Bone Abstracts

Thyrotoxicosis results in osteoporosis, and thyroid hormone (T3) stimulates osteoclastic bone resorption by unknown mechanisms. We previously demonstrated that knockout mice lacking thyroid hormone receptor α (TRα0/0) are euthyroid but have high bone mass, whereas mice lacking TRβ (TRβ−/−) are thyrotoxic and osteoporotic. Tartrate resistant acid phosphatase (TRAcP) staining revealed osteoclast numbers were reduced by 13% (<...

Objectives: i) To evaluate the bone mineral density (BMD), and clinical outcomes of intravenous bisphosphonate treatment (IVT) and after treatment discontinuation in children with osteogenesis imperfecta (OI). ii) To compare the clinical outcome of those who discontinued IVT and those who had progressed from IVT to maintenance oral bisphosphonate therapy.Methods: A retrospective study was conducted on 28 children with OI who had discontinued IVT (21 pami...

Objectives: Cyclical intravenous pamidronate (PAM) and zoledronic acid (ZOL) increases bone mineral density (BMD) and reduces fractures in children with osteogenesis imperfecta (OI). The aims of this study were to evaluate fracture and BMD outcomes after treatment discontinuation in children with OI treated with ZOL compared to PAM.Methods: 21 patients (mean age 5.1±3.8 years) received PAM (1 mg/kg per day x 3 days q 3 months for the first year). Se...

Bone accrual and the attainment of peak bone mass influence an individual’s predisposition to fracture or osteoporosis later in life. The developmental tempo and the movement of the periosteal and endosteal surfaces of the appendicular skeleton during growth result in variations in bone mineral content and density. During puberty the differential in peak height and peak bone mass accretion negatively influence bone strength. A surrogate measure of bone strength is the met...

Skeletal development during childhood and adolescence is an important determinant of adult bone health. Patterns of growth differ between populations, but it is unclear how these differences relate to changes in bone size and volumetric density. We aimed to examine ethnic differences in skeletal phenotype in the context of pubertal growth and development in 279 adolescent males from Johannesburg, South Africa.We performed annual peripheral quantitative c...

Objective: To determine the relationship between maternal and child bone density in a cohort of mothers and their children with and without rickets.Methods: Using a case-control design without matching, areal forearm bone mineral density (aBMD) was measured in 52 and 135 Nigerian children with and without rickets, respectively, and their mothers. The metaphyseal site was located at the site of minimal bone density of the distal radius and ulna. The diaph...

Background: Acquired hypophosphataemic rickets is an unusual presentation in children and usually consequent on renal tubular damage. One of the factors important in phosphate homeostasis is FGF23. Healthy individuals maintain normal phosphate homeostasis by coupling FGF23 production with proteolytic cleavage. Iron deficiency stimulates FGF23 transcription and is a novel mechanism of FGF23 elevation. We present two children who presented with iron deficiency anaemia and hypoph...

GH is an important anabolic hormone involved in the regulation of longitudinal bone growth. However, acromegaly patients have a higher prevalence of vertebral fractures despite normal bone mineral density (BMD), suggesting that GH overexpression has adverse effects on skeletal architecture and strength. We used giant bovine GH (bGH) transgenic mice to analyse the effects of high serum GH levels on BMD, architecture and mechanical strength. Five month-old hemizygous male bGH mi...

Introduction: Intracellular fat within muscle and visceral tissue has been suggested to adversely influence bone development.Design: We aimed to compare associations between intramuscular and subcutaneous fat and cortical bone outcomes in young adults, in cross-sectional analyses based on the Avon Longitudinal Study of Parents and Children.Method: Data were collected from a research clinic conducted at 17 years of age. Intramuscula...

Introduction: Bone mineral density decreases before menopause and is held to be due to trabecular, not cortical, bone loss. Yet neither a negative bone balance, nor accelerated remodelling occurs before 45 years of age. We hypothesized that bone loss will first appear after 45 years and will be cortical (as 80% of bone is cortical).Methods/design: Images of distal tibia acquired using high-resolution peripheral quantitative computed tomography (Scanco Me...