[Blood coagulation in normotensives and hypertensives in relation to their body mass index].

UNLABELLED

BACKGROUND AND PERSPECTIVE: Various parameters of the coagulation cascade and fibrinolysis are important predictors of myocardial infarction and stroke, for which hypertension is a risk factor. It is unclear whether an elevated blood pressure by itself can produce activated clotting.

PATIENTS AND METHODS

Coagulation tests were done on overweight hypertensive (n=40); aged 49 +/- 8 years; group 3), overweight normotensives (n=19; aged 51 +/- 8 years; group 2) and normal-weight normotensives (n=20; aged 51 +/- 8; group 1).

RESULTS

Plasminogen-activator-inhibitor 1 (PAI-1), a measure of impaired fibrinolysis, was elevated in group 2 (20.5 +/- 11 U/ml; p < 0.001), compared with group 1 (11.6 +/- 6 U/ml), and was even higher in group 3 (27.5 +/- 9 U/ml; p < 0.05). Fibrinogen and factor VIII, parameters that promote clotting, were elevated in group 2 (360 +/- 61 mg/dl and 143 +/- 15 %, respectively; p < 0.001), and in group 3 (368 +/- 63 mg/dl and 146 +/- 18%; p < 0.001) compared to group 1 (304 +/- 40 mg/dl and 127 +/- 17%). Correspondingly, fibrin monometers, a measure of intravascular coagulation, were elevated in group 3 (p < 0.05) and partial thromboplastin time (PTT) decreased (p < 0.001). Pearson correlation showed a significant (p < 0.001) positive relationship between PAI-1 and body mass index (BMI) (0.539), triglycerides (0.512), blood pressure (0.388 to 0.534), fibrinogen (0.404, and a negative one with HDL-cholesterol (0.625). BMI also correlated with fibrinogen (0.509; p < 0.001) and factor VIII (0.337; p < 0.01).

CONCLUSIONS

Fibrinolysis and activated coagulation are reduced in hypertensive subjects: this favours the occurrence of myocardial infarction and stroke. In addition to the level of blood pressure, the extent of the changes are effected especially by BMI and metabolic risk factors.