Blood pressure in haemophilia and its relation to clotting factor usage

Abstract Background Patients with haemophilia have a higher prevalence of hypertension than the general population that cannot be explained by traditional cardiovascular risk factors such as age, race, diabetes or obesity. Patients with severe haemophilia, who are on clotting factor prophylaxis, have a higher prevalence of hypertension compared to patients with milder forms of haemophilia, who infuse clotting factor less frequently. This raises the question of whether there is a link between clotting factor usage and blood pressure in haemophilia patients. Methods Data was collected from 193 patients with severe haemophilia presenting to three haemophilia treatment centres in the United States and Canada, including age, body mass index (BMI), blood pressure (BP), Hepatitis C (HCV) and Human Immunodeficiency Virus (HIV) infection status, and clotting factor usage from pharmacy prescriptions (units/kg/year). The correlation between BP and factor usage was examined using quantile regression models. Results Systolic and diastolic BP plotted against factor use showed a cone-shaped scatter of points. There was no association between clotting factor usage and higher systolic or diastolic BP. Conclusion Our observations provide no evidence for an association between increased clotting factor usage and high BP.