Haemophilic Arthropathy Is a Risk Factor for Reduced Bone Mineral Density and Vitamin D Deficiency

Introduction: Recent studies indicate an increased risk for developing low bone mineral density (BMD) in patients with haemophilia. This has been suggested to result from less physical activity, and impaired vitamin D metabolism due to viral liver disease. Here we present the preliminary results of an ongoing study aiming to identify the risk factors for impaired bone health in adult haemophilia patients.

Material and Method: Twenty-nine severe and 7 moderate haemophilia A and B patients were included in the study. Patient characteristics were given in Table-1. All patients had haemophilic arthropathy in ≥1 joints and were on prophylactic factor replacement therapy except 2 on demand patients. None of the patients had decompensated chronic liver disease. Eleven patients had a history of joint intervention (RAS or joint replacement). None of the patients had received on vitamin D supplementation. DEXA scans to screen BMD, blood chemical analysis including liver and kidney function tests, vit. D (25 hydroxy vitamin D) calcium, parathormone, alkaline phosphatase were obtained from all patients at study entry.

Results: Osteoporosis and/or osteopenia according to WHO criteria were detected by DEXA scans in 2/3 of the patients. Twenty-six patients (72%) had vit. D levels below 20ng/mL, with half of them having levels less than 10ng/mL. Median lumbar and femur T scores were in the osteopenia range, being -1.2 and -2.2, respectively. Osteoporosis/penia rates and vit. D levels did not significantly differ between patients with severe and moderate haemophilia. However, patients with severe haemophilia had lower lumbar T scores (p=0.048) and seemed to acquire low BMD 2 times more likely than moderate haemophiliacs. Patients with a history of joint intervention had significantly lower vit. D levels (p=0.005) and 1.4 times more risk for low BMD.

Conclusion: Preliminary results of our study are in line with the recent literature indicating an increased frequency for osteopenia and osteoporosis in patients with haemophilia. Despite their young age our cohort of patients had lower BMD and vitamin D levels than the age-matched healthy population. This is an interesting finding in a country like Turkey where the average yearly total number of hours of bright sunshine is over 3000. Data at hand suggest increased risk for reduced BMD especially in severe haemophiliacs with impaired joint mobility. The most probable underlying cause for reduced BMD seems to be haemophilic arthropathy related inactivity. Furthermore, impaired bone health seems to be partially associated with less sunlight exposure, which is probably a result of increased home confinement of patients with haemophilia due to joint disease. The study is still recruiting. We hope to clarify other questions regarding factors influencing bone health in haemophiliacs when the study is completed and additional data on radiological and physical examination as well as on quality of life are obtained.