Prevalence of diabetes mellitus in patients with acromegaly

Correlation between insulin-like growth factor and complexity of glucose time series index in patients with newly diagnosed acromegaly: a PILOT study

BACKGROUND

Acromegaly has a high risk of abnormal glucose metabolism. The complexity of the glucose time series index (CGI) is calculated from refined composite multi-scale entropy analysis of the continuous glucose monitoring (CGM) data. CGI is a new indicator of glucose imbalance based on ambulatory glucose monitoring technology, which allows for earlier response to glucose metabolism imbalance and correlates with patient prognosis.

OBJECTIVE

To compare the differences in glucose metabolic profile and CGI between acromegaly with normal glucose tolerance (NGT) and healthy subjects.

METHODS

Eight newly diagnosed patients with acromegaly (GH group) and eight age- and gender-matched healthy subjects (Control group) were included in this study. All participants underwent oral glucose tolerance test (OGTT) and 72-h CGM. A refined composite multi-scale entropy analysis was performed on the CGM data to calculate the CGI and we compare the differences in glycemic profiles and CGI between the two groups.

RESULTS

After OGTT, compared with the control group, patients in the GH group had higher 2 h blood glucose (BG) (mmol/L) [GH vs control, 6.7 (6.1, 7.0) vs 5.2 (3.8, 6.3), P  = 0.012], 3 h BG [5.1 (3.8, 6.5) vs 4.0 (3.4, 4.2), P = 0.046], mean BG [6.3 (6.1, 6.5) vs 5.5 (5.1, 5.9), P = 0.002], 2 h insulin (mU/L) [112.9 (46.8, 175.5) vs 34.1 (17.1, 55.6), P = 0.009], and 3 h insulin [26.8 (17.1, 55.4) vs 10.4 (4.2, 17.8), P = 0.016]. CGI was lower in the GH group [2.77 (1.92, 3.15) vs 4.2 (3.3, 4.8), P = 0.008]. Spearman's correlation analysis showed insulin-like growth factor (IGF) (r = -0.897, P < 0.001) and mean glucose (r = -0.717, P = 0.003) were significantly negatively correlated with CGI. Multiple linear stepwise regression showed that IGF-1 (r = -0.652, P = 0.028) was independent factor associated with CGI in acromegaly.

CONCLUSION

IGF-1 was significantly associated with CGI, and CGI may serve as a novel marker to evaluate glucose homeostasis in acromegaly with normal glucose tolerance.

Feline Comorbidities: Hypersomatotropism-induced diabetes in cats

PRACTICAL RELEVANCE

Diabetes mellitus is the second-most common feline endocrinopathy, affecting an estimated 1/200 cats. While the underlying causes vary, around 15-25% of cats with diabetes mellitus develop the condition secondarily to progressive growth hormone (GH)-induced insulin resistance. This typically results in a form of diabetes that is challenging to manage, whereby the response to insulin is very variable or high doses are required to achieve even minimal diabetic control.

CLINICAL CHALLENGES

Although uncontrolled chronic excessive GH may result in phenotypic changes that raise suspicion for acromegaly, many cats with hypersomatotropism (HST) do not have these changes. In these situations, a clinician's index of suspicion may be increased by the presence of less dramatic changes such as marked polyphagia, stertor or uncontrolled diabetes mellitus. The current diagnostic test of choice is demonstration of a markedly increased serum insulin-like growth factor 1 (IGF1) concentration, but some affected cats will have only a marginal increase; additionally, chronic insulin administration in cats results in an increase in serum IGF1, making the diagnosis less clear cut and requiring additional confirmatory tests.

EVIDENCE BASE

Over the past two decades, HST has increasingly been recognised as an underlying cause of diabetes mellitus in cats. This review, which focuses on diagnosis and treatment, utilises data from observational studies, clinical trials and case series, as well as drawing on the experience of the authors in managing this condition.

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.

Cardiovascular Effects of Excess Growth Hormone: How Real is the Threat?

Patients with acromegaly carry a high risk of developing cardiovascular diseases (CVD). In fact, CVD is the leading cause of mortality among this group of patients. The most frequent cardiovascular complications are heart failure (HF), valvular disease, hypertension, arrhythmias, and coronary artery disease (CAD). The pathophysiology centers on the family of growth hormone (GH). These hormones are involved in normal cardiac development and function; however, excess of insulin-like growth factor-1 (IGF-1), the principally active hormone, can also cause negative effects on the cardiovascular system. HF in acromegaly usually presents with biventricular enlargement and diastolic dysfunction and is strongly associated with the duration of GH excess rather than the degree of hormone elevation. There is a high prevalence of valvular disease affecting aortic and mitral valves among patients with longer disease duration. The development of hypertension in acromegaly may be attributed to the effects of chronic GH/IGF-1 excess on different organ systems, which act via several mechanisms. The aspect of arrhythmia and CAD complicating acromegaly are currently not fully understood.

Systemic comorbidities of acromegaly in real-life experience: which difference among young and elderly patients?

INTRODUCTION

Acromegaly is a rare but potentially life-threatening disease, if not promptly managed, for the systemic complications due to the GH/IGF-I hypersecretion. According to the increased population life span, the number of older acromegaly patients is growing. We aim to investigate clinical features of elderly acromegaly (elderly-ACRO) and to identify the risk factors for the occurrence of comorbidities in elderly-ACRO.

MATERIALS AND METHODS

A retrospective and multi-center study was performed on acromegaly patients. Acromegaly comorbidities were compared among elderly-ACRO (>65 years), young acromegaly patients (young-ACRO if ≤65 years) and a control group of age and gender-matched subjects.

RESULT

Fifty of the 189 enrolled patients were elderly-ACRO (26.5%). Cardiovascular, metabolic, neurological/psychiatric and joint/articular disorders, nodular thyroid disease, sleep apnoea syndrome and skeletal fragility occurred more frequently in elderly-ACRO as compared to controls. Cardiovascular and metabolic disorders, nodular thyroid disease occurred significantly more frequently in elderly-ACRO as compared to young-ACRO and controls. On the other hand, neurological/psychiatric, joint/articular disorders and bone fragility occur with a similar frequency among elderly and young-ACRO. We found that elderly-ACRO had an increased risk for the occurrence of systemic arterial hypertension (p < 0.001, OR: 5.4 95%IC:2.6-10.9), left ventricular hypertrophy (p = 0.01, OR: 3 95%IC: 1.5-5.8) and metabolic disorders (p = 0.006, OR: 4.1 95%IC: 2-8.3).

CONCLUSION

Our results may suggest that some acromegaly comorbidities may be predominantly due to acromegaly "per-se" rather than to aging. On the contrary, cardiovascular and metabolic disorders seem to be due to aging as well.

Acromegaly: Clinical Care in Central and Eastern Europe, Israel, and Kazakhstan

Acromegaly is a rare condition typically caused by benign pituitary adenomas, resulting in excessive production of growth hormone. Clinical manifestations of acromegaly are diverse, varying from the overgrowth of body tissue to cardiovascular, metabolic, and osteoarticular disorders. Symptoms may emerge slowly, overlapping with other diseases and often involve many different healthcare specialists. In the last decade, efforts to provide an accurate and timely diagnosis of acromegaly have improved disease management and clinical experience. Despite this progress, marked differences in the diagnosis, treatment, and management of acromegaly exist from country-to-country. To address these inconsistencies in the region comprising Central and Eastern Europe, Israel, and Kazakhstan, a panel of acromegaly experts from 13 of these countries was convened. Acromegaly experts from each country provided available information on the approaches from their country, including regional treatment centers and multidisciplinary teams, treatment access, reimbursement and availability, and physician education, disease awareness, and patient advocacy. Across several areas of acromegaly management, divergent approaches were identified and discussed, including the provision of multidisciplinary care, approved and available treatments, and disease awareness programs. These were recognized as areas of potential improvement in the management of acromegaly, in addition to participation in national and regional acromegaly registries. Further experience exchange will facilitate the identification of specific strategies that can be adapted in each country, and widespread participation in acromegaly registries will enable their evaluation. It is anticipated that this approach will support the optimization of acromegaly patient care across this region.

Prevalence of Comorbidities among Patients with Acromegaly

Background and Objective

Acromegaly is a chronic disorder resulting from excessive secretion of growth hormone and (GH) and insulin-like growth factor 1 (IGF-1) and is associated with several comorbidities. These complications contribute significantly to morbidity and mortality associated with this condition thus early diagnosis leads to better outcomes. There have been studies in other countries to assess the comorbidities associated with acromegaly. However, we do not have any recent data with regards to Pakistan. So, in order to demonstrate the prevalence of demographics, hormonal disorders, and other complications associated with acromegaly we conducted this study.

Methods

It is a retrospective review of patients' records presented to the tertiary care Hospital, Karachi, Pakistan for the diagnosis and management of acromegaly and the complications associated with this condition between the time periods 2000 till 2020. A total of 89 patients fulfilled the inclusion criteria of acromegaly and were included in the study. Comorbid conditions were described based on current guidelines. Patient baseline characteristics were recorded along with other complications arising during treatment.

Results

Eighty-nine patients were included. 64% were male, over 70% were older than 30 years old and more than 40% of patients had BMI greater than 30. HTN, pre-hypertension, and CCF were reported in 35.95%, 3.37%, and 6.74%. Diabetes mellitus, hypocortisolism, hypothyroidism, hypogonadism, and hyperprolactinemia were reported in 39.32%, 38.20%, 37.07%, 34.46%, and 16.85% of cases. The prevalence of osteoarthritis, blood disorder, skin changes, thyroid cancer, and spinal stenosis was found out to be around 1.12% each.

Conclusions

Acromegaly is associated with cardiovascular and endocrinal disorders. Screening for these disorders at the time of diagnosis can lead to early management and better outcomes translating into decreased mortality.

Prevalence of comorbidities and associated factors in acromegaly patients in the Turkish population

Background/aim

The presence of comorbidities in patients with acromegaly causes an increase in morbidity and/or mortality and a decrease in quality of life. In this study, we aimed to investigate the demographic, clinical and laboratory features, prevalence of acromegaly-related comorbidities, and factors associated with these comorbidities in patients with acromegaly.

Materials and methods

In the study, 96 patients who were followed up with the diagnosis of acromegaly were included. Clinical, laboratory and imaging features, and accompanying comorbidities of the patients were recorded from the patient files.

Results

Of the patients included in the study, 63 (65.6%) were female and 33 (34.4%) were male. The mean age of diagnosis was 42.61± 12.08, and the mean follow-up period was 9.97 ± 7.26 years. Median insulin-like growth factor 1 level was 238.16 ng/mL (30.5–820), median growth hormone level was 2.05 ug/L (0.1–29.4). A total of 60 (62.5%) of the patients were in the well-controlled group, and 36 (37.5%) had active disease at the time of inclusion. Diabetes mellitus (DM) was detected in 30 (31.3%) patients, prediabetes in 19 (28.8%) patients, hypertriglyceridemia in 38 (42.2%) patients, hypertension (HT) in 41 (42.7%) patients, cardiovascular disease in 5 (5.2%) patients, malignancy in 9 (9.4%) patients, obstructive sleep apnea syndrome in 8 (8.3%) patients, carpal tunnel syndrome in 11 (11.5%) patients, arthropathy in 5 (5.2%) patients, hearing loss in 7 (7.3%) patients, thyroid nodule in 56 (67.5%) patients, thyroid cancer in 4 (4.2%) patients, colonic polyp in 19 (38.8%) patients.

Conclusion

In this study, we revealed that the most common comorbidities in acromegaly patients in the Turkish population are thyroid nodules, low high-density lipoprotein (HDL cholesterol (HDL-C) level, hypertriglyceridemia, HT, colonic polyps, DM, and prediabetes, and female sex and age at diagnosis are the most important factors associated with comorbidities.

Diabetes Mellitus of Pituitary Origin: A Case Report

We describe the case report of 36-year-old female who presented to the emergency department with diabetic ketoacidosis. On detailed clinical examination, coarse facial features in the form of large fleshy nose, thick lips, prognathism, and thickening of hands and feet were noticed, suggestive of acromegaly. Subsequently, she was diagnosed with acromegaly due to somatotropinoma. Impaired glucose tolerance and diabetes mellitus are frequently associated with acromegaly. Persistent growth hormone excess impairs insulin sensitivity, increases gluconeogenesis, reduces glucose uptake in adipose tissue and muscle, and alters pancreatic β-cell function. Rarely, diabetic ketoacidosis can be the presenting manifestation, as seen in this case.

Patterns of Abnormal Glucose Metabolism in Acromegaly and Impact of Treatment Modalities on Glucose Metabolism

Background: Chronic exposure to high levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1) leads to metabolic complications, most importantly dysglycemia in the form of diabetes mellitus and pre-diabetes. Dysglycemia if diagnosed early in the course of the disease can decrease complications. Treatment modalities in the form of surgery and medical therapy have varied impacts on glucose metabolism.

Objective: To determine the frequency of diabetes mellitus, impaired glucose tolerance, and impaired fasting glucose in Pakistani patients with acromegaly and to establish the impact of the intervention (surgery/medical) on glucose metabolism.

Methods: This study was a retrospective review of patient records. Eighty-nine patients fulfilling the Endocrine Society criteria for acromegaly diagnosis were included. A data of baseline, GH, IGF-1 level, hemoglobin A1C (HbA1C), fasting blood glucose (FBG), and random blood glucose (RBS) levels were reviewed before and after the intervention (surgery/medical therapy). Normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes mellitus (DM) were defined based on the American Diabetes Association (ADA) criteria. Patients were grouped into normoglycemic (NGT) and dysglycemic (IFG, IGT, and DM) based on FBG, RBS, and HbA1C.

Results: Major risk factors for dysglycemia included age (15-45 years), male sex (33.70%), obesity (45.7%), and macroadenoma (77.52%). Both mean GH levels (58.29 vs. 54.36 ng/dl) and IGF-1 levels (862.98 vs. 824.32 ng/dl) were higher among the normoglycemic than dysglycemia. Pre-surgery NGT, IFG, IGT, IFG, and IGT/DM combined were found in 48.31%, 5.61%, 1.1%, 5.61%, and 39.32% of the subjects respectively. Post-surgery, HbA1C improved in 79.5%, deteriorated in 6.8%, and remained the same in 13.6%. Similarly, it improved in 67% post-medical therapy. Both FBG and RBS improved post-surgery and medical therapy. Further, the number of anti-diabetic drugs used also decreased post-surgery.

Conclusion: Dysglycemia is more common among patients with acromegaly as compared to the general population and tends to be poorly controlled in untreated acromegaly. Glycemic control improves significantly after surgery and medical therapy.

Insights from the clinical phenotype of subjects with Laron syndrome in Ecuador

The Ecuadorian cohort of subjects with LS has taught us valuable lessons since the late 80's. We have learned about migration of Sephardic Jews to our country, their isolation in remote hamlets and further inbreeding. These geographical, historical and social determinants induced dissemination of a growth hormone (GH) receptor mutation which widely occurred in those almost inaccessible villages. Consequently, the world's largest Laron syndrome (LS) cohort emerged in Loja and El Oro, two of the southern provinces of Ecuador. We have been fortunate to study these patients since 1987. New clinical features derived from GH insensitivity, their growth patterns as well as treatment with exogenous insulin-like growth factor I (IGF-I) have been reported. Novel biochemical characteristics in the field of GH insensitivity, IGFs, IGF binding proteins (BP) and their clinical correlates have also been described. In the last few years, studies on the morbidity and mortality of Ecuadorian LS adults surprisingly demonstrated that despite obesity, they had lower incidence of diabetes and cancer than their relatives. These events were linked to their metabolic phenotype of elevated but ineffective GH concentrations and low circulating IGF-I and IGFBP-3. It was also noted that absent GH counter-regulation induces a decrease in insulin resistance (IR), which results in low but highly efficient insulin levels which properly handle metabolic substrates. We propose that the combination of low IGF-I signaling, decreased IR, and efficient serum insulin concentrations are reasonable explanations for the diminished incidence of diabetes and cancer in these subjects.

[Selective screening of patients with associated somatic diseases as a method of early detection of acromegaly]

Backgraund

Backgraund: Acromegaly is a multi-organ disabling disease, the effectiveness of treatment of which directly depends on timely diagnosis. Latent course and delayed diagnosis increase the exposure of pathological hypersecretion of growth hormone and insulin-like growth factor-1, contributing to the development of irreversible systemic and metabolic changes in the body that negatively affect survival.

Aims

Aims: The aim of the study was to clinically test a comprehensive diagnostic approach using selective screening to detect cases of acromegaly in patients with combined somatic diseases.

Materials and methods

Materials and methods: The diagnostic search algorithm included a 2-stage questionnaire, expert assessment of the clinical status, laboratory and instrumental examination. The inpatient examination included the use of additional laboratory and instrumental methods and expert evaluation of the results obtained by filling out a doctor’s questionnaire. When the score was higher than 18 points, a more specific examination was performed: double determination of the insulin-like growth factor-1 level, oral glucose tolerance test with determination of the nadir of growth hormone value, and MRI of the brain with contrast enhancement. The diagnosis of acromegaly was made on the basis of personal data, expert assessment of the clinical status, results of laboratory and instrumental examinations.

Results

Results: A survey of 1249 patients with combined systemic and metabolic disorders conducted using the point system allowed us to suspect acromegaly in 367 patients (29.4%), who were offered further examination. The majority of patients were previously seen by specialists for diabetes mellitus (79.3%) or thyroid pathology (10%). In the result of inpatient ­examination of 329 patients, 35 (10.6%) patients showed an increase in the blood level of IGF-I. In 19 patients, a persistent increase in the level of IGF-I was combined with the absence of GH suppression of less than 0.4 ng/ml against the background of glucose load. During MRI in 9 patients, pituitary adenoma was detected (in 2 — microadenoma and 7 — ­macroadenoma).

Conclusions

Conclusions: As a result of the study, among the group of 1249 patients (mean age 58±13 years) with the presence of concomitant diseases, 9 newly identified patients with acromegaly were found who were prescribed adequate treatment. The introduction of selective screening technology into the practice of an endocrinologist will improve the effectiveness of diagnostic search for patients with acromegaly, more accurately assess the prevalence of the disease in Russia and the need for specialized medical care.

Acromegaly Cases Exhibiting Increased Growth Hormone Levels during Oral Glucose Loading with Preadministration of Dipeptidyl Peptidase-4 Inhibitor

Objective Glucose-dependent insulinotropic polypeptide (GIP) is speculated to worsen growth hormone (GH) hypersecretion in acromegaly and to be a cause of paradoxical increases in GH (PI-GH) during 75-g oral glucose tolerance testing (75-g OGTT). Dipeptidyl peptidase-4 inhibitors (DPP4is), which increase the circulating concentration of active GIP, are frequently administered to diabetic patients, including those with acromegaly. We aimed to determine whether or not the administration of a DPP4i increases GH concentration, especially in patients demonstrating PI-GH during a DPP4i-OGTT, in which a DPP4i was administered immediately before 75-g OGTT. Methods This prospective cross-sectional study was carried out on acromegalic patients admitted to Hokkaido University hospital between June 2011 and May 2018. The participants underwent both 75-g OGTT and DPP4i-OGTT. For those who underwent surgery, immunohistochemical staining and quantitative polymerase chain reaction (PCR) for the GIP receptor (GIPR) were performed on the resected pituitary adenomas. Results Twenty-five percent of the participants had PI-GH confirmed (3 of 12 cases). Two of the three participants who demonstrated PI-GH exhibited higher circulating GH concentrations during DPP4i-OGTT than during OGTT. The increase in plasma glucose was reduced during DPP4i-OGTT compared to during 75-g OGTT, suggesting that the increase in GH during DPP4i-OGTT was due not to high glucose concentrations but instead increased GIP caused by the administration of DPP4i. The adenoma from one participant with PI-GH displayed positive immunostaining for GIPR and a higher GIPR messenger ribonucleic acid (mRNA) expression than the others. Conclusion DPP4i may enhance the GH secretion response during glucose loading, especially in individuals with PI-GH.

The Beta-Cell Function and Glucose Profile of Newly Diagnosed Acromegalic Patients with Normal Glucose Tolerance

OBJECTIVES

Untreated acromegaly is a nature model for unveiling the diabetogenic effects of GH. CGMS can uncover more glucose profile of acromegaly. This study aimed to evaluate the insulin resistance (IR), β-cell function, and glycemic spectrum of patients with newly diagnosed acromegaly with normal glucose tolerance (NGT).

METHODS

This study was conducted in Huashan Hospital from January 2015 to February 2019. Eight newly diagnosed acromegalic patients without history of diabetes and eight age- and gender-matched healthy subjects were enrolled. All participants underwent oral glucose tolerance test (OGTT) and 72 h continuous glucose monitoring (CGM). Parameters on β-cell function and IR were calculated. Mean blood glucose (MBG) in 24 hours was adopted for the evaluation of the glycemic level, and standard deviation of blood glucose (SDBG) and mean amplitude of glycemic excursion (MAGE) were used for glucose fluctuation.

RESULTS

HbA1c in the acromegaly group was significantly higher than in the control. During OGTT, glucose peaked at 60 min in acromegaly and at 30 min in controls. After glucose load, the acromegaly group had significantly higher insulin levels than controls, especially in 120 min and 180 min. Both insulin sensitivity index and disposal index after glucose load of acromegaly were significantly lower than those of controls. Moreover, acromegalic subjects had significantly higher MBG than controls.

CONCLUSIONS

The newly diagnosed acromegalic patients with NGT were characterized by IR and impaired β-cell function after glucose load. CGM showed that MBG of NGT acromegaly patients was higher than that of normal people.

Diabetes Mellitus of Pituitary Origin: A Case Report

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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.

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.

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.

Risk for Acromegaly-related Comorbidities by Sex in Korean Acromegaly

CONTEXT

Reports on the incidence, characteristics, and comorbidity in Asian patients with acromegaly are scarce.

OBJECTIVE

To evaluate the incidence of acromegaly and the risk of comorbidities in East Asia, especially South Korea.

DESIGN

This nationwide population-based cohort study using the Korean Health Insurance Review and Assessment claims database evaluated the incidence of acromegaly, initially diagnosed from 2010 to 2013. We identified comorbidities during, before, and 2 years after diagnosis. Acromegaly and control cases (718 and 7180, respectively) were included in the analysis.

SETTING

A longitudinal case-control study using a nationwide population cohort.

RESULTS

The mean annual incidence rate of acromegaly was 3.57 cases per 1 000 000. Malignancies occurred in 61 patients with acromegaly (8.5%) during the study period and thyroid cancer was the most common malignancy (n = 38). In the acromegaly group, the overall risk of malignancy was higher: hazard ratio (HR), 2.82 (95% confidence interval [CI]: 2.12-3.74). Malignancy risk was more pronounced in females, with increased risk from the prediagnosis period that is sustained until the postdiagnosis period. Prevalence of diabetes mellitus (DM) and heart failure increased significantly in acromegalic patients. Over the entire period, DM developed in 51.1% and 57.0% of male and female acromegalic patients, respectively. Mortality risk was higher (HR 1.65, 95%; CI: 1.13-2.41) and statistically significant in females (HR 1.75, 95%; CI: 1.07-2.84).

CONCLUSION

Comorbidities associated with acromegaly differed by sex in Korean subjects. High malignancy and mortality risk should be considered in female patients when managing acromegaly in Korea.

Acromegaly in the elderly patients

BACKGROUND

Acromegaly is a rare disease characterized by a chronic exposition to growth hormone (GH) and insulin-like growth factor-1 (IGF-1), caused in most cases by a pituitary GH-secreting adenoma. Chronic GH excess induces systemic complications (metabolic, cardiovascular, respiratory, neoplastic, and musculoskeletal) and increased mortality if not appropriately treated. Recent epidemiological data report an improved life span of patients with acromegaly probably due to better acromegaly management; additionally, the number of pituitary incidentaloma in general population also increased over time due to more frequent imaging. Therefore, the number of elderly patients, newly diagnosed with acromegaly or in follow-up, is expected to grow in the coming years and clinicians will need to be aware of particularities in managing these patients.

PURPOSE

This review aims to explore different aspects of acromegaly of the elderly patients, focusing on epidemiology, diagnosis, clinical presentation, complications, and management options.

METHODS

Available literature has been assessed through PubMed (data until August 2019) by specific keywords.

CONCLUSIONS

Available data on acromegaly in the elderly patient are sparse, but point to important differences. Further studies are needed comparing elderly with younger patients with acromegaly to better define a tailored diagnostic and therapeutic management.

High-Performance Liquid Chromatography-Mass Spectrometry-Based Lipid Metabolite Profiling of Acromegaly

CONTEXT

Metabolic disorders, especially dysregulated lipid metabolism, increase the risk of cardiovascular mortality in acromegaly. Previous studies measuring plasma macromolecular lipids have yielded conflicting results.

PURPOSE

To explore the plasma lipid metabolite profiles by metabolomics analysis and identify potential metabolites associated with cardiac function in acromegaly.

METHODS

Plasma was obtained from 80 newly diagnosed, untreated patients with acromegaly and 80 healthy controls. Echocardiography was performed. Based on the results of an oral glucose tolerance test (OGTT), patients were categorized into 2 groups: normal glucose tolerance (NGT, n = 28) and impaired glucose tolerance or diabetes mellitus (IGT/DM, n = 52). High-performance liquid chromatography-mass spectrometry (HPLC-MS)-based metabolomics analysis was conducted. Data were processed by principal components analysis (PCA), orthogonal partial least square-discriminant analysis (OPLS-DA), and MetaboAnalyst 4.0. Associations between metabolic substances and cardiovascular parameters were also explored.

RESULTS

Metabolomics uncovered a distinct metabolic pattern between acromegaly and healthy controls, and perturbed pathways mainly include glycerophospholipid metabolism, sphingolipid metabolism, as well as linoleic acid metabolism. Collective analysis showed that phosphatidylethanolamine (PE) (22:6/16:0) was positively correlated with LV mass, while lysophosphatidylcholine (LysoPC) (16:0) was positively correlated with fractional shortening (FS) and left ventricle ejection fraction (LVEF).

CONCLUSION

Patients with acromegaly have distinct lipid metabolite profiling, while PE (22:6/16:0) and LysoPC (16:0) are correlated with cardiac structure and function, which may contribute to the risk of cardiovascular complications.

Metabolic profiling of acromegaly using a GC-MS-based nontargeted metabolomic approach

PURPOSE

Acromegaly is a rare disease caused by chronic hypersecretion of growth hormone, which leads to multiple comorbidities and reduced life expectancy. The objective of this study was to characterize the serum metabolic profiles of acromegaly patients and identify metabolic biomarkers using metabolomics.

METHODS

Twenty-nine active acromegaly patients and age- and sex-matched normal controls were recruited. Serum samples were collected, and serum metabolites were analyzed using gas chromatography-mass spectrometry coupled with a series of multivariate statistical analyses.

RESULTS

The orthogonal projections to latent structures-discriminate analysis (OPLS-DA) model identified and validated significant metabolic differences between individuals with acromegaly and normal controls (R²Y = 0.908 and Q²Y = 0.601). Compared with normal controls, acromegaly patients had elevated levels of 5-aminovaleric acid, glyceric acid, L-dithiothreitol, dihydrocoumarin, N-acetyl-L-glutamic acid, gluconic acid, and monoolein (P < 0.05) and reduced serum levels of D-erythronolactone, taurine, carbamoyl-aspartic acid, and mucic acid (P < 0.01). Furthermore, glyceric acid and taurine possessed higher area under the receiver operating characteristic curve values (AUC values, 0.914 and 0.931, respectively), suggesting an excellent clinical ability to distinguish acromegaly patients from normal controls. Pathway analysis revealed that the pentose phosphate pathway and the taurine and hypotaurine metabolic pathway are significant pathways (P = 0.002 and 0.004, respectively).

CONCLUSIONS

Metabolic activity is significantly altered in the serum of individuals with active acromegaly. Glyceric acid and taurine may be considered potential biomarkers for distinguishing acromegaly patients from normal controls.

Italian Association of Clinical Endocrinologists (AME) and Italian AACE Chapter Position Statement for Clinical Practice: Acromegaly - Part 1: Diagnostic and Clinical Issues

Acromegaly is a rare disease. Improvements in lifespan in these patients have recently been reported due to transsphenoidal surgery (TSS), advances in medical therapy, and strict criteria for defining disease remission. This document reports the opinions of a group of Italian experts who have gathered together their prolonged clinical experience in the diagnostic and therapeutic challenges of acromegaly patients. Both GH and IGF-I (only IGF-I in those treated with Pegvisomant) are needed in the diagnosis and follow-up. Comorbidities (cardio-cerebrovascular disease, sleep apnea, metabolic derangement, neoplasms, and bone/joint disease) should be specifically addressed. Any newly diagnosed patient should be referred to a multidisciplinary team experienced in the treatment of pituitary adenomas.

The acromegalic spine: fractures, deformities and spinopelvic balance

INTRODUCTION

Axial skeleton arthropathy and osteoporotic vertebral fractures are common findings in acromegalic patients and can result in severe spinal deformity.

OBJECTIVE

To investigate the presence of spinal fractures and deformities, sagittal imbalances, and spinopelvic compensatory mechanisms in acromegalics.

PATIENTS AND METHODS

58 patients with acromegaly from a referral neuroendocrinology center were prospectively evaluated by panoramic spine radiographs to detect the presence of fractures and scoliosis, to measure thoracic kyphosis, lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and sagittal vertical axis (SVA). Sagittal imbalance criteria were considered: thoracic kyphosis > 50°, PI-LL > 10°, PT > 20° and SVA > 5 cm. Their medical records were analyzed for clinical and laboratorial data.

RESULTS

The prevalence of fractures was 13.8%, predominantly in the thoracic spine, with mild and anterior wedge compressions. Scoliosis was present in 34.5% of the cases, all with degenerative lumbar curve apex. Thoracic kyphosis > 50º occurred in 36.8% of patients, PI-LL > 10° in 48.3%, PT > 20° in 41.4% and SVA > 5 cm in 12.1%.

CONCLUSION

Increased number of vertebral fractures and high prevalence of spinal deformities related to sagittal imbalance were detected, indicating the importance of monitoring bone comorbidities in acromegaly, with radiological evaluation of the spine as part of the follow up.

Prevalence of diabetes among children treated with growth hormone in Israel

AIMS

To determine the long-term risk of diabetes in a cohort of children treated with recombinant human growth hormone in Israel, using data from the Israeli National Diabetes Register.

METHODS

Between 1988 and 2009, 2513 children were approved for growth hormone treatment. They were assigned to one of two groups. The first group included children treated for isolated growth hormone deficiency and who were small for gestational age and the second included those treated for multiple pituitary hormone deficiency, chronic renal failure, Turner syndrome or Prader-Willi syndrome. The cohort was cross-linked with the Israeli National Diabetes Register for 2014 (mean follow-up duration 12.1±5.3 years), and prevalent cases of diabetes were identified. Standardized prevalence ratios for diabetes were calculated for people aged 10-29 years.

RESULTS

In 2014, a total of 23 individuals were identified with diabetes (four with pre-existing diabetes, seven developed diabetes before age 17 years and 12 developed it at a later age). In the isolated growth hormone deficiency and small-for-gestational-age group there was no difference in the prevalence of diabetes compared with the general population (standardized prevalence ratio 2.05, 95% CI 0.94-3.89). In the group that included people with multiple pituitary hormone deficiency, chronic renal failure, Turner syndrome and Prader-Willi syndrome there was a significantly higher diabetes prevalence (standardized prevalence ratio 11.94, 95% CI 6.53-20.00) compared with the general population.

CONCLUSIONS

No difference in diabetes prevalence was found in the isolated growth hormone deficiency and small-for-gestational-age group, compared with the general population. Children treated with growth hormone with pre-existing risk factors had an increased prevalence of diabetes. It is advisable to monitor blood glucose levels closely during and after growth hormone treatment, especially in such children.

Loss of Adipose Growth Hormone Receptor in Mice Enhances Local Fatty Acid Trapping and Impairs Brown Adipose Tissue Thermogenesis

Growth hormone (GH) binds to its receptor (growth hormone receptor [GHR]) to exert its pleiotropic effects on growth and metabolism. Disrupted GH/GHR actions not only fail growth but also are involved in many metabolic disorders, as shown in murine models with global or tissue-specific Ghr deficiency and clinical observations. Here we constructed an adipose-specific Ghr knockout mouse model Ad-GHRKO and studied the metabolic adaptability of the mice when stressed by high-fat diet (HFD) or cold. We found that disruption of adipose Ghr accelerated dietary obesity but protected the liver from ectopic adiposity through free fatty acid trapping. The heat-producing brown adipose tissue burning and white adipose tissue browning induced by cold were slowed in the absence of adipose Ghr but were recovered after prolonged cold acclimation. We conclude that at the expense of excessive subcutaneous fat accumulation and lower emergent cold tolerance, down-tuning adipose GHR signaling emulates a healthy obesity situation which has metabolic advantages against HFD.

Correlation analysis between short-term insulin-like growth factor-I and glucose intolerance status after transsphenoidal adenomectomy in acromegalic patients: a large retrospective study from a single center in China

OBJECTIVES

Our study aimed to investigate the associations of glucose tolerance status with insulin-like growth factor-I (IGF-I) and other clinical laboratory parameters of acromegalic patients before and after the patients underwent transsphenoidal adenomectomy (TSA) by conducting a single-center, retrospective study.

SUBJECTS AND METHODS

A total of 218 patients with acromegaly who had undergone TSA as the first treatment were retrospectively analyzed. Serum IGF-I, growth hormone (GH) and glucose levels were measured before and after surgery.

RESULTS

The follow-up levels for random GH, GH nadir, and the percentage of the upper limit of normal IGF-I (%ULN IGF-I) were decreased significantly. The percentages of normal (39.0%), early carbohydrate metabolism disorders (33.0%) and diabetes mellitus (28.0%) changed to 70.2%, 16.5% and 13.3%, respectively, after TSA. %ULN IGF-I at baseline was higher in the diabetes mellitus (DM) group than in the normal glucose tolerance group and impaired glucose tolerance (IGT) /impaired fasting glucose (IFG) groups before TSA, and the DM group exhibited a greater reduction in %ULN IGF-I value after surgery. The follow-up %ULN IGF-I value after surgery was significantly lower in the improved group, and Pearson's correlation analysis revealed that the reductions in %ULN IGF-I corresponded with the reductions in glucose level.

CONCLUSION

This study examined the largest reported sample with complete preoperative and follow-up data. The results suggest that the age- and sex-adjusted IGF-I level, which reflects altered glucose metabolism, and the change of it are associated with improved glucose tolerance in acromegalic patients both before and after TSA.

Diabetes in patients with acromegaly treated with pegvisomant: observations from acrostudy

PURPOSE

To explore the effects of pegvisomant (PEGV) on glucose metabolism in patients with acromegaly within ACROSTUDY, an international, observational, prospective safety surveillance study.

METHODS

Patients were retrospectively divided into two cohorts, with (DM group) or without diabetes mellitus (no-DM). Parameters of glucose metabolism and IGF-I values were analyzed yearly both cross-sectionally for 4 years (yrs) and longitudinally at 1 and 4-5 yrs of PEGV treatment.

RESULTS

Among 1762 patients, 510 (28.9%) had DM before PEGV start. At cross-sectional analyses, in the DM group mean blood glucose was 140.0 ± 58.7 mg/dl at baseline, 116.4 ± 44.8 mg/dl at year 1 and 120.0 ± 44.3 mg/dl at yr 4. Mean HbA1c was 6.6 ± 1.2 % at yr 1 vs. 7.0 ± 1.4 % at baseline. HbA1c was above 6.5% in 61.9% at baseline and ranged from 45.4 to 53.8% at subsequent yearly time points. At the 4-yr longitudinal analysis, in the DM group (n = 109), mean blood glucose decreased by 20.2 mg/dl at yr 4, mean HbA1c was 7.0 ± 1.5% at baseline vs. 6.8 ± 1.4%. Patients achieved IGF-I normalization in 52.1% and 57.4% of cases in the DM and no-DM groups, respectively at 1 year. The mean daily PEGV dose (mg/day) was higher in the DM group (18.2 vs. 15.3) while the absolute change of IGF-I values from baseline was similar in both groups. PEGV was well tolerated in both groups without any unexpected AEs.

CONCLUSIONS

Patients with DM had a moderate decrease in mean fasting glucose values during PEGV treatment.

Systemic Complications of Acromegaly and the Impact of the Current Treatment Landscape: An Update

Acromegaly is a chronic systemic disease with many complications and is associated with increased mortality when not adequately treated. Substantial advances in acromegaly treatment, as well as in the treatment of many of its complications, mainly diabetes mellitus, heart failure, and arterial hypertension, were achieved in the last decades. These developments allowed change in both prevalence and severity of some acromegaly complications and furthermore resulted in a reduction of mortality. Currently, mortality seems to be similar to the general population in adequately treated patients with acromegaly. In this review, we update the knowledge in complications of acromegaly and detail the effects of different acromegaly treatment options on these complications. Incidence of mortality, its correlation with GH (cumulative exposure vs last value), and IGF-I levels and the shift in the main cause of mortality in patients with acromegaly are also addressed.

Effects of growth hormone on pregnancy rates of patients with thin endometrium

PURPOSE

To investigate whether growth hormone (GH) could improve pregnancy rates of patients with thin endometrium by clinical study and laboratory experiments.

MATERIALS AND METHODS

Ninety-three patients were randomized to either the GH-received group (40) or the routine exogenous administration of estrogens control group (53) for clinical study. The human endometrial carcinoma cell line RL95-2 was used for testing the role of GH with Western blot and real-time PCR by exposure to various concentrations of GH (0.1 nM,1 nM,10 nM,100 nM).

RESULTS

Patients treated with GH had a significantly (P < 0.05) greater endometrium thickness on day 3 (7.87±0.72 vs 6.34±0.86), higher implantation rates (24.4% vs 10.5%) and greater clinical pregnancy rates (42.5% vs 18.9%) compared with the control group. No adverse events were associated with the use of GH. Administration of GH significantly up-regulated the expression of VEGF, ItgB3 and IGF-I expression in RL95-2 cells at both mRNA and protein levels (P < 0.05). AG490, an inhibitor of JAK2, nearly completely inhibited the up-regulative effect of GH through the JAK2-STAT5 pathway, and GH-induced effects could be mediated through autocrine IGF-I together with its hepatic counterpart. IGF-I mRNA was detected in the RL95-2 cells.

CONCLUSION

GH may improve pregnancy outcomes of patients with thin endometrium who undergo frozen embryo transfer by acting on human endometrial cells to promote proliferation and vascularization and to up-regulate receptivity-related molecular expression.

Surgical outcomes and predictors of glucose metabolism alterations for growth hormone-secreting pituitary adenomas: a hospital-based study of 151 cases

PURPOSE

The surgical outcome on glucose metabolism in acromegaly patients is not fully understood. We aimed to investigate the impact of surgery on glucose metabolism and identify key factors that influence alterations of glucose metabolic status in acromegaly patients.

METHODS

Oral glucose tolerance test was performed in 151 newly diagnosed acromegaly patients before and 3-12 months after surgery. Insulin resistance and insulin secretion was assessed. Patients were grouped as cured, discordant, and having active disease according to postoperative growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels. Receiver-operating characteristic curves were generated to determine the optimal cut-off points to predict the impact of surgery on glucose metabolism.

RESULTS

At baseline, 32.5%, 41.7%, and 25.8% patients were categorized as having normal glucose tolerance (NGT), impaired glucose tolerance (IGT), and diabetes mellitus (DM), respectively. After surgery, improved glucose tolerance was observed in 87.3% patients with IGT and 66.7% patients with DM. Deterioration was observed in 14.3% patients with NGT. Glucose tolerance improved in patients with lower preoperative FBG, 2 h-BG, and HbA1c and higher HOMA-β and IGI/IR. The proportion of NGT was significantly increased in surgically cured patients (28.3% vs. 79.2%, P < 0.001) and those with normal GH but elevated IGF-1 levels (25.6% vs. 79.5%, P < 0.001), but not in patients with active disease (42.9% vs. 57.1%, P = 0.131). Baseline FBG < 6.35 mmol/l predicted improved glucose metabolism after surgery.

CONCLUSIONS

Glucose metabolic status improved in patients with preserved β-cell function. Preoperative FBG was an independent predictor for improved glucose tolerance status after surgery.

Disposition Index in Active Acromegaly

Background: The relative contribution of reduced insulin sensitivity (S_i) or insulin secretion to impaired fasting glucose (IFG) or diabetes mellitus (DM) has not been clarified in active acromegaly. An intravenous glucose tolerance test (IVGTT) was never used for the calculation of S_i, acute insulin response (AIR_g), and disposition index (DI) in this population. Our aim was to assess S_i, AIR_g and DI using an IVGTT in acromegaly with normal (NGT) and abnormal glucose tolerance. Methods: We performed an IVGTT in 13 patients (8 NGT, 2 IFG, and 3 DM; 5 males, age 47.9 ± 11 years, body mass index 29.7 ± 4.1 kg/m²) with active acromegaly (insulin-like growth factor-1 4.1 ± 1.3 × upper limit of normal, basal GH 29.1 ± 25 ng/mL) and 3 healthy controls (2 males, age 39 ± 3 years, body mass index 23 ± 5 kg/m²). No patient had any growth hormone- or glucose-lowering medication. Results: NGT patients had significantly lower S_i than healthy controls but higher AIR_g. Hyperglycemic and normoglycemic patients had similar S_i. DM patients had severely diminished AIR_g (5-260 pmol × min/L) while IFG patients maintained their insulin secretion (3,862 and 912 pmol × min/L). Patients with abnormal glucose tolerance (IFG + DM) had a significantly lower DI (353 ± 350) than both NGT patients (3,685 ± 2,544) and healthy controls (5,837 ± 1,894; p < 0.01 for ANOVA). Conclusions: Disposition index suggests that although reduced insulin sensitivity is characteristic of active acromegaly it is the impaired insulin secretion that mainly drives glucose intolerance. The clinical utility of DI in predicting DM in acromegaly must be further investigated.

Time-Dependent Molecular Responses Differ between Gastric Bypass and Dieting but Are Conserved Across Species

The effectiveness of Roux-en-Y gastric bypass (RYGB) against obesity and its comorbidities has generated excitement about developing new, less invasive treatments that use the same molecular mechanisms. Although controversial, RYGB-induced improvement of metabolic function may not depend entirely upon weight loss. To elucidate the differences between RYGB and dieting, we studied several individual organ molecular responses and generated an integrative, interorgan view of organismal physiology. We also compared murine and human molecular signatures. We show that, although dieting and RYGB can bring about the same degree of weight loss, post-RYGB physiology is very different. RYGB induces distinct, organ-specific adaptations in a temporal pattern that is characterized by energetically demanding processes, which may be coordinated by HIF1a activation and the systemic repression of growth hormone receptor signaling. Many of these responses are conserved in rodents and humans and may contribute to the remarkable ability of surgery to induce and sustain metabolic improvement.

Persistence of Diabetes and Hypertension After Multimodal Treatment of Acromegaly

CONTEXT

Diabetes and hypertension are frequent comorbidities of acromegaly.

OBJECTIVE

To analyze the course of diabetes and hypertension at diagnosis and after multimodal therapy in a large cohort of patients with acromegaly.

DESIGN AND SETTING

Retrospective study at a tertiary care center.

PATIENTS AND METHODS

A total of 522 patients with acromegaly treated according to a preestablished protocol.

MAIN OUTCOME MEASURES

Prevalence of diabetes and hypertension and its relationship with biochemical indices of acromegalic control.

RESULTS

The cohort was stratified according to disease activity upon last visit to clinic: (1) surgical remission (n = 122), (2) pharmacologically controlled (n = 92), (3) active disease (n = 148), (4) insulinlike growth factor (IGF)-1 discordance (n = 64), and (5) growth hormone (GH) discordance (n = 96). The prevalence of diabetes and hypertension at diagnosis was 30% and 37%, respectively, and did not change upon the last visit (30.6% and 38%). Both comorbidities were more prevalent at diagnosis and on the last visit than in the general population. Diabetes was less prevalent on the last visit in patients who achieved surgical remission than in those who persisted with active disease (25% vs 40%, P = 0.01). Upon multivariate analysis, diabetes was associated with an IGF-1 at diagnosis >2× upper limit of normal, with the persistence of active acromegaly, the presence of hypertension upon the last visit, with the presence of a macroadenoma, and with female sex.

CONCLUSION

Our findings underscore the importance of an integral approach when managing these patients, focusing not only on the control of GH and IGF-1 levels but also on the timely diagnosis and the specific treatment of each comorbidity.

Postoperative Changes in Metabolic Parameters of Patients with Surgically Controlled Acromegaly: Assessment of New Stringent Cure Criteria

The criteria for surgical cure of acromegaly have become more stringent during the past decades and a change from Cortina to new consensus criteria has recently been proposed. However, the superiority of the new consensus over Cortina criteria with respect to postoperative metabolic parameters remains to be ascertained. We retrospectively assessed metabolic parameters, the body habitus, and other health-related parameters of 48 patients with surgically controlled acromegaly who met the Cortina criteria [normalized insulin-like growth factor-1 (IGF-1) level and nadir growth hormone (GH) level <1.0 ng/ml during postoperative oral glucose tolerance test]. The 48 patients were divided into two groups. Group A (n = 33) met the new consensus criteria (normalized IGF-1 and nadir GH level <0.4 ng/ml). Group B (n = 15) met Cortina criteria, but their nadir GH ranged from 0.4 to 1.0 ng/ml. In both groups, the level of triglyceride and homeostasis model assessment-insulin resistance (HOMA-IR) was significantly decreased 1 year after the operation (P < 0.05). High-density lipoprotein cholesterol showed a significant increase only in group B (P = 0.02). However, the two groups did not differ with respect to the postoperative improvement rate of these parameters and the other health-related parameters including body mass index, blood pressure, anterior pituitary function, and self-estimated quality of life scale. In conclusion, our findings show that with respect to changes in metabolic parameters and the body habitus assessed 1 year after surgery, the stricter consensus criteria seemed not to be superior to Cortina criteria.

GH and GHR signaling in human disease

Along with its inherent properties in growth promotion, cell division and regeneration, growth hormone (GH) exerts a variety of miscellaneous and widespread actions on the human body after binding to its receptor (GHR). Indeed, GH influences the metabolism of carbohydrates, lipids and proteins; shapes body composition, influences cardiovascular profile, quality of life, and induces other direct and indirect physiologic effects. Besides this salutary actions, GH and its derived peptide insulin-like growth factor-I (IGF-I), main product of the GH/GHR interaction, have been implicated in the genesis of diseases such as cancer and insulin-resistant diabetes. The effects of these peptides are difficult to discern in healthy individuals but can be better evaluated in disease states in which their action in target tissues is abnormal. In consequence, we selected acromegaly and Laron syndrome due to GH receptor deficiency (GHRD) as models for excess and absence of GH action, and focused in the role of GH/GHR signaling in the genesis of cancer and diabetes. Considering that malignancy has been linked at epidemiological level to type 2 diabetes and high body mass index, suggesting that hyperinsulinemia is an independent contributor to cancer genesis and progression, we propose that the GH-derived IGF-I is also an independent influence for progression to neoplasia since its absence associates with less DNA damage, diminished mutagenesis and efficient apoptosis. Regarding development of type 2 diabetes, we support the notion that GH, by influencing insulin sensitivity via its counter-regulatory properties on carbohydrate metabolism, is an important contributor for development of this disease.

Diabetes Secondary to Acromegaly: Physiopathology, Clinical Features and Effects of Treatment

Acromegaly is a rare disease due to chronic GH excess and to the consequent increase in IGF-1 levels. Both GH and IGF-1 play a role in intermediate metabolism affecting glucose homeostasis. Indeed, chronic GH excess impairs insulin sensitivity, increases gluconeogenesis, reduces the glucose uptake in adipose tissue and muscle and alters pancreatic β cells function. As a consequence, glucose metabolism alterations are a very frequent complication in acromegaly patients, further contributing to the increased cardiovascular risk and mortality. Treatment modalities of acromegaly differently impact on glucose tolerance. Successful surgical treatment of acromegaly ameliorates glucose metabolism abnormalities. Drugs used to treat acromegaly patients may per se affect glucose homeostasis, therefore influencing patients' management. Indeed pegvisomant has been shown to positively impact on glucose metabolism, while somatostatin analogs, especially pasireotide, can cause hyperglycaemia. On the other hand, robust data on the effect of dopamine agonists on glycaemic profile are still lacking. This review summarizes the available data on diabetes mellitus in acromegaly patients, with a focus on the potential effects of the medical treatment of the disease on glucose homeostasis, providing an overview of the current state of the art.

Increased Risk of Persistent Glucose Disorders After Control of Acromegaly

Purpose:

Combining surgery and medical treatments allows the control of growth hormone hypersecretion in 80% of cases. Our objective was to determine the rate of acromegaly comorbidities once hypersecretion of growth hormone is controlled.

Methods:

Our retrospective monocentric study was based on 130 patients followed on a regular basis, with acromegaly controlled by medical treatments or cured by surgery or radiation technique. Our main outcome measures were the prevalence of major metabolic complications of acromegaly (diabetes, hypertension, low-density lipoprotein cholesterol, triglycerides) at diagnosis and last follow-up in comparison with French epidemiological data.

Results:

As expected, controlling hypersecretion significantly improved the metabolic complications of acromegaly. However, the proportion of patients having at least one metabolic complication of acromegaly at last follow-up (mean, 72 months after remission) was 27% for altered glucose tolerance or diabetes, 39% for hypertension, 34.3% for hypercholesterolemia, and 13.3% for hypertriglyceridemia. Interestingly, our data showed that diabetes was the only comorbidity different with a higher prevalence in patients in remission versus a general population of a similar median age (21.6% vs 6.9%, respectively).

Conclusions:

The follow-up of glucose disorders needs to be maintained on a long-term basis in patients controlled for acromegaly.

Plasma biomarker proteins for detection of human growth hormone administration in athletes

Human growth hormone (GH) is a naturally occurring hormone secreted by the pituitary gland with anabolic and growth-promoting activities. Since an increased availability of recombinant GH (rGH) for the treatment of GH-deficient patients, GH has been abused in sports and it is prohibited. "GH-isoform" and "biomarkers" tests are currently available for detection of GH abuse in sports, however both methods suffer from shortcomings. Here, we report on a proteomic approach to search for novel protein biomarkers associated with rGH administration in non-elite athletes. In this study, participants received either placebo or rGH for 8 weeks, and were followed over a 6-week washout period. We used 2-D DIGE and iTRAQ LC-MS/MS analyses to expose rGH-dependent marker proteins. Eight rGH-dependent plasma proteins namely apolipoproptein-L1, alpha-HS-glycoprotein, vitamin D-binding protein, afamin, insulin-like growth factor-binding protein-3, insulin-like growth factor-binding protein-ALS, lumican and extracellular matrix proteins 1 were identified. Apolipoprotein L1 and alpha-HS-glycoprotein were validated by Western blots to confirm their identities and expression patterns in rGH- and placebo-treated subject cohorts. Independent confirmation of these putative GH-responsive biomarkers would be of value for clinical practices and may have sports anti-doping utility.

Glucose metabolism before and after treatment in patients with acromegaly

INTRODUCTION

The aim of this study was to ascertain the prevalence of carbohydrate changes in patients diagnosed with acromegaly, and to evaluate what happens two years after treatment. It was also intended to assess which factors are associated to the occurrence of such changes.

MATERIAL AND METHODS

Sixty-six patients diagnosed with acromegaly at our center were enrolled and divided into groups with normal glucose metabolism, prediabetes, and diabetes. After 2 years of treatment of acromegaly, prevalence carbohydrate changes was assessed again depending on the patient condition (cured, controlled with medical treatment, or uncontrolled).

RESULTS

At the time of diagnosis of acromegaly, 27.3% of the patients had diabetes (n=18), 39.4% had prediabetes (n=26), and 33.3% had no changes (n=22). Significant differences were found in IGF-1 and z-score of IGF-1 (median of 18.1 in diabetics and 10.6 in non-diabetics, P=.005). Two years after treatment, there was a significant decrease in the prevalence of diabetes and prediabetes in cured patients (from 29.2% to 8.3% and from 45.8% to 16.7%, respectively, P=.003), but not in patients controlled with medical treatment or not controlled.

CONCLUSION

At our center, 66.6% of patients with acromegaly had changes in carbohydrate metabolism at diagnosis, with a prevalence of diabetes of 27.3%. Two years after treatment of acromegaly, prevalence of diabetes and prediabetes decreased in cured patients.

Effects of anti-somatostatin agents on glucose metabolism

The anti-somatostatin agents used to treat acromegaly, Cushing's disease and neuroendocrine tumours also have hyperglycaemic effects. This is particularly true for pasireotide. Hyperglycaemic events are seen in 57-73% of patients with Cushing's treated with pasireotide, with a need to initiate antidiabetic treatment in about 50% of these patients. In acromegaly, treatment with pasireotide induces hyperglycaemia in 29-61% of patients. Pasireotide-induced hyperglycemia occurs early, within the first 3 months of treatment, due to a decrease in insulin secretion secondary to a fall in secretion of GLP-1 and GIP, and potentially also due to a direct inhibitory effect of pasireotide on beta cells. Close monitoring of blood glucose is mandatory in all patients during the first 3 months of treatment with pasireotide. Where necessary, antidiabetic treatment should be initiated, preferably with a DPP-4 inhibitor or a GLP-1 receptor agonist, both of which have proven efficacy in the control of hyperglycaemia induced by pasireotide.

Acromegaly in a non-diabetic cat

Case summary

A 14-year-old, neutered male European shorthair cat was evaluated for a routine health check. The owner did not report any clinical signs except for respiratory stridor. On physical examination the main findings were broad facial features and increased interdental spaces. On haematology, a mild, non-regenerative anaemia was detected, whereas the serum biochemistry profile and urinalysis were unremarkable. The serum glucose concentration was within the reference interval. Serum insulin-like growth factor-1 concentration was markedly elevated (>1600 ng/ml). The basal serum growth hormone concentration was elevated and decreased only mildly after somatostatin administration. Basal serum insulin concentration was high, and the insulin concentration increased considerably after glucose loading, consistent with insulin resistance. CT scanning of the skull showed an enlarged pituitary gland and increased skull bone thickness. The final diagnosis was acromegaly.

Relevance and novel information

These findings demonstrate that acromegaly should be pursued and suspected in cats other than those with diabetes mellitus.

Treatment of acromegaly patients at the Federal University of Triângulo Mineiro (UFTM): Experience Report

OBJECTIVE:

To evaluate the effectiveness of the treatment of acromegaly patients at the Federal University of Triangulo Mineiro.

METHODS:

Cross-sectional and retrospective study of thirty cases treated over a period of two decades.

RESULTS:

17 men (56.7%) aged 14-67 years and 13 women aged 14-86 years were analyzed. Twenty-one patients underwent transphenoidal surgery, whichwas associated with somatostatin receptor ligands in 11 patients (39.3%), somatostatin receptor ligands + radiotherapyin 5 patients (17.8%), radiotherapy in 3 patients (10.7%), and radiotherapy + somatostatin receptorligands + cabergoline in 1 patient (3.6%). Additionally, 2 patients underwent radiotherapy and surgeryalone. Six patients received somatostatin receptor ligands before surgery, and 2 were not treated due to refusal and death. Nine patients have died, and 20 are being followed; 13 (65%) have growth hormonelevels o1 ng/mL, and 11 have normal insulin-like growth factor 1 levels.

CONCLUSION:

The current treatment options enable patients seen in regional reference centers to achieve strict control parameters, which allows them to be treated close to their homes.

Acromegaly: clinical features at diagnosis

BACKGROUND

Acromegaly is a rare and underdiagnosed disorder caused, in more than 95% of cases, by a growth hormone (GH)-secreting pituitary adenoma. The GH hypersecretion leads to overproduction of insulin-like growth factor 1 (IGF-1) which results in a multisystem disease characterized by somatic overgrowth, multiple comorbidities, physical disfigurement, and increased mortality.

OBJECTIVE

This article aims to review the clinical features of acromegaly at diagnosis.

DISCUSSION/CONCLUSION

Acromegaly affects both males and females equally and the average age at diagnosis ranges from 40 to 50 years (up to 5% of cases < the age 20). Due to insidious onset and slow progression, acromegaly is often diagnosed five to more than ten years after its onset. The typical coarsening of facial features include furrowing of fronthead, pronounced brow protrusion, enlargement of the nose and the ears, thickening of the lips, skin wrinkles and nasolabial folds, as well as mandibular prognathism that leads to dental malocclusion and increased interdental spacing. Excessive growth of hands and feet (predominantly due to soft tissue swelling) is present in the vast majority of acromegalic patients. Gigantism accounts for up to 5% of cases and occurs when the excess of GH becomes manifest in the young, before the epiphyseal fusion. The disease also has rheumatologic, cardiovascular, respiratory, neoplastic, neurological, and metabolic manifestations which negatively impact its prognosis and patients quality of life. Less than 15% of acromegalic patients actively seek medical attention for change in appearance or enlargement of the extremities. The presentation of acromegaly is more often related to its systemic comorbidities or to local tumor effects.

Complications of acromegaly: cardiovascular, respiratory and metabolic comorbidities

Acromegaly is associated with an enhanced mortality, with cardiovascular and respiratory complications representing not only the most frequent comorbidities but also two of the main causes of deaths, whereas a minor role is played by metabolic complications, and particularly diabetes mellitus. The most prevalent cardiovascular complications of acromegaly include a cardiomyopathy, characterized by cardiac hypertrophy and diastolic and systolic dysfunction together with arterial hypertension, cardiac rhythm disorders and valve diseases, as well as vascular endothelial dysfunction. Biochemical control of acromegaly significantly improves cardiovascular disease, albeit completely recovering to normal mainly in young patients with short disease duration. Respiratory complications, represented mainly by sleep-breathing disorders, particularly sleep apnea, and respiratory insufficiency, frequently occur at the early stage of the disease and, although their severity decreases with disease control, this improvement does not often change the indication for a specific therapy directed to improve respiratory function. Metabolic complications, including glucose and lipid disorders, are variably reported in acromegaly. Treatments of acromegaly may influence glucose metabolism, and the presence of diabetes mellitus in acromegaly may affect the choice of treatments, so that glucose homeostasis is worth being monitored during the entire course of the disease. Early diagnosis and prompt treatment of acromegaly, aimed at obtaining a strict control of hormone excess, are the best strategy to limit the development or reverse the complications and prevent the premature mortality.

Diabetes in Patients With Acromegaly

Acromegaly is a clinical syndrome which results from growth hormone excess. Uncontrolled acromegaly is associated with cardiovascular mortality, due to an excess of risk factors including diabetes mellitus, hypertension and cardiomegaly. Diabetes mellitus is a frequent complication of acromegaly with a prevalence of 12-37%. This review will provide an overview of a number of aspects of diabetes mellitus and glucose intolerance in acromegaly including the following: 1. Epidemiology and pathophysiology of abnormalities of glucose homeostasis 2. The impact of different management options for acromegaly on glucose homeostasis 3. The management options for diabetes mellitus in patients with acromegaly RECENT FINDINGS: Growth hormone and IGF-1 have complex effects on glucose metabolism. Insulin resistance, hyperinsulinaemia and increased gluconeogenesis combine to produce a metabolic milieu which leads to the development of diabetes in acromegaly. Treatment of acromegaly should ameliorate abnormalities of glucose metabolism, due to reversal of insulin resistance and a reduction in gluconeogenesis. Recent advances in medical therapy of acromegaly have varying impacts on glucose homeostasis. These adverse effects influence management choices in patients with acromegaly who also have diabetes mellitus or glucose intolerance. The underlying mechanisms of disorders of glucose metabolism in patients with acromegaly are complex. The aim of treatment of acromegaly is normalisation of GH/IGF-1 with reduction of co-morbidities. The choice of therapy for acromegaly should consider the impact of therapy on several factors including glucose metabolism.

Hyperglycemia induced by pasireotide in patients with Cushing's disease or acromegaly

PURPOSE

Cushing's disease (CD) and acromegaly are characterized by excessive hormone secretion resulting in comorbidities such as impaired glucose metabolism, diabetes and hypertension. Pasireotide is a new-generation, multireceptor-targeted somatostatin receptor ligand approved for CD (subcutaneous [SC] injection formulation) and acromegaly (long-acting release [LAR] formulation). In clinical studies of pasireotide, hyperglycemia-related adverse events (AEs) were frequently observed. This review highlights differences in reported rates of hyperglycemia in pasireotide trials and discusses risk factors for and management of pasireotide-associated hyperglycemia.

METHODS

Clinical trials evaluating pasireotide in patients with CD or acromegaly were reviewed.

RESULTS

The frequency of hyperglycemia-related AEs was lower in patients with acromegaly treated with pasireotide LAR (57.3-67.0 %) than in patients with CD treated with pasireotide SC (68.4-73.0 %). Fewer patients with acromegaly treated with pasireotide LAR discontinued therapy because of hyperglycemia-related AEs (Colao et al. in J Clin Endocrinol Metab 99(3):791-799, 2014, 3.4 %; Gadelha et al. in Lancet Diabetes Endocrinol 2(11):875-884, 2014, 4.0 %) than did patients with CD treated with pasireotide SC (Boscaro et al. in Pituitary 17(4):320-326, 2014, 5.3 %; Colao et al. in N Engl J Med 366(10):914-924, 2012, 6.0 %). Hyperglycemia-related AEs occurred in 40.0 % of patients with acromegaly treated with pasireotide SC, and 10.0 % discontinued treatment because of hyperglycemia. Ongoing studies evaluating pasireotide LAR in patients with CD and management of pasireotide-induced hyperglycemia in patients with CD or acromegaly (ClinicalTrials.gov identifiers NCT01374906 and NCT02060383, respectively) will address these key safety issues.

CONCLUSIONS

Disease pathophysiology, drug formulation, and physician experience potentially influence the differences in reported rates of pasireotide-induced hyperglycemia in CD and acromegaly. Hyperglycemic effects associated with pasireotide have a predictable pattern, can be managed with antidiabetic agents, and are reversible upon discontinuation.

Challenges in the diagnosis and management of acromegaly: a focus on comorbidities

INTRODUCTION

Acromegaly is a rare, insidious disease resulting from the overproduction of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), and is associated with a range of comorbidities. The extent of associated complications and mortality risk is related to length of exposure to the excess GH and IGF-1, thus early diagnosis and treatment is imperative. Unfortunately, acromegaly is often diagnosed late, when patients already have a wide range of comorbidities. The presence of comorbid conditions contributes significantly to patient morbidity/mortality and impaired quality of life.

METHODS

We conducted a retrospective literature review for information relating to the diagnosis of acromegaly, and its associated comorbidities using PubMed. The main aim of this review is to highlight the issues of comorbidities in acromegaly, and to reinforce the importance of early diagnosis and treatment.

FINDINGS AND CONCLUSIONS

Successful management of acromegaly goes beyond treating the disease itself, since many patients are diagnosed late in disease evolution, they present with a range of comorbid conditions, such as cardiovascular disease, diabetes, hypertension, and sleep apnea. It is important that patients are screened carefully at diagnosis (and thereafter), for common associated complications, and that biochemical control does not become the only treatment goal. Mortality and morbidities in acromegaly can be reduced successfully if patients are treated using a multimodal approach with comprehensive comorbidity management.

Current and Emerging Aspects of Diabetes Mellitus in Acromegaly

Diabetes mellitus is a frequent complication of acromegaly, a disease characterized by chronic hypersecretion of growth hormone (GH) by a pituitary adenoma. Diabetes occurs commonly but not only as a consequence of an insulin-resistant state induced by GH excess. The development of diabetes in patients with acromegaly is clinically relevant, since such a complication is thought to increase the already elevated cardiovascular morbidity and mortality risk of the disease. Emerging data suggest that a specific cardiomyopathy can be identified in acromegaly patients with diabetes. Moreover, the presence of diabetes may also influence therapeutic decision making in acromegaly, since traditional and newly developed drugs used in this clinical setting may impact glucose metabolism regardless of control of GH hypersecretion.