Endocrine Abstracts

Primary HPT shows a great variability in its clinical course and severity, which might be related to polymorphic variants of the CASR gene. The aim of the study was to evaluate the frequency of two known CASR single nucleotide polymorphisms (SNPs), i.e. G/T at codon 986 and G/A at codon 990, in a homogenous North-Italian cohort of PHPT patients compared with a sex and age matched healthy population and the possible correlation of these CASR gene variants with the clinical and ...

Studies of TSHR−/− mice suggest that TSH inhibits bone turnover, but these mice have congenital hypothyroidism and the actions of TSH cannot be separated from effects of thyroid hormone deficiency. We characterised skeletal development in hyt/hyt mice, which have a point mutation in the Tshr gene, and Pax8−/− mice with thyroid gland agenesis. Hyt/hyt mice have a 100-fold increase in TSH but inactive TSHRs, whereas Pax8&...

Recent studies suggest TSH inhibits bone remodeling, indicating that TSH deficiency rather than thyroid hormone excess could cause bone loss in thyrotoxicosis. The findings predict that TSH receptor (TSHR) stimulating antibodies (TSHRAb) should inhibit bone turnover, whereas Graves’ disease patients exhibit high bone turnover with increased fracture susceptibility. We characterized TSH-action in primary human and mouse osteoblasts and osteoclasts, and explored whether a p...

The aim of the study was to evaluate factors determining bone mineral density (BMD) and serum concentrations of osteocalcin (OC) and carboxyterminal telopeptide of type I collagen (ICTP) in acromegaly. Material consisted of 121 patients with active acromegaly, aged 23–80 years. In the whole group BMD, assessed by DXA, was: 0.35±0.15 at L2–L4, 0.60±0.11 at femoral neck, 0.05±0.12 at Ward’s triangle and 0.59±0.13 at trocha...

Previous studies suggest that in patients with adrenal incidentalomas (AI) subclinical hypercortisolism (SH) exerts a deleterious effect on bone mineral density (BMD), but scarce data are available about vertebral fractures. We evaluate BMD and prevalence of vertebral fractures in a sample of AI subjects with and without SH.Forty-seven consecutive AI inpatients were evaluated (17M, 30F). The patients were subdivided into two groups: with or without subcl...

T3-receptor alpha (TRa) is the predominant TR isoform in bone. To investigate its function, we analysed mice harbouring a dominant negative R384C mutation in TRa1 (TRa1m/+). The homozygous TRa1m/m mutation is lethal whereas heterozygotes are euthyroid displaying only transient postnatal hypothyroidism. Critically, dominant negative activity of the mutation is overcome by a 10-fold increase in T3, which is achieved by crossing TRa1m/+ mutants wi...

Thyroid hormones stimulate bone formation and linear growth in children. Paradoxically, childhood thyrotoxicosis causes short stature and craniosynostosis due to early closure of the growth plates and skull sutures. In adults, however, thyroid hormone excess increases bone turnover and results in progressive bone loss and osteoporosis. Activating mutations of fibroblast growth factor receptor-3 (FGFR3) cause achondroplastic dwarfism and we have shown that T3 augments FGFR sign...

Background: From 1999 to the end of June 2005, 186 patients (26 men) with truly asymptomatic pHPT based on the NIH 1990 criteria were included at 11 centres in Scandinavia. The mean age at inclusion was 63.2±7.8 (S.D.) years. After informed consent the patients were randomised to operation (93) or medical observation (94), in order to investigate the effect of operation on Quality of Life and co-morbidity. At present, 159 patients are ongoing, 3 dead, and 2...