Summary

Increased fracture risk in patients with Ehlers-Danlos syndromes has been reported, but the reasons for it are incompletely understood. We aimed to investigate possible determinants of this increased risk and found that hEDS/HSD patients present with a cortical bone size deficit compared with control subjects, possibly related to lower mechanical loading.

Introduction

The Ehlers-Danlos syndromes (EDS) comprise a group of heritable connective tissue disorders caused by defects in the biosynthesis, secretion, and/or organization of fibrillar collagens which might impair bone strength. Our aim was to compare fracture prevalence, volumetric and areal bone mineral density (BMD), bone geometry, muscle size and the muscle-bone interaction, body composition and longitudinal changes therein between patients with hypermobile EDS (hEDS) or hypermobility spectrum disorder (HSD), and healthy control subjects.

Methods

Cross-sectional data comprised 39 female hEDS/HSD patients (age 41 ± 11 years) and 43 age-matched controls. After 8 years, 27 hEDS/HSD and 17 control subjects were re-evaluated. Tibial trabecular and cortical volumetric BMD, bone mineral content (BMC), cortical bone geometry, and lower leg muscle cross-sectional area (CSA) were measured using pQCT. Body composition, areal BMD, and BMC were determined by DXA.

Results

At baseline, patients with hEDS/HSD presented with a smaller cortical bone area, smaller cortical thickness and muscle CSA, and a higher fracture prevalence than control subjects (all p < 0.05). No differences in areal or volumetric BMD were found. Longitudinally, muscle CSA decreased in both groups and muscle density decreased in the hEDS/HSD group (p < 0.001) whereas all bone parameters remained unchanged.

Conclusion

hEDS/HSD patients have a cortical bone size deficit compared with controls, possibly contributing to their increased fracture risk. They presented with decreased muscle CSA but normal bone/muscle area ratio, suggesting that this bone size deficit is likely secondary to decreased mechanical loading. Further, there were no arguments for accelerated bone loss in hEDS/HSD subjects.

中文翻译：

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hEDS / HSD患者较高的骨折发生率和较小的骨尺寸—前瞻性队列研究

概要

据报道，Ehlers-Danlos综合征患者的骨折风险增加，但其原因尚不完全清楚。我们旨在研究这种风险增加的可能决定因素，并发现与对照组相比，hEDS / HSD患者存在皮质骨大小不足，可能与较低的机械负荷有关。

介绍

Ehlers-Danlos综合征（EDS）包括一组可遗传的结缔组织疾病，这些疾病是由可能损害骨骼强度的原纤维胶原蛋白的生物合成，分泌和/或组织缺陷引起的。我们的目的是比较高活动性EDS（hEDS）或高活动性谱系障碍（HSD）患者之间的骨折患病率，体积和面积骨矿物质密度（BMD），骨骼几何形状，肌肉大小以及肌肉与骨骼的相互作用，身体组成和纵向变化）和健康对照对象。

方法

横断面数据包括39名女性hEDS / HSD患者（41±11岁）和43个年龄匹配的对照。8年后，对27名hEDS / HSD和17名对照受试者进行了重新评估。使用pQCT测量胫骨小梁和皮质体积BMD，骨矿物质含量（BMC），皮质骨几何形状和小腿肌肉横截面积（CSA）。身体成分，面积BMD和BMC由DXA确定。

结果

在基线时，与对照组相比，hEDS / HSD患者表现出较小的皮质骨面积，较小的皮质厚度和肌肉CSA以及较高的骨折发生率（所有p  <0.05）。没有发现面积或体积的骨密度差异。纵向上，两组的肌肉CSA均降低，而hEDS / HSD组的肌肉密度降低（p  <0.001），而所有骨骼参数均保持不变。

结论

与对照组相比，hEDS / HSD患者的皮质骨大小不足，可能导致骨折风险增加。他们表现出肌肉CSA降低，但骨骼/肌肉面积比正常，表明这种骨骼尺寸不足很可能是由于机械负荷降低所致。此外，在hEDS / HSD受试者中没有关于加速骨质流失的争论。