Haemostatic alterations in overweight children: associations between metabolic syndrome, thrombin generation, and fibrinogen levels

Background: The metabolic syndrome (MetS) is associated with central obesity and leads to increased morbidity and mortality due to cardiovascular disease (CVD). Since obesity is associated with a hypercoagulable state, it has been speculated that hypercoagulation is linking MetS to CVD.

Methods: We prospectively examined 81 overweight children and 32 normal-weight children aged 10-16 years. We analyzed blood pressure, fasting lipids, glucose, insulin, fibrinogen, and thrombin generating test determining time to peak (TTPeak), peak, time preceding the thrombin burst (lag-time), and 'endogenous' thrombin potential (ETP).

Results: Overweight children demonstrated significantly higher fibrinogen levels (p<0.001), shorter lag-time (p<0.001), and TTPeak (p=0.038) compared to normal-weight children. Furthermore, ETP (p<0.001) and peak (p<0.001) were significantly higher in overweight than in normal-weight children. Fibrinogen and all parameters of the clotting test correlated significantly (p always <0.05) to body mass index (BMI) but not significantly to insulin resistance index HOMA-IR or occurrence of MetS in multiple linear backward regression analyses adjusted for age and gender.

Conclusions: The increased fibrinogen levels and the changes in the thrombin generation test points towards a haemostatic alteration in overweight children. The parameters of the clotting test were related to the degree of overweight but not to insulin resistance or occurrence of MetS questioning a direct association between MetS and the coagulation system. Longitudinal studies are needed to confirm these findings.