Impact of smoking cessation and lifetime exposure on c-reactive protein

Hastie, C.E., Haw, S. and Pell, J.P. (2008) Impact of smoking cessation and lifetime exposure on c-reactive protein. Nicotine and Tobacco Research, 10(4), pp. 637-642. (doi: 10.1080/14622200801978722)

Abstract

C-reactive protein (CRP) levels predict coronary heart disease (CHD) risk. Levels are raised among smokers, but the effect of smoking cessation is unclear. Exposure to secondhand smoke (SHS) may be a confounder. Lifetime smoking exposure may have a dose effect on CRP among smokers, but it is unclear if this persists after cessation. We analyzed cross-sectional data on 4,072 adults recruited to a Scotland-wide population health survey who did not have CHD and were not on nicotine replacement therapy. CRP fell with time from cessation but was still raised up to 5 years after adjustment for case-mix (<i>p</i><.001). SHS exposure was greater among ex-smokers than never-smokers (median cotinine 0.5ng/ml vs. 0.4ng/ml, <i>p</i><.001) but did not explain the difference. Among smokers, there was a dose relationship between pack years and CRP on both univariate, <i>F</i>(4,1279)=31.841, <i>p</i><.001, and multivariate, <i>F</i>(4,1085)=3.499, <i>p</i>=.008, analysis. Among ex-smokers there was also a dose relationship between pack-years and CRP, <i>F</i>(4,751)=14.108, <i>p</i><.001, which was independent of time from cessation and case-mix, <i>F</i>(4,466)=3.744, <i>p</i>=.005. That CRP does not fall to normal levels immediately and that lifetime smoking exposure continues to impact on CRP levels post cessation suggest that CRP is not raised as a direct effect of cigarette smoke but rather via a secondary mechanism, such as tissue damage causing an inflammatory stimulus. Our results reinforce the need to encourage smoking cessation as early as possible.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hastie, Dr Claire and Pell, Professor Jill
• Authors: Hastie, C.E., Haw, S., and Pell, J.P.
• Subjects: R Medicine > RA Public aspects of medicine > RA0421 Public health. Hygiene. Preventive Medicine; R Medicine > RA Public aspects of medicine
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Public Health; College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Centre for Population and Health Sciences
• Journal Name: Nicotine and Tobacco Research
• ISSN: 1469-994X