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. 2013 Sep 24;179(1):48–56. doi: 10.1093/aje/kwt208

Appendix Table 1.

Cross-sectional and Longitudinal Associations of C-Reactive Protein With Baseline Quartiles of Spirometry Measures in the European Prospective Investigation Into Cancer in Norfolk, 1993–2011

Quartile of Spirometry Measure Cross-sectional Association (n = 18,110)
 Longitudinal Association (n = 5,130)
Age- and Sex-adjusted
 Multivariable-adjusted
 Age- and Sex-adjusted
 Multivariable-adjusted
Mean Differencea 95% CI Mean Differencea 95% CI Annual Changeb 95% CI Annual Changeb 95% CI
All Participants
FEV1c
 1 0 Referent 0 Referent 0.02 0.02, 0.03 0.02 0.01, 0.03
 2 −0.21 −0.25, −0.16 −0.17 −0.21, −0.13 0.03 0.03, 0.04 0.03 0.02, 0.04
 3 −0.43 −0.48, −0.38 −0.32 −0.36, −0.27 0.04 0.04, 0.04 0.03 0.02, 0.04
 4 −0.73 −0.78, −0.67 −0.54 −0.59, −0.48 0.04 0.04, 0.05 0.03 0.02, 0.04
  P value <0.001 <0.001 <0.001 0.1
FVCd
 1 0 Referent 0 Referent 0.02 0.02, 0.03 0.02 0.01, 0.03
 2 −0.20 −0.24, −0.15 −0.14 −0.19, −0.10 0.04 0.03, 0.04 0.03 0.02, 0.04
 3 −0.36 −0.40, −0.31 −0.24 −0.29, −0.20 0.04 0.04, 0.04 0.03 0.02, 0.04
 4 −0.61 −0.67, −0.56 −0.43 −0.48, −0.37 0.04 0.04, 0.05 0.03 0.02, 0.04
  P value <0.001 <0.001 <0.001 0.07
Never Smokerse
FEV1c
 1 0 Referent 0 Referent 0.03 0.03, 0.04 0.02 0.00, 0.03
 2 −0.19 −0.26, −0.13 −0.17 −0.23, −0.11 0.04 0.03, 0.04 0.02 0.01, 0.04
 3 −0.36 −0.44, −0.29 −0.28 −0.34, −0.21 0.05 0.04, 0.05 0.03 0.02, 0.04
 4 −0.62 −0.71, −0.52 −0.44 −0.53, −0.35 0.05 0.05, 0.06 0.03 0.02, 0.05
  P value <0.001 <0.001 <0.001 0.004
FVCd
 1 0 Referent 0 Referent 0.03 0.02, 0.04 0.01 0.00, 0.03
 2 −0.17 −0.24, −0.11 −0.14 −0.20, −0.08 0.04 0.04, 0.05 0.03 0.01, 0.04
 3 −0.32 −0.39, −0.25 −0.21 −0.27, −0.14 0.05 0.04, 0.05 0.03 0.01, 0.04
 4 −0.50 −0.59, −0.42 −0.33 −0.41, −0.24 0.05 0.05, 0.06 0.03 0.01, 0.04
  P value <0.001 <0.001 <0.001 0.004

Abbreviations: CI, confidence interval; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity.

a Mean difference in loge-CRP levels between quartiles 2, 3, and 4 of spirometry measures and the lowest (reference) quartile. All analyses were adjusted for baseline covariates: age, sex, height, body mass index (weight in kilograms divided by height in meters squared), smoking status, physical activity level, alcohol intake, corticosteroid medication use, menopausal status, and hormone replacement therapy use.

b Annual change was calculated as an interaction of baseline FEV1 or FVC quartiles with time in participants who had at least 1 follow-up health examination. All regression models were adjusted for baseline age and sex. Multivariable models were additionally adjusted for height, body mass index, smoking status, physical activity level, alcohol intake, corticosteroid medication use, menopausal status, and hormone replacement therapy use, all of which were treated as time-varying variables.

c The ranges of values for each quartile of FEV1 were as follows: quartile 1: 11–198 mL; quartile 2: 199–243 mL; quartile 3: 244–295 mL; and quartile 4: 296–592 mL.

d The ranges of values for each quartile of FVC were as follows: quartile 1: 15–239 mL; quartile 2: 240–295 mL; quartile 3: 296–362 mL; and quartile 4: 363–738 mL.

e The number of never smokers available for analysis was 8,382 participants for the cross-sectional analysis and 2,852 participants for the longitudinal analysis.