De-intensification of basal-bolus insulin regimen after initiation of a GLP-1 RA improves glycaemic control and promotes weight loss in subjects with type 2 diabetes

AIMS

To evaluate the impact of adding a glucagon-like peptide-1 receptor agonist (GLP-1 RA) in people with type 2 diabetes (T2D) in basal-bolus (BB) insulin regimen, on insulin requirement, HbA1c, weight loss up to 24 months.

METHODS

Data on subjects with T2D on BB who initiated a GLP-1 RA have been retrospectively collected. HbA1c, body weight, and insulin dose were recorded at baseline, 6, 12, and 24 months after initiation of GLP-1 RA therapy. A linear mixed model for repeated measures was used to evaluate the changes in HbA1c, body weight, and insulin requirement over time.

RESULTS

We included 156 subjects (63.5% males; age 62 ± 11 years, HbA1c 70 ± 22.0 mmol/mol; 8.6 ± 4.2%). Compared to baseline, HbA1c and body weight were significantly lower at 6 months after introducing a GLP-1RA and remained stable up to 24 months (all p < 0.0001 vs. baseline). At 24 months, 81% of subjects discontinued prandial insulin, while 38.6% discontinued basal insulin as well. Insulin requirement at baseline (aOR 0.144; 95% CI, 0.046-0.456; P = 0.001) was the only significant predictor of prandial insulin discontinuation.

CONCLUSIONS

Replacing prandial insulin with GLP-1 RA is a valuable strategy to simplify the BB insulin regimen while improving glycaemic control and promoting weight loss in subjects with T2D.

SIRT1 rs7896005 polymorphism affects major vascular outcomes, not all-cause mortality, in Caucasians with type 2 diabetes: A 13-year observational study

AIMS

SIRT1 exerts effects on ageing and lifespan, as well cardiovascular (CV) disease risk. SIRT1 gene is very polymorph with a few tagging single nucleotide polymorphisms (SNPs) so far identified. Some SNPs, including rs7896005, were associated with type 2 diabetes (T2DM). We aimed to ascertain whether this SNP may be associated with CV disease at baseline as well with these same outcomes and all-cause mortality over a 13-year follow-up.

MATERIALS AND METHODS

Genotypes of SIRT1 gene were determined using TaqMan SNP assay.

RESULTS

Out of 905 T2DM, 9.1% had the AA genotype, 43.2% the AG, and 47.7% the GG. Hardy-Weinberg Equilibrium was met (minor allele frequency 0.306; p = 0.8899). At baseline, there was no difference across genotypes for sex, age, diabetes duration, CV risk factors, treatments, and microangiopathy. Major CV outcomes, myocardial infarction (MI), any coronary heart disease (CHD), and peripheral artery disease (PAD) were more frequent in GG than in AA/AG (p from 0.013 to 0.027), with no association with cerebrovascular events. By fully adjusted regression, GG remained independently related to major CV outcomes, MI, CHD, and PAD. Over follow-up, we recorded 258 major CV events (28.5%; AA/AG 25.2%, GG 32.2%; p = 0.014) with an adjusted hazard ratio (HR) of GG versus AA/AG of 1.296 (95% CI 1.007-1.668, p = 0.044); 169 coronary events (18.7%; AA/AG 15.4%, GG 22.2%; p = 0.006) with HR 1.522 (1.113-2.080, p = 0.008); 79 (8.7%) hospitalisation for heart failure (AA/AG 7.0%, GG 10.6%; p = 0.045) and HR 1.457 (0.919-2.309, p = 0.109); 36 PAD (4.0%; AA/AG 2.3%, GG 5.8%; p = 0.007) with HR 2.225 (1.057-4.684, p = 0.035). No association was found with cerebrovascular events, end stage renal disease, and all-cause mortality.

CONCLUSIONS

The rs7896005 SNP of SIRT1 might play a role in cardiovascular disease, mainly CHD risk in T2DM. Results call for larger association studies as well as studies to ascertain mechanisms by which this variant confers increased risk.

Screening for drugs potentially interfering with MCT8-mediated T3 transport in vitro identifies dexamethasone and some commonly used drugs as inhibitors of MCT8 activity

BACKGROUND

Monocarboxylate transporter 8 (MCT8) is the first thyroid hormone transporter that has been linked to a human disease. Besides genetic alterations other factors might impair MCT8 activity.

AIM

This study aimed at investigating whether some common drugs having a structural similarity with TH and/or whose treatment is associated with thyroid function test abnormalities, or which behave as antagonists of TH action can inhibit MCT8-mediated T₃ transport.

METHODS

[¹²⁵I]T₃ uptake and efflux were measured in COS-7 cells transiently transfected with hMCT8 before and after exposure to increasing concentrations of hydrocortisone, dexamethasone, prednisone, prednisolone, amiodarone, desethylamiodarone, dronedarone, buspirone, carbamazepine, valproic acid, and L-carnitine. The mode of inhibition was also determined.

RESULTS

Dexamethasone significantly inhibited T₃ uptake at 10 μM; hydrocortisone reduced T₃ uptake only at high concentrations, i.e. at 500 and 1000 μM; prednisone and prednisolone were devoid of inhibitory potential. Amiodarone caused a reduction of T₃ uptake by MCT8 only at the highest concentrations used (44% at 50 μM and 68% at 100 μM), and this effect was weaker than that produced by desethylamiodarone and dronedarone; buspirone resulted a potent inhibitor, reducing T₃ uptake at 0.1-10 μM. L-Carnitine inhibited T₃ uptake only at 500 mM and 1 M. Kinetic experiments revealed a noncompetitive mode of inhibition for all compounds. All drugs inhibiting T₃ uptake did not affect T₃ release.

CONCLUSION

This study shows a novel effect of some common drugs, which is inhibition of T₃ transport mediated by MCT8. Specifically, dexamethasone, buspirone, desethylamiodarone, and dronedarone behave as potent inhibitors of MCT8.

Bilateral testicular metastases of medullary thyroid carcinoma in an adult male with multiple endocrine neoplasia 2A syndrome: case report and review of literature

INTRODUCTION

Medullary thyroid cancer (MTC) is a rare endocrine tumor, which can be sporadic or familial, as a component of multiple endocrine neoplasia 2 (MEN2). Overall, 10% of MTC cases have already developed at presentation or will develop metastasis during follow-up. Testicular metastases are exceptional and only one case of unilateral testis involvement by metastatic MTC has been already reported in literature. We described the first known case of asymptomatic bilateral testicular MTC metastases, discovered incidentally at testicular ultrasound (US) performed for unrelated reasons.

CASE PRESENTATION

A Latin American 32-year-old man with MEN 2A syndrome and metastatic MTC underwent andrological and urological examination due to premature ejaculation. US imaging showed two symmetrical hypoechoic lesions involving both testes. Suspecting a bilateral testicular cancer, the patient underwent excision biopsy of both testicular lesions. Histopathology and immunohistochemical examinations documented metastatic MTC of both testicular lesions.

CONCLUSION

Beyond its rarity, testis should be considered as a potential metastatic site of MTC, especially in patients with advanced disease.

ESTABLISHED FACTS

Distant metastases are present at the diagnosis in 10-15% of patients with medullary thyroid carcinoma (MTC). Testicular metastases are anecdotal. Only one case of unilateral testis involvement by metastatic MTC has been reported in the literature.

NOVEL INSIGHTS

Testis should be considered as a possible site of metastases in patients with diffuse metastatic MTC. Testicular ultrasound could be considered as an useful tool for the evaluation and follow-up of metastatic MTC.

Insulin discovery: A pivotal point in medical history

The discovery of insulin in 1921 - due to the efforts of the Canadian research team based in Toronto - has been a landmark achievement in the history of medicine. Lives of people with diabetes were changed forever, considering that in the pre-insulin era this was a deadly condition. Insulin, right after its discovery, became the first hormone to be purified for human use, the first to be unraveled in its amino acid sequence and to be synthetized by DNA-recombinant technique, the first to be modified in its amino acid sequence to modify its duration of action. As such the discovery of insulin represents a pivotal point in medical history. Since the early days of its production, insulin has been improved in its pharmacokinetic and pharmacodynamic properties in the attempt to faithfully reproduce diurnal physiologic plasma insulin fluctuations. The evolution of insulin molecule has been paralleled by evolution in the way the hormone is administered. Once-weekly insulins will be available soon, and glucose-responsive "smart" insulins start showing their potential in early clinical studies. The first century of insulin as therapy was marked by relentless search for better formulations, a search that has not stopped yet. New technologies may have, indeed, the potential to provide further improvement of safety and efficacy of insulin therapy and, therefore, contribute to improvement of the quality of life of people with diabetes.

Effect of aging on clinical features and metabolic complications of women with polycystic ovary syndrome

PURPOSE

To assess the distribution of clinical features and metabolic abnormalities of polycystic ovary syndrome (PCOS) women according to their age.

METHODS

Retrospective study on 602 women (mean age 23.9 ± 6.2 years), diagnosed according to International PCOS Network Guidelines criteria as having PCOS in a University-based Hospital. Anthropometric features, hormonal and metabolic parameters were measured and compared between the different age groups (group A ≤ 20 years; group B 21-30 years; group C > 30 years).

RESULTS

Patients in group A were more often hyperandrogenic, while in group C hypertension, dyslipidemia, obesity, impaired fasting glucose, and insulin resistance (IR) were more prevalent. After adjusting for BMI, age correlated positively with sex hormone-binding globulin (SHBG), IR, total- and LDL-cholesterol, and negatively with DHEAS, insulin, and free androgen index (FAI). SHBG was significantly associated with IR and atherogenic dyslipidemia, while FAI levels were linked to hypertension, independently of other factors considered. Furthermore, the regression analysis showed a stronger relationship between BMI and metabolic outcomes, regardless of age.

CONCLUSION

Polycystic ovarian syndrome (PCOS) phenotype changes with age. Clinical and biochemical hyperandrogenism are a major concern in young PCOS women, while metabolic burden tends to increase with aging. Some of the cardiovascular risk factors are dependent on FAI and SHBG levels, whereas BMI confirms its key role in the genesis of most of the metabolic sequelae in PCOS, independently of age.

Glycaemic control during the lockdown for COVID-19 in adults with type 1 diabetes: A meta-analysis of observational studies

AIMS

To assess the effects of lockdown due to COVID-19 pandemic on glucose metrics, measured by glucose monitoring systems, in adult individuals with type 1 diabetes.

METHODS

We conducted a systematic literature search for English language articles from MEDLINE, Scopus and Web of Science up to February 28, 2021, using "diabetes", "lockdown", and "glucose" as key search terms. Time in range (TIR) was the main outcome; other metrics were time above range (TAR), time below range (TBR), mean blood glucose (MBG) and its variability (%CV), estimated HbA1c (eA1c) or glucose management indicator (GMI).

RESULTS

Seventeen studies for a total of 3,441 individuals with type 1 diabetes were included in the analysis. In the lockdown period, TIR 70-180 mg/dl increased by 3.05% (95% CI 1.67-4.43%; p < 0.0001) while TAR (>180 mg/dL and > 250 mg/dL) declined by 3.39% (-5.14 to -1.63%) and 1.96% (-2.51 to -1.42%), respectively (p < 0.0001 for both). Both TBR < 70 and <54 mg/dL remained unchanged. MBG slightly decreased by 5.40 mg/dL (-7.29 to -3.51 mg/dL; p < 0.0001) along with a reduction in %CV. Pooled eA1c and GMI decreased by 0.18% (-0.24 to -0.11%; p < 0.0001) and a similar reduction was observed when GMI alone was considered (0.15%, -0.23 to -0.07%; p < 0.0001). Sensor use was only slightly but not significantly reduced during lockdown.

CONCLUSIONS

This meta-analysis shows that well-controlled people with type 1 diabetes on both MDI and CSII with continuous or flash glucose monitoring did not experience a deterioration in glucose control throughout the COVID-19 lockdown, showing a modest, though statistically significant improvement in many glucose control parameters.

Impact of COVID-19 lockdown on glucose control of elderly people with type 2 diabetes in Italy

AIMS

to evaluate the effect of home confinement related to COVID-19 lockdown on metabolic control in subjects with T2DM in Italy.

METHODS

we evaluated the metabolic profile of 304 individuals with T2DM (65% males; age 69 ± 9 years; diabetes duration 16 ± 10 years) attending our Diabetes Unit early at the end of lockdown period (June 8 to July 7, 2020) and compared it with the latest one recorded before lockdown.

RESULTS

There was no significant difference in fasting plasma glucose (8.6 ± 2.1 vs 8.8 ± 2.5 mmol/L; P = 0.353) and HbA1c (7.1 ± 0.9 vs 7.1 ± 0.9%; P = 0.600) before and after lockdown. Worsening of glycaemic control (i.e., ΔHbA1c ≥ 0.5%) occurred more frequently in older patients (32.2% in > 80 years vs 21.3% in 61-80 years vs 9.3% in < 60 years; P = 0.05) and in insulin users (28.8 vs 16.5%; P = 0.012). On multivariable analysis, age > 80 years (OR 4.62; 95%CI: 1.22-16.07) and insulin therapy (OR 1.96; 95%CI: 1.10-3.50) remained independently associated to worsening in glycaemic control.

CONCLUSIONS

Home confinement related to COVID-19 lockdown did not exert a negative effect on glycaemic control in patients with T2DM. However, age and insulin therapy can identify patients at greatest risk of deterioration of glycaemic control.

The Role of Nuclear Medicine in the Clinical Management of Benign Thyroid Disorders, Part 2: Nodular Goiter, Hypothyroidism, and Subacute Thyroiditis

Part 2 of this series of Continuing Education articles on benign thyroid disorders deals with nodular goiter, hypothyroidism, and subacute thyroiditis. Together with Part 1 (which dealt with various forms of hyperthyroidism), this article is intended to provide relevant information for specialists in nuclear medicine dealing with the clinical management of patients with benign thyroid disorders, the primary audience for this series. Goiter, an enlargement of the thyroid gland, is a common endocrine abnormality. Constitutional factors, genetic abnormalities, or dietary and environmental factors may contribute to the development of nodular goiter. Most patients with nontoxic nodular goiter are asymptomatic or have only mild mechanical symptoms (globus pharyngis). Work-up of these patients includes measurement of thyroid-stimulating hormone, free triiodothyronine, free thyroxine, thyroid autoantibodies, ultrasound imaging, thyroid scintigraphy, and fine-needle aspiration biopsy of nodules with certain ultrasound and scintigraphic features. Treatment for multinodular goiter includes dietary iodine supplementation, surgery, radioiodine therapy (to decrease thyroid size), and minimally invasive ablation techniques. Hypothyroidism ranges from rare cases of myxedema to more common mild forms (subclinical hypothyroidism). Primary hypothyroidism often has an autoimmune etiology. Clinical presentations differ in neonates, children, adults, and elderly patients. Work-up includes thyroid function tests and ultrasound imaging. Nuclear medicine is primarily used to locate ectopic thyroid tissue in congenital hypothyroidism or to detect defects in iodine organification with the perchlorate discharge test. Treatment consists of thyroid replacement therapy with l-thyroxine, adjusting the daily dose to the individual patient's metabolic and hormonal requirements. Subacute thyroiditis is a self-limited inflammatory disorder of the thyroid gland, often associated with painless or painful swelling of the gland and somatic signs or symptoms. Inflammation disrupts thyroid follicles resulting in a rapid release of stored thyroxine and triiodothyronine causing an initial thyrotoxic phase, often followed by transient or permanent hypothyroidism. Although subacute thyroiditis is often related to a viral infection, no infective agent has been identified. Subacute thyroiditis may be caused by a viral infection in genetically predisposed individuals. Work-up includes lab tests, ultrasound imaging, and radionuclide imaging. Thyroid scintigraphy demonstrates different findings depending on the phase of the illness, ranging from very low or absent tracer uptake in the thyroid gland in the hyperthyroid phase to a normal appearance in the late recovery phase. Since subacute thyroiditis is self-limited, treatment is directed toward relief of pain. High-dose nonsteroidal antiinflammatory drugs are usually the first-line treatment. If severe pain persists, a course of corticosteroids may be necessary. Permanent hypothyroidism develops in up to 15% of patients with subacute thyroiditis, even more than 1 y after presentation.

Clinical features, risk of mass enlargement, and development of endocrine hyperfunction in patients with adrenal incidentalomas: a long-term follow-up study

PURPOSE

To evaluate the risk of mass enlargement and endocrine function modification in patients with adrenal incidentaloma (AI).

METHODS

In this retrospective study, we examined clinical and hormonal characteristics of 310 patients with AI (200 females and 110 males; age: 58.3 ± 12.9 years), followed up for a median (interquartile range) of 31.4 months (13.0-78.6) and evaluated for possible modification in adrenal mass size and hormonal function. The hormonal evaluation included morning serum cortisol and plasma ACTH at 8 a.m., aldosterone, plasma renin activity/direct renin concentration, and 24-h urine metanephrines/normetanephrines. One microgram overnight dexamethasone suppression test (DST) was performed. Autonomous cortisol secretion (ACS) was diagnosed in the presence of cortisol after 1 mg DST > 5 μg/dl (138 nmol/l) or >1.8 and ≤5 μg/dl (50-138 nmol/l) and at least one of the following: (i) low ACTH; (ii) increased 24-h urinary-free cortisol; (iii) absence of cortisol rhythm; and (iv) post-LDDST cortisol level > 1.8 μg/dl (50 nmol/l). When there was no biochemical evidence of adrenal hormonal hyperactivity, AIs were classified as nonfunctioning (NFAIs). The mass was considered significantly enlarged when the size increase was more than 20% and at least 5 mm compared to baseline.

RESULTS

At diagnosis, NFAIs were found in 209 patients, while ACS and overt adrenal hyperfunction were diagnosed in 81 and 20 patients, respectively. During follow-up, 3.3% and 1.5% of patients with NFAI developed subtle and overt endocrine hyperfunction, respectively, while a significant mass enlargement was observed in 17.7% of all AIs. The risk of developing ACS was significantly higher in patients with adenoma >28 mm (hazard ratio [HR] 12.4; 95% confidence interval [CI], 2.33-66.52, P = 0.003), in those with bilateral adrenal tumors (HR: 5.36; 95% CI, 1.17-24.48, P = 0.030), and with low/suppressed ACTH values (HR: 11.2, 95% CI 2.06-60.77; P = 0.005). The risk of mass enlargement was lower for patients in the fourth quartile of body mass index than those in the first quartile (HR 0.33; 95% CI, 0.14-0.78; P = 0.012).

CONCLUSIONS

In patients with AI, the risk of developing hormonal hyperfunction and mass enlargement is overall low, although some tumor characteristics and anthropometric features might increase this risk. Taking account of all these aspects is important for planning a tailored follow-up in AI patients.

MON-661 Association of 25-Hydroxyvitamin D Serum Levels with Markers of Glycemic Control in Diabetic and Nondiabetic Patients on Maintenance Hemodialysis

Introduction: In type 2 diabetic patients (T2DM) with end-stage renal disease (ESRD) on hemodialysis (HD), an inverse relationship between 25(OH)D and glycated hemoglobin (HbA1c) have been reported. However, because of anemia and altered red cells turnover, glycated albumin (GA) has been proposed as a more reliable glycemic marker in these subjects. Therefore, we have examined whether an association exists between 25(OH)D and GA in HD diabetic and nondiabetic (ND) subjects.

Material and methods: A total of 121 HD (M/F: 69/31%; age 69±15), of whom 43 (35.5%) had T2DM, were analyzed. Median Hb level was 10.2 g/dL (IQR, 9.35-10.9) and median albumin was 3.44 g/dL (IQR, 3.09-3.77). The median dialysis vintage was 29.3 months (IQR, 11.6-67.44). In all subjects, 25(OH)D, HbA1c, and GA were determined on the morning of the dialysis.

Results: Median 25(OH)D concentration in the whole study population was 25.5 mcg/mL (IQR, 17.7-33.75), while median HbA1c level was 37 mmol/mol (IQR, 32-43) and GA was 16.5% (IQR, 14.3-20.2). The median serum concentration of 25(OH)D was lower in T2DM group compared to ND (19.0 vs. 27.3 mcg/mL; P=0.002). In the entire cohort, there was an inverse relationship between 25(OH)D and GA (r: -0.255; P=0.005), while there was no significant correlation between HbA1c and 25(OH)D (r:-0.158; p=0.086). The relationship between GA and 25(OH)D levels was confirmed among T2DM patients (r: -0.375; P=0.013) but not in ND (r: -0.036; P=0.751), while HbA1c didn’t significantly correlate with 25(OH)D neither in T2DM (r: -0.255; P=0.099) nor in ND (r: -0.002; P=0.986). Both in the whole cohort as well in T2DM, the independent association of GA and 25(OH)D persisted upon adjustment for age, sex, BMI, dialysis duration, and vitamin D supplementation. By these regression analyses, it was calculated that 10 mcg/mL decline in 25(OH)D was associated with a 2.4% increase in GA. When T2DM individuals were considered, this increase was 75% greater (4.2%).

Conclusions: In HD patients, serum 25(OH)D is more strongly associated with GA than HbA1c in both diabetic and nondiabetic subjects. This might reflect the higher reliability of GA in assessing glucose control in this category of subjects. Furthermore, lower serum 25(OH)D concentration was associated with poorer glycemic control among T2DM subjects, but not in ND. Since 25(OH)D deficiency was more prevalent in T2DM than ND, these findings could emphasize the importance of adequate vitamin D repletion in this category of patients. Whether correction of vitamin D insufficiency might affect GA levels remains to be explored.

Tako-tsubo Syndrome as First Manifestation in a Case of Pheochromocytoma Developed From a Non-functional Adrenal Incidentaloma

Background: Pheochromocytoma is a catecholamine secreting tumor that, in extremely rare cases, may develop over time from a non-functional adrenal adenoma. Catecholamine excess can lead to a kind of cardiomyopathy similar to that seen in tako-tsubo syndrome (TTS). Case report: A 69 years old female with a history of type 2 diabetes, hypertension, and a non-functional right adrenal adenoma diagnosed 3 years earlier was referred to our center for further investigations. During the evaluation, she had a hypertensive crisis with chest pain, tachycardia, and diaphoresis. Suspecting an acute coronary syndrome, she underwent coronary angiography, which showed the typical features of TTS. The high 24 h-urinary metanephrines excretion and abdominal MRI findings were suggestive of pheochromocytoma. Right laparoscopic adrenalectomy was performed, with the resolution of all symptoms. Pathology findings confirmed the diagnosis of pheochromocytoma. After 12 months, the patient was still asymptomatic, with the echocardiography displaying a complete recovery of the left-ventricular function. Conclusions: The development of a pheochromocytoma from an adrenal non functional adenoma is an extremely rare event, but potentially life-threating because of the catecholamine-associated cardiovascular toxicity. In particular, TTS is a form of cardiomyopathy that has been increasingly described as associated with catecholamine-secreting tumors. The exclusion of pheochromocytoma in a patient with TTS has important therapeutic implications, since the administration of β-blockers may be extremely harmful in patients with catecholamine surge in the absence of adequate α-blockage.