The Adrenal Vein Sampling Outcomes Study (AVOS): success rates following adrenalectomy for unilateral primary aldosteronism.

The objective was to determine the clinical and biochemical success rates and assess the nature of follow-up after adrenalectomy in patients with unilateral primary aldosteronism (PA), subtyped by adrenal vein sampling (AVS) in West Australia (WA) using the Primary Aldosteronism Surgical Outcome (PASO) criteria. Clinical and biochemical outcomes were retrospectively evaluated in patients with unilateral PA who underwent adrenalectomy according to AVS between September 2017 and September 2020. Pre- and post-surgical data were collected using a standardised questionnaire, review of clinic letters and examination of private and public pathology results and radiological reports.

The challenge of improving the diagnostic yield from metanephrine testing in suspected phaeochromocytoma and paraganglioma.

Background Plasma-free metanephrines (PFM) or urinary fractionated metanephrines (UFM) are the preferred biochemical tests for the diagnosis of phaeochromocytoma and paraganglioma (PPGL). Borderline increased results should be followed up to either exclude or confirm diagnosis. Methods We extracted all PFM and UFM results reported by our laboratory over a six-month period from the laboratory information system.

Clinical utility of bone turnover markers in the management of common metabolic bone diseases in adults.

Bone turnover marker (BTMs) concentrations in blood and urine reflect bone-remodelling activity, and may be useful adjuncts in the diagnosis and management of metabolic bone diseases. Newer biomarkers, mainly bone regulatory proteins, are currently being investigated to elucidate their role in bone metabolism and disease and may in future be useful in clinical diagnosis and management of metabolic bone disease. BTM concentrations increase around menopause in women, and at a population level the degree of increase in BTMs reflect bone loss.

Improved technical success and radiation safety of adrenal vein sampling using rapid, semi-quantitative point-of-care cortisol measurement.

Unlabelled: Objective Primary aldosteronism is a curable cause of hypertension which can be treated surgically or medically depending on the findings of adrenal vein sampling studies. Adrenal vein sampling studies are technically demanding with a high failure rate in many centres. The use of intraprocedural cortisol measurement could improve the success rates of adrenal vein sampling but may be impracticable due to cost and effects on procedural duration.

Isolated brachydactyly type E and idiopathic pancreatitis in a patient presenting to a lipid disorders clinic.

An 18-year-old female tertiary student was referred to a lipid clinic with hypertriglyceridaemia discovered after presentation with acute pancreatitis. The patient's only medication was l-thyroxine for treatment of hypothyroidism. She was overweight, normotensive, with unremarkable facies.

25-Hydroxyvitamin D C3-epimer is universally present in neonatal Western Australian samples but is unlikely to contribute to diagnostic misclassification.

Background: The presence of C3-epimer (C-3-epi-25-hydroxyvitamin D) in infant serum may complicate 25-hydroxyvitamin D (25(OH)D) measurement when using liquid chromatography tandem mass spectrometry assays that do not separately measure the epimer. We measured the concentration of C3-epi-25(OH)D in neonatal samples in Western Australian using umbilical cord blood samples and a liquid chromatography tandem mass spectrometry assay that separately quantifies 25(OH)D and C3-epi-25(OH)D.

Methods: A total of 120 anonymized cord blood samples were analysed using a liquid chromatography tandem mass spectrometry assay that utilizes two CSH fluoro-phenyl columns in series.

Measuring vitamin D.

When assessing vitamin D status, measure serum 25-hydroxyvitamin D concentration as this reflects total body vitamin D reserves. Recent Australasian guidelines outline who should be tested for vitamin D deficiency, who should be treated and when repeat testing should be performed. A 25-hydroxyvitamin D threshold of at least 50 nanomol/L at the end of winter is a suitable treatment target.

Controversy and consensus regarding vitamin D: Recent methodological changes and the risks and benefits of vitamin D supplementation.

A dramatic and sustained surge in vitamin D test numbers has been attributed to the extraskeletal and probable intra/paracrine effects of vitamin D and not the important role of vitamin D in the regulation of extracellular calcium homeostasis and bone metabolism. This review summarizes recent data regarding the skeletal and extraskeletal effects of vitamin D, provides an overview of current methods of 25-hydroxyvitamin D measurement and includes the beneficial and adverse effects of vitamin D replacement. The role of 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D, vitamin D binding protein and free hormone levels are explored and potential future developments in this area are discussed.

Is vitamin D testing at a tertiary referral hospital consistent with guideline recommendations?

To determine if 25 hydroxyvitamin D (25OHD) testing at our tertiary referral hospital is consistent with guideline recommendations concerning the clinical indications for testing, the timing of repeat testing and utilisation of the test result, we conducted a retrospective audit of electronic laboratory and patient case records. We included adult inpatients and outpatients who had serum 25OHD measured during a randomly selected one-week audit period and who had patient case records available for detailed review. The audit sample comprised 184 serum 25OHD measurements (134 initial and 50 repeat tests).

Long-term efficacy, safety, and patient acceptability of ibandronate in the treatment of postmenopausal osteoporosis.

Several second-generation bisphosphonates (BPs) are approved in osteoporosis treatment. Efficacy and safety depends on potency of farnesyl pyrophosphate synthase (FPPS) inhibition, hydroxyapatite affinity, compliance and adherence. The latter may be influenced by frequency and route of administration.

A diagnostic conundrum: heterophilic antibody interference in an adrenocorticotropic hormone immunoassay not detectable using a proprietary heterophile blocking reagent.

Context: Heterophilic antibodies are a well-described interferent but poorly appreciated and are often not a recognized problem affecting most immunoassays. We describe for the first time heterophilic antibodies interference affecting an adrenocorticotropic hormone (ACTH) assay in a patient with Cushing's syndrome due to bilateral nodular adrenal hyperplasia.

Case: A 60-year-old retired female nurse underwent extensive invasive investigations, which were ultimately unnecessary, as a result of initial analytical interference in the ACTH assay, which could not be resolved using a proprietary heterophilic binding reagent.

Calculated free and bioavailable vitamin D metabolite concentrations in vitamin D-deficient hip fracture patients after supplementation with cholecalciferol and ergocalciferol.

We previously showed that oral cholecalciferol and ergocalciferol have comparable effects in decreasing circulating parathyroid hormone (PTH), despite a greater increase in total serum 25-hydroxyvitamin D (25OHD) concentration with cholecalciferol supplementation. However, the effects of cholecalciferol and ergocalciferol on total serum 1,25-dihydroxyvitamin D (1,25(OH)2D), vitamin D-binding protein (DBP), free 25OHD and free 1,25(OH)2D concentrations have not been previously studied. We randomized 95 hip fracture patients (aged 83±8 years) with vitamin D deficiency (serum 25OHD <50 nmol/L) to oral supplementation with either cholecalciferol 1000 IU/day (n=47) or ergocalciferol 1000 IU/day (n=48) for three months.

Vitamin D: methods of 25 hydroxyvitamin D analysis, targeting at risk populations and selecting thresholds of treatment.

Interest in vitamin D has intensified with the association of vitamin D deficiency (VDD) with many diseases. This review will outline the limitations of current 25 hydroxyvitamin D (25OHD) methods, the target treatment threshold, and review the classical (endocrine/bone) and non-classical (paracrine/non-bone) actions of vitamin D. Recent standardisation by the National Institutes of Standards and Technology and use of LC tandem mass methodology has reduced inter-method bias but insensitivity and imprecision of automated methods have challenged assay performance.

Screening for vitamin D deficiency: defining vitamin D deficiency, target thresholds of treatment and estimating the benefits of treatment.

Vitamin D sufficiency has been associated with improved health outcomes but cost benefit analyses of published data adopt a number of assumptions. Firstly, definitions of vitamin D deficiency vary. Secondly, available methods used for the analysis of 25-hydroxyvitamin D (25OHD) have significant limitations which could affect the adoption of specific target thresholds for treatment.

Effects of three-monthly oral 150,000 IU cholecalciferol supplementation on falls, mobility, and muscle strength in older postmenopausal women: a randomized controlled trial.

Daily vitamin D in addition to calcium supplementation reduces falls and fractures in older women. However, poor adherence to therapy is a common clinical problem. To examine the effects of supervised oral 3-monthly vitamin D therapy on falls, muscle strength, and mobility, we conducted a 9-month randomized, double-blind, placebo-controlled trial in 686 community-dwelling ambulant women aged over 70 years.

Improved plasma free metadrenaline analysis requires mixed mode cation exchange solid-phase extraction prior to liquid chromatography tandem mass spectrometry detection.

Background: The investigation and effective management of phaeochromocytoma involves biochemical measurement of either conjugated total urine or plasma free metadrenalines. Current analytical methods include enzyme-linked immunosorbent assays, high-performance liquid chromatography (HPLC) with electrochemical detection (ECD) or liquid chromatography tandem mass spectrometry (LCMS/MS). Since the first two methods are either extremely laborious, necessitate low sample run numbers, result in slow turnaround times or are subject to analytical interference, a robust, routine clinical method is not achievable.

Serum 25-hydroxyvitamin D levels in vitamin D-insufficient hip fracture patients after supplementation with ergocalciferol and cholecalciferol.

Vitamin D insufficiency is commonly associated with hip fracture. However, the equipotency of ergocalciferol and cholecalciferol supplementation in this patient group has not been studied in a randomized trial using high-performance liquid chromatography (HPLC) measurement of serum 25-hydroxyvitamin D (25OHD). The objective of this study was to determine if ergocalciferol and cholecalciferol are equipotent therapies in vitamin D-insufficient hip fracture patients.

Thyroxine autoantibody interference is an uncommon cause of inappropriate TSH secretion using the Immulite 2000 assay.

Background: Inappropriate TSH secretion, as defined by an elevated free thyroxine (fT4) and non-suppressed thyrotropin (TSH) result, can be caused by acute illness, medications, TSH secreting tumours, thyroid hormone resistance or immunoassay interference including thyroid hormone autoantibody interference. T4 autoantibody (T4AAb) prevalence has not been determined. We determined the prevalence of inappropriate TSH secretion using the Immulite 2000 assay and the prevalence of T4AAb within this subgroup.

Selective monitoring of vitamin D2 and D3 supplementation with a highly specific 25-hydroxyvitamin D3 immunoassay with negligible cross-reactivity to 25-hydroxyvitamin D2.

Background: The effects of vitamin D2 and D3 supplementation on circulating concentrations of 25(OH)D3 require reliable analytical tools for specific determination of 25(OH)D3 and 25(OH)D2. We have developed a highly specific 25-OH Vitamin D3 ELISA with negligible cross-reactivity towards 25(OH)D2.

Methods: 25(OH)D3 concentrations were measured in several study participants; 1) 641 healthy men and women; 2) 39 postmenopausal women receiving 400-800 IU vitamin D3 daily for 4 months; 3) 45 men and women with hip fracture receiving 1000 IU vitamin D2 daily for 3 months.