Systemic inflammation in young adults is associated with abnormal lung function in middle age.
BACKGROUND
Systemic inflammation is associated with reduced lung function in both healthy individuals and those with chronic obstructive pulmonary disease (COPD). Whether systemic inflammation in healthy young adults is associated with future impairment in lung health is uncertain.


RESULTS
We evaluated the association between plasma fibrinogen and C-reactive protein (CRP) in young adults and lung function in the Coronary Artery Risk Development in Young Adults cohort study. Higher year 7 fibrinogen was associated with greater loss of forced vital capacity (FVC) between years 5 and 20 (439 mL in quartile 4 vs. 398 mL in quartile 1, P<0.001) and forced expiratory volume in 1 second (FEV(1)) (487 mL in quartile 4 vs. 446 mL in quartile 1, P<0.001) independent of cigarette smoking, body habitus, baseline lung function and demographic factors. Higher year 7 CRP was also associated with both greater loss of FVC (455 mL in quartile 4 vs. 390 mL in quartile 1, P<0.001) and FEV(1) (491 mL in quartile 4 vs. 442 mL in quartile 1, P = 0.001). Higher year 7 fibrinogen and CRP were associated with abnormal FVC at year 20 (odds ratio (OR) per standard deviation 1.51 (95% confidence interval (CI): 1.30-1.75) for fibrinogen and 1.35 (95% CI: 1.14-1.59) for CRP). Higher year 5 fibrinogen was additionally associated with abnormal FEV(1). A positive interaction was observed between pack-years cigarette smoking and year 7 CRP for the COPD endpoint, and among participants with greater than 10 pack-years of cigarette exposure, year 7 CRP was associated with greater odds of COPD at year 20 (OR per standard deviation 1.53 (95% CI: 1.08-2.16).


CONCLUSIONS
Systemic inflammation in young adults is associated with abnormal lung function in middle age. In particular, elevated CRP may identify vulnerability to COPD among individuals who smoke.


BACKGROUND
ClinicalTrials.gov NCT00005130.
Kalhan
Ravi
R
Asthma-Chronic Obstructive Pulmonary Disease Program, Division of Pulmonary and Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America. r-kalhan@northwestern.edu
Tran
Betty T
BT
Colangelo
Laura A
LA
Rosenberg
Sharon R
SR
Liu
Kiang
K
Thyagarajan
Bharat
B
Jacobs
David R
DR
Smith
Lewis J
LJ
D000328:Adult; D002097:C-Reactive Protein / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D007249:Inflammation / Q000378:metabolism* / Q000503:physiopathology*; D016015:Logistic Models; D008168:Lung / Q000503:physiopathology*; D008297:Male; D015999:Multivariate Analysis; D012307:Risk Factors; D013147:Spirometry; D013997:Time Factors; D014797:Vital Capacity / Q000502:physiology
D005340:Fibrinogen; D002097:C-Reactive Protein