Gastric emptying during and following resolution of moderate diabetic ketoacidosis in type 1 diabetes: a case series.

INTRODUCTION: To use the 'gold standard' technique of scintigraphy to quantify gastric emptying (GE) as soon as practicable during an admission with diabetic ketoacidosis (DKA) and following its resolution at least 7 days later. RESEARCH DESIGN AND METHODS: Five patients with type 1 diabetes, age 29±12 years; Body Mass Index 23±3 kg/m2; hemoglobin A1c 11.3%±1.9%, were studied during an admission with DKA and following its resolution. Solid and liquid GE were measured using scintigraphy. Solid emptying was assessed via the percentage intragastric retention at 100 min and that of liquid by the 50% emptying time. RESULTS: There was no difference in either solid or liquid GE at the initial study compared with the follow-up. Median (IQR) solid retention was 47±20 versus 38%±33%, respectively; p=0.31, and time to empty 50% of liquid was 37±25 min versus 35±15 min, p=0.31, at the initial and follow-up GE study, respectively. CONCLUSIONS: GE of solids and liquids is not affected by moderate DKA, inferring that earlier reintroduction of oral intake may be appropriate.

SGLT2 Inhibitor-Associated Ketoacidosis vs Type 1 Diabetes-Associated Ketoacidosis.

This cohort study examines the natural history and response to treatment of sodium glucose cotransporter 2 (SGLT2) inhibitor­associated ketoacidosis compared with that of type 1 diabetes­associated ketoacidosis.

Approach to the Patient: Reninoma.

A reninoma is a functional tumor of afferent arteriolar juxtaglomerular cells that secretes the enzyme renin, leading to hyperactivation of the renin-angiotensin-aldosterone system. Reninoma is a potentially curable cause of pathological secondary hyperaldosteronism that results in often severe hypertension and hypokalemia. The lack of suppression of plasma renin contrasts sharply with the much more common primary aldosteronism, but diagnosis is often prompted by screening for that condition. The major differential diagnosis of reninoma is renovascular hypertension. Fewer than 200 cases of reninoma have been described. Reninomas have been reported across a broad demographic but have a 2:1 predilection for women, often of childbearing age. Aldosterone receptor blockade, angiotensin-converting enzyme inhibitors, or angiotensin receptor blockers offer effective medical management but are contraindicated in pregnancy, so surgical curative resection is ideal. The current optimal imaging and biochemical workup of reninoma and management approach (ideally, tumor excision with subtotal renal resection) are described.

Beware of little expenses: Low-value endocrinological blood tests in geriatric medical inpatients.

OBJECTIVES: Blood tests for endocrinological derangements are frequently requested in general medical inpatients, in particular those in the older age group. Interrogation of these tests may present opportunities for healthcare savings. METHODS: This multicentre retrospective study over a 2.5-year period examined the frequency with which three common endocrinological investigations [thyroid stimulating hormone (TSH), HbA1c, 25-hydroxy Vitamin D3] were performed in this population, including the frequency of duplicate tests within a given admission, and the frequency of abnormal test results. The Medicare Benefits Schedule was used to calculate the cost associated with these tests. RESULTS: There were 28,564 individual admissions included in the study. Individuals ≥65 years old were the majority of inpatients in whom the selected tests were performed (80% of tests). TSH was performed in 6730 admissions, HbA1c was performed in 2259 admissions, and vitamin D levels were performed in 5632 admissions. There were 6114 vitamin D tests performed during the study period, of which 2911 (48%) returned outside the normal range. The cost associated with vitamin D level testing was $183,726. Over the study period, 8% of tests for TSH, HbA1c, and Vitamin D were duplicates (where a second test was performed within a single admission), which was associated with a cost of $32,134. CONCLUSIONS: Tests for common endocrinological abnormalities are associated with significant healthcare costs. Avenues by which future savings may be pursued include the investigation of strategies to reduce duplicate ordering and examining the rationale and guidelines associated with ordering tests such as vitamin D levels.

Euglycemic Ketoacidosis in Two Patients Without Diabetes After Introduction of Sodium-Glucose Cotransporter 2 Inhibitor for Heart Failure With Reduced Ejection Fraction.

OBJECTIVE: Ketoacidosis induced by sodium-glucose cotransporter 2 inhibitor (SGLT2i) treatment has been consistently observed in clinical practice in patients with type 2 diabetes despite minimal indication from the landmark cardiovascular outcome trials. It has been postulated that individuals without diabetes will not develop this complication due to an adequate insulin secretory capacity, which will protect against significant ketone formation. Cardiovascular outcome trials examining SGLT2i use in individuals with heart failure but not diabetes have not reported ketoacidosis. RESEARCH DESIGN AND METHODS: We describe the first two case reports of severe nondiabetic ketoacidosis after initiation of an SGLT2i for the treatment of heart failure with reduced ejection fraction, and we describe the management strategies employed and implication for the pathophysiology of SGLT2i-associated ketoacidosis. RESULTS: Each individual presented with ketoacidosis triggered by reduced oral nutrition intake. For both individuals, ketoacidosis resolved with intravenous glucose administration, encouragement of consumption of oral glucose-containing fluid, and minimal insulin administration. CONCLUSIONS: These two cases demonstrate that SGLT2i-associated ketoacidosis is possible in individuals without diabetes.

Postprandial plasma GLP-1 levels are elevated in individuals with postprandial hypoglycaemia following Roux-en-Y gastric bypass - a systematic review.

BACKGROUND AND AIMS: Bariatric surgery is the most effective treatment in individuals with obesity to achieve remission of type 2 diabetes. Post-bariatric surgery hypoglycaemia occurs frequently, and management remains suboptimal, because of a poor understanding of the underlying pathophysiology. The glucoregulatory hormone responses to nutrients in individuals with and without post-bariatric surgery hypoglycaemia have not been systematically examined. MATERIALS AND METHODS: The study protocol was prospectively registered with PROSPERO. PubMed, EMBASE, Web of Science and the Cochrane databases were searched for publications between January 1990 and November 2021 using MeSH terms related to post-bariatric surgery hypoglycaemia. Studies were included if they evaluated individuals with post-bariatric surgery hypoglycaemia and included measurements of plasma glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), insulin, C-peptide and/or glucagon concentrations following an ingested nutrient load. Glycated haemoglobin (HbA1c) was also evaluated. A random-effects meta-analysis was performed, and Hedges' g (standardised mean difference) and 95% confidence intervals were reported for all outcomes where sufficient studies were available. The τ2 estimate and I2 statistic were used as tests for heterogeneity and a funnel plot with the Egger regression-based test was used to evaluate for publication bias. RESULTS: From 377 identified publications, 12 were included in the analysis. In all 12 studies, the type of bariatric surgery was Roux-en-Y gastric bypass (RYGB). Comparing individuals with and without post-bariatric surgery hypoglycaemia following an ingested nutrient load, the standardised mean difference in peak GLP-1 was 0.57 (95% CI, 0.32, 0.82), peak GIP 0.05 (-0.26, 0.36), peak insulin 0.84 (0.44, 1.23), peak C-peptide 0.69 (0.28, 1.1) and peak glucagon 0.05 (-0.26, 0.36). HbA1c was less in individuals with hypoglycaemia - 0.40 (-0.67, -0.12). There was no evidence of substantial heterogeneity in any outcome except for peak insulin: τ2 = 0.2, I2 = 54.3. No publication bias was evident. CONCLUSION: Following RYGB, postprandial peak plasma GLP-1, insulin and C-peptide concentrations are greater in individuals with post-bariatric surgery hypoglycaemia, while HbA1c is less. These observations support the concept that antagonism of GLP-1 would prove beneficial in the management of individuals with hypoglycaemia following RYGB.PROSPERO Registration Number: CRD42021287515.

Type 2 Diabetes risk alleles in Peptidyl-glycine Alpha-amidating Monooxygenase influence GLP-1 levels and response to GLP-1 Receptor Agonists.

Patients with type 2 diabetes vary in their response to currently available therapeutic agents (including GLP-1 receptor agonists) leading to suboptimal glycemic control and increased risk of complications. We show that human carriers of hypomorphic T2D-risk alleles in the gene encoding peptidyl-glycine alpha-amidating monooxygenase (PAM), as well as Pam-knockout mice, display increased resistance to GLP-1 in vivo. Pam inactivation in mice leads to reduced gastric GLP-1R expression and faster gastric emptying: this persists during GLP-1R agonist treatment and is rescued when GLP-1R activity is antagonized, indicating resistance to GLP-1's gastric slowing properties. Meta-analysis of human data from studies examining GLP-1R agonist response (including RCTs) reveals a relative loss of 44% and 20% of glucose lowering (measured by glycated hemoglobin) in individuals with hypomorphic PAM alleles p.S539W and p.D536G treated with GLP-1R agonist. Genetic variation in PAM has effects on incretin signaling that alters response to medication used commonly for treatment of T2D.

Peri-colonoscopy Implications of Sodium-Glucose Cotransporter-2 Inhibitor Therapy: A Mini-review of Available Evidence.

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are a class of oral glucose-lowering agents commonly used for the treatment of type 2 diabetes. With increased use, there has been an increase in the incidence of the rare but life-threatening complication of euglycemic diabetic ketoacidosis. A common but underappreciated precipitant is colonoscopy. In this work, we outline the pathophysiology of the interaction between colonoscopy and SGLT2i use, the evidence regarding SGLT2i use in the periprocedural setting and Australian Diabetes Society guidelines.

Intraprocedural cortisol testing improves adrenal vein cannulation success and diagnostic accuracy in assessment of primary aldosteronism, in a medium throughput centre.

Primary aldosteronism is the most common cause of secondary hypertension. Identifying individuals who have unilateral secretion from aldosterone secreting adenomas allows adrenalectomy. Surgical treatment when feasible may be superior to medical management with improved cardiovascular outcomes and reduced medication dependence. Adrenal vein sampling (AVS) is required to biochemically lateralise aldosterone secretion prior to adrenalectomy. However, diagnostic success of AVS is variable and can be poor even at tertiary centres; failure is largely due to unsuccessful adrenal vein cannulation. Intra-procedural rapid semiquantitative cortisol testing (RCT) identifies correct catheter placement in real time. We compared diagnostic success rates of AVS before and after the introduction of intraprocedural cortisol testing at the Royal Adelaide Hospital-a medium throughput tertiary centre (average 6.2 procedures a year over the last 8 years). We observed an increase in success rate from 63% to 94%. Intraprocedural cortisol testing also led to a net financial saving of ~$100 AUD per procedure. RCT is likely to be cost effective if pre-RCT success rate is less than 78%. Procedure time and number of samples collected, however, were increased with RCT. This suggests that intraprocedural cortisol testing will improve success in low to medium throughput centres and may make AVS feasible in less specialised centres.

Accidental exposure to glimepiride from adulterated medication resulting in severe hypoglycaemia.

Summary: Sulphonylureas are insulinotropic and are not only useful in patients with diabetes but also act in non-diabetic individuals where hypoglycaemia and hyperinsulinism mimic insulinoma. We present a 63-year-old man who presented with inadvertent sulphonylurea-induced life-threatening hypoglycaemia on two occasions, resulting in hazardous and invasive investigation. Biochemistry revealed endogenous hyperinsulinaemia, with elevated serum c-peptide and insulin concentrations during symptomatic hypoglycaemia, and plasma glucose of 1.7 mmol/L. There was no history of sulphonylurea use prompting anatomical insulinoma studies to locate an insulinoma. However, a routine plasma insulinoma screen-detected glimepiride. Directed history implicated a medication taken for erectile dysfunction prior to disturbed consciousness, with alcohol. The tablets, obtained online, were analysed by mass spectrometry and contained tadalafil and dapoxetine as advertised but also contained glimepiride. Learning points: Symptomatic unexplained hypoglycaemia requires investigation with plasma glucose level, c-peptide, insulin level, pro-insulin, beta-hydroxybutyrate, and a sulphonylurea screen regardless of known exposure to sulphonylureas. Consider contamination of alternative or undisclosed medication, including PDE-5 inhibitor erectile dysfunction drugs. Concomitant alcohol may impair glycogenolysis and gluconeogenesis, exacerbating hypoglycaemia.

Effects of androgens on glucose metabolism.

Type 2 diabetes (T2D) and obesity are common and associated with increased morbidity and mortality. Cross-sectional and longitudinal studies have demonstrated a clear association between T2D, obesity and reduced total testosterone concentration. This relationship becomes less significant or absent with correction for changes in body composition, supporting the notion that changes in body composition are mediating these effects. Moreover, this mediating effect of body composition changes is bi-directional, as evidenced by interventional studies of weight loss and testosterone treatment. On the one hand, in obese men, serum testosterone increases markedly with weight loss. On the other hand, testosterone improves body composition. This relationship is driven by multiple complex interaction between obesity and insulin resistance and the hypothalamic-pituitary-testicular axis, at all levels. Data from randomised control trials have demonstrated that intervention with testosterone therapy increases muscle mass and reduces adiposity. Most recently it has been shown that treatment with testosterone prevents progression of impaired glucose tolerance to T2D, or reverses newly diagnosed T2D beyond lifestyle intervention alone. At present there are insufficient safety data to support the use of testosterone for prevention of type 2 diabetes.

Type 2 diabetes risk alleles in PAM impact insulin release from human pancreatic ß-cells.

The molecular mechanisms underpinning susceptibility loci for type 2 diabetes (T2D) remain poorly understood. Coding variants in peptidylglycine α-amidating monooxygenase (PAM) are associated with both T2D risk and insulinogenic index. Here, we demonstrate that the T2D risk alleles impact negatively on overall PAM activity via defects in expression and catalytic function. PAM deficiency results in reduced insulin content and altered dynamics of insulin secretion in a human ß-cell model and primary islets from cadaveric donors. Thus, our results demonstrate a role for PAM in ß-cell function, and establish molecular mechanisms for T2D risk alleles at this locus.

Comparative effects of prolonged and intermittent stimulation of the glucagon-like peptide 1 receptor on gastric emptying and glycemia.

Acute administration of glucagon-like peptide 1 (GLP-1) and its agonists slows gastric emptying, which represents the major mechanism underlying their attenuation of postprandial glycemic excursions. However, this effect may diminish during prolonged use. We compared the effects of prolonged and intermittent stimulation of the GLP-1 receptor on gastric emptying and glycemia. Ten healthy men received intravenous saline (placebo) or GLP-1 (0.8 pmol/kg ⋅ min), as a continuous 24-h infusion ("prolonged"), two 4.5-h infusions separated by 20 h ("intermittent"), and a 4.5-h infusion ("acute") in a randomized, double-blind, crossover fashion. Gastric emptying of a radiolabeled mashed potato meal was measured using scintigraphy. Acute GLP-1 markedly slowed gastric emptying. The magnitude of the slowing was attenuated with prolonged but maintained with intermittent infusions. GLP-1 potently diminished postprandial glycemia during acute and intermittent regimens. These observations suggest that short-acting GLP-1 agonists may be superior to long-acting agonists when aiming specifically to reduce postprandial glycemic excursions in the treatment of type 2 diabetes.

The effect of exogenous glucose-dependent insulinotropic polypeptide in combination with glucagon-like peptide-1 on glycemia in the critically ill.

OBJECTIVE: Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) have additive insulinotropic effects when coadministered in health. We aimed to determine whether GIP confers additional glucose lowering to that of GLP-1 in the critically ill. RESEARCH DESIGN AND METHODS: Twenty mechanically ventilated critically ill patients without known diabetes were studied in a prospective, randomized, double-blind, crossover fashion on 2 consecutive days. Between T0 and T420 minutes, GLP-1 (1.2 pmol/kg·min(-1)) was infused intravenously with either GIP (2 pmol/kg·min(-1)) or 0.9% saline. Between T60 and T420 minutes, nutrient liquid was infused into the small intestine at 1.5 kcal/min. RESULTS: Adding GIP did not alter blood glucose or insulin responses to small intestinal nutrient. GIP increased glucagon concentrations slightly before nutrient delivery (P=0.03), but not thereafter. CONCLUSIONS: The addition of GIP to GLP-1 does not result in additional glucose-lowering or insulinotropic effects in critically ill patients with acute-onset hyperglycemia.