Effect of marathon running on inflammatory and hemostatic markers.

Department of Medicine, McLean Hospital, Belmont, MA; Beth Israel Deaconess Medical Center, Boston, MA; Massachusetts General Hospital and Brigham and Women's Hospital, Boston, MA; Royal North Shore Hospital, Sydney, Australia; and Harvard Medical School, Boston, MA

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Although increasing levels of regular physical activity are incrementally cardioprotective (1,2), prolonged strenuous exercise such as marathon running may trigger acute myocardial infarction (3) (AMI) and sudden cardiac death (4,5). The mechanism of such events is not well understood but may be due to hemodynamic, vasoconstrictive and prothrombotic effects with disruption of unstable coronary plaques leading to acute coronary thrombosis (6,7). While several studies have demonstrated exercise-induced activation of both fibrinolysis and coagulation (8), the effect of marathon running on hemostatic balance has not been well studied. We therefore measured changes in C-reactive protein (CRP), vonWillebrand factor (vWF), D-dimer, fibrinogen, fibrinolytic activity, white blood cell (WBC) counts, and platelet activation in middle-aged runners before and alter the Boston Marathon. An imbalance in prothrombotic and fibrinolytic factors following strenuous physical exertion may transiently increase the risk for intrava scular including coronary thrombosis and trigger acute ischemic events.

Subjects were attendees at the prerace Scientific Symposia of the American Medical Athletic Association as entrants in the 100th to 105th Boston Athletic Association Marathons from 1966 to 2001 with a mean age of 47.6 years, who reported no smoking or known coronary heart disease by yearly questionnaire. Blood samples were drawn without stasis from an antecubital vein using a 21 gauge butterfly needle the morning before, within four hours following the race, and the next morning. Samples were drawn at the same time points for platelet studies in 2000 from subjects reporting no use of anti-inflammatory drugs in the prior two weeks and for complete blood counts in 2001. Whole blood was collected in 3.2% sodium citrate (9:1, vol/vol), centrifuged at 2500g for 20 minutes at 40C to obtain platelet-poor plasma for the measurement of CRP, vWF, D-dimer, fibrinolytic activity, and fibrinogen. Whole blood was similarly collected and processed in 15% (K3) ethylenediamine tetra acetic acid at a final concentration of 1mg /nil for determination of vWF. C-reactive protein and D-dimer levels were determined using commercially available enzymelinked immunosorbant assays by TintEliza Biopool and Diagnostica Stage, respectively. VonWillebrand factor was determined by an enzyme-linked immunoassay procedure described by Penny et al(9), fibrinolytic activity by a fibrin plate assay as described by Brackman et al(10), and fibrinogen levels by the Clauss method(11). Whole blood for platelet aggregation studies was collected in 3.2% sodium citrate (9:1, vol/vol), centrifuged within one hour of collection at 125 g for 10 minutes at room temperature to obtain platelet-rich plasma for testing after 30 minutes. Platelet aggregation testing was performed using a platelet aggregometer (PACKS-4 Platelet Aggregation Chromogenic Kinetic System, Helena Laboratories) in response to 10 ug/mL collagen, 10 uM adenosine diphosphate, 10 uM epinephrine, 500 ug/mL arachdonate, and 1.5 mg/mL ristocetin. Complete blood counts were performed in an ADVIA 120 automated hematology autoanalyzer. Total and high density lipoprotein cholesterol were measured using an Abbot Diagnostics ABA-200 biochromatic analyzer and Abbot A-Gent enzymatic reagents. Creatinine, blood urea nitrogen and electrolytes were determined using a Hitachi 917 chemistry autoanalyzer. The student-paired t-test (Sigma Stat, Jandel Scientific) was used to compare results from pooled data before and after the 1996 and 1997 marathons as there were no significant differences in baseline values between the two races.

Comparing pre-race values to within four hours post-race in 55 finishers 1996-97, marathon running resulted in a two-fold or greater increase in CRP (343 + 611 ng/ml to 762 + 973 ng/ml [p < 0.001]), vWF (109 + 47 % to 233 + 65 % [p < 0.001]), D-dimer (177 + 137 ng/ml to 529 + 279 ng/ml [p < 0.001]), and fibrinolytic activity (75 + 48 mm2 to 213 + 95 mm2 [p < 0.001]), while fibrinogen levels decreased (278 + 52 mg/dl to 260 + 45 mg/dl [p < 0.001] (see Table 1). Comparing pre-race specimens to within four hours after the marathon in 32 runners in 2001, WBC and platelet counts increased (5.5 + 0.2 th/cmm to 17.4 + 1.5 th/cmm [p < 0.005]) and 226 + 26th/cmm to 253 + 27 th/cmm [p<0.05]) respectively, while the hematocrit and hemoglobin levels were unchanged. Platelet studies showed a shortened lag time to aggregation with collagen and an increase with epinephrine (n = 5, 2000).

When comparing prerace values to the morning following the race in 13 runners in 1997, vWF and D-Dimer remained increased (108 + 36% to 190 + 39% [p <0.001] and 168 + 119 ng/ml to 376 + 269 ng/ml [p< 0.004] respectively), (see Figure 1) with no difference in fibrinolytic activity. WBC counts remained elevated at 9.4 + 1.2 th/cmm (p = 0.001, n = 9, 2001) with no change in platelet counts but a persistantly shortened lag time to platelet aggregation with collagen and increase with epinephrine. Hematocrit and red blood cell counts decreased within 24 hours post-race (44.8 + 0.8% to 43.6 + 0.1% [p<0.05] and 4.94 + 0.1 mil/cmm to 4.66 + 0.10 mil/cmm [p <0.05] respectively) with no change in hemoglobin concentration. The blood urea nitrogen increased from 15 + 3.5 mg/dl to 19 + 3.5 mg/dl (p = 0.001) with no change in serum creatinine or electrolytes. Total and high density lipoprotein cholesterol were 204 + 9 mg/dl and 50 + 3 mg/dl respectively, remaining unchanged post-race. There were no acute cardiac events repo rted over five years among these runners most of whom completed subsequent marathons with comparable finishing times averaging four hours and 20 minutes.

Episodes of strenuous physical exercise may increase the relative risk for AMI (3) and sudden cardiac death as reported in one in 50,000 marathon runners during or within 24 hours after competition (4), representing a five-fold increase over the one per million person-hours expected in a general population without known cardiac disease(12). Within four hours after competition, both prothrombotic factors and fibrinolytic activity were increased in these middle-aged marathon runners, suggesting that hemostatic balance was initially preserved (8). The two-fold increase in fibrinolytic activity may be due in part to release of tissue plasminogen activator from endothelial cells and to a circadian rhythm with higher levels in the afternoon than the morning (13,14).

Elevated WBC counts, CRP, and vWF may be due in part to an acute inflammatory response to exertional rhabdomyolysis with release of vWF from the endothelium due to shear stress and distention of the vascular bed from enhanced blood flow (15). The concurrent decrease in fibrinogen and increase in D-dimer with platelet activation are consistent with subclinical intravascular coagulation occurring within four hours after the race. A concurrent increase in blood urea nitrogen suggests some degree of post-race hemoconcentration although serum creatinine, hematocrit, hemoglobin, and red blood cell counts remained unchanged.

The morning following the race, fibrinolytic activity returned to baseline while WBC counts, vWF, and t)-dimer remained increased with on-going platelet activation consistent with a secondary hemostatic imbalance. A modest decrease in hematocrit and red blood cell counts within 24 hours after the race suggests hemolysis although serum haptoglobin levels were not measured.

In contrast to normal values for traditional cardiovascular risk factors including total and HDL cholesterol, there was a post-race increase in novel inflammatory markers of cardiac risk in these middle-aged runners as predictive of poor prognosis in patients with acute coronary syndromes(16,17,18,19). There was no apparent increase in cardiac events over five years among these runners who also showed a 5.6-fold post-race increase in cTnI by a high-sensitivity method(20). As these findings may not be extrapolated to other subjects, further studies of novel markers of cardiovascular risk in younger and elite athletes are indicated as possible triggers for acute cardiac events during exercise.

Middle-aged male marathon runners showed an increase in inflammatory and prothrombotic markers with platelet activation within four hours after competition balanced by a two-fold rise in fibrinolytic activity. Selective persistence of procoagulant effects the morning after the race indicates a secondary hemostatic imbalance which may trigger acute cardiac events associated with strenuous exercise.

Table 1

Effect of Marathon Running on Inflammatory Markers and Hemostatic
Factors

                                     Before      <4 hours

C-Reactive Protein (ng/ml)          343 + 611   762 + 973 *
vonWillebrand Factor (%)            109 + 47    233 + 65 *
D-Dimer (ng/ml)                     177 + 137   529 + 279 *
Fibrinolytic Activity ([mm.sup.2])   75 + 48    213 + 95 *
Fibrinogen (mg/dl)                  278 + 52    260 + 45 *
White Blood Cell Count
 (th/[cmm.sup.3])                   5.5 + 0.2  17.4 + 1.5 *

Compared to pre-race values, there were 2-fold or greater increases
within 4-hours post-race in WBC counts (n=32, 2001), CRP, vWF, D-dimer,
and fibrinolytic activity with a decrease in fibrinogen levels (n=55,
1996-1997).

* (p = 0.001)

TABLE 1

Effect of Marathon Running on Inflammatory Markers and Hemostatic
Factors

                                             Before
                                            the Race

C-reactive protein (ng/ml)              343 [+ or -] 611
von Willebrand factor (%)               109 [+ or -] 47
D-dimer (ng/ml)                         177 [+ or -] 137
Fibrinolytic activity ([mm.sup.2])       75 [+ or -] 48
Fibrinogen (mg/dl)                      278 [+ or -] 52
White blood cell count (th/[mm.sup.3])  5.5 [+ or -] 0.2

                                            < 4 h After
                                             the Race

C-reactive protein (ng/ml)               762 [+ or -] 973 *
von Willebrand factor (%)                233 [+ or -] 65 *
D-dimer (ng/ml)                          529 [+ or -] 279 *
Fibrinolytic activity ([mm.sup.2])       213 [+ or -] 95 *
Fibrinogen (mg/dl)                       260 [+ or -] 45 *
White blood cell count (th/[mm.sup.3])  17.4 [+ or -] 1.5 *

* p = 0.001.

Compared with prerace values, there were twofold or greater increases
within 4 hours after the race in WBC counts (n = 32, 2001), CRP, vWF,
D-dimer, and fibrinolytic activity, with a decrease in fibrinogen levels
(n = 55, 1996 to 1997).

FIGURE 1

Effect of marathon running on hemostatic markers: compared with prerace
values, vWF, D-dimer, and WBC counts were increased within 4 and 24
hours after the race.

                  1997 Boston Marathon  1997 Boston Marathon
                        (N = 13)              (N = 13)

                          vWF                 D-dimer

Pre-Race            109 [+ or -] 47       177 [+ or -] 137
4 hrs Post Race     233 [+ or -] 65 *     529 [+ or -] 279 *
24 hrs Post Race    190 [+ or -] 36 *     376 [+ or -] 269 *

                  2001 Boston Marathon
                        (N = 7)

                          WBC

Pre-Race            5.5 [+ or -] 0.2
4 hrs Post Race    17.4 [+ or -] 1.5 *
24 hrs Post Race    9.4 [+ or -] 1.2 *

* p <0.005.

Note: Table made from bar graph

References

(1.) Schnohr-P, Parner J, Lange P. Mortality in joggers: population based study of 4658 men. BMJ 2000; 321:602-603.

(2.) Sesso HD, Paffenbarger RS, Lee IM. Physical activity and coronary heart disease in men. The Harvard Alumni Health Study. Circulation 2000; 102(9):975-980.

(3.) Mittleman MA, Maclure M, Tofler GH, Sherwood JB, Goldberg RJ, Muller JE. Triggering of acute myocardial infarction by heavy physical exertion: protection against triggering by regular exertion. N Engl J Med 1993; 329:1677-1683.

(4.) Maron BJ, Poliac LC, Roberts WC. Risk of sudden cardiac death associated with marathon running. J Am coll Cardiol 1996; 28(2):428-431.

(5.) Albert CM, Mittleman MA, Chae CU, Lee I-M, Hennekens CH, Manson JE. Triggering of sudden death by vigorous exertion. N Engl Med 2000;43:1355-1361.

(6.) Burke AP, Farb A, Malcom GT, Liang Y, Smialek JE, virmani R. Plaque rupture and sudden death related to exertion in men with coronary artery disease. JAMA 1999;281:921-926.

(7.) Giri S, Thompson PD, Kiernan FJ, Clive J, Fram DB, Mitchel JF, Hirst J, McKay RG, Waters DD. Clinical and angiograpitic characteristics of exertion-related acute myocardial infarction. JAMA 1999; 282:1731-1736.

(8.) Bartsch P, Welsch B, Albert M, Friedmann B, Levi M, Krulthof EK. Balanced activation of coagulation and fibrinolysis after a 2-h triathlon. J Am Coll Sports Med 1995;1465-1470.

(9.) Penny WF, Weinstein M, Salzman EQ, Ware JA. Correlation of circulating vonWillebrand factor levels with cardiovascular hemodynamics. Circulation 1991;83:1630-1636.

(10.) Brackman K. A standardized fibrin plate method and librinolytic assay of plasminogen, in Schelma Hokema (eds): Fibrinolysis. Amsterdam 1967: 1-124.

(11.) Clauss A. Gerinnungspbysiologische Schtnellmethode zur Bestimmung des Fibinogens. Acta Hematol 1957; 17:237-247.

(12.) Muller JE. Circadian variation and triggering of acute coronary events. Am Heart J 1999; 137:51-S8.

(13.) Kapiotis S, Jilma B, Quehenberger P, Ruzicka K, Handler S, Speiser W. Morning hypercoagulability and Hypofibrinolysis. Diurnal variations in circulating activated factor VII, prothrombin fragment F1+2, and plasmin-plasmin inhibitor complex. circulation 1997; 96(1):19-21.

(14.) Bremmer W, Fraser MD, Sothern RB, Kanabrocld EL, Ryan M, McCormick JB, Dawson S, Connors ES, Rothschild R, Third JL, Vahed S, Nemchausky BM, Shirazi P, Olwin JH. Relation between circadian patterns in levels of circulating lipoprotein (a), fibrinogen, platelets, and related lipid variables in men. Am Heart J 2000; 139:164-173.

(15.) Lin x, El-Sayed MS, Waterhoue J, Reilly T. Activation and disturbance of blood haemostatsis following strenuous physical exercise. Int J Sports Mcd 1999; 20: 149-153.

(16.) Bartsch P. Platelet activation with exercise and risk of cardiac events. Lancet 1999; 354-1747-1748.

(17.) Morrow DA, Rifal N, Antman EM, Weiner DL, McCabe CH, Cannon CP, Braunwald B. C-reactive protein is a potent predictor of mortality independently of and in combination with troponin T in acute coronary syndromes: a TIMI 11A substudy. Thombolysis in myocardial infarction. J Am Coll Cardiol 1998; 31:1460-1465.

(18.) Montalescot G, Philipee F, Ankri A, Vicaut B, Bearez B, Poulard JE, Carrie D, Flammang D, Dutoit A, Carayon A, Jardel C, Citevrot M, Bastard JP, Bigoozi F, Thomas D. Early increase of von Willebrand factor predicts adverse outcome in unstable coronary artery disease: beneficial effects of enoxaparin. Circulation 1998; 98:294-299.

(19.) Cannon CP, McCabe CH, Wilcox RG, Bentley JH, Braunwald E. Association of white blood cell count with increased mortality in acute myocardial infarction and unstable angina pectoris. Am J Cardiol 2001; 87:636-639.

(20.) Siegel AJ, Lewandrowski EL, Chun KZ Sholar MB, Fiscitman AJ, Lewandrowski KB. Changes in cardiac markers including B-natriuretic peptide in runners following tie Boston marathon. Am, J Cardiol 2001; 88:920-923.

"Reprinted from The American Journal of Cardiology Vol. 88, pp. 920-923, Copyright 2001, with permission from Excerpia Medica, Inc."

Contents in Brief: Middle-aged male marathon runners showed an increase in inflammatory and prothrombotic markers with platelet activation within 4 hours after competition balanced by a 2-fold rise in fibrinolytic activity. Selective persistence of procoagulant effects the morning after the race indicates a secondary hemostatic imbalance which may trigger acute cardiac events associated with strenuous exercise.

Address correspondence and reprint requests to:

Arthur J. Siegel, M.D.

McLean Hospital, Department of Internal Medicine

115 Mill Street, Belmont, MA 02478

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