Anti-Müllerian hormone concentration is associated with central adiposity and reproductive hormones in expectant fathers.

Objective: The role of the anti-Müllerian hormone (AMH) as an indicator of physical and reproductive health in men is unclear. We assessed the relationships between AMH and follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and metabolic parameters, in a cohort of expectant fathers.

Design: ORIGINS Project prospective cohort study.

Self-collection: An appropriate alternative during the SARS-CoV-2 pandemic.

Objectives: To evaluate the reliability of self-collection for SARS-CoV-2 and other respiratory viruses because swab collections for SARS-CoV-2 put health workers at risk of infection and require use of personal protective equipment (PPE).

Methods: In a prospective study, patients from two states in Australia attending dedicated COVID-19 collection clinics were offered the option to first self-collect (SC) nasal and throat swabs (SCNT) prior to health worker collect (HC) using throat and nasal swabs (Site 1) or throat and nasopharyngeal swabs (Site 2). Samples were analysed for SARS-CoV-2 as well as common respiratory viruses.

Where in the world? Latitude, longitude and season contribute to the complex co-ordinates determining cortisol levels.

Objective: Cortisol is a critical stress hormone with circadian rhythms synchronized by light. There are seasonal differences in expression of pro-inflammatory genes and in some diseases moderated by glucocorticoids. As light changes with season and with latitude and longitude, we assessed changes in population cortisol associated with these parameters.

Rationalizing Thyroid Function Testing: Which TSH Cutoffs Are Optimal for Testing Free T4?

Context: Thyroid function testing often uses thyrotropin (TSH) measurement first, followed by reflex testing for free thyroxine (T4) if TSH is outside the reference range. The utility of different TSH cutoffs for reflex testing is unknown.

Objective: To examine different TSH cutoffs for reflex free T4 testing.

A time-adjusted cortisol cut-off can reduce referral rate for Synacthen stimulation test whilst maintaining diagnostic performance.

Objective: Cortisol cut-offs can predict requirement for Synacthen stimulation tests (SST). We assessed the performance of a standard cortisol cut-off (375 nmol/L) across the morning and compared this with a time-adjusted cut-off.

Design: Retrospective audit PATIENTS: Community reference set (n=12 550) and SST patients (n=757).

Longitudinal changes in maternal serum concentrations of antimüllerian hormone in individual women during conception cycles and early pregnancy.

Objective: To study antimüllerian hormone (AMH) from gestation week 0-7.

Design: Longitudinal study of 85 pregnant women with AMH and reproductive hormones sampled during conception cycle and early pregnancy until week 7.

Setting: Fertility clinic.

Quantifying the intraindividual variation of antimüllerian hormone in the ovarian cycle.

Objective: To quantify intraindividual variability of antimüllerian hormone (AMH) as analytical and biological coefficients of variation and assess the effects of variation on clinical classification.

Design: Retrospective cohort study.

Setting: Not applicable.

The log TSH-free T4 relationship in a community-based cohort is nonlinear and is influenced by age, smoking and thyroid peroxidase antibody status.

Background: The TSH-T4 relationship was thought to be inverse log-linear, but recent cross-sectional studies of selected populations report a complex, nonlinear relationship. The TSH-T4 relationship has not been evaluated in an unselected, community-based cohort, and there are limited data regarding clinical factors which affect it.

Objective: To analyse the TSH-free T4 relationship in a community-based cohort.

Reconciling the Log-Linear and Non-Log-Linear Nature of the TSH-Free T4 Relationship: Intra-Individual Analysis of a Large Population.

Context: The TSH-T4 relationship was thought to be inverse log-linear, but recent cross-sectional studies report a complex, nonlinear relationship; large, intra-individual studies are lacking.

Objective: Our objective was to analyze the TSH-free T4 relationship within individuals.

Methods: We analyzed data from 13 379 patients, each with six or more TSH/free T4 measurements and at least a 5-fold difference between individual median TSH and minimum or maximum TSH.

Chronic kidney disease in the Top End of the Northern Territory of Australia, 2002-2011: a retrospective cohort study using existing laboratory data.

Background: The Northern Territory of Australia has a very high incidence of treated end-stage kidney disease (ESKD), largely confined to Indigenous Australians living in remote, under-resourced areas. Surveillance of chronic kidney disease (CKD) is still in its infancy in Australia. We estimate the prevalence and rate of progression of measured CKD across a region using inexpensive readily available laboratory information.

Genome-wide association study with 1000 genomes imputation identifies signals for nine sex hormone-related phenotypes.

Genetic factors contribute strongly to sex hormone levels, yet knowledge of the regulatory mechanisms remains incomplete. Genome-wide association studies (GWAS) have identified only a small number of loci associated with sex hormone levels, with several reproductive hormones yet to be assessed. The aim of the study was to identify novel genetic variants contributing to the regulation of sex hormones.

Brief report: Does PTH increase with age, independent of 25-hydroxyvitamin D, phosphate, renal function, and ionized calcium?

Context: Circulating PTH concentrations increase with age. It is uncertain whether an age-related PTH increase occurs independent of changes in circulating 25-hydroxyvitamin D, phosphate, renal function, and ionized calcium.

Objective: The purpose of this article was to analyze the relationship between PTH and age, controlling for 25-hydroxyvitamin D, phosphate, renal function, and ionized calcium.

Does the thyroid-stimulating hormone measured concurrently with first trimester biochemical screening tests predict adverse pregnancy outcomes occurring after 20 weeks gestation?

Context: Maternal hypothyroidism in early pregnancy is associated with adverse outcomes, but not consistently across studies. First trimester screening for chromosomal anomalies is routine in many centers and provides an opportunity to test thyroid function.

Objective: To determine if thyroid function tests performed with first trimester screening predicts adverse pregnancy outcomes.

Impact of routine reporting of estimated glomerular filtration rate using the CKD-EPI formula in a community population: A cross-sectional cohort study.

Aim: Most laboratories are moving to report estimated glomerular filtration rates (eGFR) using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula. However, data on the prevalence of chronic kidney disease (CKD) in the population and its economic impact have to date been modelled using data derived from the modification of diet in renal disease (MDRD) equation. Evaluating the impact of CKD-EPI on prevalence has important implications for referral patterns and health expenditure.

The effects of season, daylight saving and time of sunrise on serum cortisol in a large population.

Cortisol is critical for maintenance of health and homeostasis and factors affecting cortisol levels are of clinical importance. There is conflicting information about the effects of season on morning cortisol and little information on the effects of sunlight on population cortisol assessment. The aim of this study was to assess whether changes in median serum cortisol occurred in a population in conjunction with changing seasons, daylight saving time (DST) or time of sunrise.

The relationship between TSH and free T₄ in a large population is complex and nonlinear and differs by age and sex.

Context: The relationship between TSH and T₄ is thought to be inverse log-linear, but recent studies have challenged this. There are limited data regarding age and sex differences in the TSH-T₄ relationship.

Objective: The purpose of this study was to evaluate the TSH-free T₄ relationship in a large sample.

Variation in antimüllerian hormone concentration during the menstrual cycle may change the clinical classification of the ovarian response.

Objective: To assess the variability of antimüllerian hormone (AMH) concentrations in women with "adequate ovarian reserve" during unstimulated menstrual cycles and to determine the impact on clinical classifications.

Design: Pilot cohort study.

Setting: Private fertility clinic.

Waiting for an elevated FSH--too late a marker of reduced ovarian reserve?

Aim: To assess age at which median follicle-stimulating hormone (FSH) is elevated above 10 U/L.

Background: Fertility and ovarian reserve decrease over the 4th decade with evidence that sensitive markers such as anti-Mullerian hormone fall even earlier. Despite its limitations, a basal or day 2-3 FSH is commonly used to assess ovarian reserve with levels over 10 U/L often used as a cut-point for further investigations.

Age-specific TSH reference ranges have minimal impact on the diagnosis of thyroid dysfunction.

Objective: The use of age-specific reference ranges for TSH is advocated, but the impact of this on laboratory diagnosis of thyroid dysfunction is unclear. Our aims were to determine age-specific TSH reference ranges and to examine interassay differences in performance.

Design: We analysed TSH results from 223,045 consecutive samples assayed over 1 year by a single pathology provider using the Siemens Centaur assay.