Current and Emerging Aspects of Diabetes Mellitus in Acromegaly

Standards of care for medical management of acromegaly in pituitary tumor centers of excellence (PTCOE)

PURPOSE

A series of consensus guidelines on medical treatment of acromegaly have been produced in the last two decades. However, little information is available on their application in clinical practice. Furthermore, international standards of acromegaly care have not been published. The aim of our study was to report current standards of care for medical therapy of acromegaly, using results collected through an audit performed to validate criteria for definition of Pituitary Tumor Centers of Excellence (PTCOE).

METHODS

Details of medical treatment approaches to acromegaly were voluntarily provided by nine renowned international centers that participated in this audit. For the period 2018-2020, we assessed overall number of acromegaly patients under medical treatment, distribution of patients on different treatment modalities, overall biochemical control rate with medical therapy, and specific control rates for different medical treatment options.

RESULTS

Median number of total patients and median number of new patients with acromegaly managed annually in the endocrinology units of the centers were 206 and 16.3, respectively. Median percentage of acromegaly patients on medical treatment was 48.9%. Among the patients on medical treatment, first-generation somatostatin receptor ligand (SRL) monotherapy was used with a median rate of 48.7%, followed by combination therapies with a median rate of 29.3%. Cabergoline monotherapy was used in 6.9% of patients. Pegvisomant monotherapy was used in 7 centers and pasireotide monotherapy in 5 centers, with median rates of 7.9% and 6.3%, respectively.

CONCLUSIONS

Current standards of care in PTCOEs include use of first-generation SRLs as the first medical option in about 50% of patients, as recommended by consensus guidelines. However, some patients are kept on this treatment despite inadequate control suggesting that cost-effectiveness, availability, patient preference, side effects, and therapeutic inertia may play a possible role also in PTCOE. Moreover, at odds with consensus guidelines, other monotherapies for acromegaly appear to have a marginal role as compared to combination therapies as extrapolated from PTCOE practice data. Presence of uncontrolled patients in each treatment category suggest that further optimization of medical therapy, as well as use of other therapeutic tools such as radiosurgery may be needed.

Insights from an Italian Delphi panel: exploring resistance to first-generation somatostatin receptor ligands and guiding second-line medical therapies in acromegaly management

PURPOSE

First-line medical therapy for acromegaly management includes first-generation somatostatin receptor ligands (fgSRLs), but resistance limits their use. Despite international guidelines, the choice of second-line therapy is debated.

METHODS

We aim to discuss resistance to fgSRLs, identify second-line therapy determinants and assess glycemia's impact to provide valuable insights for acromegaly management in clinical practice. A group of Italian endocrinologists expert in the pituitary field participated in a two-round Delphi panel between July and September 2023. The Delphi questionnaire encompassed a total of 75 statements categorized into three sections: resistance to fgSRLs therapy and predictors of response; determinants for the selection of second-line therapy; the role of glycemia in the therapeutic management. The statements were rated on a 6-point Likert scale.

RESULTS

Fifty-nine (79%) statements reached a consensus. IGF-1 levels resulted central for evaluating resistance to fgSRLs, that should be defined considering also symptomatic clinical response, degree of tumor shrinkage and complications, using clinician- and patient-reported outcome tools available. Factors to be evaluated for the choice of second-line medical therapy are hyperglycemia-that should be managed as in non-acromegalic patients-tumor remnant, resistant headache and compliance. Costs do not represent a main determinant in the choice of second-line medical treatment.

CONCLUSION

The experts agreed on a holistic management approach to acromegaly. It is therefore necessary to choose currently available highly effective second-line medical treatment (pegvisomant and pasireotide) based on the characteristics of the patients.

Glucose intolerance in acromegaly is driven by low insulin secretion; results from an intravenous glucose tolerance test

PURPOSE

Insulin sensitivity (Si) and its role in glucose intolerance of acromegaly has been extensively evaluated. However, data on insulin secretion is limited. We aimed to assess stimulated insulin secretion using an intravenous glucose tolerance test (IVGTT) in active acromegaly.

METHODS

We performed an IVGTT in 25 patients with active acromegaly (13 normal glucose tolerance [NGT], 6 impaired glucose tolerance [IGT] and 6 diabetes mellitus [DM]) and 23 controls (8 lean NGT, 8 obese NGT and 7 obese IGT). Serum glucose and insulin were measured at 20 time points along the test to calculate Si and acute insulin response (AIRg). Medical treatment for acromegaly or diabetes was not allowed.

RESULTS

In acromegaly, patients with NGT had significantly (p for trend < 0.001) higher AIRg (3383 ± 1082 pmol*min/L) than IGT (1215 ± 1069) and DM (506 ± 600). AIRg was higher in NGT (4764 ± 1180 pmol*min/L) and IGT (3183 ± 3261) controls with obesity than NGT (p = 0.01) or IGT (p = 0.17) acromegaly. Si was not significantly lower in IGT (0.68 [0.37, 0.88] 106*L/pmol*min) and DM (0.60 [0.42, 0.84]) than in NGT (0.81 [0.58, 1.55]) patients with acromegaly. NGT (0.33 [0.30, 0.47] 106*L/pmol*min) and IGT (0.37 [0.21, 0.66]) controls with obesity had lower Si than NGT (p = 0.001) and IGT (p = 0.43) acromegaly.

CONCLUSION

We demonstrated that low insulin secretion is the main driver behind glucose intolerance in acromegaly. Compared to NGT and IGT controls with obesity, patients with NGT or IGT acromegaly had higher Si. Together, these findings suggest that impaired insulin secretion might be a specific mechanism for glucose intolerance in acromegaly.

Management of pasireotide-induced hyperglycemia in patients with acromegaly: An experts' consensus statement

Pasireotide is a somatostatin analogue for the treatment of acromegaly, a chronic condition caused by excess growth hormone. Despite the therapeutic benefits of pasireotide as a second-line treatment for inadequately controlled acromegaly, a major concern is its hyperglycemic side-effect. Here, we provide guidance on how to select appropriate patients with acromegaly for treatment with pasireotide. We summarize baseline characteristics of patients at high risk for pasireotide-associated hyperglycemia and recommend a monitoring strategy based on the risk profile. Self-monitoring of blood glucose levels (SMBG), measurements of fasting plasma glucose (FPG), postprandial plasma glucose (PPG) and regular HbA1c measurements are the foundation of our proposed monitoring approach. The pathophysiology of pasireotide-induced hyperglycemia involves decreased secretion of the incretin hormones GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 (glucagon-like peptide-1). Our expert recommendations address the specific pathophysiology of pasireotide-induced hyperglycemia by recommending the incretin-based therapeutics dipeptidyl peptidase-4 inhibitors (DPP-4i) and glucagon-like peptide-1 receptor agonists (GLP-1 RA) in all appropriate patients as an alternative to first-line monotherapy with metformin. Furthermore, we emphasize the importance of adequate control of acromegaly, excellent diabetes education, nutrition and lifestyle guidance and advise to consult expert diabetologists in case of uncertainty in the management of patients with hyperglycemia under pasireotide.

Consensus on criteria for acromegaly diagnosis and remission

PURPOSE

The 14th Acromegaly Consensus Conference was convened to consider biochemical criteria for acromegaly diagnosis and evaluation of therapeutic efficacy.

METHODS

Fifty-six acromegaly experts from 16 countries reviewed and discussed current evidence focused on biochemical assays; criteria for diagnosis and the role of imaging, pathology, and clinical assessments; consequences of diagnostic delay; criteria for remission and recommendations for follow up; and the value of assessment and monitoring in defining disease progression, selecting appropriate treatments, and maximizing patient outcomes.

RESULTS

In a patient with typical acromegaly features, insulin-like growth factor (IGF)-I > 1.3 times the upper limit of normal for age confirms the diagnosis. Random growth hormone (GH) measured after overnight fasting may be useful for informing prognosis, but is not required for diagnosis. For patients with equivocal results, IGF-I measurements using the same validated assay can be repeated, and oral glucose tolerance testing might also be useful. Although biochemical remission is the primary assessment of treatment outcome, biochemical findings should be interpreted within the clinical context of acromegaly. Follow up assessments should consider biochemical evaluation of treatment effectiveness, imaging studies evaluating residual/recurrent adenoma mass, and clinical signs and symptoms of acromegaly, its complications, and comorbidities. Referral to a multidisciplinary pituitary center should be considered for patients with equivocal biochemical, pathology, or imaging findings at diagnosis, and for patients insufficiently responsive to standard treatment approaches.

CONCLUSION

Consensus recommendations highlight new understandings of disordered GH and IGF-I in patients with acromegaly and the importance of expert management for this rare disease.

Metabolic Syndrome Components in Patients with Pituitary Adenoma

Pituitary adenomas are benign tumors of the anterior portion of the pituitary gland (adenohypophysis), representing the 25% of all the tumor alterations. Pituitary adenomas are classified by the type of hormone secreted, cellularity, size, and structural alterations by the hormonal segregation. The diagnosis consists on the histopathological identification of cell types and the image-guided by magnetic resonance or tomography; the treatment can be both pharmacological and surgical. Metabolic Syndrome is the set of clinical conditions that increase the risk of cardiovascular diseases with an estimated prevalence of 25% worldwide. The alterations of metabolic syndrome are obesity, hypertension, dyslipidemia, insulin resistance, and diabetes mellitus type II. Pituitary adenomas and metabolic syndrome have an important relationship, hormone-secreting by pituitary adenomas affects a myriad of signaling pathways, which allows a favorable environment for the appearance of the metabolic syndrome. Moreover, patients with pituitary adenomas are shown to have an improvement in metabolic parameters after the medical/surgical treatment. The objective of this review is to explore the possible mechanisms through which PAs contributes to MetSx.

Efficacy and Safety of Pegvisomant in the Treatment of Acromegaly

Pegvisomant, the first and currently only clinically available growth hormone receptor antagonist, is an effective therapeutic option for the medical treatment of acromegaly, a rare disorder characterized by excessive growth hormone secretion. With now over 20 years of real world experience, its safety and efficacy is well-established. However, several aspects of its clinical use are still controversially discussed. The high cost of pegvisomant has limited its use in several countries, and recent studies have reported a lower efficacy than the initial clinical trials. A reported increase in tumor volume under therapy varies between studies and has been attributed to either actual growth or re-expansion after cessation of somatostatin receptor ligand therapy. Furthermore, different combinations of pegvisomant and other therapeutic agents aiming at reduction of acromegaly disease activity have been proposed to increase or retain effectiveness while lowering side effects and cost. This review aims to assess current clinical data on the safety and efficacy of pegvisomant while also addressing controversies surrounding its use.

Pilot study to define criteria for Pituitary Tumors Centers of Excellence (PTCOE): results of an audit of leading international centers

PURPOSE

The Pituitary Society established the concept and mostly qualitative parameters for defining uniform criteria for Pituitary Tumor Centers of Excellence (PTCOEs) based on expert consensus. Aim of the study was to validate those previously proposed criteria through collection and evaluation of self-reported activity of several internationally-recognized tertiary pituitary centers, thereby transforming the qualitative 2017 definition into a validated quantitative one, which could serve as the basis for future objective PTCOE accreditation.

METHODS

An ad hoc prepared database was distributed to nine Pituitary Centers chosen by the Project Scientific Committee and comprising Centers of worldwide repute, which agreed to provide activity information derived from registries related to the years 2018-2020 and completing the database within 60 days. The database, provided by each center and composed of Excel® spreadsheets with requested specific information on leading and supporting teams, was reviewed by two blinded referees and all 9 candidate centers satisfied the overall PTCOE definition, according to referees' evaluations. To obtain objective numerical criteria, median values for each activity/parameter were considered as the preferred PTCOE definition target, whereas the low limit of the range was selected as the acceptable target for each respective parameter.

RESULTS

Three dedicated pituitary neurosurgeons are preferred, whereas one dedicated surgeon is acceptable. Moreover, 100 surgical procedures per center per year are preferred, while the results indicated that 50 surgeries per year are acceptable. Acute post-surgery complications, including mortality and readmission rates, should preferably be negligible or nonexistent, but acceptable criterion is a rate lower than 10% of patients with complications requiring readmission within 30 days after surgery. Four endocrinologists devoted to pituitary diseases are requested in a PTCOE and the total population of patients followed in a PTCOE should not be less than 850. It appears acceptable that at least one dedicated/expert in pituitary diseases is present in neuroradiology, pathology, and ophthalmology groups, whereas at least two expert radiation oncologists are needed.

CONCLUSION

This is, to our knowledge, the first study to survey and evaluate the activity of a relevant number of high-volume centers in the pituitary field. This effort, internally validated by ad hoc reviewers, allowed for transformation of previously formulated theoretical criteria for the definition of a PTCOE to precise numerical definitions based on real-life evidence. The application of a derived synopsis of criteria could be used by independent bodies for accreditation of pituitary centers as PTCOEs.

Discordant biochemical parameters of acromegaly remission do not influence the prevalence or aggressiveness of metabolic comorbidities: a single-center study

Purpose

The discrepancy between the biomarkers of disease's activity in acromegalic patients (GH and IGF-1) is almost frequent representing a challenge for the development of comorbidities in the long term. The aim of this study was to evaluate the prevalence and severity of metabolic comorbidities (diabetes, hypertension, and dyslipidemia) in surgically treated acromegalic patients with disease control and discordant GH and/or IGF-1 levels compared with those with concordant values.

Patients and methods

Retrospective monocentric observational study on acromegalic surgically treated patients with biochemical remission (group A) or mild discordant GH or IGF-1 levels (group B). Metabolic complications and medical therapy were assessed at diagnosis and at the last follow-up visit. Severity of the disease was set for drug titration or shift to another molecule or more than before.

Results

There were 18 patients that met the inclusion criteria [group A: nine patients; group B: nine patients, follow-up 7 years (IQR 5.0;11.25)]. The prevalence of female patients was significantly higher in the remission group compared with the discordant group (p < 0.02). Considering metabolic complications, at the last follow-up, 61.1% was affected by hypertension, 33.3% by diabetes, and 61.1% by dyslipidemia, without differences between groups. Drug characteristics (dose, shift, number) during the follow-up did not differ significantly between groups.

Conclusion

Metabolic complications, mainly dyslipidemia, are frequent in cured acromegalic patients, but GH/IGF-1 discrepancy does not seem to represent a risk factor for their presence or persistence. More extended studies are needed to confirm our results in a long-term period.

Uric acid levels correlate with disease activity in growth hormone-secreting pituitary adenoma patients

Objective

Few studies reported the effects of growth hormone-secreting pituitary adenoma (GHPA) on uric acid (UA) metabolism and the relationship between growth hormone (GH)/insulin-like growth factor-1 (IGF-1) levels and UA are controversial. This study aimed to evaluate the relationship between IGF-1 and UA in patients with GHPA and to further clarify whether UA levels are associated with GHPA disease activity by follow-up.

Methods

A longitudinal study of 424 GHPA patients presenting to Beijing Tiantan Hospital, Capital Medical University between January 2015 and January 2023 was conducted. Spearman's correlation tests were performed to examine the relationship between IGF-1 and UA at baseline. Univariate and multivariate linear regression analysis was conducted to investigate the independent association between UA and IGF-1. Changes in postoperative IGF-1 and UA levels were followed prospectively, and the differences in UA levels between the biochemical remission and nonremission groups were compared.

Results

At baseline, male patients, the lower the age, the higher the IGF-1 and body mass index (BMI), and the higher the UA levels. IGF-1 was significantly associated with UA after controlling for sex, age, and BMI (r = 0.122, P = 0.012). In adjusted multiple linear regression analysis, IGF-1 was independently associated with UA, and UA levels increased significantly with increasing IGF-1. During postoperative follow-up, UA decreased gradually as IGF-1 levels decreased. At 12 months postoperatively, UA levels were significantly lower in the biochemical remission group than in the nonremission group (P = 0.038).

Conclusions

In patients with GHPA, UA levels are associated with disease activity. Changes in UA levels should be taken into account in the comprehensive treatment of GHPA, patients presenting with HUA should be given lifestyle guidance and appropriate urate-lowering treatment according to their condition to better improve their prognosis.

Diabetes Mellitus Secondary to Endocrine Diseases: An Update of Diagnostic and Treatment Particularities

Secondary diabetes mellitus is frequently ignored in specialized literature. In this narrative review, the main endocrinopathies accompanied by increased glycemic values are identified, as well as the mechanisms by which the excess or deficiency of certain hormones impact beta cell function or insulin resistance. The main endocrinopathies (acromegaly, Cushing's syndrome, Basedow-Graves' disease, pheochromocytoma, somatostatinoma and glucagonoma) and their characteristics are described along with the impact of hormone changes on blood sugar, body mass index and other parameters associated with diabetes. The overall information regarding the complex molecular mechanisms that cause the risk of secondary diabetes and metabolic syndrome is of crucial importance in order to prevent the development of the disease and its complications and particularly to reduce the cardiovascular risk of these patients. The purpose of this study is to highlight the particular features of endocrine pathologies accompanied by an increased risk of developing diabetes, in the context of personalized therapeutic decision making. The epidemiological, physiopathological, clinical and therapeutic approaches are presented along with the importance of screening for diabetes in endocrine diseases.

Fibroblast Growth Factor 23: Potential Marker of Invisible Heart Damage in Diabetic Population

Two-dimensional speckle-tracking echocardiography (2DSTE) detects myocardial dysfunction despite a preserved left ventricular ejection fraction. Fibroblast growth factor 23 (FGF23) has become a promising biomarker of cardiovascular risk. This study aimed to determine whether FGF23 may be used as a marker of myocardial damage among patients with diabetes mellitus type 2 (T2DM) and no previous history of myocardial infarction. The study enrolled 71 patients with a median age of 70 years. Laboratory data were analyzed retrospectively. Serum FGF23 levels were determined using a sandwich enzyme-linked immunosorbent assay. All patients underwent conventional echocardiography and 2DSTE. Baseline characteristics indicated that the median time elapsed since diagnosis with T2DM was 19 years. All subjects were divided into two groups according to left ventricular diastolic function. Individuals with confirmed left ventricular diastolic dysfunction had significantly lower levels of estimated glomerular filtration rate and higher values of hemoglobin A1c. Global circumferential strain (GCS) was reduced in the majority of patients. Only an epicardial GCS correlated significantly with the FGF23 concentration in all patients. The study indicates that a cardiac strain is a reliable tool for a subtle myocardial damage assessment. It is possible that FGF23 may become an early diagnostic marker of myocardial damage in patients with T2DM.

Secondary diabetes mellitus in acromegaly

Secondary diabetes mellitus (DM) is a common complication of acromegaly, encountered in up to 55% of cases. Vice versa, the prevalence of acromegaly is markedly higher in cohorts of patients with type 2 DM (T2DM). The presence of secondary DM depends primarily on acromegaly status and is associated with increased cardiovascular morbidity, malignancy rate and overall mortality. The principal pathophysiologic mechanism is increased insulin resistance due to excessive lipolysis and altered fat distribution, reflected at the presence of intermuscular fat and attenuated, dysfunctional adipose tissue. Insulin resistance is ascribed to the direct, diabetogenic effects of growth hormone (GH), which prevail over the insulin-sensitizing effects of insulin-like growth factor 1 (IGF-1), probably due to higher glucometabolic potency of GH, IGF-1 resistance, or both. Inversely, GH and IGF-1 act synergistically in increasing insulin secretion. Hyperinsulinemia in portal vein leads to enhanced responsiveness of liver GH receptors and IGF-1 production, pointing towards a mutually amplifying loop between GH-IGF-1 axis and insulin. Secondary DM occurs upon beta cell exhaustion, principally due to gluco-lipo-toxicity. Somatostatin analogues inhibit insulin secretion; especially pasireotide (PASI) impairs glycaemic profile in up to 75% of cases, establishing a separate pathophysiologic entity, PASI-induced DM. In contrast, pegvisomant and dopamine agonizts improve insulin sensitivity. In turn, metformin, pioglitazone and sodium-glucose transporters 2 inhibitors might be disease-modifying by counteracting hyperinsulinemia or acting pleiotropically. Large, prospective cohort studies are needed to validate the above notions and define optimal DM management in acromegaly.

New tools for bone health assessment in secreting pituitary adenomas

Pituitary hormones regulate skeletal physiology, and excess levels affect bone remodeling and alter bone microstructure. Vertebral fractures (VFs) are an early phenomenon of impaired bone health in secreting pituitary adenomas. However, they are not accurately predicted by areal bone mineral density (BMD). Emerging data demonstrate that a morphometric approach is essential for evaluating bone health in this clinical setting and is considered to be the gold standard method in acromegaly. Several novel tools have been proposed as alternative or additional methods for the prediction of fractures, particularly in pituitary-driven osteopathies. This review highlights the novel potential biomarkers and diagnostic methods for bone fragility, including their pathophysiological, clinical, radiological, and therapeutic implications in acromegaly, prolactinomas, and Cushing's disease.

De-escalation treatment with pasireotide for acromegaly: a long-term experience

INTRODUCTION

Pasireotide long-acting release (LAR) is approved for second-line treatment of acromegaly. Starting pasireotide LAR 40 mg every 4 weeks is recommended and then up-titrate to 60 mg monthly in case of IGF-I uncontrolled levels. We present three patients treated with a de-escalation approach with pasireotide LAR. CASE 1: A 61-year-old female diagnosed with resistant acromegaly was treated with pasireotide LAR 60 mg every 28 days. When IGF-I reached the lower age range, therapy was decreased to pasireotide LAR 40 mg and then to 20 mg. In 2021 and 2022, IGF-I value remained within the normal range. CASE 2: A 40-year-old female diagnosed with resistant acromegaly underwent three neurosurgeries. In 2011, she was enrolled in the PAOLA study and assigned to pasireotide LAR 60 mg. Due to IGF-I overcontrol and radiological stability, therapy was downscaled to 40 mg in 2016 and to 20 mg in 2019. The patient developed hyperglycemia, which was treated with metformin. CASE 3: A 37-year-old male diagnosed with resistant acromegaly was treated with pasireotide LAR 60 mg in 2011. In 2018, therapy was decreased to 40 mg due to IGF-I overcontrol and in 2022 to 20 mg. He developed hyperglycemia, but HbA1c values remained under 48 nmol/L for 7 years.

CONCLUSION

De-escalation treatment with pasireotide LAR may allow a greater proportion of patients to achieve control of acromegaly, particularly in selected cases of clinically aggressive acromegaly potentially responsive to pasireotide (high IGF-I values, invasion of the cavernous sinuses, partial resistance to first-line somatostatin analogues and positive expression of somatostatin receptor 5). Another benefit may be IGF-I oversuppression overtime. The major risk seems to be hyperglycemia.

Modern approach to resistant acromegaly

BACKGROUND

Targets of acromegaly treatment are normalization of biochemical values, removal/reduction/stabilization of the pituitary mass, control of clinical activity and mortality with a multimodal/multidisciplinary approach. Despite significant technological and pharmacological progress, still several patients with acromegaly bear a resistant somatotroph adenoma and active disease may persist for many years with resultant poor clinical outcomes.

AIM

To review briefly definition and pathophysiology of resistance to acromegaly treatment and the options of medical treatment in this context, exploring the role of novel clinical and molecular biomarkers in the personalization of therapy and proposing updates to the currently available guidelines for the treatment of resistant GH-secreting adenomas.

CONCLUSIONS

In the last few years, in parallel with the increased number of medical options available for the therapy of acromegaly, relevant advances occurred in the understanding of the role of novel molecular and clinical biomarkers in predicting the responsiveness to second-line medical treatments, such as Pegvisomant and Pasireotide LAR, and helping clinicians in the personalization of the follow-up and treatment of resistant somatotroph adenomas. The integration of these findings into the existing guidelines may represent a possibly important step forward in the management of "difficult" acromegaly patients.

Type 1 and other types of diabetes mellitus in the perioperative period. What the anaesthetist should know

Diabetes mellitus is often treated as a uniform disease in the perioperative period. Type 2 diabetes is most commonly encountered, and only a minority of surgical patients have been diagnosed with another type of diabetes. Patients with a specific type of diabetes can be particularly prone to perioperative glycaemic dysregulation. In addition, certain type-related features and pitfalls should be taken into account in the operating theatre. In this narrative review, we discuss characteristics of types of diabetes other than type 2 diabetes relevant to the anaesthetist, based on available literature and data from our clinic.

Glucose metabolism, gut-brain hormones, and acromegaly treatment: an explorative single centre descriptive analysis

PURPOSE

Active acromegaly is associated with impaired glucose metabolism, which improves upon treatment. Treatment options include surgery, medical therapy with somatostatin analogues (SSA) and Pegvisomant (PEG), and irradiation. The objective of the study was to describe the differential effect of various treatment regimens on the secretion of glucose, insulin, glucagon, glucagon-like peptide-1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) in patients with acromegaly.

METHODS

23 surgically treated, non-diabetic patients with acromegaly and 12 healthy controls underwent an oral glucose tolerance test (OGTT) and subsequently isoglycaemic intravenous glucose infusion on a separate day. Baseline hormone concentrations, time-to-peak and area under the curve (AUC) on the OGTT-day and incretin effect were compared according to treatment regimens.

RESULTS

The patients treated with SSA (N = 15) had impaired GIP-response (AUC, P = 0.001), and numerical impairment of all other hormone responses (P > 0.3). Patients co-treated with PEG (SSA + PEG, N = 4) had increased secretion of insulin and glucagon compared to patients only treated with SSA (SSA ÷ PEG, N = 11) (insulin_AUC mean ± SEM, SSA + PEG 49 ± 8.3 nmol/l*min vs SSA ÷ PEG 25 ± 3.4, P = 0.007; glucagon_AUC, SSA + PEG 823 ± 194 pmol/l*min vs SSA ÷ PEG 332 ± 69, P = 0.009). GIP secretion remained significantly impaired, whereas GLP-1 secretion was numerically increased with PEG (SSA + PEG 3088 ± 366 pmol/l*min vs SSA ÷ PEG 2401 ± 239, P = 0.3). No difference was found in patients treated with/without radiotherapy nor substituted or not with hydrocortisone.

CONCLUSION

SSA impaired the insulin, glucagon, and incretin hormone secretions. Co-treatment with PEG seemed to counteract the somatostatinergic inhibition of the glucagon and insulin response to OGTT. We speculate that PEG may exert its action through GH-receptors on pancreatic δ-cells. Clinical trial registration NCT02005978.

Effects of Anterior Pituitary Adenomas' Hormones on Glucose Metabolism and Its Clinical Implications

Pituitary adenomas have recently become more common and their incidence is increasing yearly. Functional pituitary tumors commonly secrete prolactin, growth hormones, and adrenocorticotropic hormones, which cause diseases such as prolactinoma, acromegaly, and Cushing's disease, but rarely secrete luteinizing, follicle-stimulating, thyroid-stimulating, and melanocyte-stimulating hormones. In addition to the typical clinical manifestations of functional pituitary tumors caused by excessive hormone levels, some pituitary tumors are also accompanied by abnormal glucose metabolism. The effects of these seven hormones on glucose metabolism are important for the treatment of diabetes secondary to pituitary tumors. This review focuses on the effects of hormones on glucose metabolism, providing important clues for the diagnosis and treatment of related diseases.

[Other specific types of diabetes and exocrine pancreatic insufficiency (update 2023)]

The heterogenous category "specific types of diabetes due to other causes" encompasses disturbances in glucose metabolism due to other endocrine disorders such as acromegaly or hypercortisolism, drug-induced diabetes (e.g. antipsychotic medications, glucocorticoids, immunosuppressive agents, highly active antiretroviral therapy (HAART), checkpoint inhibitors), genetic forms of diabetes (e.g. Maturity Onset Diabetes of the Young (MODY), neonatal diabetes, Down‑, Klinefelter- and Turner Syndrome), pancreatogenic diabetes (e.g. postoperatively, pancreatitis, pancreatic cancer, haemochromatosis, cystic fibrosis), and some rare autoimmune or infectious forms of diabetes. Diagnosis of specific diabetes types might influence therapeutic considerations. Exocrine pancreatic insufficiency is not only found in patients with pancreatogenic diabetes but is also frequently seen in type 1 and long-standing type 2 diabetes.

Ectopic lipid metabolism in anterior pituitary dysfunction

Over the past decades, adapted lifestyle and dietary habits in industrialized countries have led to a progress of obesity and associated metabolic disorders. Concomitant insulin resistance and derangements in lipid metabolism foster the deposition of excess lipids in organs and tissues with limited capacity of physiologic lipid storage. In organs pivotal for systemic metabolic homeostasis, this ectopic lipid content disturbs metabolic action, thereby promotes the progression of metabolic disease, and inherits a risk for cardiometabolic complications. Pituitary hormone syndromes are commonly associated with metabolic diseases. However, the impact on subcutaneous, visceral, and ectopic fat stores between disorders and their underlying hormonal axes is rather different, and the underlying pathophysiological pathways remain largely unknown. Pituitary disorders might influence ectopic lipid deposition indirectly by modulating lipid metabolism and insulin sensitivity, but also directly by organ specific hormonal effects on energy metabolism. In this review, we aim to I) provide information about the impact of pituitary disorders on ectopic fat stores, II) and to present up-to-date knowledge on potential pathophysiological mechanisms of hormone action in ectopic lipid metabolism.

Durable biochemical response and safety with oral octreotide capsules in acromegaly

OBJECTIVE

The objective of this study is to report results from the open-label extension (OLE) of the OPTIMAL trial of oral octreotide capsules (OOC) in adults with acromegaly, evaluating the long-term durability of therapeutic response.

DESIGN

The study design is an OLE of a double-blind placebo-controlled (DPC) trial.

METHODS

Patients completing the 36-week DPC period on the study drug (OOC or placebo) or meeting predefined withdrawal criteria were eligible for OLE enrollment at 60 mg/day OOC dose, with the option to titrate to 40 or 80 mg/day. The OLE is ongoing; week 48 results are reported.

RESULTS

Forty patients were enrolled in the OLE, 20 each having received OOC or placebo, with 14 and 5 patients completing the DPC period as responders, respectively. Ninety percent of patients completing the DPC period on OOC and 70% of those completing on placebo completed 48 weeks of the OLE. Maintenance of response in the OLE (i.e. insulin-like growth factor I (IGF1) ≤ 1.0 × upper limit of normal (ULN)) was achieved by 92.6% of patients who responded to OOC during the DPC period. Mean IGF1 levels were maintained between the end of the DPC period (0.91 × ULN; 95% CI: 0.784, 1.045) and week 48 of the OLE (0.90 × ULN; 95% CI: 0.750, 1.044) for those completing the DPC period on OOC. OOC safety was consistent with previous findings, with no increased adverse events (AEs) associated with the higher dose and improved gastrointestinal tolerability observed over time.

CONCLUSIONS

Patients with acromegaly maintained long-term biochemical response while receiving OOC, with no new AEs observed with prolonged OOC exposure.

Clinical Biology of the Pituitary Adenoma

All endocrine glands are susceptible to neoplastic growth, yet the health consequences of these neoplasms differ between endocrine tissues. Pituitary neoplasms are highly prevalent and overwhelmingly benign, exhibiting a spectrum of diverse behaviors and impact on health. To understand the clinical biology of these common yet often innocuous neoplasms, we review pituitary physiology and adenoma epidemiology, pathophysiology, behavior, and clinical consequences. The anterior pituitary develops in response to a range of complex brain signals integrating with intrinsic ectodermal cell transcriptional events that together determine gland growth, cell type differentiation, and hormonal production, in turn maintaining optimal endocrine health. Pituitary adenomas occur in 10% of the population; however, the overwhelming majority remain harmless during life. Triggered by somatic or germline mutations, disease-causing adenomas manifest pathogenic mechanisms that disrupt intrapituitary signaling to promote benign cell proliferation associated with chromosomal instability. Cellular senescence acts as a mechanistic buffer protecting against malignant transformation, an extremely rare event. It is estimated that fewer than one-thousandth of all pituitary adenomas cause clinically significant disease. Adenomas variably and adversely affect morbidity and mortality depending on cell type, hormone secretory activity, and growth behavior. For most clinically apparent adenomas, multimodal therapy controlling hormone secretion and adenoma growth lead to improved quality of life and normalized mortality. The clinical biology of pituitary adenomas, and particularly their benign nature, stands in marked contrast to other tumors of the endocrine system, such as thyroid and neuroendocrine tumors.

Reduced irisin levels in patients with acromegaly

Objectives

Several metabolic disturbances are seen in acromegaly however, data regarding the contribution of irisin to these disturbances is currently insufficient. In a cohort of patients with acromegaly, we measured serum irisin levels in active and controlled cases and determined independent factors that effect serum irisin including fibronectin type III domain-containing protein 5 (FNDC5) genotyping.

Methods

A cross-sectional case-control study including 46 patients with acromegaly (28 F/18 M, age: 50.3 ± 12.1 year, BMI: 30.7 ± 5.1 kg/m2) and 81 age-, gender-, body mass index- and body composition-matched healthy controls was conducted. 15 acromegalic patients (33%) had active disease. Irisin levels were measured by enzyme-linked immunosorbent assay. Three different regions (rs3480, rs1746661, and rs16835198) of FNDC5 were subjected to polymorphism analyses.

Results

Both groups were overweight and had similar body composition. Irisin levels were lower in patients with acromegaly than controls (median [IQR]: 44.8 [41.7–46.7] ng/mL vs. 51.7 [45.5–60.1] ng/mL, p≤0.001, respectively). Active and controlled patients had similar irisin levels. Irisin was not correlated with growth hormone (GH), insulin-like growth factor 1 (IGF-1), and IGF-1 index. In multiple linear regression model, somatostatin receptor ligand use (β=−20.30, 95% CI [−34]–[−6], p=0.006) was determined as the only independent factor that affect serum irisin.

Conclusions

Serum irisin levels are low in patients with acromegaly who are on somatostatin receptor ligand therapy. Single nucleotide polymorphisms (SNPs) of FNDC5 have no independent effects on circulating irisin levels under somatostatin ligand action. Endocrine muscle functions also seem to be regulated by somatostatin action, which requires further studies.

COVID-19 and hypopituitarism

Besides the pulmonary manifestations caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), an emerging endocrine phenotype, which can heavily impact on the severity of the syndrome, has been recently associated with coronavirus disease 2019 (COVID-19). Patients with pituitary diseases or the pituitary gland itself may also be involved in COVID-19 clinical presentation and/or severity, causing pituitary apoplexy.Moreover, hypopituitarism is frequently burdened by several metabolic complications, including arterial hypertension, hyperglycemia, obesity and vertebral fractures, which have all been associated with poor outcomes and increased mortality in patients infected by SARS-CoV-2.This review will discuss hypopituitarism as a condition that might have a bidirectional relationship with COVID-19 due to the frequent presence of metabolic comorbidities, to the direct or indirect pituitary damage or being per se a potential risk factor for COVID-19. Finally, we will address the current recommendations for the clinical management of vaccines in patients with hypopituitarism and adrenal insufficiency.

The role of growth hormone and IGF-1 in retinopathy: a prospective study of retinopathy in patients with acromegaly and impaired fasting glucose

AIMS

To investigate the effects of the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis on the incidence and progression of retinopathy.

METHODS

We enrolled 91 patients with acromegaly and 123 subjects with impaired fasting glucose (IFG) between 2008 and 2016 to examine the incidence and prevalence of retinopathy. Patients attended follow-ups in our clinics and underwent examinations according to the national guidelines for diabetes management. Both cohorts attended follow-ups until June 2019.

RESULTS

Both groups had similar HbA1c, cholesterol, and blood pressure levels. However, patients with acromegaly had higher GH (8.05 ± 16.18 vs. 0.78 ± 1.25 ng/mL) and IGF-1 (547.0 ± 342.1 vs. 146.7 ± 51.4 ng/mL) levels than in subjects with IFG. During the follow-up period, 8 patients (8.8%) with acromegaly and 12 patients (9.8%) with IFG developed some degree of retinopathy. Three patients with acromegaly and two with IFG progressed to proliferative retinopathy. Patients with acromegaly had the same incidence of non-proliferative retinopathy (odds ratio [OR] 0.830; 95% CI 0.318-2.164) and a non-statistically significantly higher incidence of proliferative retinopathy (OR 2.461; 95% CI 0.404-14.988).

CONCLUSION

The data reveals that GH and IGF-1 might play a crucial role in the development of proliferative retinopathy and influence its progression. Therefore, we suggest screening patients with acromegaly should be similar to diabetes patients.

Diabetes Mellitus Predicts Weight Gain After Surgery in Patients With Acromegaly

OBJECTIVE

Metabolic complications are common in patients with acromegaly. However, this occasionally does not improve post-surgery and may be related to postoperative weight gain. We aimed to investigate the postoperative weight change and factors associated with postoperative weight gain in patients with acromegaly.

DESIGN AND METHODS

Overall, 113 consecutive patients with body weight records pre- and 3-6 months post-surgery between October 2009 and March 2021 were enrolled. Patients were divided into three groups: weight loss (weight decrease ≥3%), stable, and weight gain (weight increase ≥3%). Hormone status, metabolic comorbidities, and anthropometric parameters were compared between the groups.

RESULTS

Among 113 patients, 29 (25.7%) and 26 (23.0%) patients lost and gained weight, respectively, post-surgery. There were no significant differences in baseline characteristics, including age at diagnosis, sex, body mass index, and growth hormone levels among the three groups. The prevalence of diabetes mellitus at diagnosis was significantly higher in the weight gain group than in the other groups. Patients with diabetes (n=22) had a 5.2-fold higher risk of postoperative weight gain than those with normal glucose tolerance (n=37) (P=0.006). In the diabetes mellitus group, the percentage lean mass decreased (-4.5 [-6.6-2.0]%, P=0.002), and the percentage fat mass significantly increased post-surgery (18.0 [4.6-36.6]%, P=0.003), whereas the normal glucose tolerance group did not show body composition changes post-surgery.

CONCLUSION

In patients with acromegaly, 23% experienced ≥3% weight gain post-surgery. Diabetes mellitus at diagnosis is a significant predictor of weight and fat gain post-surgery.

Integrated or Independent Actions of Metformin in Target Tissues Underlying Its Current Use and New Possible Applications in the Endocrine and Metabolic Disorder Area

Metformin is considered the first-choice drug for type 2 diabetes treatment. Actually, pleiotropic effects of metformin have been recognized, and there is evidence that this drug may have a favorable impact on health beyond its glucose-lowering activity. In summary, despite its long history, metformin is still an attractive research opportunity in the field of endocrine and metabolic diseases, age-related diseases, and cancer. To this end, its mode of action in distinct cell types is still in dispute. The aim of this work was to review the current knowledge and recent findings on the molecular mechanisms underlying the pharmacological effects of metformin in the field of metabolic and endocrine pathologies, including some endocrine tumors. Metformin is believed to act through multiple pathways that can be interconnected or work independently. Moreover, metformin effects on target tissues may be either direct or indirect, which means secondary to the actions on other tissues and consequent alterations at systemic level. Finally, as to the direct actions of metformin at cellular level, the intracellular milieu cooperates to cause differential responses to the drug between distinct cell types, despite the primary molecular targets may be the same within cells. Cellular bioenergetics can be regarded as the primary target of metformin action. Metformin can perturb the cytosolic and mitochondrial NAD/NADH ratio and the ATP/AMP ratio within cells, thus affecting enzymatic activities and metabolic and signaling pathways which depend on redox- and energy balance. In this context, the possible link between pyruvate metabolism and metformin actions is extensively discussed.

International Multicenter Validation Study of the SAGIT® Instrument in Acromegaly

CONTEXT

The SAGIT® instrument (SAGIT) has been developed to enable accurate characterization of acromegaly disease activity.

OBJECTIVE

We evaluated the ability of SAGIT to discriminate acromegaly disease control status.

METHODS

This multicenter, noninterventional, prospective and retrospective, longitudinal study, conducted at academic and private clinical practice sites, included patients aged ≥ 18 years with a diagnosis of controlled (n = 109) or non-controlled (n = 105) acromegaly, assessed by clinical global evaluation of disease control (CGE-DC) questionnaire, investigator therapeutic decision, and international guidelines. Control status was not determined at baseline for 13 patients. Since 9 patients were enrolled retrospectively, all presented analyses are based on the prospective population (N = 227). Patients were assessed over a 2-year follow-up period. Classification and regression tree (CART) analyses were performed to investigate how SAGIT components at baseline (signs/symptoms [S], associated comorbidities [A], growth hormone levels [G], insulin-like growth factor 1 levels [I], tumor features [T]) discriminate between controlled and non-controlled acromegaly.

RESULTS

Baseline mean subscores S, G, I, and T were significantly lower in patients with CGE-DC controlled vs CGE-DC non-controlled acromegaly. SAGIT components I and G for CGE-DC and S, A, G, I, and T for the clinician's therapeutic decision were retained by CART analyses. For international guidelines, only SAGIT component I was retained. The risk for undergoing ≥ 1 treatment change during the study was 3.44 times greater for CGE-DC non-controlled acromegaly relative to CGE-DC controlled acromegaly.

CONCLUSION

The SAGIT instrument is a valid and sensitive tool to comprehensively and accurately assess acromegaly severity.

Neutrophil-to-Lymphocyte, Platelet-to-Lymphocyte Ratios, and Systemic Immune-Inflammation Index as Potential Biomarkers of Chronic Inflammation in Patients with Newly Diagnosed Acromegaly: A Single-Centre Study

Acromegaly is a rare disease caused by overproduction of growth hormone (GH) by a pituitary adenoma, and consequently increased insulin-like growth factor 1 (IGF-1) concentration. The GH/IGF-1 axis and immune cells interactions are hypothesized to be involved in subclinical inflammation. This retrospective study aimed to investigate the differences in neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR) ratios, and systemic immune-inflammation index (SII) in GH-secreting adenomas compared with non-functioning pituitary adenomas (NFPAs) concerning clinical and radiological findings. After evaluation of 665 patients with pituitary tumors, 62 individuals with newly diagnosed acromegaly and 134 with NFPAs were enrolled in the analysis. The control group consisted of 120 healthy individuals. Fifty-eight patients with acromegaly were re-evaluated after medical or surgical therapies. NLR, PLR, SII values, and neutrophil count were significantly higher (p ≤ 0.001), whereas lymphocyte count was lower in acromegaly than in NFPAs (p = 0.001). No significant differences between NFPAs and controls were observed in analyzed ratios. Higher preoperative NLR, PLR, SII values were found in patients who failed to achieve a cure with surgery (p < 0.05). Although NLR, PLR, and SII values were significantly higher in acromegaly, these indices cannot be used to discriminate GH-secreting pituitary tumors from NFPAs. Treatment of acromegaly decreased the value of NLR and SII, but it requires further studies to consolidate the real clinical role of these inflammation-related ratios.

Glucose metabolism outcomes in acromegaly patients on treatment with pasireotide-LAR or pasireotide-LAR plus Pegvisomant

INTRODUCTION

Disorders of glucose metabolism are a serious acromegaly comorbidity and may be differently impacted by medical treatments of acromegaly. In this retrospective longitudinal multicenter study, we investigated the outcome of glucose metabolism and its predictors in patients treated with Pasireotide LAR (PAS-LAR) alone or in combination with Pegvisomant (PAS-LAR + Peg-V).

SUBJECTS AND METHODS

Acromegaly patients treated continously with PAS-LAR or PAS-LAR + Peg-V for at least 6 months.

RESULTS

Forty patients (25 females, 15 males) were enrolled. At last visit, 27/40 patients (67.5%) reached biochemical control of acromegaly. Overall, glucose metabolism improved in 3 (all in PAS-LAR + Peg-V; 7.5%), worsened in 26 (65%) and remained unchanged in 11 patients (27.5%). Glucose metabolism worsened in 25 patients (73.5%) treated with PAS-LAR and in a single patient (16.7%) treated with PAS-LAR + Peg-V (p < 0.001). Among patients treated with Pas-LAR alone, GH at baseline was higher in those with worsening of glucose metabolism (p = 0.04) as compared to those with stable glucose status. A significantly higher reduction of HbA1c was observed in patients treated with PAS-LAR + Peg-V, as compared with those treated with PAS-LAR alone (p = 0.005).

CONCLUSIONS

Our data confirmed that glucose metabolism in patients treated with PAS-LAR is often worsened, and may be predicted by entity of baseline GH hypersecretion and by the dose of PAS-LAR. Moreover, our data, although limited by small numbers, may suggest that the combination treatment PAS-LAR + Peg-V can improve glucose homeostasis in selected patients.

Prevalence and predictors of abnormal glucose tolerance and its resolution in acromegaly: Single Centre retrospective study of 90 cases

Aims The aim of the study was to evaluate the prevalence and predictors of abnormal glucose tolerance (Diabetes + Prediabetes) and its resolution in Acromegaly.

SETTINGS AND DESIGN

Retrospective observational study.

METHODS AND MATERIAL

Ninety patients with acromegaly and followed up post operatively for 1 year were included. The study cohort was divided into two groups: Group A: abnormal glucose tolerance [AGT: Diabetes + prediabetes (n = 40)] and Group B: normal glucose tolerance (NGT) (n = 50).The impact of the following parameters: age, sex, Waist Circumference(WC), Body Mass Index (BMI), duration of acromegaly, Growth Hormone (GH) levels, Insulin like Growth Factor 1 (IGF1) levels, pituitary tumour size, hypertension, and family history of diabetes as predictors for diabetes were studied pre surgery and post-surgery at 3 months and 1 year affecting glycaemia. Unpaired t-test, chi-square test and binary logistic regression analysis were used for statistical analysis.

RESULTS

The prevalence of AGT in our cohort was 44.44% (Diabetes 37.77%, prediabetes 6.66%).Patients with AGT were older (44.2 ± 12.21 years vs. 34.92 ± 11.62 years; p = 0.00040) and had higher WC (in cm) (91.35 ± 7.87 vs.87.12 ± 6.07; p = 0.005) than NGT. Hypertension and family history of diabetes were significantly more frequent in patients with AGT. GH and IGF1 levels were not significantly different between the groups. On binary logistic regression, Sex (p = 0.0105) (OR = 6.0985), waist circumference (p = 0.0023) (OR = 1.2276) and hypertension (p = 0.0236) (OR = 1.632) were found to be significant predictors of AGT in acromegaly. After surgery 42.5% and 62.5% patients became normoglycemic at 3 months and 1 year respectively. On binary logistic regression there were no predictors for achieving normoglycemia at 3 months or 1 year, however the delta change in GH, BMI and tumour size were significant.

CONCLUSIONS

The prevalence of AGT was 44.44%. Female sex, WC and hypertension were found to be significant predictors of AGT in acromegaly. Post-surgery normoglycemia was achieved in 42.5% at 3 months and 62.5% at 1 year with no predictors for normalisation of AGT.

Sodium glucose cotransporter 2 inhibitors treatment in acromegalic patients with diabetes-a case series and literature review

PURPOSE

Diabetes mellitus (DM) represents one of the most frequent comorbidities in patients with acromegaly. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) represent an important class for diabetes management. However, limited data is reported regarding the use of this class in patients with acromegaly and diabetes.

METHODS

Reporting data regarding patients with acromegaly and diabetes under treatment with SGLT2i.

RESULTS

29 acromegalic patients with diabetes were identified. Treatment with SGLT-2i was documented in nine patients, out of them 5 females and 4 males with a mean age (SD) of 61 ± 12 yr. The mean (SD) duration of treatment with SGLT2i was 27.5 ± 7.3 months. Mean HbA1c before and after SGLT-2i initiation was 8.1 ± 1.1 and 7.0 ± 0.9% respectively. Mean IGF-1 level (SD) before SGLT-2i initiation was 177 ± 68 ng/mL and the mean GH level (SD) was 0.7 ± 0.5 µg/L. All nine patients are still under treatment with SGLT2i and none of them had reported any adverse reaction related to SGLT2i.

CONCLUSIONS

The present article provides us for the first time with new data regarding the use of SGLT2i among acromegalic patients with diabetes.

COVID-19 and the pituitary

BACKGROUND

Despite COVID-19 being identified as severe respiratory viral infection, progressively many relevant endocrine manifestations have been reported greatly contributing to the severity of the clinical presentation. Systemic involvement in COVID-19 is due to the ubiquitous expression of angiotensin-converting enzyme 2 (ACE2) receptor, responsible for the entry in the cells of SARS-CoV-2, Several reports in humans and animal models showed a significant ACE2 mRNA expression in hypothalamus and pituitary cells. Moreover, higher mortality and poorer outcomes have been widely described in COVID-19 patients with obesity, diabetes and vertebral fractures, which are all highly prevalent in subjects with pituitary dysfunctions.

AIM

To review the main endocrine manifestations of COVID-19 with their possible implications for pituitary diseases, the possible direct and indirect involvement of the pituitary gland in COVID-19, the impact of COVID-19 on the management of established pituitary diseases which can be already at increased risk for worse outcomes and on neurosurgical activities as well as vaccination.

CONCLUSIONS

Our review underlines that there could be a specific involvement of the pituitary gland which fits into a progressively shaping endocrine phenotype of COVID-19. Moreover, the care for pituitary diseases need to continue despite the restrictions due to the emergency. Several pituitary diseases, such as hypopituitarism and Cushing disease, or due to frequent comorbidities such as diabetes may be a risk factor for severe COVID-19 in affected patients. There is the urgent need to collect in international multicentric efforts data on all these aspects of the pituitary involvement in the pandemic in order to issue evidence driven recommendations for the management of pituitary patients in the persistent COVID-19 emergency.

COVID-19 and endocrine and metabolic diseases. An updated statement from the European Society of Endocrinology

BACKGROUND

COVID-19 has completely changed our daily clinical practice as well as our social relations. Many organs and biological systems are involved in SARS-Cov-2 infection, either due to direct virus-induced damage or to indirect effects that can have systemic consequences. Endocrine system is not only an exception but its involvement in COVID-19 is so relevant that an "endocrine phenotype" of COVID-19 has progressively acquired clinical relevance.

AIM

We have been appointed by the European Society of Endocrinology (ESE) to update with the current statement ESE members and the whole endocrine community on the emerging endocrine phenotype of COVID-19 and its implication for the prevention and management of the disease.

CONCLUSIONS

Diabetes has a major role in this phenotype since it is one of the most frequent comorbidities associated with severity and mortality of COVID-19. Careful management including treatment modifications may be required for protecting our patients rather with known diabetes from the most dangerous consequences of COVID-19 or hospitalized with COVID-19, but also in patients with SARS-CoV-2 induced newly onset diabetes. Obesity increases susceptibility to SARS-CoV-2 and the risk for COVID-19 adverse outcome. Adequate nutritional management needs to be granted to patients with obesity or undernourishment in order to limit their increased susceptibility and severity of COVID-19 infection. Lack of vitamin D, hypocalcemia and vertebral fractures have also emerged as frequent findings in the hospitalized COVID-19 population and may negatively impact on the outcome of such patients. Also, in patients with adrenal insufficiency prompt adaptation of glucocorticoid doses may be needed. Moreover, in this updated statement role of sex hormones as well as peculiar pituitary and thyroid aspects of COVID-19 have been included. Finally, in view of the mass vaccination, potential implications for endocrine patients should be considered.

HOMA-IR in acromegaly: a systematic review and meta-analysis

PURPOSE

This review is aimed at examining whether the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) is higher in Caucasian, adult, treatment-naïve patients with acromegaly (ACRO) than in the reference population independently of diabetes presence and to evaluate the impact of treatment [surgery and somatostatin analogues (SSAs)] on its assessment.

METHODS

We systematically reviewed in PubMed and Web of Science from July 1985 to December 2019, registered with the code number CRD42020148737. The inclusion criteria comprised studies conducted in Caucasian adult treatment-naïve patients with active ACRO in whom HOMA-IR or basal insulin and glucose were reported. Three reviewers screened eligible publications, extracted the outcomes, and assessed the risk of biases.

RESULTS

Of 118 originally selected studies, 15 met the inclusion criteria. HOMA-IR was higher in ACRO than the reference population, with mean difference and (95% confidence intervals) of 2.04 (0.65-3.44), even in ACRO patients without diabetes, 1.89 (1.06-2.73). HOMA-IR significantly decreased after treatment with either surgery or SSAs - 2.53 (- 3.24- - 1.81) and - 2.30 (- 3.05- - 1.56); respectively. However, the reduction of HOMA-IR due to SSAs did not improve basal glucose.

CONCLUSION

HOMA-IR in treatment-naïve ACRO patients is higher than in the reference population, even in patients without diabetes. This finding, confirms that insulin resistance is an early event in ACRO. Our results also suggest that HOMA-IR is not an adequate tool for assessing insulin resistance in those patients treated with SSAs.

Results from ACROCOVID: an international survey on the care of acromegaly during the COVID-19 era

With most global healthcare resources focused on COVID-19, altered resource allocation is disrupting the continuum of care for chronic endocrine conditions, including acromegaly. In order to assess the effects of COVID-19 on care of patients with acromegaly, we conducted an international online survey of endocrinologists. The questionnaire was drafted by a Steering Committee of acromegaly experts and covered both respondent demographics, contact and communication with patients, and patient care. Respondent awareness was generated through social media campaigns and the survey completed online using Google forms. The majority of endocrinologists who responded (N = 84) were based in Europe (67.9%) and were female (58.3%). Slightly more than half of respondents worked in a specialized pituitary center (52.4%) and a large minority cared for more than 50 acromegaly patients (47.6%). Most respondents (85.7%) indicated surgery was their first-line treatment, with only 14.3% indicating medical therapy as a first-choice treatment option. One-third (33.3%) of respondents reported having delayed a planned surgery due to a lack of COVID-19 testing provision and 54.8% due to a lack of surgical provision; 19.1% indicated that a lack of personal protective equipment had reduced their ability to treat patients with acromegaly. Just 21.4% of respondents reported no negative effects from the pandemic on diagnostic practice patterns, and just 19.1% reported no negative effect on patient follow-up practices. Many respondents (55.9%) indicated that remote methods had improved their ability to communicate with their patients and 69.0% indicated that they would continue to use methods of consultation necessitated by the COVID-19 pandemic. Our data suggest the COVID-19 pandemic is substantially affecting the care of acromegaly. However, these results also suggest that endocrinologists are embracing aspects of the 'new normal' to create a novel continuum of care better suited to the presumed post-COVID-19 environment. The goal of these changes must be both to improve care while shielding patients from more severe involvement in concomitant acute illnesses such COVID-19.

A Pituitary Society update to acromegaly management guidelines

Guidelines and consensus statements ensure that physicians managing acromegaly patients have access to current information on evidence-based treatments to optimize outcomes. Given significant novel recent advances in understanding acromegaly natural history and individualized therapies, the Pituitary Society invited acromegaly experts to critically review the current literature in the context of Endocrine Society guidelines and Acromegaly Consensus Group statements. This update focuses on how recent key advances affect treatment decision-making and outcomes, and also highlights the likely role of recently FDA-approved therapies as well as novel combination therapies within the treatment armamentarium.

Myokines in Acromegaly: An Altered Irisin Profile

INTRODUCTION

The muscle is an endocrine organ controlling metabolic homeostasis. Irisin and myostatin are key myokines mediating this process. Acromegaly is a chronic disease with a wide spectrum of complications, including metabolic disturbances.

PURPOSE

To examine the influence of acromegaly on irisin and myostatin secretion and their contribution to metabolic profile and body composition.

MATERIALS AND METHODS

In 43 patients with acromegaly and 60 controls, serum levels of irisin, myostatin, growth hormone (GH), insulin-like growth factor 1 (IGF-1), parameters of glucose, and lipid metabolism were determined. Body composition was assessed with dual-energy x-ray absorptiometry.

RESULTS

The irisin concentration was significantly lower in patients with acromegaly compared to controls (3.91 vs. 5.09 μg/ml, p = 0.006). There were no correlations between irisin and GH/IGF-1 levels. In the study group, irisin was negatively correlated with fasting insulin (r = -0.367; p = 0.042), HOMA-IR (r = -0.510; p = 0.011), and atherogenic factors: Castelli I (r = -0.416; p = 0.005), Castelli II (r = -0.400; p = 0.001), and atherogenic coefficient (AC) (r = -0.417; p = 0.05). Irisin and myostatin concentrations were also lower in acromegalics with insulin resistance than without (2.80 vs. 4.18 μg/ml, p = 0.047; 81.46 vs. 429.58 ng/L, p = 0.018, respectively). There were no differences between study group and controls in myostatin concentration. Myostatin levels negatively correlated with GH (r = -0.306; p = 0.049), HOMA-IR (r = -0.046; p = 0.411), and insulin levels (r = -0.429; p = 0.016).

CONCLUSIONS

Decreased irisin concentrations in acromegaly may suggest impaired hormonal muscle function contributing to metabolic complications in this disorder. However, learning more about the association between myostatin and GH in acromegaly requires further studies. Nevertheless, it appears that myostatin is not critical for muscle mass regulation in acromegaly.

Changes in cardiovascular risk factors in patients with acromegaly after trans-sphenoidal adenomectomy

The surgical treatment of acromegaly reduces mortality, however its impact on cardiovascular risk factors is unclear. This study was carried out to determine the changes in cardiovascular risk factors in patients with acromegaly who received trans-sphenoidal surgery. We recruited 127 patients with acromegaly who received trans-sphenoidal adenomectomy between August 2003 and May 2014 and follow-up for 12 months. Fasting GH and IGF-1 levels were evaluated every 3 months, and cardiovascular risk factors were assessed before and 12 months after surgery. The main outcomes were changes in cardiovascular risk factors after surgery. One year after trans-sphenoidal adenomectomy, 68 patients (53.5%) had a fasting GH level <2.0 ng/mL, IGF-1 was normalized in 74 patients (58.3%), and both fasting GH and IGF-1 were under control in 51 patients (40.2%). Levels of glycated hemoglobin (HbA1c) (8.57 ± 3.19 vs. 6.66 ± 0.90%, p = 0.001) and triglycerides (130.6 ± 61.5 vs. 108.0 ± 47.5 mg/dL, p = 0.027) were significantly decreased and serum creatinine was significantly increased (0.665 ± 0.222 vs. 0.754 ± 0.223 mg/dL, p = 0.001) after trans-sphenoidal adenomectomy. However, there were no significant changes in body weight, systolic blood pressure, diastolic blood pressure, total cholesterol, high-density lipoprotein cholesterol and cardiovascular risk score after trans-sphenoidal adenomectomy. In the patient with high cardiovascular risk before surgery, systolic blood pressure, total cholesterol, fasting glucose, triglycerides and high-density lipoprotein cholesterol improved after trans-sphenoidal adenomectomy. In this study, HbA1c and triglycerides were significantly decreased after trans-sphenoidal adenomectomy in the patients with acromegaly irrespective of endocrinological outcomes. The other traditional cardiovascular factors might be improved after trans-sphenoidal adenomectomy in the patients with a high cardiovascular risk.

Effect of growth hormone on insulin signaling

Growth hormone (GH) is a pleiotropic hormone that coordinates an array of physiological processes, including effects on bone, muscle, and fat, ultimately resulting in growth. Metabolically, GH promotes anabolic action in most tissues except adipose, where its catabolic action causes the breakdown of stored triglycerides into free fatty acids (FFA). GH antagonizes insulin action via various molecular pathways. Chronic GH secretion suppresses the anti-lipolytic action of insulin and increases FFA flux into the systemic circulation; thus, promoting lipotoxicity, which causes pathophysiological problems, including insulin resistance. In this review, we will provide an update on GH-stimulated adipose lipolysis and its consequences on insulin signaling in liver, skeletal muscle, and adipose tissue. Furthermore, we will discuss the mechanisms that contribute to the diabetogenic action of GH.

Risk factors and management of pasireotide-associated hyperglycemia in acromegaly

Pasireotide, a multireceptor-targeted somatostatin analog with highest affinity for somatostatin receptor subtype (SST) 5, has demonstrated superior efficacy over the SST2-preferential somatostatin analogs octreotide and lanreotide. The safety profile is similar to those of octreotide and lanreotide, except for a higher frequency and degree of hyperglycemia. This analysis investigated baseline characteristics and occurrence and management of hyperglycemia during pasireotide treatment in patients with acromegaly treated in two prospective clinical studies, SOM230C2305 (C2305) and SOM230C2402 (C2402; PAOLA). One hundred and seventy-eight patients naïve to medical therapy at baseline (C2305) and 125 uncontrolled on first-generation somatostatin analogs at baseline (C2402) received long-acting pasireotide in these studies. Of patients treated with pasireotide in studies C2305 and C2402, respectively, 75.3 (134/178) and 65.6% (82/125) developed hyperglycemia or experienced worsening of existing hyperglycemia. Occurrence of hyperglycemia during pasireotide treatment was less frequent in patients with lower age (<40 years, C2402; <30 years, C2305), normal glucose tolerance, and no history of hypertension or dyslipidemia at baseline. Thirteen (4%) patients discontinued pasireotide because of hyperglycemia-related adverse events. Metformin alone or in combination with other oral antidiabetic medications controlled elevations in glucose levels in most pasireotide-treated patients; 78% of C2305 patients and 73 (pasireotide 40 mg) and 60% (pasireotide 60 mg) of C2402 patients achieved the ADA/EASD goal of HbA1c <7% (<53 mmol/mol) at the end of the core phase. Not all patients develop hyperglycemia, and it is reversible upon pasireotide withdrawal. Close monitoring, patient education and prompt action remain key elements in addressing hyperglycemia during pasireotide treatment.

Discordant biological parameters of remission in acromegaly do not increase the risk of hypertension or diabetes: a study with the Liege Acromegaly Survey database

PURPOSE

Acromegaly is a rare disease due to growth hormone (GH)-secreting pituitary adenoma. GH and IGF-1 levels are usually congruent, indicating either remission or active disease; however, a discrepancy between GH and IGF-1 may occur. We aimed to evaluate the outcome of diabetes mellitus (DM) and hypertension (HT) in acromegalic patients with congruent GH and/or IGF-1 levels vs. discordant biochemical parameters.

METHODS

Retrospective analysis of the data of 3173 patients from the Liege Acromegaly Survey (LAS) allowed us to include 190 patients from 8 tertiary referral centers across Europe, treated by surgery, with available data concerning DM and HT both at diagnosis and at the last follow-up (LFU). We recorded the number of anti-HT and anti-DM drugs used at the first evaluation and at LFU for every patient.

RESULTS

Ninety-nine patients belonged to the REM group (concordant parameters), 65 patients were considered as GH_dis (high random GH/controlled IGF-1), and 26 patients were considered as IGF-1_dis (high IGF-1/controlled random GH). At diagnosis, 72 patients (37.8%) had HT and 54 patients had DM (28.4%). There was no statistically significant difference in terms of the number of anti-HT and anti-DM drugs at diagnosis versus LFU (mean duration: 7.3 ± 4.5 years) between all three groups.

CONCLUSION

The long-term outcome of DM and HT in acromegaly does not tend to be more severe in patients with biochemical discordance in comparison with patients considered as in remission on the basis of concordant biological parameters, suggesting that patients with biochemical discordance do not require a closer follow-up.

Associations between circulating bone-derived hormones lipocalin 2, osteocalcin, and glucose metabolism in acromegaly

PURPOSE

The aim was to examine changes in the bone-derived hormone lipocalin 2 (LCN2) levels in patients with active acromegaly and to investigate the potential roles of LCN2 and osteocalcin in glucose metabolism.

METHODS

We recruited 50 consecutive acromegalic patients. Of those, 39 patients with complete postoperative follow-up data were included. Thirty sex-, age-, and BMI-matched healthy individuals were recruited as normal controls. The pre- and postoperative serum LCN2 and osteocalcin levels were compared. The homeostasis model assessment insulin resistance (HOMA-IR) index and secretion [β-cell function (HOMA-β)] were calculated.

RESULTS

Compared with controls, acromegalic subjects had lower LCN2 levels (34.15 ± 9.95 vs 57.50 ± 29.75 ng/mL, P < 0.01) and higher osteocalcin levels (55.45 ± 34.02 vs 19.46 ± 6.69 ng/mL, P < 0.01). Acromegalic patients also had elevated HOMA-IR levels, and the HOMA-β and the area under the curve for insulin (AUC INS) levels were slightly but nonsignificantly increased. The serum levels of LCN2 significantly increased after surgery (37.03 ± 9.73 vs 45.15 ± 15.33 ng/mL, P < 0.05), and those of osteocalcin significantly decreased [43.51 (26.73-65.66) vs 24.79 (18.39-32.59) ng/mL, P < 0.01]. Total lean mass was the only positive predictor of LCN2, and elevated serum IGF-I was a positive predictor of osteocalcin. Low LCN2 and elevated serum osteocalcin levels were predictors of the AUC INS, and osteocalcin was a positive predictor of HOMA-β.

CONCLUSION

The bone-derived hormones, osteocalcin and LCN2 changed significantly in active acromegaly, were altered after treatment and served as predictors of β-cell function in acromegaly. This study shows that the bone could be involved in regulating glucose metabolism in acromegaly.

Acromegaly: Update on Management and Long-Term Morbidities

Acromegaly is a systemic disease associated with great morbidity and increased mortality if not adequately treated. In the past decades much improvement has been achieved in its treatment and in the knowledge of its comorbidities. We provide an update of acromegaly management with current recommendations. We also address long-term comorbidities emphasizing the changing face of the disease in more recent series, with a decrease of cardiovascular disease severity and an increased awareness of comorbidities like bone disease, manifested mainly as vertebral fractures and the change in the main cause of death (from cardiovascular disease to cancer in more recent series).

Pituitary Tumors Centers of Excellence

Pituitary tumors are common and require complex and sophisticated procedures for both diagnosis and therapy. To maintain the highest standards of quality, it is proposed to manage patients in pituitary tumors centers of excellence (PTCOEs) with patient-centric organizations, with expert clinical endocrinologists and neurosurgeons forming the core. That core needs to be supported by experts from different disciplines such as neuroradiology, neuropathology, radiation oncology, neuro-ophthalmology, otorhinolaryngology, and trained nursing. To provide high-level medical care to patients with pituitary tumors, PTCOEs further pituitary science through research publication, presentation of results at meetings, and performing clinical trials.

Assessment of left ventricular deformation in patients with type 2 diabetes mellitus by cardiac magnetic resonance tissue tracking

To quantify the global and regional left ventricular (LV) myocardial strain in type 2 diabetes mellitus (T2DM) patients using cardiac magnetic resonance (CMR) tissue-tracking techniques and to determine the ability of myocardial strain parameters to assessment the LV deformation. Our study included 98 adult T2DM patients (preserved LV ejection fraction [LVEF], 72; reduced LVEF, 26) and 35 healthy controls. Conventional LV function, volume-time curve parameters and LV remodeling index were measured using CMR. Global and regional LV myocardial strain parameters were measured using CMR tissue tracking and compared between the different sub-groups. Receiver operating characteristic analysis was used to assess the diagnostic accuracy. Regression analyses were conducted to determine the relationship between strain parameters and the LV remodeling index. The results show that global radial peak strain (PS) and circumferential PS were not significantly different between the preserved-LVEF group and control group (P > 0.05). However, longitudinal PS was significantly lower in the preserved-LVEF group than in the control group (P = 0.005). Multivariate linear and logistic regression analyses showed that global longitudinal PS was independently associated (β = 0.385, P < 0.001) with the LV remodeling index. In conclusion, early quantitative evaluation of cardiac deformation can be successfully performed using CMR tissue tracking in T2DM patients. In addition, global longitudinal PS can complement LVEF in the assessment of cardiac function.

Drug treatment strategies for secondary diabetes in patients with acromegaly

INTRODUCTION

Acromegaly is a rare disease due to oversecretion of growth hormone (GH). Even though the disease is often portrayed by its most apparent clinical features, given the abundance of GH receptors throughout the body, it truly is a systemic disease leading to numerous complications and comorbidities. A distinct medical issue in the context of acromegaly is diabetes: It can be a complication as a consequence of GH excess and its mediators, but it can also result from treatment of acromegaly.

AREAS COVERED

This review provides an overview of the effects of acromegaly pathophysiology on glucose homeostasis. Furthermore, it devotes an extensive section on the influence that acromegaly treatment has on glucose metabolism, including approved as well as currently investigated drugs. It also summarizes observations from the use of anti-diabetic medication in patients with acromegaly.

EXPERT OPINION

Glucose imbalance is an important aspect of acromegaly comorbidity and deserves more attention. Even though numerous studies have investigated glucose homeostasis in acromegaly, there is still a clear need for more basic, translational, and also clinical research to advance the understanding of the underlying mechanisms and how to best address them.