title: Cortical porosity not superior to conventional densitometry in identifying hemodialysis patients with fragility fracture.
abstract: Hemodialysis (HD) patients face increased fracture risk, which is further associated with elevated risk of hospitalization and mortality. High-resolution peripheral computed tomography (HR-pQCT) has advanced our understanding of bone disease in chronic kidney disease by characterizing distinct changes in both the cortical and trabecular compartments. Increased cortical porosity (Ct.Po) has been shown to be associated with fracture in patients with osteopenia or in postmenopausal diabetic women. We tested whether the degree of Ct.Po identifies hemodialysis patients with prevalent fragility fractures in comparison to bone mineral density (BMD) assessed by dual X-ray absorptiometry (DXA). We performed a post-hoc analysis of a cross-sectional study in 76 prevalent hemodialysis patients. Markers of mineral metabolism, coronary calcification score, DXA-, and HR-pQCT-data were analyzed, and Ct.Po determined at radius and tibia. Ct.Po was significantly higher in patients with fracture but association was lost after adjusting for age and gender (tibia p = 0.228, radius p = 0.5). Instead, femoral (F) BMD neck area (p = 0.03), F T-score neck area (p = 0.03), radius (R) BMD (p = 0.03), R T-score (p = 0.03), and cortical HR-pQCT indices such as cortical area (Ct.Ar) (tibia: p = 0.01; radius: p = 0.02) and cortical thickness (Ct.Th) (tibia: p = 0.03; radius: p = 0.02) correctly classified patients with fragility fractures. Area under receiver operating characteristic curves (AUC) for Ct.Po (tibia AUC: 0.711; p = 0.01; radius AUC: 0.666; p = 0.04), Ct.Ar (tibia AUC: 0.832; p<0.001; radius AUC: 0.796; p<0.001), and F neck BMD (AUC: 0.758; p = 0.002) did not differ significantly among each other. In conclusion, measuring Ct.Po is not superior to BMD determined by DXA for identification of HD patients with fragility fracture.
authors.affiliation: Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria.
authors.forename: Bernhard
authors.identifier: http://orcid.org/0000-0002-4491-0562
authors.initials: B
authors.lastname: Bielesz
authors.affiliation: Division of General Radiology and Pediatric Radiology, Department of Biomedical Imaging and Image-Guided Therapy, Vienna, Austria.
authors.forename: Janina M
authors.initials: JM
authors.lastname: Patsch
authors.affiliation: Computational Imaging Research (CIR) Laboratory, Department of Biomedical Imaging and Image-Guided Therapy, Vienna, Austria.|Software Competence Center Hagenberg, Hagenberg, Austria.
authors.forename: Lukas
authors.initials: L
authors.lastname: Fischer
authors.affiliation: Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria.
authors.forename: Marija
authors.initials: M
authors.lastname: Bojic
authors.affiliation: Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Winnicki
authors.affiliation: Division of General Radiology and Pediatric Radiology, Department of Biomedical Imaging and Image-Guided Therapy, Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Weber
authors.affiliation: Department of Medicine III, Nephrology, Transplantation, Rheumatology, Geriatrics, Ordensklinikum Linz, Linz, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cejka
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D015519:Bone Density; D003430:Cross-Sectional Studies; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000502:physiology / Q000503:physiopathology*; D050723:Fractures, Bone / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016062:Porosity; D012372:ROC Curve; D011884:Radius / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006435:Renal Dialysis; D051436:Renal Insufficiency, Chronic / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D013977:Tibia / Q000000981:diagnostic imaging / Q000502:physiology / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed