Inverse correlation between thyroid function and hemostatic markers for coronary heart disease in obese children and adolescents.

BACKGROUND

Childhood obesity may be associated with thyroid dysfunction. Both obesity and hypothyroidism are related to increased risk of coronary heart disease (CHD) in adults through high levels of serum lipids and/or hemostatic abnormalities.

OBJECTIVE

To investigate a possible relationship between thyroid function and hemostatic markers for CHD in obese children and adolescents.

STUDY

DESIGN

Thirty-nine obese children and adolescents were investigated for thyroid function and markers for CHD after overnight fast. Thyroid hormones were measured by radioimmunoassay. Factor VII coagulant activity (VIIc) and factor VIII coagulant activity (VIIIc) were determined using one stage clotting assays; fibrinogen was measured according to the method of Clauss; von Willebrand factor antigen (vWF-Ag), tissue type plasminogen activator antigen (tPA-Ag), and plasminogen activator inhibitor-1 antigen (PAI-1-Ag) were determined by ELISA.

RESULTS

We found a significant inverse correlation between fT4 and factor VIIc (r = -0.33, p = 0.03) and fibrinogen (r = -0.35, p = 0.02), which remained significant after adjustment for body fat mass. Factor VIIIc (r = -0.26, p = 0.066) and vWF-Ag (r = -0.28, p = 0.053) tended to be correlated negatively to fT4. fT4 did not correlate with tPA-Ag and PAI-1-Ag. fT3 was inversely related to factor VIIc (r = -0.3, p = 0.039), which was not independent of body fat mass, and showed a less impressive negative correlation with fibrinogen (r = -0.27, p = 0.058). fT3 did not correlate with vWF-Ag, tPA-Ag, or PAI-1-Ag. There was no relationship between TSH and the determined hemostatic markers.

CONCLUSION

Our study demonstrates a close relationship between thyroid function and hemostatic markers for CHD in obese children and adolescents and suggests that thyroid dysfunction is associated with an unfavorable hemostatic state even in pediatric patients.