Year: 2017
Type: dissertation
Abstract: Objective: Osteoporosis is a disease characterized by low bone mineral density and\ndeteriorated bone microstructure. This thesis aimed to determine whether cortical\nporosity is associated with previous fracture and increase the knowledge regarding the\nregulation of this bone trait.\nMethods: The studies included in this thesis were based on two well-defined cohorts.\nThe first was a sub-sample from the Swedish part of the Osteoporotic fractures in men\n(MrOS) study. This cohort comprised of 456 older men (mean age 80.2 years). The\nsecond cohort was the Sahlgrenska University hospital Prospective Evaluation of Risk\nof Bone fractures – SUPERB study, which is based on 3030 elderly women (75-80\nyears). Two sub-populations were used selected either on an X-ray verified hip\nfracture or available measurements of bone material properties. Bone mineral density\nwas assessed with dual-energy X-ray absorptiometry. Bone geometry and\nmicrostructure were measured at the tibia with high-resolution peripheral quantitative\ncomputed tomography. Microindentation was performed with the hand-held\nOsteoprobe to assess bone material strength.\nResults: Cortical porosity was associated with prevalent fracture in older men and\nprevalent hip fracture in older women independently of areal bone mineral density and\nclinical risk factors. Serum levels of 25-hydroxyvitamin D were inversely associated\nwith cortical porosity independently of parathyroid hormone, indicating that vitamin D\nmight directly regulate this bone trait. A high amount of adipose tissue was associated\nwith higher cortical porosity and lower bone material strength. Conclusions: Cortical porosity is higher in individuals with a prevalent fracture, low vitamin D levels, or large amount of adipose tissue. These results indicate that cortical\nporosity is important for bone strength and has a role in the etiology of bone fractures.
Author: Daniel Sundh
Language: English
Subfield: Orthopedics and Sports Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2607436890