Effects of exercise training on 5 inflammatory markers associated with cardiovascular risk.
BACKGROUND
Cross-sectional studies suggest that regular exercise has anti-inflammatory effects, leading to lower levels of several proatherogenic inflammatory markers. However, this has yet to be confirmed by randomized prospective trials. We performed a randomized controlled trial to assess whether exercise training decreases levels of 5 inflammatory markers linked to future cardiovascular risk: white blood cell count, fibrinogen, C-reactive protein, soluble intercellular adhesion molecule 1, and soluble CD40 ligand.


METHODS
One hundred fifty-two healthy female smokers were randomized to either 12 weeks of exercise training or health education as part of a smoking cessation program. Smoking was held steady for the first 6 weeks, and thereafter, smoking cessation was actively attempted. One hundred four participants completed 6 weeks, and 88 completed 12 weeks. Fitness and circulating inflammatory marker levels were measured at baseline, 6 weeks, and 12 weeks. To avoid potential confounding from changes in smoking exposure during the second 6 weeks of the trial, the primary end point was change in inflammatory marker levels from baseline to 6 weeks. Change in inflammatory markers from baseline to 12 weeks was a secondary end point.


RESULTS
At baseline, greater physical fitness was associated with lower white blood cell, fibrinogen, and C-reactive protein levels, but these associations were not statistically significant after adjusting for body mass index (P > .1 for all). Fitness improved significantly in the exercise group at both 6 and 12 weeks. However, there were no differences in levels of any inflammatory marker between the exercise and control groups at either 6 weeks (primary end point) or 12 weeks (secondary end point) (P > .05 for all comparisons).


CONCLUSIONS
In female smokers, baseline associations between fitness and inflammatory markers were largely attributable to differences in body fat; regular exercise did not reduce levels of any of the inflammatory markers studied despite a significant improvement in fitness at both 6 and 12 weeks.
Hammett
Christopher J K
CJ
Green Lane Cardiovascular Service, Auckland City Hospital, Auckland, New Zealand.
Prapavessis
Harry
H
Baldi
J Chris
JC
Varo
Nerea
N
Schoenbeck
Uwe
U
Ameratunga
Rohan
R
French
John K
JK
White
Harvey D
HD
Stewart
Ralph A H
RA
D000328:Adult; D015415:Biomarkers / Q000097:blood*; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D023201:CD40 Ligand / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006266:Health Education; D006304:Health Status; D006801:Humans; D007249:Inflammation / Q000097:blood*; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D007958:Leukocyte Count; D010809:Physical Fitness; D012044:Regression Analysis; D012307:Risk Factors; D012907:Smoking / Q000097:blood*; D016540:Smoking Cessation; D018709:Statistics, Nonparametric; D013997:Time Factors
D015415:Biomarkers; D018799:Intercellular Adhesion Molecule-1; D023201:CD40 Ligand; D005340:Fibrinogen; D002097:C-Reactive Protein