Utility of the Fragility Score (FS) Determined Through Radiofrequency Ecographic Multi-Spectrometry (REMS) in the Follow-Up of Patients with Axial Spondyloarthritis (AxSpA)

Abstract

Objectives: Bone mineral density (BMD) variation under vitamin D supplementation, determined using dual-energy X-ray absorptiometry (DXA), is the gold standard and the main tool used in most studies in this domain. However, the scientific literature is lacking with regard to the usefulness of REMS in BMD follow-up, especially the importance of the fragility score (FS). The main objective of this study was to determine whether FS follow-up is relevant in a group of patients with axial spondyloarthritis and whether REMS could have clinical applicability. Methods: Patients with a certain diagnosis of axial spondyloarthritis (AxSpA) were recruited from two medical healthcare centers and were scanned using Radiofrequency Echographic Multi-Spectrometry in order to obtain their fragility score (FS), an objective measurement of bone quality. The main group was randomized into a vitamin D supplementation branch and a non-supplementation branch and followed up every 6 months for 18 months in total. Comparisons between the branches were made using MiniTab v.20 statistical software. Results: Lower FS values were obtained in patients who initially had high scores, suggesting a positive impact of vitamin D on bone quality (p = 0.008). Muscle strength was evaluated through a visual analogue scale (VAS), with improvements being seen in the supplementation branch (p < 0.005). Furthermore, although some patients had experienced falls in previous years, during the study period, no new events were recorded in either group. Conclusions: The FS is a reliable tool for evaluating bone architecture and is useful in everyday practice for the management of patients taking vitamin D supplements.

Keywords: Radiofrequency Echographic Multi-Spectrometry; axial spondylarthritis; fragility score; muscle strength; vitamin D supplementation.

Figure 1

Boxplots comparing the evolution of the FS in the two study groups. (A) While initially there was an increase in the FS in the supplementation group, at 6 months, a more stable value was observed. (B) In the non-treatment group, there was no significant change over time in regards to the FS group with (*) representing a group of 5 individuals with higher FS scores, beyond the whiskers range of 30.2-42.3 during statistical testing (one-way ANOVA, p = 0.008 in the supplementation group and p = 0.924 in the other).

Figure 2

Differences seen between patients with lower initial FS values and higher initial FS values in the course of this study. Patients with higher FS values seemed to benefit more from vitamin D supplementation, with a clear reduction in their FS values (one-way ANOVA, p < 0.005).

Figure 3

Evolution in time of muscle strength measured using a VAS. A subjective increase in muscle strength can be seen in the supplementation group, which suggests a possible influence of vitamin D on muscle health in AxSpA (one-way ANOVA, p < 0.005).