Bone mineral density low in hemophilia patients: Study
Researchers say findings point to need for earlier osteoporosis screenings
Bone mineral density, or the amount of mineral in bone tissue, is decreased in 63.1% of people with hemophilia, according to a study from Germany.
Study findings also indicated the degree of loss depended on hemophilia severity. Patients with severe hemophilia had lower bone mineral density in the left and right upper portions of their thigh bones than those with mild hemophilia.
“These findings should be considered in clinical routine to ensure best care and to protect [people with hemophilia] from the consequences of undiagnosed osteoporosis, such as fracture risk, reduced mobility, and spine misalignments,” the researchers wrote.
The results show that people with hemophilia “are at higher risk of developing osteoporosis, especially with increasing age, calling for action to include screening for osteoporosis in clinical routine at age 30 and older, including vitamin D supplementation if necessary,” they wrote.
The study, “The influence of severity of haemophilia on bone mineral density and fracture risk,” was published in Research and Practice in Thrombosis and Haemostasis.
Relationship between disease severity, osteoporosis
Hemophilia is a rare disorder caused by a lack of specific clotting proteins: clotting factor VIII in the case of hemophilia A and clotting factor IX in the case of hemophilia B. This puts patients at a higher risk of experiencing excessive and prolonged bleeding episodes.
People with hemophilia are also at higher risk of having low bone mineral density, which can eventually lead to the development of conditions like osteopenia and osteoporosis, in which bones weaken and, over time, become prone to fracture.
Although several studies have described an association between severe hemophilia and low bone mineral density, “data assessing the relationship between severity of hemophilia and occurrence of osteoporosis is lacking,” the researchers wrote.
The researchers in Germany aimed to assess the impact of hemophilia severity on bone mineral density and determine the prevalence of osteoporosis in a group of 255 patients with mild, moderate, or severe hemophilia A or B.
Bone mineral density was measured in the patients’ lower spine and hip bones using dual x-ray absorptiometry. The Fracture Risk Assessment Tool (FRAX) was also used to calculate the risk of fractures based on bone mineral density. The trabecular bone score (TBS), which evaluates bones’ internal microarchitecture and can be used to assess bone quality and predict the risk of fractures independently of bone mineral density, was also determined.
The study involved 52 people with mild hemophilia, 53 with moderate hemophilia, and 150 with severe hemophilia.
Results showed that more than half of the patients (63.1%) had low bone mineral density. Density was significantly lower in the upper portion of both thigh bones in severe hemophilia patients than in those with mild disease.
Of the 104 hemophilia patients who were older than 50, 19.2% were diagnosed with osteoporosis and 53.8% with osteopenia, a condition in which bone mineral density is lower than normal but not low enough to reach the diagnosis criteria for osteoporosis. Of the 151 patients who were younger than 50, 11.9% had mineral density that was below the expected range for their age.
Patients who were older and whose disease was more severe were more likely to have lower bone mineral density, according to a statistical analysis that found that age and disease severity influenced bone mineral density.
TBS was calculated in 219 patients and was classified as normal in 178 (81.3%). No significant differences in TBS values were seen between people with different hemophilia severities.
FRAX was calculated in the subset of 186 patients aged 30 and older. The mean risk of having a bone fracture over the next 10 years was 4.4%. After adjusting values for TBS, the mean bone fracture risk dropped to 2.8%.
“The largely normal TBS indicates that the microarchitecture of the bone does not appear to be affected,” the researchers wrote. “Accordingly, a TBS adjustment reduces FRAX by … 1.6%.”
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