Effects of physical training and its cessation on the hemostatic system of obese children.
BACKGROUND
Physical training can improve hemostatic function in adults, thereby reducing heart disease risk, but no information is available in children on whether physical training can enhance hemostatic function.


OBJECTIVE
The purpose of this investigation was to examine the effects of a physical training program on hemostatic variables in a biethnic group of obese children.


METHODS
Children were randomly assigned to 2 groups. Group 1 participated in physical training for 4 mo and then ceased physical training for 4 mo, whereas group 2 did no physical training for the first 4 mo and then participated in physical training for 4 mo. Plasma hemostatic variables [fibrinogen, plasminogen activator inhibitor 1 (PAI-1), and D-dimer) were measured at months 0, 4, and 8.


RESULTS
Analyses of variance revealed no significant group-by-time interactions for the hemostatic variables. When data from both groups were combined there was a significant decrease in D-dimer after 4 mo of physical training (P < 0.05). Factors explaining individual differences in responsiveness to the physical training revealed that individuals with greater percentage fat before physical training showed greater reductions in fibrinogen and D-dimer, and that blacks showed greater reductions in D-dimer than whites (P < 0.05). Stepwise multiple linear regression showed that only higher prephysical training concentrations of fibrinogen, PAI-1, and D-dimer explained significant proportions of the variation in changes in these variables.


CONCLUSIONS
In obese children, 4-mo periods of physical training did not lead to significant changes in hemostatic variables. Children with greater adiposity and concentrations of hemostatic factors before physical training showed greater reductions in hemostatic variables after physical training than did children with lesser values.
Ferguson
M A
MA
Georgia Prevention Institute, Department of Pediatrics and Physiology, Medical College of Georgia, Augusta 30912-3710, USA.
Gutin
B
B
Owens
S
S
Barbeau
P
P
Tracy
R P
RP
Litaker
M
M
D000704:Analysis of Variance; D000886:Anthropometry; D001777:Blood Coagulation; D002648:Child; D004734:Energy Metabolism; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005340:Fibrinogen / Q000032:analysis; D006801:Humans; D016014:Linear Models; D008297:Male; D009765:Obesity / Q000097:blood* / Q000208:ethnology; D010806:Physical Education and Training; D005082:Physical Exertion / Q000502:physiology*; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D011740:Pyrimidine Dimers; D044469:Racial Groups
D005338:Fibrin Fibrinogen Degradation Products; D017395:Plasminogen Activator Inhibitor 1; D011740:Pyrimidine Dimers; C036309:fibrin fragment D; D005340:Fibrinogen