Reduction of the Plasma Concentration of C-Reactive Protein Following Nine Months of Endurance Training

An intense physical exercise induces an inflammatory reaction as demonstrated by the delayed increase in blood of acute phase proteins and among them of C-reactive protein (CRP). There is also evidence for a diminished acute phase reaction due to regular exercise suggesting a suppression of the inflammatory response through training. With this background CRP was measured by a sensitive enzyme immunoassay under resting conditions before and after 9 months of training in 14 subjects preparing for a marathon with the aim of studying the effect of training on the base-line CRP concentration. The mean distance run per week increased significantly from 31 ± 9 km at the beginning to 53 ± 15 km after 8 months of training (p < 0.01). The aerobic capacity rose significantly after training as demonstrated by the increase of running velocity during a maximal treadmill test from 3.82 ± 0.29 m/s pre-training to 4.17 ± 0.17 m/s post-training at a blood lactate concentration of 4 mmol/L (p < 0.01). In 10 of 12 runners base-line CRP was diminished after training in spite of a continuous increase of training intensity. The CRP median fell from 1.19 mg/L before to 0.82 mg/L after training (p < 0.05). Since intense physical exercise is known to be associated with an inflammatory reaction of muscles and tendons, the CRP decrease was unexpected. In 2 subjects the CRP concentration rose markedly because of a borrelia infection and a knee injury, respectively. These values were caused by a pathological condition and were not considered for the statistical evaluation. In 10 non-training control subjects the CRP median did not change significantly during the same 9 months period. The decrease of the CRP base-line concentration after training suggests that intensive regular exercise has a systemic anti-inflammatory effect. This is of particular interest with regard to several recent reports confering on the concentration of CRP in plasma a predictive value for the risk of cardiac infarction, venous thrombosis or stroke.

Key words:

C-reactive protein - CRP - training - physical exercise - CHD - inflammation

References

• 1 Bruunsgaard H, Galbo H, Halkjaer-Kristensen J, Johansen T L, MacLean D A, Pedersen B K. Exercise-induced increase in serum interleukin-6 in humans is related to muscle injury.  J Physiol. 1997;  499 833-841
• 2 Criswell D, Powers S, Dodd S, Lawler J, Edwards W, Renshler K, Grinton S. High intensity training-induced changes in skeletal muscle antioxidant enzyme activity.  Med Sci Sports Exerc. 1993;  25 1135-1140
• 3 Danesh J, Collins R, Appleby P, Peto R. Association of fibrinogen, C-reactive protein, albumin, or leucocyte count with coronary heart disease: meta-analysis of prospective studies.  JAMA. 1998;  279 1477-1482
• 4 Dufaux B, Ilsemann K, Assmann G. Competitive enzyme immunoassay for apolipoprotein AII.  J Clin Chem Clin Biochem. 1983;  21 39-43
• 5 Dufaux B, Order U, Greyer H, Hollmann W. C-reactive protein serum concentrations in well-trained athletes.  Int J Sports Med. 1984;  5 102-106
• 6 Evelo C TA, Palmen N GM, Artur Y, Janssen G ME. Changes in blood glutathione concentrations, and in erythrocyte glutathione reductase and glutathione S-transferase activity after running training and after participation in contests.  Eur J Appl Physiol. 1992;  64 354-358
• 7 Heck H, Mader A, Hess G, Mucke S, Muller R, Hollmann W. Justification of the 4 mmol/l lactate threshold.  Int J Sports Med. 1985;  6 117-130
• 8 Itoh H, Ohkuwa T, Yamamoto T, Sato Y, Miyamura M, Naoi M. Effects of endurance physical training and hydroxyl radical generation in rat tissues.  Life Sci. 1998;  63 1921-1929
• 9 Kuller L H, Tracy R P, Shaten J, Meilahn E N. Relation of C-reactive protein and coronary heart disease in the MRFIT nested case-control study.  Am J Epidemiol. 1996;  144 537-547
• 10 Laughlin M H, Simpson T, Sexton W L, Brown O R, Smith J K, Korthuis R J. Skeletal muscle oxidative capacity, antioxidant enzymes, and muscle training.  J Appl Physiol. 1990;  68 2337-2343
• 11 Leeuwenburgh C, Fiebig R, Chandwaney R, Ji L L. Aging and exercise training in skeletal muscle: responses of glutathione and antioxidant enzyme systems.  Am J Physiol. 1994;  267 445
• 12 Liesen H, Dufaux B, Hollmann W. Modifications of serum glycoproteins during the days following prolonged physical exercise and the influence of physical training.  Eur J Appl Physiol. 1977;  37 243-254
• 13 Ridker P M, Cushman M, Stampfer M J, Tracy R P, Hennekens C H. Inflammation, aspirin, and the risk of cardiovascular disease in apparently healthy men.  N Engl J Med. 1997;  336 973-979
• 14 Tessier F, Hida H, Favier A, Marconnet P. Muscle GSH-Px activity after prolonged exercise, training, and selenium supplementation.  Bio Trace Elem Res. 1995;  47 279-285
• 15 Tisi P V, Hulse M, Chulakadabba A, Gosling P, Shearman C P. Exercise training for intermittent claudication: does it adversely affect biochemical markers of the exercise-induced inflammatory response?.  Eur J Vasc Endovasc Surg. 1997;  14 344-350