Decreased trabecular bone score in patients affected by Fabry disease.

Abstract

Background: Fabry disease (FD) is an inherited X-linked lysosomal storage disease characterized by increased risk of osteoporosis and fractures. The impact of FD on clinical measures of bone quality is unknown. This considered, aim of our study was to evaluate whether trabecular bone microarchitecture, measured by trabecular bone score (TBS), is altered in patients with FD compared to control subjects.

Methods: This retrospective monocentric study enrolled 14 patients (M/F 1/1, median age 46 [37-63] years, range 31-72 years) newly diagnosed with FD between January 2016 and July 2023 who underwent dual-energy X-ray absorptiometry (DXA) image at the time of diagnosis and 42 matched controls. In all subjects, data about bone mineral density (BMD) and lumbar spine TBS were collected and total calcium, parathyroid hormone (PTH), 25(OH) vitamin D, alkaline phosphatase (ALP), creatinine and estimated glomerular filtration rate (eGFR) were evaluated. In subjects with FD, globotriaosylsphingosine (lyso-Gb3), 24-hour proteinuria and albumin-creatinine ratio were also assessed.

Results: Patients with FD presented significantly lower lumbar spine TBS (1.29 [1.22-1.38] vs. 1.42 [1.39-1.47], p < 0.001) and lower lumbar spine BMD (0.916 ± 0.166 vs. 1.031 ± 0.125 g/cm², p = 0.008) compared to controls; moreover, FD was shown to be an independent risk factor for both low lumbar spine TBS (β = -0.118, p < 0.001) and BMD (β = -0.115, p = 0.009). No differences were found in serum calcium, ALP, 25(OH) vitamin D and eGFR in both groups, but FD patients had significantly higher PTH levels compared to controls (p = 0.016). Finally, 8 patients with FD presented either moderately or severely increased albuminuria and only 2 patients presented normal lyso-Gb3 levels.

Conclusion: Patients affected by FD present significantly lower lumbar spine TBS and BMD compared to controls. Our findings strongly support the importance of carrying out a thorough evaluation of bone status in all patients affected by FD at baseline.