Endocrinopathies in beta thalassemia: a narrative review

Beta thalassemia is the most common genetic blood disorder, characterized by reduced production or complete absence of beta-globin chains. The combination of systematic red blood cell transfusion and iron chelation therapy is the most readily available supportive treatment and one that has considerably prolonged the survival of thalassemia patients. Despite this, the development of endocrine abnormalities correlated with beta thalassemia still exists and is mostly associated with iron overload, chronic anemia, and hypoxia. A multifactorial approach has been employed to investigate other factors involved in the pathogenesis of endocrinopathies, including genotype, liver disease, HCV, splenectomy, socioeconomic factors, chelation therapy, and deficiency of elements. The development of specific biomarkers for predicting endocrinopathy risk has been the subject of extensive discussion. The objective of the present narrative review is to present recent data on endocrinopathies in beta thalassemia patients, including the prevalence, the proposed pathogenetic mechanisms, the risk factors, the diagnostic methods applied, and finally the recommended treatment options.

β-Thalassemia and Diabetes Mellitus: Current State and Future Directions

β-Thalassemia major is a congenital hemoglobin disorder that requires regular blood transfusion. The disease is often associated with iron overload and diabetes mellitus, among other complications. Pancreatic iron overload in β-thalassemia patients disrupts β-cell function and insulin secretion and induces insulin resistance. Several risk factors, including family history of diabetes, sedentary lifestyle, obesity, gender, and advanced age increase the risk of diabetes in β-thalassemia patients. Precautionary measures such as blood glucose monitoring, anti-diabetic medications, and healthy living in β-thalassemia patients notwithstanding, the prevalence of diabetes in β-thalassemia patients continues to rise. This review aims to address the relationship between β-thalassemia and diabetes in an attempt to understand how the pathology and management of β-thalassemia precipitate diabetes mellitus. The possible employment of surrogate biomarkers for early prediction and intervention is discussed. More work is still needed to better understand the molecular mechanism(s) underlying the link between β-thalassemia and diabetes and to identify novel prognostic and therapeutic targets.

Perturbations in lipid metabolism and gut microbiota composition precede cardiac dysfunction in a mouse model of thalassemia

Cardiomyopathy is a major complication of thalassemia, yet the precise underlying molecular mechanisms remain unclear. We examined whether altered lipid metabolism is an early driving factor in the development of cardiomyopathy using the Th3/+ mouse model of thalassemia. At age 20 weeks, male and female Th3/+ mice manifested anemia and iron overload; however, only males displayed metabolic defects and altered cardiac function. Untargeted lipidomics indicated that the circulating levels of 35 lipid species were significantly altered in Th3/+ mice compared to wild-type controls: triglycerides (TGs) with saturated fatty acids (FAs; TG42:0 and TG44:0) were elevated, while TGs with unsaturated FAs (TG(18:2_20:5_18:2 and TG54:8)) were reduced. Similarly, phosphatidylcholines (PCs) with long chain FAs (palmitic (16:0) or oleic (18:1)) were increased, while PCs with polyunsaturated FAs decreased. Circulating PC(16:0_14:0), GlcCer(d18:1/24:0) correlated significantly with iron overload and cardiac hypertrophy. 16S rRNA gene profiling revealed alterations in the intestinal microbiota of Th3/+ mice. Differentially abundant bacterial genera correlated with PC(39:6), PC(18:1_22:6), GlcCer(d18:1/24:1) and CE(14:0). These results provide new knowledge on perturbations in lipid metabolism and the gut microbiota of Th3/+ mice and identify specific factors which may represent early biomarkers or therapeutic targets to prevent development of cardiomyopathy in β-thalassemia.

Endocrinopathies in Hemoglobinopathies: What Is the Role of Iron?

Hemoglobinopathies, including β-thalassemia and sickle cell disease (SCD), are common genetic blood disorders. Endocrine disorders are frequent manifestations of organ damage observed mainly in patients with β-thalassemia and rarely in SCD. Iron overload, oxidative stress-induced cellular damage, chronic anemia, and HCV infection contribute to the development of endocrinopathies in β-thalassemia. The above factors, combined with vaso-occlusive events and microcirculation defects, are crucial for endocrine dysfunction in SCD patients. These endocrinopathies include diabetes mellitus, hypothyroidism, parathyroid dysfunction, gonadal and growth failure, osteoporosis, and adrenal insufficiency, affecting the quality of life of these patients. Thus, we aim to provide current knowledge and data about the epidemiology, pathogenesis, diagnosis, and management of endocrine disorders in β-thalassemia and SCD. We conducted a comprehensive review of the literature and examined the available data, mostly using the PubMed and Medline search engines for original articles. In the era of precision medicine, more studies investigating the potential role of genetic modifiers in the development of endocrinopathies in hemoglobinopathies are essential.

Diabetes and two kinds of primary tumors in a patient with thalassemia: a case report and literature review

Background

Thalassemia is a group of common genetic hematologic disorders characterized by deficient synthesis of the hemoglobin chain. Due to effective blood transfusion and optimization of chelate therapy, the survival of thalassemia patients and their overall quality of life have improved noticeably in the past few decades. As a consequence, the longer life expectancy has led to the manifestation of several concomitant morbidities, including heart disease, infections, cirrhosis, endocrine abnormalities, various malignancies, and so on. In this context, the probability and updated literature about some malignancy cases in patients with thalassemia build new scenarios for the next few years. We describe the first report of a thalassemic patient developing diabetes and head and neck cancer and try to summarize the possible predisposing factors and mechanisms behind their phenomenon.

Case presentation

The current case report describes a 50-year-old Asian man who has been diagnosed with thalassemia since childhood. In early 2017, he was also diagnosed with diabetes and started on insulin-hypoglycemic treatment. The patient was then diagnosed with primary non-keratinizing undifferentiated carcinoma of the nasopharynx in late February 2013. A biopsy of the left tongue revealed squamous cell carcinoma (SCC) in late March 2019.

Conclusions

We report the first case of a thalassemic patient developing diabetes and squamous cell carcinoma of the head and neck and discuss the possibility of a link between the three diseases. This specific case should alert physicians to the possibility of endocrinopathy and malignancy in thalassemic patients.

Nutritional Aspects of Iron in Health and Disease

Dietary iron assimilation is critical for health and essential to prevent iron-deficient states and related comorbidities, such as anemia. The bioavailability of iron is generally low, while its absorption and metabolism are tightly controlled to satisfy metabolic needs and prevent toxicity of excessive iron accumulation. Iron entry into the bloodstream is limited by hepcidin, the iron regulatory hormone. Hepcidin deficiency due to loss-of-function mutations in upstream gene regulators causes hereditary hemochromatosis, an endocrine disorder of iron overload characterized by chronic hyperabsorption of dietary iron, with deleterious clinical complications if untreated. The impact of high dietary iron intake and elevated body iron stores in the general population is not well understood. Herein, we summarize epidemiological data suggesting that a high intake of heme iron, which is abundant in meat products, poses a risk factor for metabolic syndrome pathologies, cardiovascular diseases, and some cancers. We discuss the clinical relevance and potential limitations of data from cohort studies, as well as the need to establish causality and elucidate molecular mechanisms.

Discovery-Based Proteomics Identify Skeletal Muscle Mitochondrial Alterations as an Early Metabolic Defect in a Mouse Model of β-Thalassemia

Although metabolic complications are common in thalassemia patients, there is still an unmet need to better understand underlying mechanisms. We used unbiased global proteomics to reveal molecular differences between the th^3/+ mouse model of thalassemia and wild-type control animals focusing on skeletal muscles at 8 weeks of age. Our data point toward a significantly impaired mitochondrial oxidative phosphorylation. Furthermore, we observed a shift from oxidative fibre types toward more glycolytic fibre types in these animals, which was further supported by larger fibre-type cross-sectional areas in the more oxidative type fibres (type I/type IIa/type IIax hybrid). We also observed an increase in capillary density in th^3/+ mice, indicative of a compensatory response. Western blotting for mitochondrial oxidative phosphorylation complex proteins and PCR analysis of mitochondrial genes indicated reduced mitochondrial content in the skeletal muscle but not the hearts of th^3/+ mice. The phenotypic manifestation of these alterations was a small but significant reduction in glucose handling capacity. Overall, this study identified many important alterations in the proteome of th^3/+ mice, amongst which mitochondrial defects leading to skeletal muscle remodelling and metabolic dysfunction were paramount.

Iron and the Pathophysiology of Diabetes

High iron is a risk factor for type 2 diabetes mellitus (T2DM) and affects most of its cardinal features: decreased insulin secretion, insulin resistance, and increased hepatic gluconeogenesis. This is true across the normal range of tissue iron levels and in pathologic iron overload. Because of iron's central role in metabolic processes (e.g., fuel oxidation) and metabolic regulation (e.g., hypoxia sensing), iron levels participate in determining metabolic rates, gluconeogenesis, fuel choice, insulin action, and adipocyte phenotype. The risk of diabetes related to iron is evident in most or all tissues that determine diabetes phenotypes, with the adipocyte, beta cell, and liver playing central roles. Molecular mechanisms for these effects are diverse, although there may be integrative pathways at play. Elucidating these pathways has implications not only for diabetes prevention and treatment, but also for the pathogenesis of other diseases that are, like T2DM, associated with aging, nutrition, and iron.

Does TNF-α 308 G/A (rs1800629) gene polymorphism associate with liver and pancreas disorders in Iraqi adults with beta thalassemia major?

BACKGROUND

TNF-α has been considered as the key regulator of inflammatory responses and is known to be participated in the pathogenesis of several diseases.

OBJECTIVE

The aim of this study was to explore the relationship of (rs1800629) gene polymorphism associated to liver and pancreas disorders in sample of β-thalassemia major adult Iraqi Patients.

MATERIAL AND METHOD

Blood samples were obtained from 40 patients suffered from beta thalassemia with pancreas disorder, along with 40 patient suffered from thalassemia with liver disorder, and 40 patient suffered from thalassemia without pancreas or liver, from Ibn Al-Baladi Hospital, Baghdad, and 40 samples from age and gender-matched apparently healthy individuals as control group, all subjects with age more than 18 years. TNF-308G/A (rs1800629) gene polymorphisms were assessed by Tetra- ARMS-PCR.

RESULTS

The result of showed that heterogeneous GA and homogeneous AA genotypes were higher, while GG wild genotype was lower in beta thalassemia major patients with liver and pancreas disorders compared to control group.

CONCLUSION

It can be concluded that the prevalence of TNF-α 308 G/A SNP plus (A) allele could be associated with risk of liver and pancreas disorders in sample of beta thalassemia major adult.

Indicators of glucose dysregulation and the relationship with iron overload in Chinese children with beta thalassemia major

INTRODUCTION

Patients with beta thalassemia major (TM) have a higher risk of diabetes and an abnormal oral glucose tolerance test (OGTT), but there is no single agree monitoring parameter that reflects glycemic status. The possible mechanisms include iron overload and blood transfusion, but they require further investigation.

PURPOSE

This study explored the role of glycated hemoglobin A1c (HbA1c), fructosamine, and glycated albumin (GA) in evaluating the glucose dysregulation and to determine the potential relationship between iron deposition and glucose metabolism disorder in beta TM.

METHODS

A cross-sectional study was performed on 118 patients with beta TM and the control group consisted of 33 healthy children with no statistical differences in age, sex, and body mass index (BMI). Fast plasma glucose (FPG), fast insulin (FINS), insulin resistance index (HOMA-IRI), and insulin sensitivity index (HOMA-ISI) were compared between the patient and control groups. HbA1c, GA, fructosamine, and serum ferritin (SF) were measured in the patient group. OGTT, as well as heart and liver magnetic resonance imaging (MRI) T2*, was performed. For all statistical analyses, SPSS 21.0 was used and p < 0.05 was accepted as statistically significant.

RESULTS

FPG, FINS, and HOMA-IRI were significantly increased while HOMA-ISI decreased in the beta TM patients when compared with those in the control group. In patients with beta TM, 17 (14.41%) of patients had been diagnosed with diabetes, while 48 (40.68%) had both impaired fasting glucose and impaired glucose tolerance. HbA1c, GA, and fructosamine were increased according to the degree of abnormal glucose metabolism. Statistically significant differences were found in age, SF, and cardiac T2* between the abnormal and normal OGTT groups.

CONCLUSION

HbA1c may be used as a significant measure for monitoring glycemic levels in patients with beta TM. Furthermore, GA and fructosamine were alternative indicators of glucose status. Patients with heart iron deposition or an SF > 4000 μg/L were prone to abnormal glucose metabolism, so chelation therapy should be reinforced.

Gestational Diabetes Mellitus in Pregnant Women with Beta-Thalassemia Minor: A Matched Case-Control Study

Pregnancy in women with thalassemia minor is considered safe. However, a higher incidence of maternal and neonatal complications in women with the disorder has been reported in the literature. This study aimed to determine whether there is an increased risk of gestational diabetes mellitus (GDM) in pregnant women with beta-thalassemia minor. We conducted a retrospective matched case-control study of 230 pregnant women who delivered at the Department of Obstetrics and Feto-Maternal Medicine at the Medical University of Vienna between the years 2008 and 2020, whereof 115 women had beta-thalassemia minor. We found no significant difference in the occurrence of GDM between the case group and control group of age and BMI-matched healthy women. However, we observed a significantly lower hemoglobin (Hb) and hematocrit (Ht) level during the first, the second, and the third trimesters of pregnancy, and postpartum (all: p < 0.001) among women with beta-thalassemia minor compared to the healthy controls. Neonates of women with beta-thalassemia were more likely to experience post-natal jaundice and excessive weight loss (p < 0.001). We conclude that GDM is not more likely to occur in pregnant women with beta-thalassemia minor. However, clinicians should be made aware of the risk of adverse maternal and neonatal outcomes. Furthermore, women with beta-thalassemia minor should undergo regular laboratory screening and multidisciplinary pregnancy care.

Good Clinical Practice of the Italian Society of Thalassemia and Haemoglobinopathies (SITE) for the Management of Endocrine Complications in Patients with Haemoglobinopathies

Background: The treatment of endocrinopathies in haemoglobinopathies is a continually expanding research area; therefore, recommendations supporting the appropriateness of treatments are a pressing need for the medical community. Methods: The Management Committee of SITE selected and gathered a multidisciplinary and multi-professional team, including experts in haemoglobinopathies and experts in endocrinopathies, who have been flanked by experts with methodological and organizational expertise, in order to formulate recommendations based on the available scientific evidence integrated by personal clinical experience. The project followed the systematic approach for the production of clinical practice guidelines according to the methodology suggested by the National Center for Clinical Excellence, Quality and Safety of Care (CNEC). Results: Out of 14 topics, 100 clinical questions were addressed, and 206 recommendations were elaborated on. The strength of recommendations, panel agreement, a short general description of the topic, and the interpretation of evidence were reported. Conclusions: Good Practice Recommendations are the final outcome of translational research and allow one to transfer to the daily clinical practice of endocrine complications in haemoglobinopathies.

Associations of Habitual Mineral Intake with New-Onset Prediabetes/Diabetes after Acute Pancreatitis

Associations between habitual dietary intake of minerals and glucose metabolism have been extensively studied in relation to metabolic disorders. However, similar research has yet to be conducted in individuals after acute pancreatitis (AP). The main aim was to investigate the associations between habitual intake of 13 minerals and glycaemic status: new-onset prediabetes/diabetes after AP (NODAP), pre-existing prediabetes/type 2 diabetes (T2DM), and normoglycaemia after AP (NAP). Associations between the dietary intake of minerals and markers of glucose metabolism (glycated haemoglobin and fasting plasma glucose) were also studied. The EPIC-Norfolk food frequency questionnaire was used in a cross-sectional fashion to determine the habitual intake of 13 dietary minerals. ANCOVA as well as multiple linear regression analyses were conducted and five statistical models were built to adjust for covariates. The study included 106 individuals after AP. In the NODAP group, intake of 4 minerals was significantly less when compared with the NAP group: iron (B = -0.076, p = 0.013), nitrogen (B = -0.066, p = 0.003), phosphorous (B = -0.046, p = 0.006), and zinc (B = -0.078, p = 0.001). Glycated haemoglobin was significantly associated with iodine intake (B = 17.763, p = 0.032) and manganese intake (B = -17.147, p = 0.003) in the NODAP group. Fasting plasma glucose was significantly associated with manganese intake (B = -2.436, p = 0.027) in the NODAP group. Habitual intake of minerals differs between individuals with NODAP, T2DM, and NAP. Prospective longitudinal studies and randomised controlled trials are now warranted to further investigate the associations between mineral intake and NODAP.

The effect of zinc deficiency and iron overload on endocrine and exocrine pancreatic function in children with transfusion-dependent thalassemia: a cross-sectional study

BACKGROUND

Children with transfusion-dependent thalassemia (TDT) suffer from secondary hemosiderosis and the delirious effects this iron overload has on their different body organs, including the pancreas. They are also more prone to develop zinc deficiency than the general pediatric population. This study aimed to determine the effect of zinc deficiency and iron overload on the endocrine and exocrine pancreas in TDT children.

METHODS

Eighty children, already diagnosed with TDT, were included in this study. We assessed the following in the participant children: serum ferritin, serum zinc, endocrine pancreatic function (oral glucose tolerance test (OGTT), fasting insulin level and from them, HOMA-IR was calculated), and exocrine pancreatic function (serum lipase and serum amylase).

RESULTS

Forty-four TDT children had a subnormal zinc level, while 36 of them had a normal serum zinc level. TDT children with low serum zinc had significantly more impaired endocrine pancreatic function and an abnormally high serum lipase than children with normal serum zinc, p < 0.05 in all. Serum zinc was significantly lower in TDT children with serum ferritin above the ferritin threshold (≥2500 ng/ml) than those below (59.1 ± 20.2 vs. 77.5 ± 28.13), p = 0.02. TDT children, having a serum ferritin ≥2500 ng/ml, had significantly more frequently impaired endocrine pancreatic function and abnormally high serum lipase than TDT children below the ferritin threshold, p < 0.05 in all.

CONCLUSION

In children with transfusion-dependent thalassemia, zinc deficiency aggravates iron-induced pancreatic exocrine and endocrine dysfunction.

The different patterns of insulin response during Oral Glucose Tolerance Test (OGTT) in transfused young patients with β-Thalassemia

BACKGROUND AND AIM

Dysregulation of glucose metabolism is a common complication of transfusions in Transfusion Dependent Thalassemia (TDT) patients. For early diagnosis of glucose disturbances, screening is recommended. The age of starting and the type of screening vary; the more common methods are assessment of RPG, FPG, 2h PG and 2 hours OGTT. The combined assessment of glucose tolerance and insulin response during OGTT is rarely recommended. The main objective of the study is the evaluation of simultaneous assessment of Glucose Tolerance (GT) and Insulin Response (IR) during OGTT in patients with TDT.

METHODS

43 TDT patients aged 12-28years, without clinical evidence of glucose disturbances, were randomly selected for the study. The 2-hour OGTT in 30 minutes intervals was applied. Plasma glucose and insulin were assessed in all samples using routine laboratory methods.

RESULTS

Of 43 patients 31(72%) had Normal GT; of them 9 (29%) had normal insulin response  (NIR), 14 (45%) high IR and 8(26%) delayed peak IR. Delayed peak IR was found in 8 of the 9 patients with Impaired GT and in 2 of the 3 with diabetic GT. Deficient IR (hypoinsulinemia) was found in two patients.

CONCLUSIONS

Simultaneous assessment of GT and IR during OGTT in TDT patients, seems to be a most sensitive and creditable screening test for early diagnosis of glucose disturbances. High IR and delayed peak IR in normoglycemic patients are valuable indices for diagnosis of the pre-diabetic state that precede the development of glucose disturbances in TDT patients and start proper follow and management.

A study of isolated hyperglycemia (blood glucose ≥155 mg/dL) at 1-hour of oral glucose tolerance test (OGTT) in patients with β-transfusion dependent thalassemia (β-TDT) followed for 12 years

OBJECTIVE

Subjects with normal glucose tolerance (NGT) but 1-hour post-load plasma glucose (1-h OGTT) ≥ 155 mg/dl (8.6 mmol/L; H-NGT) have an increased risk for developing Type 2 diabetes mellitus (T2DM), determining a new risk factor category with deeper metabolic impairment. The aim of this study was to evaluate the H-NGT as a diagnostic predictor of future dysglycemia in β-transfusion dependent thalassemia (β-TDT). Indices of insulin secretion and insulin sensitivity derived at baseline from OGTTs, were also reviewed.

STUDY DESIGN AND METHODS

OGTT and indices of insulin secretion and insulin sensitivity, derived at baseline during OGTT, in 17 β-TDT with H-NGT and 29 β-TDT with normal OGTT (NGT) and without H-NGT followed for 12 years were studied.

RESULTS

H-NGT was associated with decreased insulin sensitivity and progressive deterioration of glucose tolerance. At baseline, serum ferritin and serum alanine aminotransferase (ALT) levels were higher in patients with H-NGT compared to patients with NGT. A strong correlation was observed between ALT and 1-hour plasma glucose value during OGTT in the total group of 36 patients . Compliance to iron chelation therapy was poor in β-TDT patients with H-NGT. An inverse correlation was found between 1-hour plasma glucose value during OGTT and insulin secretion-sensitivity index-2 (ISSI-2) (r: -0.3298; p: 0.025), between ISSI-2 and ALT (r: -0.3262; p: 0.027), and between 1-hour plasma glucose value and ISSI-2 (r: -0.537; p: 0.005) in the whole group of β-TDT patients enrolled in our study.

CONCLUSIONS

This retrospective study displayed that finding an isolated high 1-hour post-load glucose level (≥155 mg/dL; H-NGT) during the OGTT may serve as a simple biomarker to detect high-risk patients, with chronic liver disease and/or iron overload, who need periodic glycemic surveillance. Measuring the ISSI 2 represented another valuable predictive marker in the assessment of glycemia in these patients.

Novel Therapeutic Advances in β-Thalassemia

Simple Summary

Beta-thalassemia (β-thalassemia) is an autosomal recessive inherited disorder that causes decreased production of hemoglobin. Ineffective erythropoiesis and excess iron deposition are the most significant pathophysiological problems. Chronic red blood cell transfusions along with control of iron overload are the main principles of treatment. Yet, the patients have a problematic quality of life. Recently, novel therapies have emerged based on better knowledge of the pathophysiology of the disease. Aiming at ineffective erythropoiesis through the TGF-β ligand traps, such as luspatercept, has been shown to reduce the transfusion burden. Therapeutic approaches aiming at the iron metabolism mechanisms as well as the pathway of the production of erythroid cyclic guanosine monophosphate are being used in clinical trials with encouraging results. Significant improvements in the technique of hemopoietic stem cell transplantation have been accomplished, with a focus on the improvement of the conditioning regimen and the donor selection. Gene therapy has exhibited remarkable advances using lentiviral β-globin gene insertion techniques or gene editing platforms that target the suppression of γ-globin repressors. All these approaches will have a positive result in the quality of life of thalassemia patients.

Abstract

The main characteristic of the pathophysiology of β-thalassemia is reduced β-globin chain production. The inevitable imbalance in the α/β-globin ratio and α-globin accumulation lead to oxidative stress in the erythroid lineage, apoptosis, and ineffective erythropoiesis. The result is compensatory hematopoietic expansion and impaired hepcidin production that causes increased intestinal iron absorption and progressive iron overload. Chronic hemolysis and red blood cell transfusions also contribute to iron tissue deposition. A better understanding of the underlying mechanisms led to the detection of new curative or “disease-modifying” therapeutic options. Substantial evolvement has been made in allogeneic hematopoietic stem cell transplantation with current clinical trials investigating new condition regimens as well as different donors and stem cell source options. Gene therapy has also moved forward, and phase 2 clinical trials with the use of β-globin insertion techniques have recently been successfully completed leading to approval for use in transfusion-dependent patients. Genetic and epigenetic manipulation of the γ- or β-globin gene have entered the clinical trial setting. Agents such as TGF-β ligand traps and pyruvate kinase activators, which reduce the ineffective erythropoiesis, have been tested in clinical trials with favorable results. One TGF-β ligand trap, luspatercept, has been approved for use in adults with transfusion-dependent β-thalassemia. The induction of HbF with the phosphodiesterase 9 inhibitor IMR-687, which increase cyclic guanosine monophosphate, is currently being tested. Another therapeutic approach is to target the dysregulation of iron homeostasis, using, for example, hepcidin agonists (inhibitors of TMPRSS6 and minihepcidins) or ferroportin inhibitors (VIT-2763). This review provides an update on the novel therapeutic options that are presently in development at the clinical level in β-thalassemia.

Low back pain in beta thalassemia major revealing sacral extramedullay hematopoeisis: A case report

Extramedullary hematopoiesis (EMH) is a well-known complication of beta thalassemia major and frequently occurs in typical sites such as liver or spleen. However, when presenting in unusual sites as sacrum, other diagnosis should be excluded by histopathology prior to deciding on treatment plan.

Long-Term Follow-up of β-Transfusion-Dependent Thalassemia (TDT) Normoglycemic Patients with Reduced Insulin Secretion to Oral Glucose Tolerance Test (OGTT): A Pilot Study

Objective

To study the endocrine pancreas’ function in transfusion-dependent β-thalassemia (β-TDT) patients with a normal glucose tolerance test (NGT) and hypoinsulinemia. In addition, the prospective long–term follow-up using an annual oral glucose tolerance test (OGTT) to detect any abnormality of glucose metabolism.

Patients and methods

Seven β-TDT patients (mean age 22.4 ± 4.2 years) with NGT and inadequate insulin response (hypoinsulinemia) to OGTT were referred for a second opinion to an Italian Centre.

Results

The first-phase insulin response (FPIR), expressed as the sum of 1 and 3 minutes insulin, to intravenous glucose tolerance test (IVGTT), was between the 1^st and 3^rd percentile in two patients and between the 3^rd and 10^th percentile in five. The results were not associated with β-cell autoimmunity. After 43 ± 26 months (range 11 – 80 months) of follow-up, two patients developed impaired glucose tolerance (IGT), three both IGT and impaired fasting glucose (IFG) and two overt diabetes mellitus (DM). Interestingly, the patients who developed DM had, at baseline, the lowest value of the insulinogenic index (IGI: 0.08 and 0.25), defined as the ratio of the increment of plasma insulin to plasma glucose during the first 30 minutes after OGTT. Moreover, a significant correlation was found between the IGI at baseline and at follow-up in the patients who developed IGT with or without IFG (R= 0.927; P: 0.023). A significant reduction of Matsuda insulin sensitivity index (ISIM) and Insulin Secretion-Sensitivity Index-2 (ISSI-2) was documented in the study cohort at the diagnosis of IFG, IGT, and DM. There was a significant inverse correlation between ISSI-2 and area under the curve plasma glucose (AUC-PG).

Conclusions

These data demonstrated, for the first time, progressive deterioration in glucose homeostasis in β-TDT subjects with NGT and hypoinsulinemia and that the ISSI-2 index may be a valuable parameter to identify patients at high risk for developing glucose dysregulation.

Hyponatremia in Patients with Hematologic Diseases

Hyponatremia is the most common electrolyte disorder in clinical practice and is associated with increased morbidity and mortality. It is frequently encountered in hematologic patients with either benign or malignant diseases. Several underlying mechanisms, such as hypovolemia, infections, toxins, renal, endocrine, cardiac, and liver disorders, as well as the use of certain drugs appear to be involved in the development or the persistence of hyponatremia. This review describes the pathophysiology of hyponatremia and discusses thoroughly the contributing factors and mechanisms that may be encountered specifically in patients with hematologic disorders. The involvement of the syndrome of inappropriate antidiuretic hormone (SIADH) secretion and renal salt wasting syndrome (RSWS) in the development of hyponatremia in such patients, as well as their differential diagnosis and management, are also presented. Furthermore, the distinction between true hyponatremia and pseudohyponatremia is explained. Finally, a practical algorithm for the evaluation of hyponatremia in hematologic patients, as well as the principles of hyponatremia management, are included in this review.

Regulatory Connections between Iron and Glucose Metabolism

Iron is essential for energy metabolism, and states of iron deficiency or excess are detrimental for organisms and cells. Therefore, iron and carbohydrate metabolism are tightly regulated. Serum iron and glucose levels are subjected to hormonal regulation by hepcidin and insulin, respectively. Hepcidin is a liver-derived peptide hormone that inactivates the iron exporter ferroportin in target cells, thereby limiting iron efflux to the bloodstream. Insulin is a protein hormone secreted from pancreatic β-cells that stimulates glucose uptake and metabolism via insulin receptor signaling. There is increasing evidence that systemic, but also cellular iron and glucose metabolic pathways are interconnected. This review article presents relevant data derived primarily from mouse models and biochemical studies. In addition, it discusses iron and glucose metabolism in the context of human disease.

Combating iron overload: a case for deferoxamine-based nanochelators

While iron is a nutrient metal, iron overload can result in multiple organ failures. Iron chelators, such as deferoxamine, are commonly used to ameliorate iron overload conditions. However, their uses are limited due to poor pharmacokinetics and adverse effects. Many novel chelator formulations have been developed to overcome these drawbacks. In this review, we have discussed various nanochelators, including linear and branched polymers, dendrimers, polyrotaxane, micelles, nanogels, polymeric nanoparticles and liposomes. Although these research efforts have mainly been focused on nanochelators with longer half-lives, prolonged residence of polymers in the body could raise potential safety issues. We also discussed recent advances in nanochelation technologies, including mechanism-based, long-acting nanochelators.

Iron Overload Associated Endocrine Dysfunction Leading to Lower Bone Mineral Density in Thalassemia Major

CONTEXT

Patients with thalassemia major (TM) have a lower bone mineral density (BMD) and higher risk of fracture than the general population. The possible mechanisms include anemia, iron overload, malnutrition, and hormonal deficiency, but these have not been thoroughly investigated.

OBJECTIVE

To identify major mineral and hormonal factors related to BMD in adult TM patients to provide human evidence for the proposed mechanisms.

DESIGN

Retrospective study.

SETTING

Referral center.

PATIENTS

Twenty-nine patients with β-TM, aged 23 to 44 years who were followed-up during 2017 to 2018 were enrolled.

OUTCOME MEASUREMENTS

Endocrine profiles, including thyroid, parathyroid, and pituitary function, glucose, vitamin D, calcium, phosphate, and fibroblast growth factor 23 (FGF23) were obtained. The relationships among the above parameters, body height, fractures, and BMD were analyzed.

RESULTS

Abnormal BMD was observed in 42.9% of women and 23.1% of men. The mean final heights of women and men were 3.7 cm and 7.3 cm lower than the mean expected values, respectively. Fracture history was recorded in 26.7% of women and 35.7% of men. BMD was negatively correlated with parathyroid hormone, FGF23, thyrotropin, and glycated hemoglobin (HbA1c) levels, and positively correlated with testosterone, IGF-1, and corticotropin levels (all P < .05). Moreover, hypothyroidism was associated with lower BMD in both the lumbar spine (P = .024) and the femoral neck (P = .004). Patients with hypothyroidism had a higher percentage of abnormal BMD (P = .016).

CONCLUSION

Hypothyroidism, higher HbA1c, and lower adrenocorticotropin were predictors of abnormal BMD in patients with β-TM. Whether the correction of these factors improves BMD warrants further research.

Zinc supplementation improves glucose homeostasis in patients with β-thalassemia major complicated with diabetes mellitus: A randomized controlled trial

OBJECTIVES

The development of abnormal glucose tolerance in β-thalassemia major (β-TM) is associated with alterations in the oxidant-antioxidant status. Zinc is an antioxidant and an essential element for insulin synthesis, storage, and secretion. This randomized controlled trial assessed the effect of oral zinc supplementation on glucose homeostasis in pediatric β-TM patients complicated with diabetes mellitus (DM).

METHODS

Eighty patients were randomly assigned into two groups: an intervention group that received oral zinc in a dose of 40 mg/d for 12 wk and a placebo group. Hemolysis markers, serum ferritin, fasting blood glucose (FBG), fructosamine, fasting C-peptide, urinary albumin excretion (UAE), and serum zinc levels were assessed. Homeostasis model assessment insulin resistance index (HOMA-IR) was calculated.

RESULTS

Baseline clinical and laboratory parameters were consistent among both groups. Baseline zinc levels were decreased in both groups compared with control values. After 12 wk, supplementation with zinc for the intervention group resulted in a significant decrease in lactate dehydrogenase, serum ferritin, FBG, fructosamine, HOMA-IR, and UAE, whereas fasting C-peptide was higher compared with baseline levels and with the placebo group (P < 0.05). Baseline serum zinc was negatively correlated to FBG (r = -0.534, P < 0.001) and fructosamine (r = -0.555, P < 0.001) but positively correlated to fasting C-peptide (r = 0.777, P = 0.002).

CONCLUSIONS

Zinc supplementation as an adjuvant therapy in β-TM patients with DM reduced iron burden, decreased hyperglycemia, increased insulin secretion, and improved glycemic control without any adverse effects.

Metabolomic Investigation of β-Thalassemia in Chorionic Villi Samples

BACKGROUND

Beta-thalassemias are blood disorders characterized by poorly understood clinical phenotypes ranging from asymptomatic to severe anemia. Metabolic composition of the human placenta could be affected by the presence of pathological states such as β-thalassemia. The aim of our study was to describe metabolic changes in chorionic villi samples of fetuses affected by β-thalassemia compared to a control group by applying a metabolomics approach.

METHODS

Chorionic villi samples were differentiated according to the genetic diagnosis of β-thalassemia: control (Group 1, n = 27); heterozygous (Group 2, n = 7); homozygous (Group 3, n = 7). Gas chromatography-mass spectrometry was used to detect the metabolic composition of the samples. Subsequently, multivariate and univariate statistical analysis was performed. The discriminant metabolites were used to identify the altered pathways.

RESULTS

Supervised multivariate models were devised to compare the groups. The model resulting from the comparison between Group 1 and Group 3 was the most significant. Discriminant metabolites were identified, and the most altered pathways were as follows: pentose phosphate pathway (PPP), arachidonic acid metabolism, glycolysis, and gluconeogenesis, suggesting the presence of an energetic shift toward the PPP and the presence of oxidative stress in β-thalassemia chorionic villi samples.

CONCLUSIONS

The metabolomics approach identified a specific metabolic fingerprint in chorionic villi of fetuses affected by β-thalassemia.

Reflection of treatment proficiency of hydroxyurea treated β-thalassemia serum samples through nuclear magnetic resonance based metabonomics

β-Thalassemia is a widespread autosomal recessive blood disorder found in most parts of the world. Fetal hemoglobin (HbF), a form of hemoglobin is found in infants, replaced by adult hemoglobin (HbA) after birth. Hydroxyurea (HU) is one of the most effective HbF inducer used for the treatment of anemic diseases. We aimed to improve the understanding of HU therapy in β-thalassemia by metabonomics approach using ¹H NMR spectroscopy. This study includes 40 cases of β-thalassemia before and after HU therapy along with 40 healthy as controls. Carr-Purcell-Meiboom-Gill (CPMG) sequence was used to identify forty-one putative metabolites. Generation of models like partial least square discriminant analysis (PLS-DA) and orthogonal projections to latent structures discriminant analysis (OPLS-DA) based on different metabolites including lipids, amino acids, glucose, fucose, isobutyrate, and glycerol revealed satisfactory outcomes with 85.2% and 91.1% classification rates, respectively. The concentration of these metabolites was altered in β-thalassemia samples. However, after HU treatment metabolic profile of same patients showed closeness towards healthy. Deviant metabolic pathways counting lipoprotein changes, glycolysis, TCA cycle, fatty acid and choline metabolisms were identified as having significant differences among study groups. Findings of this study may open a better way to monitor HU treatment effectiveness in β-thalassemia patients, as the results suggested that metabolic profile of β-thalassemia patients shows similarity towards normal profile after this therapy.

Prevalence of abnormal glucose homeostasis in Chinese patients with non-transfusion-dependent thalassemia

Purpose: To determine the prevalence and underlying pathology of abnormal glucose homeostasis in Chinese patients with non-transfusion-dependent thalassemia (NTDT). Patients and methods: In this study, we enrolled 211 patients aged 4-63 years with NTDT, including 79 β thalassemia intermedia patients, 114 Hb H disease patients and 18 Hb E/β thalassemia patients. All had oral glucose tolerance test, serum ferritin (SF), homeostasis model assessment (HOMA) and liver iron concentration (LIC) measurement. One hundred and twenty healthy age-matched controls were also used for the comparative purpose. Iron load was assessed by using SF and hepatic load by LIC using validated MRI techniques. Results: The 211 patients were divided into three groups according to their fasting and 2 hrs postprandial blood glucose levels: hypoglycemic, normal glucose tolerance (NGT) and hyperglycemic groups. In this study, 149 patients had NGT, 33 had hypoglycemia, 4 had diabetes and 25 had impaired glucose tolerance (IGT). None had impaired fasting glucose. There was a significant correlation between 2 hrs postprandial blood glucose levels and age, PINS120, HOMA-IR, alanine aminotransferase and LIC (P<0.05). Risk factors for IGT in NTDT patients were older age (≥24 years) and SF concentration of ≥2,500 ng/mL. Conclusion: Age ≥24 years and SF ≥2,500 ng/mL of NTDT patients were at a greater risk for impaired glucose tolerance.

Retrospective Analysis of Endocrine Dysfunctions in a Population of Adult Polytransfused Patients: Correlation of GH-IGF1 Axis Alteration with Cardiac Performance

Endocrine complications of haemochromatosis and heart failure mostly affect morbidity and mortality in polytransfused patients. This study analyzes endocrine dysfunctions and the impact of GH-IGF-1 axis alteration on cardiac performance in a population of 31 patients. A retrospective study on 31 Caucasian polytransfused outpatients, 27 adults and 4 pediatric, residing in Apulia, Italy, followed from 2005 to 2016, was conducted. Patients underwent basal and dynamic hormonal evaluation. GHRH plus arginine test was performed in 21 patients (19 adults and 2 children). Among them, 9 patients were affected by left ventricle diastolic dysfunction and/or atrial or ventricular dilatation (HD group) and 12 patients did not have cardiovascular disease (non-HD group). Twenty-nine out of 31 patients (94%) had at least one endocrinopathy. We found severe or mild GH deficit (GHD) in all HD patients versus 3 patients in the non-HD group (p=0.001). Mean IGF-1 levels were significantly lower in the HD group than in non-HD subjects (53±30 versus 122±91 μg/L, p=0.04). Our study confirms the need to perform a dynamic evaluation of the GH-IGF1 axis in polytransfused patients, especially when heart dysfunction emerges. An intervention study with GH replacement therapy in a larger randomized adult population will clarify the role of GH/IGF axis on cardiovascular outcomes in this patient population.

Endocrine Complications

More than five decades ago, thalassemia major (TM) was fatal in the first decade of life [...]

The Impact of Iron Overload in Patients with Acute Leukemia and Myelodysplastic Syndrome on Hepatic and Endocrine functions

Patients with hematologic malignancies undergoing chemotherapy and requiring blood transfusion usually have an elevated serum ferritin. These findings have led to the suggestion that iron overload is common and may have deleterious effects in these patients. However, the relationship between serum ferritin and parenchymal iron overload in such patients is unknown. Therefore, we measured the liver iron content (LIC) by the FerriScan® method and investigated the liver function and some endocrine tests in 27 patients with acute leukemia (AL) or myelodysplastic syndromes (MDS). Using FerriScan® method, the normal mean LIC levels are: 4.3±2.9 mg Fe/g dry weight (d.w.). In our patients, the mean serum ferritin level was 1965±2428 ng/mL. In our patients, the mean total iron in the blood received by them was 7177±5009 mg. In 6 out of 27 patients LIC was >7 mg Fe/g d.w. and in 11/27 serum ferritin was >1000 ng/ml. Measuring fasting blood glucose revealed 3/27 with diabetes mellitus and 4/27 with impaired fasting glucose (IFG). All patients had normal serum concentrations of calcium, parathormone (PTH), free thyroxine (FT4) and thyrotropin (TSH). Four patients had elevated serum alanine transferase (ALT). LIC was correlated significantly with ferritin level (r=0.5666; P<0.001) and the cumulative amount of iron in the transfused blood (r=0.523; P<0.001). LIC was correlated significantly with ALT (r=0.277; P = 0.04) and fasting blood glucose (FBG) was correlated significantly with the amount of iron transfused (r=0.52, p<0.01) and ALT level (r=0.44; P<0.01). The age of patients did not correlate with LIC, FBG or ALT. In conclusions, these results contribute to our understanding of the prevalence of dysglycemia and hepatic dysfunction in relation to parenchymal iron overload in patients with hematologic malignancies undergoing chemotherapy and requiring blood transfusions. (www.actabiomedica.it)

Prevalence of diabetes mellitus in Chinese children with thalassaemia major

OBJECTIVE

Diabetes mellitus is a common endocrinopathy in patients with β-thalassaemia major (β-TM), which is high prevalent in southern China. This study aimed to determine the cause and prevalence of glycaemic disorders in Chinese children with β-TM.

METHODS

In this prospective study, fasting glucose and insulin (FINS) levels were assessed in 267 β-TM and 80 non-TM control children. Homeostatic model assessment (HOMA) and the quantitative insulin sensitivity check index (QUICKI) were evaluated. Iron overload was assessed by serum ferritin (SF), total units of blood transfused and cardiac T2*.

RESULTS

β-TM had higher FPG (P < 0.001), FINS (P < 0.001) and HOMA-IR (P < 0.05), but lower QUICKI (P < 0.01) than those of controls. The impaired fasting glucose (IFG) was present in 30% of children, whereas 2% had diabetes. The prevalence of IFG in β-TM group was higher in children aged >10 years (OR 6.5; 95% CI 3.7-11.4; P < 0.001), SF of >2500 μg/l (OR 4.8; 95% CI 2.1-11.1; P < 0.01), serum ALT levels of >50 IU/l (OR 2.1; 95% CI 1.2-3.7; P < 0.05) and cardiac T2* of <20 ms (OR 3.3; 95% CI 1.7-6.6; P < 0. 01). The children on deferiprone (DFP) had a reduced incidence of glycaemic aberrations than those on other chelating agents (OR 0.4; 95% CI 0.23-0.8; P < 0.05).

CONCLUSIONS

Our data suggest that IFG occurred in 30% of β TM children, perhaps due to insulin resistance secondary to iron overload. Deferiprone-containing chelating agent may have a protective effect.

β-Thalassemia Patients Revealed a Significant Change of Untargeted Metabolites in Comparison to Healthy Individuals

β-Thalassemia is one of the most prevalent forms of congenital blood disorders characterized by reduced hemoglobin levels with severe complications, affecting all dimensions of life. The mechanisms underlying the phenotypic heterogeneity of β-thalassemia are still poorly understood. We aimed to work over metabolite biomarkers to improve mechanistic understanding of phenotypic heterogeneity and hence better management of disorder at different levels. Untargeted serum metabolites were analyzed after protein precipitation and SPE (solid phase extraction) from 100 β-thalassemia patients and 61 healthy controls using GC-MS. 40 metabolites were identified having a significance difference between these two groups at probability of 0.05 and fold change >1.5. Out of these 40 metabolites, 17 were up-regulated while 23 were down-regulated. PCA and PLS-DA model was also created that revealed a fine separation with a sensitivity of 70% and specificity of 100% on external validation of samples. Metabolic pathway analysis revealed alteration in multiple pathways including glycolysis, pyruvate, propanoate, glycerophospholipid, galactose, fatty acid, starch and sucrose metabolism along with fatty acid elongation in mitochondria, glycerolipid, glyoxylate and dicarboxylate metabolism pointing towards the shift of metabolism in β-thalassemia patients in comparison to healthy individuals.

Review and Recommendations on Management of Adult Female Thalassemia Patients with Hypogonadism based on Literature Review and Experience of ICET-A Network Specialists

BACKGROUND

Multi-transfused thalassemia major (TM) patients frequently develop severe endocrine complications, mainly due to iron overload, anemia, and chronic liver disease, which require prompt diagnosis, treatment and follow-up by specialists. The most common endocrine complication documented is hypogonadotropic hypogonadism which increases with age and associated comorbidities. It is thus important for physicians to have a clear understanding of the pathophysiology and management of this disorder. Also to be aware of the side effects, contraindications and monitoring of sex steroid therapy. In this paper, practical ICET-A recommendations for the management of hypogonadism in adult females with TM are addressed.

METHODS

In March 2015, the Coordinator of the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescent Medicine (ICET-A) conducted a two-step survey to assess the attitudes and practices of doctors in the ICET-A network taking care of adult female TM patients with hypogonadism. They were clinically characterized by the absence of pubertal development or discontinuation or regression of the maturation of secondary sex characteristics, and biochemically by persistent low FSH, LH and estradiol levels. Recently a supplementary survey on adult female hypogonadism in TM was undertaken within the ICET-A network.

RESULTS

The completed questionnaires were returned by 16 of 27 specialists (59.2%) following 590 female TM patients over the age of 18 years; 315 patients (53.3%) had hypogonadism, and only 245 (74.6%) were on hormone replacement therapy (HRT). Contraceptive oral pills (COC) were the first treatment choice in 11 centers (68.7%). A wide range of COCs was used with different progestin contents. In general, the patients' compliance to treatment was reported as good in 81.2 % of centers. The frequency of required tests for follow-up HRT, in addition to the regular check-up for thalassemia, was variable in the participating centers.

CONCLUSIONS

Doctors taking care of TM patients should have sound knowledge of the pathophysiology of hypogonadism in adult females with TM. They should know the potential effects of HRT including advantages and disadvantages of estrogen and progestins. Moreover, they should keep in consideration the emotional needs of these patients dreaming of attaining a full pubertal development.

The ICET-A Recommendations for the Diagnosis and Management of Disturbances of Glucose Homeostasis in Thalassemia Major Patients

Iron overload in patients with thalassemia major (TM) affects glucose regulation and is mediated by several mechanisms. The pathogenesis of glycaemic abnormalities in TM is complex and multifactorial. It has been predominantly attributed to a combination of reduced insulin secretory capacity and insulin resistance. The exact mechanisms responsible for progression from norm glycaemia to overt diabetes in these patients are still poorly understood but are attributed mainly to insulin deficiency resulting from the toxic effects of iron deposited in the pancreas and insulin resistance. A group of endocrinologists, haematologists and paediatricians, members of the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescence Medicine (ICET-A) convened to formulate recommendations for the diagnosis and management of abnormalities of glucose homeostasis in thalassemia major patients on the basis of available evidence from clinical and laboratory data and consensus practice. The results of their work and discussions are described in this article.

Increased mitochondrial DNA deletions and copy number in transfusion-dependent thalassemia

BACKGROUND

Iron overload is the primary cause of morbidity in transfusion-dependent thalassemia. Increase in iron causes mitochondrial dysfunction under experimental conditions, but the occurrence and significance of mitochondrial damage is not understood in patients with thalassemia.

METHODS

Mitochondrial DNA (mtDNA) to nuclear DNA copy number (Mt/N) and frequency of the common 4977-bp mitochondrial deletion (ΔmtDNA⁴⁹⁷⁷) were quantified using a quantitative PCR assay on whole blood samples from 38 subjects with thalassemia who were receiving regular transfusions.

RESULTS

Compared with healthy controls, Mt/N and ΔmtDNA⁴⁹⁷⁷ frequency were elevated in thalassemia (P = 0.038 and P < 0.001, respectively). ΔmtDNA⁴⁹⁷⁷ was increased in the presence of either liver iron concentration > 15 mg/g dry-weight or splenectomy, with the highest levels observed in subjects who had both risk factors (P = 0.003). Myocardial iron (MRI T2* < 20 ms) was present in 0%, 22%, and 46% of subjects with ΔmtDNA⁴⁹⁷⁷ frequency < 20, 20-40, and > 40/1 × 10⁷ mtDNA, respectively (P = 0.025). Subjects with Mt/N values below the group median had significantly lower Matsuda insulin sensitivity index (5.76 ± 0.53) compared with the high Mt/N group (9.11 ± 0.95, P = 0.008).

CONCLUSION

Individuals with transfusion-dependent thalassemia demonstrate age-related increase in mtDNA damage in leukocytes. These changes are markedly amplified by splenectomy and are associated with extrahepatic iron deposition. Elevated mtDNA damage in blood cells may predict the risk of iron-associated organ damage in thalassemia.