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

Abstract

BackgroundEvidence states that patients with haemophilia (PwH) are frequently affected by low bone mineral density (BMD). Data assessing the relationship between severity of haemophilia and occurrence of osteoporosis is lacking. ObjectiveThis prospective cohort study aims to assess the impact of haemophilia severity on BMD and to investigate trabecular bone score (TBS) and fracture risk (FRAX®). MethodsThis prospective cohort study evaluated the BMD, TBS and FRAX® in 255 PwH using dual X-ray absorptiometry. The ISCD guidelines were used for classification: osteoporosis (T-score <-2.5), osteopenia (T-score <-1.0), normal (T-score >-1.0). Patients younger than 50 years with a Z-score <-2.0 were considered below the expected range for age. ResultsOf 255 PwH (mild: n=52, moderate: n=53, severe: n=150) aged 43±15 (years, M±SD), 63.1% showed reduced BMD. Even 11.9% of PwH 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=0.010). 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=0.540). The FRAX® was 4.4±3.0%. After adjustment of TBS, it was 2.8±3.7%. ConclusionThe present study shows that BMD is decreased in 63.1% of PwH also depending on the severity of haemophilia. 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 PwH, especially as they age.