Primary hyperparathyroidism is a common condition that affects 0.3% of the general population. Primary and tertiary care specialists can encounter patients with primary hyperparathyroidism, and prompt recognition and treatment can greatly reduce morbidity and mortality from this disease. In this paper we will review the basic physiology of calcium homeostasis and then consider genetic associations as well as common etiologies and presentations of primary hyperparathyroidism. We will consider emerging trends in detection and measurement of parathyroid hormone as well as available imaging modalities for the parathyroid glands. Surgical indications and approach will be reviewed as well as medical management of primary hyperparathyroidism with bisphosphonates and calcimimetics.

These recent findings will provide more evidence-based recommendations in the future to better assist clinicians in the management of patients with ACC. However, there is still an important need to understand the molecular mechanisms underlying this disease to design better therapeutic approaches.

SummaryA 29-year-old G4A3 woman presented at 25 weeks of pregnancy with progressive signs of Cushing’s syndrome (CS), gestational diabetes requiring insulin and hypertension. A 3.4 × 3.3 cm right adrenal adenoma was identified during abdominal ultrasound imaging for nephrolithiasis. Investigation revealed elevated levels of plasma cortisol, 24 h urinary free cortisol (UFC) and late-night salivary cortisol (LNSC). Serum ACTH levels were not fully suppressed (4 and 5 pmol/L (N: 2–11)). One month post-partum, CS regressed, 24-h UFC had normalised while ACTH levels were now less than 2 pmol/L; however, dexamethasone failed to suppress cortisol levels. Tests performed in vivo 6 weeks post-partum to identify aberrant hormone receptors showed no cortisol stimulation by various tests (including 300 IU hLH i.v.) except after administration of 250 µg i.v. Cosyntropin 1–24. Right adrenalectomy demonstrated an adrenocortical adenoma and atrophy of adjacent cortex. Quantitative RT-PCR analysis of the adenoma revealed the presence of ACTH (MC2) receptor mRNA, while LHCG receptor mRNA was almost undetectable. This case reveals that CS exacerbation in the context of pregnancy can result from the placental-derived ACTH stimulation of MC2 receptors on the adrenocortical adenoma. Possible contribution of other placental-derived factors such as oestrogens, CRH or CRH-like peptides cannot be ruled out.Learning points:Diagnosis of Cushing’s syndrome during pregnancy is complicated by several physiological alterations in hypothalamic–pituitary–adrenal axis regulation occurring in normal pregnancy.Cushing’s syndrome (CS) exacerbation during pregnancy can be associated with aberrant expression of LHCG receptor on primary adrenocortical tumour or hyperplasia in some cases, but not in this patient.Placental-derived ACTH, which is not subject to glucocorticoid negative feedback, stimulated cortisol secretion from this adrenal adenoma causing transient CS exacerbation during pregnancy.Following delivery and tumour removal, suppression of HPA axis can require several months to recover and requires glucocorticoid replacement therapy.

Due to the COVID-19 pandemic, our endocrinology clinic transitioned to virtual care on March 18, 2020. The literature suggests that self-monitoring of blood glucose paired with telemedicine consultations is an effective strategy for diabetes management, however it is unclear whether telemedicine remains effective in the context of the sudden lifestyle changes caused by the pandemic, including non-essential service closures, travel restrictions, lockdowns, and psychosocial impacts. Patients with diabetes are uniquely affected by these restrictions, as glycemic control is heavily dependent on lifestyle and access to essential medications and supplies. The purpose of this project is to determine the impact of telemedicine consultations in the context of the COVID-19 pandemic on the glycemic control of patients seen at our clinic. A retrospective chart review was performed on 300 type 1 and 2 diabetes patients seen at least once within the 6 months preceding (pre-COVID) and following (post-COVID) March 18, 2020. The primary outcome measure was hemoglobin A1c. For patients with more than 1 A1c value in each time frame, the most recent A1c was used. Demographic information was also collected. There was no significant difference in the pre-COVID and post-COVID A1c values (p=0.40) of the entire sample. There was no significant difference in the pre-COVID and post-COVID A1c values when the sample was stratified by age, diabetes duration, use of CGM, or use of pump. However, there was a significant increase in A1c for females post-COVID (p<0.05). This difference was not observed for males (p=0.22). Our data suggests that telemedicine is an overall effective strategy for optimizing glycemic control of patients with type 1 and type 2 diabetes during the pandemic, with no significant difference in A1c. However, the gender-specific effect of telemedicine consultations during COVID-19 on the glycemic control of females with diabetes indicates a need for further study and intervention. Disclosure A. Dissanayake: None. M. Pawlowska: Advisory Panel; Self; Novo Nordisk. B. Schroeder: Advisory Panel; Self; AstraZeneca, Novartis Pharmaceuticals Canada Inc. J. Mackenzie-feder: None. A. White: Advisory Panel; Self; Abbott Diabetes, AstraZeneca, Boehringer Ingelheim (Canada) Ltd., Eli Lilly and Company, Janssen Pharmaceuticals, Inc., Merck & Co., Inc., Novo Nordisk Canada Inc.