Bone Density in Children with Hypermobility Spectrum Disorder Compared to Children with Benign Hypermobility

Background: Hypermobility spectrum disorder (HSD), likely a multifactorial condition characterized by musculoskeletal pain, joint instability, and reduced bone mineral density (BMD), is the focus of this study. Objectives: The aim of this study was to assess and compare bone density in children diagnosed with HSD and those with benign hypermobility. Methods: This case-control study involved 73 pediatric patients diagnosed with hypermobility spectrum disorder and benign hypermobility, who were referred to the Rheumatology clinic of Mofid Hospital in Tehran between February and November 2022. Bone mineral density was measured using Z-scores from L1-L4 and the whole body less head via dual-energy X-ray absorptiometry (DEXA). Results: Significant differences were observed in the frequency distribution of spine BMD Z-scores between the two groups (P = 0.002). There was no significant correlation between spine and whole body BMD Z-scores with age and gender (P > 0.05). A notable correlation was found between spine and whole body BMD Z-scores (P < 0.001 and r = 0.64). Among the HSD group, 18 patients (81.8%) had normal BMD, while 4 patients (18.2%) exhibited low bone density, with no cases of osteoporosis. In contrast, osteoporosis was observed in 7.3% of patients in the benign hypermobility group. Conclusions: Given the high prevalence of osteoporosis in patients with benign hypermobility, clinicians should be vigilant for tendencies toward osteopenia when treating such patients.