Patients with hemophilia are at risk for developing reduced bone mineral density (BMD) due to recurrent hemarthrosis, immobilization, lack of adequate exercise, and low vitamin D levels.
To avoid osteoporosis and its complications, such as pathological fractures, it is necessary to take preventive measures during childhood while the body is growing.
Recently, it has been suggested that a low level of factor VIII may disrupt bone homeostasis creating a pro-inflammatory environment with increased osteoclastic (i.e., of bone-digesting cells) activity and bone erosion. Vitamin D deficiency exacerbates this inflammatory state that alters bone homeostasis resulting in further reduction in bone mineral density.
All this leads to increased rates of fracture, bone pain and reduced quality of life.
Prophylactic treatment with factor VIII for patients with severe hemophilia is adopted as the primary treatment strategy in several countries around the world. It has been shown that early prophylactic treatment can prevent bleeding and arthropathy. Patients with severe hemophilia who do not receive prophylaxis usually have 30-35 joint bleeds a year and are at high risk of developing severe arthropathy.
A recent study of 50 patients with severe hemophilia A aged between 6 and 16 years showed that low-dose prophylaxis in severe hemophilia preserves BMD, increases vitamin D levels, and improves the Hemophilia Joint Health Score (the value that indicates the level of joint health in people with hemophilia).
In addition, the study indicates that these patients have significantly lower levels of vitamin D than healthy controls. Therefore, vitamin D deficiency should be tested in all people with hemophilia for early detection and treatment.
Vitamin D levels are particularly important for the bone health of patients with hemophilia. Vitamin D plays an important role in regulating calcium and bone homeostasis and has effects on the immune and cardiovascular systems. Common manifestations of vitamin D deficiency are symmetrical back pain, muscle weakness, muscle aches, throbbing pain caused by pressure on the sternum and tibia, bone deformity, anxiety, and depression. In children, bones soften over time and become deformed, leading to growth retardation, enlarged epiphyses of the long bones, and leg deformities. Vitamin D deficiency is therefore particularly important for the bone health of individuals with hemophilia, particularly children with severe hemophilia.
References
Gamal Andrawes N, Hashem Fayek M, Salah El-Din N, Atef Mostafa R. Effect of low-dose factor VIII prophylaxis therapy on bone mineral density and 25(OH) vitamin D level in children with severe haemophilia A. Haemophilia. 2020 Mar;26(2):325-332. doi: 10.1111/hae.13917.
