Endocrine Abstracts

Background: Diagnosing endogenous Cushing’s syndrome (CS) is often challenging because of the difficulty in interpreting results of dynamic endocrine tests. One of the recommended initial tests is the measurement of late-night salivary cortisol (LNSaCl). Some articles describe added value of late-night salivary cortisone (LNSaCn) measurements. However, published cut-off values of LNSaCl and LNSaCn vary widely between studies, which may be related to different experimental...

In recent years measurement of steroid hormones like testosterone, androstenedione, cortisol, and cortisone has become increasingly important in both patient care and research. This is mainly due to the simple and non-invasive sample collection. We investigated in twenty healthy volunteers whether there is a difference between steroid hormone concentrations in unstimulated and parotid gland saliva as well as stimulated saliva collected while chewing without aid, using cotton a...

The adrenal and gonadal androgens testosterone, androstenedione and dehydroepiandrosterone (DHEA) play an important role in sexual development and fertility as well as in several other processes. We developed a method to assess serum testosterone, androstenedione and DHEA levels in one run using isotope-dilution liquid-chromatography tandem mass spectrometry (ID-LC-MS/MS). Sample preparation consisted of addition of internal standards (13C3-testosterone, ...

ContextContamination of collected blood samples by application of testosterone gel near the venipuncture site can cause spuriously elevated serum testosterone concentrations. Often this will be detected only in case of extreme discrepancies between lab result and clinical effects. Because in vitro testosterone cannot be metabolized as the testosterone in vivo we hypothesized that measuring estradiol, as a metabolite of testosterone after aromati...

Recently, liquid chromatography–tandem mass spectrometry (LC–MS/MS) was stated to be the method of choice to measure sex steroids.1 Information on the mutual agreement of LC–MS/MS methods, however, is scarce. Therefore, we compared seven published LC–MS/MS methods for the simultaneous measurement of testosterone, androstenedione, and DHEA. Fifty-five random serum samples obtained from volunteers were analysed in duplicate by seven published LC&#1...

Objective: The aim of the current study is to examine the effects of gender affirming hormone therapy in transgender persons on calcium and phosphate concentrations and their regulatory hormones.Design: A prospective cohort studyMethods: This study investigated changes in calcium and phosphate concentrations and their regulatory hormones in trans women and trans men during the first year of hormone therapy. Trans women received est...

Introduction: In patients with ACTH-dependent hypercortisolism, the corticotropin-releasing-hormone (CRH) test and the high dose dexamethasone suppression test (HDDST) can be used to differentiate between pituitary ACTH production (Cushing’s disease) and ectopic ACTH production. The rationale is that a pituitary adenoma will show some response to CRH and ACTH whereas an ectopic source is less responsive to ACTH and CRH. However, there is discussion about the clinical util...

Background: LC-MS/MS is replacing immunoassays for serum steroid measurement in clinical labs worldwide. The intrinsic high specificity of LC-MS/MS is supposed to guarantee accurate quantitation, however, differences in pre-analytical and analytical procedures, and overall performance may influence the result. A few studies so far investigated the reproducibility among different LC-MS/MS assays for sex steroids. No data are available for adrenal steroids.<p class="abstext"...

Background: LC-MS/MS is recommended for accurately measuring circulating steroids. However, laboratories using LC-MS/MS adopt various pre-analytical and analytical strategies, and little is known about comparability of results. Whether different blood derivatives impact LC-MS/MS measurements is unclear, and the benefit of unifying the calibration system among laboratories was not tested.Aim: Comparisons of LC-MS/MS measurements of circulating aldosterone...

Introduction: Thyroid disorders are generally diagnosed based on thyroid stimulating hormone (TSH) outside the reference interval (RI), and subsequent free thyroxine (FT4) concentrations. Most laboratories do not provide age-specific RIs for TSH and FT4 beyond childhood, although it is known that TSH concentrations vary with age which may be important to take into account. Therefore, we aimed to establish age-specific RIs for TSH and FT4 throughout life using an indirect metho...