PN, P = 0.020) in subjects with than without plaques in the ICA. This analysis did not show any statistically significant association between plaques and FEV(1) or VC.
  
  
  CONCLUSIONS
  The occurrence of plaques in the ICA was associated with low D(L,CO) and high RV, but not significantly with FEV(1) or COPD status. The results suggest that the relationships between reduced lung function, COPD and CVD are complex and not only linked to bronchial obstruction and low-grade systemic inflammation.
authors.affiliation: Clinical Physiology and Nuclear Medicine unit, Department of Clinical Sciences, Lund University, Malmö, Sweden. sophia.frantz@med.lu.se
authors.forename: Sophia
authors.initials: S
authors.lastname: Frantz
authors.forename: Ulf
authors.initials: U
authors.lastname: Nihlén
authors.forename: Magnus
authors.initials: M
authors.lastname: Dencker
authors.forename: Gunnar
authors.initials: G
authors.lastname: Engström
authors.forename: Claes-Göran
authors.initials: CG
authors.lastname: Löfdahl
authors.forename: Per
authors.initials: P
authors.lastname: Wollmer
mesh_terms: D000368:Aged; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008168:Lung / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000503:physiopathology; D010993:Plethysmography, Whole Body; D011237:Predictive Value of Tests; D011653:Pulmonary Diffusing Capacity; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D012907:Smoking / Q000453:epidemiology; D013147:Spirometry; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D014463:Ultrasonography; D014797:Vital Capacity