The cardiovascular risk factor, soluble CD40 ligand (CD154), but not soluble CD40 is lowered by ultra-endurance exercise in athletes.
BACKGROUND
Soluble CD40 ligand (sCD40L) is a powerful marker of cardiovascular risk. Exercise is known to decrease cardiovascular risk, but the impact of ultra-endurance exercise on sCD40L responses is unknown.


OBJECTIVE
To examine the relationship between ultra-endurance exercise in trained athletes and levels of sCD40L and its natural ligand sCD40.


METHODS
Control-trial, crossover design, exercise intervention study of sCD40L and sCD40 levels.


METHODS
Outdoor exercise and laboratory testing, single centre study, School of Physical Education, University of Otago, New Zealand.


METHODS
Nine trained ultra-endurance athletes.


METHODS
Athletes exercised (cycled and jogged) for 17 of 24 h. Venous blood was sampled at baseline and serially throughout exercise and 24 and 48 h after exercise. The athletes completed a 24 h control trial on a separate occasion, in randomised order.


METHODS
Mean levels of sCD40L and sCD40 during exercise and rest with 95% CIs.


RESULTS
sCD40L levels dropped steadily from baseline (median 4128 pg/ml) to a measured nadir at 24 h following exercise (median 1409 pg/ml) (p=0.01). The levels had started to rise again by 48 h after exercise. When measured as a group, sCD40L levels remained constant during a control rest period. sCD40 levels remained constant on both exercise and control days.


CONCLUSIONS
Ultra-endurance exercise lowers the levels of the cardiovascular risk marker sCD40L in athletes. These results raise the possibility that exercise-induced changes in sCD40L may provide one of the mechanisms by which exercise lowers cardiovascular risk.
Geertsema
Liesel
L
Australasian College of Sports Medicine, Christchurch, New Zealand. liesel.geertsema@gmail.com
Lucas
Samuel J E
SJ
Cotter
James D
JD
Hock
Barry
B
McKenzie
Judy
J
Fernyhough
Liam J
LJ
D000328:Adult; D001642:Bicycling / Q000502:physiology; D015415:Biomarkers / Q000378:metabolism; D023201:CD40 Ligand / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000097:blood / Q000517:prevention & control*; D018592:Cross-Over Studies; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007590:Jogging / Q000502:physiology; D008297:Male; D012307:Risk Factors; D013177:Sports / Q000502:physiology*
D015415:Biomarkers; D023201:CD40 Ligand