Endocrine Abstracts

Introduction: Gender differences in insulin resistance, body composition and lipid profile are well known and related to sex steroid hormones. In this study, we examine the metabolic profile of transsexual persons undergoing drastic sex steroid changes, during the first year of hormonal therapy.Design: This research is part of a prospective intervention study conducted in several European gender teams (Ghent, Oslo, Amsterdam, and Florence).<p class="...

Background: Hypogonadism in men is associated with low muscle mass and force. Although, androgen replacement is an effective therapy, it can have undesirable side effects. Identifying the androgen regulated molecular mechanisms that increase muscle mass and function could lead to the identification of novel muscle-specific therapeutic targets to improve the clinical outcomes of muscle wasting diseases. In this study, we examined in mice the effects of orchidectomy (after 1, 7 ...

Background: Interindividual variation in thyroid hormone concentrations is greater than intraindividual variation, suggesting that individuals have different set-points for pituitary–thyroid axis function. Variation in thyroid hormone levels within the normal range has clinical effects and is associated with a number of clinical parameters such as bone mass, BMI, metabolic parameters, and heart rate. The aim of this study was therefore to gain a better insight into the de...

Sex steroid concentrations have a strong genetic determination, but environmental factors and body composition play an important role. Intrauterine growth restriction, evidenced by low birth weight has been associated with altered gonadotropin metabolism. If this relationship is also present across the wide range of birth weight is unkown. Serum sex steroid concentrations were investigated in healthy young brothers in relation to birth weight, body composition and parental ste...

Objective: The human androgen recteptor (AR) contains a polyglutamine and a polyglycine stretch that are highly polymorphic and are coded by a CAG and GGN repeat, respectively, in exon 1 of the AR gene. Although in vitro studies indicated a possible effect on AR gene tanscription and clinical observations suggest a modulation of androgen action, the functional significance of the GGN repeat remains unclear.We wanted to assess whether the GGN repea...

Sex hormone binding globulin (SHBG) is a plasma glycoprotein responsible for high-affinity binding and transport of sex steroids. In men there is a large interindividual variation of SHBG levels, and consequently of serum total testosterone (T) and serum total estradiol (E2) levels. Family and twin studies suggested a strong genetic contribution to this variation, besides a hormonal and metabolic influence. The aim of this study was to examine the influence of a missense mutat...

Background: Thyroid incidentaloma are asymptomatic thyroid nodules that are discovered on an imaging study performed to evaluate other structures. Clinically unrecognized thyroid nodules are common and can be found in up to 50–60% of patients at autopsy.1 Increased use of imaging modalities of better quality in the modern era has resulted in an increased detection of incidental thyroid nodules. The prevalence rate is 67% with ultrasonography (US) imaging, 15% w...

Background: Data concerning pubertal development and testosterone (T) in obese male adolescents (ObA) are scarce and contrasting. Underperforming T immunoassays and poor assessment of pubertal development might explain discordant findings. Although SHBG is markedly affected, few studies report free T (FT) levels.Objective: To study if ObA have conserved FT levels despite low total T (TT) and to investigate if FT is a better indicator of androgen exposure...

Background: We have previously shown that a higher BMI and less favorable body composition are associated with relatively higher FT3 levels (within the euthyroid range) in healthy young men. In this study, we aimed to investigate whether FT3 and the ratio FT3:FT4 are also associated with cardiovascular markers in a healthy euthyroid population of middle-aged men and women.Methods: Thyroid parameters were measur...

Background: In elderly men, fracture risk is independently associated with higher serum sex hormone-binding globulin (SHBG) levels1. Previously, we observed lower free estradiol (E2) and higher SHBG levels in a three-generational family study of men with idiopathic osteoporosis2.Objective: To investigate associations between serum SHBG levels and cortical bone size at age of peak bone mass.Design: S...