Bone Abstracts

Background: Osteocalcin has an important role in bone metabolism. Uncarboxylated osteocalcin predicts risk for hip fracture and lower bone mineral density (BMD). Warfarin inhibits carboxylation of osteocalcin, providing a mechanistic link between warfarin and impaired bone metabolism. Studies examining the relationship between warfarin use and BMD have been inconsistent. The goal of this study was to further characterize this relationship.Population: CaM...

Objectives: The determinants of areal bone mineral density (aBMD) and hip geometry estimates in adolescent athletes are poorly understood. This study aimed to identify the determinants of aBMD and hip geometry estimates in adolescent male athletes.Methods: One hundred twenty one males (13.1±0.1 years) were measured: 41 swimmers, 37 footballers, 29 cyclists and 14 controls. Dual energy X-ray absorptiometry (DXA) measured aBMD at lumbar spine, femoral...

Although Vitamin D deficiency is the most common form of rickets worldwide, when there is a failure to respond to cholecalciferol, inborn errors of vitamin D metabolism should be considered. We describe two unrelated individuals who presented with early onset rickets characterised by reduced serum levels of 25(OH)D and 1,25(OH)2D, and a deficient response to Vitamin D2/D3 and calcitriol. Case 1: A Caucasian Australian girl with non-consanguineous parents ...

Objective: Autism Spectrum Disorder (ASD) is associated with lower bone mass in children. Physical activity and nutrition influence bone pathophysiology, and differences in these lifestyle factors are observed between children with vs. without ASD; however, whether these factors contribute to bone differences is unknown. We examined if: 1) differences existed in bone mineral density (BMD), content (BMC), or bone geometry in boys with vs without ASD and 2) whether physical acti...

Periostin is a matricellular protein expressed in late osteoblasts/osteocytes, which levels increase in response to PTH and mechanical loading. In turn periostin contributes to modeling based bone formation while restraining bone remodeling. Periostin is also a substrate of cathepsin K and inhibition of periostin blunts the effects of cathepsin K inhibition on bone. Considering the important role of osteocytes and their cathepsin K expression on osteolysis during lactation, we...

STRUCTURE was a phase 3, open-label study evaluating the effect of romosozumab or TPTD for 12 months in women with postmenopausal osteoporosis transitioning from bisphosphonate therapy (NCT01796301). This study enrolled women with postmenopausal osteoporosis who had taken an oral bisphosphonate for ≥3 years prior to screening and alendronate in the year prior to screening; had a BMD T-score ≤−2.5 at the total hip (TH), lumbar spine (LS), or femoral neck (FN);...

Vertebral fractures (VF) defined by morphometric analysis of spine radiographs are the most common complication of osteoporosis. Those that come to medical attention, with symptoms such as back pain and kyphosis are termed clinical vertebral fractures (CVF) and account for significant morbidity and mortality. Although much progress was made in identifying loci for bone mineral density, the genetic determinants of CVF remain unclear. Here we present the initial results from a g...

RANKL induced osteoclastogenesis is mediated by several transcription factors such as NF-κB, AP-1 and Nfatc1. We have found that also cysteine proteinases are involved in the signaling pathway downstream RANK. Thus, cystatin C, Z-RLVG-CHN2 (the sequence of which is based upon one of the enzyme inhibitory domains in cystatin C) and the fungal molecule E-64 – inhibit RANKL induced mouse and human osteoclast formation in vitro (Strålberg et ...

Aims: To describe different multinucleated giant cell phenotypes and their associations with synovitis in people with rheumatoid arthritis (RA) or osteoarthritis (OA), and in an experimental model of chronic arthritis.Material and methods: A cross-sectional comparative study was performed on samples of knee synovia from age-matched patients with RA, OA, or non-arthritic post mortem (PM) controls. OA synovia were stratified by histological inflammation gr...

Introduction: Optimal vitamin D intake for lactating women remains controversial. We hypothesized that 1200 IU/day (vs 400 IU/day) of vitamin D during breastfeeding will enhance maternal vitamin D status and bone mass.Methods: Healthy mothers after term, singleton delivery were randomized to receive vitamin D3: 1200 IU/day (800+400 IU/day from multivitamins) or 400 IU/day (placebo+400 IU/day from multivitamins) during lactation. Serum 25-hydroxyvitamin D...