Table 1

Characteristics of participants

Copenhagen City Heart StudyCopenhagen General Population Study
No eventCOPD spirometrically definedCOPD hospitalisationNo eventCOPD spirometrically definedCOPD hospitalisation
Women/men4221/3344845/735590/49516890/146401517/1575658/577
Age, years42 (32–52)49 (42–56)50 (44–55)57 (47–66)67 (57–74)68 (60–75)
Never smokers, %28125542919
Ex-smokers, %18129293241
Current smokers, %547686173940
Pack years5.0 (0–18)18 (8.8–30)23 (14–34)2.0 (0–18)19 (2.6–40)28 (5.7–45)
Body mass index, kg/m224 (22–26)24 (22–27)24 (22–27)26 (23–29)25 (23–28)26 (23–29)
Plasma CRP1.6 (1.1–2.7)1.9 (1.3–3.7)2.4 (1.5–5.0)1.5 (1.0–2.6)2.0 (1.2–4.4)2.5 (1.3–5.4)
 Minimum–maximum0.1–1030.1–1640.1–1030.1–3300.1–1220.1–71
FEV1, % predicted94 (85–104)78 (68–89)80 (67–93)92 (83–101)65 (55–73)62 (48–79)
FVC, % predicted93 (84–104)88 (77–97)85 (75–97)93 (84–102)80 (70–89)75 (62–88)
FEV1/FVC0.83 (0.78–0.87)0.74 (0.67–0.81)0.76 (0.70–0.83)0.79 (0.75–0.83)0.64 (0.58–0.67)0.66 (0.56–0.74)
  • Values are median (IQR) or percentage. Values for the Copenhagen City Heart Study are pre-outcome values taken prior to the development of COPD. COPD spirometrically defined=FEV1/FVC<0.7 and FEV1<80% of predicted, excluding asthmatics. COPD hospitalisation=ICD8:491–492; ICD10:J41–J44. We used the Copenhagen City Heart Study to test question 1 (CRP level is associated with COPD risk) and question 3 (CRP genotype is associated with COPD risk), and the Copenhagen General Population Study to test question 2 (CRP genotype is associated with CRP level) and retest question 3.