The influence of severity of hemophilia on bone mineral density and fracture risk

Abstract

Background: Evidence states that persons with hemophilia are frequently affected by low bone mineral density (BMD). Data assessing the relationship between severity of hemophilia and occurrence of osteoporosis are lacking. Objectives: This prospective cohort study aimed to assess the impact of hemophilia severity on BMD and to investigate trabecular bone score (TBS) and fracture risk (FRAX). Methods: This prospective cohort study evaluated the BMD, TBS, and FRAX in 255 persons with hemophilia using dual x-ray absorptiometry. The International Society for Clinical Densitometry guidelines were used for classification: osteoporosis (T-score −1.0). Patients younger than 50 years of age with a Z-score of <−2.0 were considered below the expected range for age. Results: Of 255 persons with hemophilia (mild: n = 52, moderate: n = 53, severe: n = 150) aged 43 ± 15 years (mean ± SD), 63.1% showed reduced BMD. Even 11.9% of persons with hemophilia aged <50 years were classified as below the expected range for age. Neck BMD decreased linearly with severity (mild: 0.907 ± 0.229, moderate: 0.867 ± 0.131, severe: 0.799 ± 0.143; P = .01). TBS was classified as “normal” in n = 178 (81.3%) with a mean value of 1.403 ± 0.136, and there were no differences between severity levels (P = .54). The FRAX was 4.4% ± 3.0%. After adjustment of TBS, it was 2.8% ± 3.7%. Conclusion: The present study shows that BMD is decreased in 63.1% of persons with hemophilia also depending on the severity of hemophilia. However, the largely normal TBS implies that the microarchitecture of the bone does not seem to be affected. It is recommended to include osteoporosis screening, including TBS analysis, in the comprehensive diagnostic work-up of persons with hemophilia, especially as they age.

Keywords

• bone mineral density
• fracture risk
• prevalence
• severity phenotype
• trabecular bone score