Prevalence and Determinants of Morphometric Vertebral  Fractures  in Adult Patients with Osteogenesis Imperfecta and Ehlers Danlos Syndrome

Presentation Number: MON 356
Date of Presentation: April 3rd, 2017

Anna Maria Formenti*1, Gherardo Mazziotti2, Chiara Dordoni1, Filippo Maffezzoni1, Stefano Frara1, Maura Saullo1, Mauro Doga1, Piergiacomo Calzavara-Pinton1, Marina Colombi1 and Andrea Giustina1
1University of Brescia, Italy, 2ASST Carlo Poma, Mantua, ITALY

Abstract

Osteogenesis Imperfecta (OI) and Ehlers-Danlos syndrome (EDS) are both pathologic conditions caused by genetically determined collagen alterations. In OI type I collagen is mutated while in EDS more heterogeneous structural and functional collagen alterations are present variably involving also collagen type 3 and 5. Besides this different genotypic background, in both diseases the skeletal phenotype is characterized by an increased fracture risk . However, it is still unknown if differences in clinical presentation of skeletal fragility between these two diseases may exist. Therefore, in this cross-sectional study we aimed at comparing the prevalence of morphometric radiologic vertebral fractures (VF), lumbar and femoral bone mineral density (BMD, Hologic DEXA)) and vitamin D in 9 adult patients with OI (6 females), median age 47 yrs (range: 21-63) vs 27 EDS patients (18 females), median age 48 yrs (range: 21-68). Frequency of hypovitaminosis D was significantly higher in EDS vs OI (85.2% vs. 22.2%; p<0.001) whereas BMD in OI was significantly lower vs EDS at all measured sites. In detail, all OI patients had pathological BMD values (2 osteoporosis, 2 osteopenia and 5 Z-score ≤ -2.0 SD) in at least one site whereas only 5 patients with EDS (1 osteoporosis, 1 osteopenia and 3 Z-score ≤ -2.0 SD) did have altered BMD (p<0.001). Despite these densitometric differences, prevalence of VFs did not differ among the two groups (OI 55.6% vs.EDS 40.7%; p=0.44). However, in OI multiple (44.4% vs. 11.1%; p=0.03) and/or severe (33% vs. 3.7%; p<0.001) VFs were more common than in EDS. In conclusion, we report for the first time that OI and EDS are associated with a similar risk of morphometric VFs with likely different underlying mechanisms, i.e low BMD in OI and hypovitaminosis D and hypomobility (reduced bone quality?) in EDS.

 

Nothing to Disclose: AMF, GM, CD, FM, SF, MS, MD, PC, MC, AG