High-sensitivity C-reactive protein and exercise-induced changes in subjects suspected of coronary artery disease

Abstract

Background

Inflammation plays a major role in the development of atherosclerosis. We wanted to investigate the effects of exercise on high-sensitivity (hs) C-reactive protein (CRP) in subjects who were suspected of having coronary artery disease (CAD).

Methods

Blood samples were obtained before, 5 minutes after, and 20 hours after an exercise test in 155 subjects who were suspected of CAD. Coronary anatomy was evaluated by computed tomography coronary angiography and/or coronary angiography.

Results

Median baseline hs-CRP was higher in subjects with ≥50% coronary artery lumen diameter stenosis (n=41), compared with non-CAD-subjects (n=114), 2.93 mg/L (interquartile range 1.03–5.06 mg/L) and 1.30 mg/L (interquartile range 0.76–2.74 mg/L), respectively, P=0.007. In multivariate analyses testing conventional risk factors, hs-CRP proved borderline significant, odds ratio =2.32, P=0.065. Adding baseline hs-CRP to the results of the exercise test did not improve the diagnostic evaluation. Baseline natural logarithm (Ln) hs-CRP was positively associated with body mass index and baseline Ln-transformed hs troponin T levels, and negatively associated with the daily life activity level. An increase in hs-CRP of 0.13 mg/L (interquartile range 0.05–0.24 mg/L) from baseline to 5 minutes after peak exercise was found (P<0.0001), but the increase was not associated with presence of CAD. From baseline to 20 hours after exercise, no increase in hs-CRP was found.

Conclusion

In conclusion, hs-CRP was not independently associated with CAD. Hs-CRP increased immediately as a response to the exercise, and the increase was modest and not associated with CAD. The results indicate that exercise has potential to cause unwanted variations in hs-CRP and that exercise prior to hs-CRP measurements in subjects included in epidemiological studies, therefore, should be avoided.

Keywords:

• inflammation
• stable angina pectoris
• atherosclerosis
• exercise testing

Acknowledgments

This study was supported by the following foundations; Danish Heart Foundation (10-04-R79-A2930-22577). Th Maigaards Eftf. Fru Lily Benthine Lunds Fond, Direktoer Kurt Boennelycke og hustru Fru Grethe Boennelyckes Fond, Fru Gudrun Elboth mindelegat, Jens Anker Andersen Fonden, Henry og Astrid Moellers Fond, Grosserer Chr. Andersen og hustru Ingeborg Ovidia Signe Andersen Legat, Beckett Fonden, Snedkermester Sophus Jacobsen og hustru Astrid Jacobsens Fond, Krista og Viggo Petersens Fond, Alfred Helsteds og Eli Moellers legat, Murermester Laurits Peter Christensen og hustru Kirsten Sigrid Christensens Fond, Arvid Nielssons Fond, Else og Mogens Wedell-Wedellsborg Fond, and Axel Muusfeldts Fond.

Disclosure

The authors report no conflicts of interest in this work.