Diabetes mellitus in patients with thalassemia major

HbA1c or fructosamine on evaluating glucose intolerance in children with beta- thalassemia

BACKGROUND

Beta-thalassemia major (β-TM) patients are more likely to experience blood glucose intolerance and to date; the blood markers that could evaluate this are debatable. So, this study aimed to assess the roles of glycated hemoglobin A1c (HbA1c) and fructosamine in evaluating glucose intolerance in children with β-TM and figuring out role of insulin resistance in these patients.

METHODS

One hundred children diagnosed with β-TM and 100 age and sex-matched controls were enrolled. Fasting plasma glucose (FPG), 2-h post-prandial blood glucose (2-h PG), HbA1c, fructosamine, fasting insulin level (FINS), insulin resistance index (HOMA-IR), and insulin sensitivity index (HOMA-IS) were evaluated.

RESULTS

FPG and 2-h PG revealed glucose intolerance in 51 patients (51%), 19 of them had diabetes mellitus. HbA1c, fructosamine, FINS, and HOMA-IR showed a high statistically significant increase in patients compared to controls, (P < 0.001). Results revealed fructosamine was more specific in detecting prediabetes state and more sensitive in identifying diabetes mellitus in our patients when compared to HbA1c.

CONCLUSIONS

Despite controversies on HbA1c in children with β-TM, it is still valuable in glucose intolerance detection. Fructosamine showed more sensitivity and specificity. Furthermore, insulin resistance was prevalent in children with β-TM highlighting the necessity of regular glycemic state evaluation.

IMPACT

Glucose intolerance is a common complication in beta thalassemia patients. Conflicting data was reported about the role of HbA1c and fructosamine in evaluating glucose intolerance in thalassemic patients. Fructosamine does not yet have a threshold that may be used to distinguish between patients who have diabetes mellitus and those who do not. Fructosamine was more specific in detecting blood glucose intolerance compared to HbA1c and was more sensitive for diagnosing diabetes mellitus. Insulin resistance was common in patients with beta-thalassemia and often present before the onset of overt diabetes.

Quantitative Magnetic Resonance Imaging for the Pancreas: Current Status

ABSTRACT

Magnetic resonance imaging (MRI) is important for evaluating pancreatic disorders, and anatomical landmarks play a major role in the interpretation of results. Quantitative MRI is an effective diagnostic modality for various pathologic conditions, as it allows the investigation of various physical parameters. Recent advancements in quantitative MRI techniques have significantly improved the accuracy of pancreatic MRI. Consequently, this method has become an essential tool for the diagnosis, treatment, and monitoring of pancreatic diseases. This comprehensive review article presents the currently available evidence on the clinical utility of quantitative MRI of the pancreas.

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.

Hepatitis C and Thalassemia: A Story with (Almost) a Happy Ending

Donor screening has nearly eliminated the risk of hepatitis C virus post-transfusion transmission in resource-rich settings. Moreover, the use of direct antiviral agents made it possible to treat the majority of patients with thalassemia and hepatitis C. However, this achievement, while extremely significant, does not erase the effects of the virus in terms of fibrogenesis and mutagenic risk, and adult patients with thalassemia are facing the long-term consequences of the chronic infection both on the liver and extrahepatically. As in the general population, it is in mainly patients with cirrhosis who are increasing in age, even though they are now HCV RNA-negative, who are at risk of hepatocellular carcinoma, which continues to be statistically much more frequent in individuals with than without thalassemia. In certain resource-limited settings, the World Health Organization has estimated that up to 25 percent of blood donations do not undergo screening. It is therefore not surprising that hepatitis virus infection is still the most prevalent in patients with thalassemia worldwide.

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.

Impaired pancreatic beta-cell function after a single dose of oral iron: a before-and-after (pre-post) study

INTRODUCTION

Although in vitro and animal studies have shown that iron loading in pancreatic beta-cells impaired insulin secretion, no human studies have documented the acute effects of oral iron on beta-cell insulin secretory capacity. In this study, we determined beta-cell insulin secretory capacity at baseline and after a single oral dose of iron (ferrous sulphate, 120 mg elemental iron) in healthy male individuals.

METHODS

Fifteen healthy male volunteers underwent an oral glucose tolerance test (OGTT) to document baseline glucose tolerance and insulin secretion kinetics (baseline OGTT). One week later, the same subjects underwent a second OGTT, two hours after an oral dose of ferrous sulfate (120 mg of elemental iron) (post-iron OGTT). Changes in disposition index, insulin secretion kinetics, glucose tolerance, insulin resistance, insulin clearance, and iron-related parameters in serum were determined.

RESULTS

Compared to baseline OGTT, the areas under the curve (AUC) for serum iron and transferrin saturation increased by 125% and 118% respectively, in the post-iron OGTT. The disposition index decreased by 20% (p=0.009) and the AUC for glucose concentrations increased by 5.7% (p<0.001) during the post-iron OGTT. The insulin secretion rate was marginally lower during the first hour (-3.5%, p=0.63), but became significantly higher during the second hour (22%, p=0.005) of the post-iron OGTT. Insulin resistance and insulin clearance rate were not affected by iron intake.

CONCLUSION

The decrease in disposition index and glucose tolerance observed after the oral dose of iron points to an acute iron-induced impairment in pancreatic beta-cell insulin secretory capacity. This article is protected by copyright. All rights reserved.

Relationships among Physical Activity, Pain, and Bone Health in Youth and Adults with Thalassemia: An Observational Study

Patients with thalassemia (Thal) engage in less physical activity than non-Thal populations, which may contribute to pain and osteoporosis. The purpose of this study was to assess relationships between physical activity, pain, and low bone mass in a contemporary sample of patients with Thal. Seventy-one patients with Thal (50 adults ≥18 years, 61% male, 82% transfusion-dependent) completed the Brief Pain Inventory Short Form and validated physical activity questionnaires for youth and adults. Nearly half of the patients reported daily somatic pain. Using multiple regression, after controlling for age and gender, sedentary behavior was positively associated with pain severity (p = 0.017, r2 = 0.28). Only 37% of adult participants met CDC recommendations for physical activity. Spine BMD Z-score was higher (−2.1 ± 0.7) in those who met activity guidelines compared to those who did not (−2.8 ± 1.2, p = 0.048). A positive relationship was observed between self-reported physical activity (hours/week) and hip BMD Z-score in adults with Thal after controlling for transfusion status and sedentary activity time (p = 0.009, r2 = 0.25). These results suggest that decreased physical activity and increased sedentary behavior contribute to low bone mass, which may be related to pain severity in some patients with Thal. Studies focused on increasing physical activity may contribute to improved bone health and reduced pain in patients with Thal.

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.

Iron Reshapes the Gut Microbiome and Host Metabolism

Compelling studies have established that the gut microbiome is a modifier of metabolic health. Changes in the composition of the gut microbiome are influenced by genetics and the environment, including diet. Iron is a potential node of crosstalk between the host-microbe relationship and metabolic disease. Although iron is well characterized as a frequent traveling companion of metabolic disease, the role of iron is underappreciated because the mechanisms of iron's influence on host metabolism are poorly characterized. Both iron deficiency and excessive amounts leading to iron overload can have detrimental effects on cardiometabolic health. Optimal iron homeostasis is critical for regulation of host immunity and metabolism in addition to regulation of commensal and pathogenic enteric bacteria. In this article we review evidence to support the notion that altering composition of the gut microbiome may be an important route via which iron impacts cardiometabolic health. We discuss reshaping of the microbiome by iron, the physiological significance and the potential for therapeutic interventions.

Quantification of pancreatic iron overload and fat infiltration and their correlation with glucose disturbance in pediatric thalassemia major patients

Background

Diabetes mellitus affects more than a quarter of patients with thalassemia major (TM) worldwide, and increases the risk for cardiac complications, contributing to significant morbidity. Pancreatic iron overload (IO) and fat infiltration have been correlated with this endocrinal complication in adult TM patients. It has been shown that in adult TM patients, iron accumulation and fat infiltration are found to be heterogeneous in the pancreatic head, body, and tail region. R2* and a fat fraction (FF) generated by gradient-echo imaging can be used as quantitative parameters to assess the iron and fat contents of the pancreas. This study aimed to determine the pattern of pancreatic iron accumulation and fat infiltration in pediatric TM patients with gradient-echo imaging and evaluate the association between pancreatic IO and fat infiltration and glucose disturbances.

Methods

A total of 90 children with TM (10.7±3.1 years) were included. All patients underwent pancreatic magnetic resonance imaging (MRI) using multi-echo gradient-echo sequences. IO was measured by R2* relaxometry in 90 patients, and FF values were measured using iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method in 40 patients. R2* and FF were assessed in the pancreatic head, body, and tail. The global R2* and global FF values were obtained by averaging the respective values from the pancreatic head, body, and tail. The correlations between global R2*, global FF, and fasting glucose were determined using Spearman's correlation analysis. The Friedman test was used to compare R2* and FF among different pancreatic regions. Receiver operating characteristic (ROC) analysis was used to determine the performance of global R2* and global FF in discriminating impaired fasting glucose from normal fasting glucose patients.

Results

The global R2* was positively correlated with the global FF in the pancreas (r=0.895, P<0.001). No significant differences were found in R2* among the 3 regions of the pancreas (χ²=4.050, P=0.132), but significant differences were found in FF among the 3 pancreatic regions (χ²=16.350, P<0.001). Both global pancreatic R2* (r=0.408, P<0.001) and global FF (r=0.523, P=0.001) were positively correlated with fasting glucose. ROC analysis showed that global pancreatic R2* and global FF had an area under the curve of 0.769 and 0.931 (both P<0.001), respectively, in discriminating between impaired and normal glucose function patients.

Conclusions

Pediatric TM patients can have homogeneous iron siderosis and heterogeneous fat infiltration in the pancreas as measured by gradient-echo imaging, both of which are risk factors for diabetes.

Combination of ferric ammonium citrate with cytokines involved in apoptosis and insulin secretion of human pancreatic beta cells related to diabetes in thalassemia

Background

Diabetes mellitus (DM) is a common complication found in β-thalassemia patients. The mechanism of DM in β-thalassemia patients is still unclear, but it could be from an iron overload and increase of some cytokines, such as interleukin1-β (IL-1β) and tumor necrosis factor-α (TNF-α). The objective of this study was to study the effect of interaction between ferric ammonium citrate (FAC) and cytokines, IL-1β and TNF-α, on 1.1B4 human pancreatic β-cell line.

Methods

The effect of the combination of FAC and cytokines on cell viability was studied by MTT assay. Insulin secretion was assessed by the enzyme-linked immunosorbent assay (ELISA). The reactive oxygen species (ROS) and cell apoptosis in normal and high glucose condition were determined by flow cytometer. In addition, gene expression of apoptosis, antioxidant; glutathione peroxidase 1 (GPX1) and superoxide dismutase 2 (SOD2), and insulin secretory function were studied by real-time polymerase chain reaction (Real-time PCR).

Results

The findings revealed that FAC exposure resulted in the decrease of cell viability and insulin-release, and the induction of ROS and apoptosis in pancreatic cells. Interestingly, a combination of FAC and cytokines had an additive effect on SOD2 antioxidants' genes expression and endoplasmic reticulum (ER) stress. In addition, it reduced the insulin secretion genes expression; insulin (INS), glucose kinase (GCK), protein convertase 1 (PSCK1), and protein convertase 2 (PSCK2). Moreover, the highest ROS and the lowest insulin secretion were found in FAC combined with IL-1β and TNF-α in the high-glucose condition of human pancreatic beta cell, which could be involved in the mechanism of DM development in β-thalassemia patients.

Early development of decreased β-cell insulin secretion in children and adolescents with hemoglobin H disease and its relationship with levels of anemia

BACKGROUND

Diabetes mellitus (DM) associated with iron overload has been reported among adults with transfusion-dependent thalassemia and those with non-transfusion-dependent thalassemia (NTDT), especially in β-thalassemia disease. However, little is known about glucose metabolism and how early its dysregulation can develop in α-thalassemia hemoglobin H (Hb H) disease, which is one of the most common types of NTDT worldwide.

PROCEDURE

We prospectively calculated glucose metabolism index in 40 patients (aged 10-25 years) with Hb H disease. Glucose metabolism data were compared between patients with deletional versus nondeletional Hb H, and between patients with normal versus abnormal insulin secretion/sensitivity.

RESULTS

Despite normal glucose tolerance in all patients, 52.5% had abnormal insulinogenic index indicating decreased β-cell insulin secretion. Patients with functional hemoglobin < 8 g/dL had significantly higher percentages of abnormal insulinogenic index. There was no significant difference in abnormal insulinogenic index between deletional and nondeletional Hb H.

CONCLUSION

Decreased β-cell insulin secretion is highly prevalent among children and adolescents with Hb H disease, and it is associated with levels of functional anemia at baseline, but not with the type of Hb H disease. This result warrants heightened awareness among hematologists due to potentially increased risk of DM later in life.

Insulin secretion-sensitivity index-2 could be a novel marker in the identification of the role of pancreatic iron deposition on beta-cell function in thalassemia major

The purpose of this study is to evaluate the impact of insulin secretion-sensitivity index-2 (ISSI-2) in the identification of the role of pancreatic iron deposition on beta-cell function in thalassemia major. Tissue iron stores were measured with magnetic resonance imaging (MRI) in the liver (R2), pancreas (R2*), and heart (T2*). ISSI-2 was assessed as a novel oral glucose tolerance test-based measure of beta-cell function. Also, the Stumvoll index showing the insulin sensitivity and Stumvoll index estimating first and second phase insulin secretion were calculated. Fourteen of the 51 Thalassemia Major patients, aged 8-34 (mean 21.1 ± 7.2) years-old, had either an impaired glucose tolerance test (n = 9, 17.6%) or diabetes mellitus (n = 5, 9.8%)-referred to as the glucose dysregulation (GD) group. The median serum ferritin and the mean liver R2 and cardiac T2* values were not significantly different between the GD and normal glucose tolerance (NGT, n = 37) groups whereas pancreas R2* was significantly higher in the GD group compared to the NGT group (p = 0.004). Patients with GD showed significantly lower ISSI-2 index (p < 0.001) as well as the Stumvoll index and Stumvoll first and second phase indices compared to those with NGT (p < 0.001). All patients with GD displayed a pancreas R2* >50 Hz and ISSI-2 <2. In conclusion, Pancreas R2* MRI combined with ISSI-2 index may be valuable parameters to identify patients at the highest risk for developing glucose dysregulation.

Glucose dysregulation in patients with iron overload: is there a relationship with quantitative pancreas and liver iron and fat content measured by MRI?

OBJECTIVES

The aim was to investigate the relationship between pancreatic and hepatic iron and fat to glucose metabolism in patients with iron overload and address conflicting results in literature as regards the relationship between pancreas iron and glucose dysregulation.

METHODS

We retrospectively evaluated pancreatic and hepatic R2*, fat fraction (FF), liver iron concentration (LIC), and glucose metabolism in 105 patients with iron overload obtained with a multi-echo gradient echo R2* technique and assessed the correlation between pancreatic R2* and FF to glucose dysregulation.

RESULTS

There were no significant differences in pancreatic R2*, liver R2*, and FF in patients with iron overload and glucose dysregulation compared to those with normoglycemia (p = 0.435, p = 0.674, and p = 0.976), whereas pancreatic FF was significantly higher, 23.5% vs 16.7% respectively (p = 0.011). Pancreatic FF and R2* demonstrated an area under the curve of 0.666 and 0.571 for discriminating glucose dysregulation. Pancreatic FF of 26.2% yielded specificity and sensitivity of 80% and 45% for prediction of glucose dysregulation. Pancreatic R2* weakly correlated with pancreatic FF, r = 0.388 (p < 0.001), and liver R2*, r = 0.201 (p = 0.033), and showed no correlation with hepatic FF r = -0.013 (p = 0.892) or LIC categories (p = 0.493).

CONCLUSION

Pancreatic FF but not pancreatic R2* was associated with glucose dysregulation in patients with iron overload. Prior studies reporting correlation of pancreatic R2* to glucose dysregulation likely relate from inadequate MRI technique or analysis employed, which unlike our study did not perform simultaneous measurements of fat and iron essential to avoid their confounding effects during quantitative analysis.

KEY POINTS

• Pancreatic fat fraction, unlike iron, is associated with glucose dysregulation in iron overload. • Simultaneous measurement of pancreatic iron and fat content with MRI is essential to avoid confounding effects of one another during quantitative analysis. • Pancreatic fat fraction could be utilized to predict glucose dysregulation in iron overload states.

Diabetes Mellitus in Thalassaemia Major Patients: A Report from the Southeast of Iran

INTRODUCTION

Diabetes Mellitus (DM) represents a major concern in Thalassaemia Major (TM) patients.

AIM

The present study was conducted to evaluate the frequency of Impaired Fasting Glucose (IFG) and DM in TM patients in Southeast of Iran.

MATERIALS AND METHODS

Fasting Blood Glucose (FBS) was determined using fasting blood samples in 148 TM patients. Demographical data was collected by a questionnaire. Clinical and laboratory variables including cell blood counts, pre-transfusion Haemoglobin (Hb) level, and five-year ferritin were extracted from medical records. Statistical analysis was performed in SPSS19.0 software using chi-square, student t-test and logistic regression.

RESULTS

Females and males comprised 83 (56.1%) and 65 (43.9%) subjects respectively. The mean age and mean five-year ferritin were 17.3±6.1 year-old and 5060.6±2395 ng/ml respectively. Overall, 39 (26.4%) patients had IFG, while 13 (8.8%) were diagnosed with DM. Significant differences were identified in the mean age, volume of transfused blood per occasion, and mean five-years ferritin between the patients with IFG or DM and the patients with normal fasting glucose level. Patients with age >25-year-old had an increased risk of both IFG (OR=4.7,95% CI: 1.3-17, p=0.01) and DM (OR= 7.1, 95% CI: 1-49.2, p=0.04). In addition, splenectomized patients showed a higher risk for IFG (OR=4.3, 95% CI: 1.5-12.1, p=0.005), and ferritin value >6000 ng/ml were associated with an elevated risk of DM (OR=7, 95% CI: 0.8-60.1, p=0.07).

CONCLUSION

Our results indicated that higher age, mean five-years ferritin, volume of blood transfused per occasion, as well as splenectomy were risk factors of IFG and DM in TM patients.

T2* Magnetic Resonance Imaging Study of Pancreatic Iron Overload and its Relation With the Diabetic State in Thalassemic Patients

The present study was performed to evaluate pancreatic hemosiderosis by means of magnetic resonance imaging (MRI) T2* and its relation to the diabetic state in thalassemic patients. One hundred thirty transfusion-dependent thalassemic patients from Zafar adult thalassemia clinic, Tehran, Iran, were enrolled in the study. Data such as age, type of thalassemia, age at diagnosis, transfusion duration, ferritin level, and fasting blood sugar results were gathered. Pancreatic MRI T2* was performed for all patients. One hundred four thalassemic patients with no sign of diabetes mellitus and 26 thalassemic patients with diabetes mellitus entered the study. Out of a total of 130 patients, 102 had pancreatic hemosiderosis. Among them, 23 of 26 diabetic patients (88.5%) and 79 of 104 nondiabetic patients (76%) showed pancreatic hemosiderosis, indicating no statistically significant difference between the 2 groups. The mean pancreatic MRI T2* relaxation time for all patients was 13.99±12.43 ms. The mean relaxation was 13.62±8.38 and 14.08±13.28 ms for diabetic and nondiabetic patients, respectively, showing no statistical difference (P=0.202). In conclusion, we did not find a significant difference between diabetic and nondiabetic thalassemic patients regarding the MRI T2* relaxation time readings or the rate of pancreatic hemosiderosis. We recommend performing studies with a higher sample size and including patients from different age groups to further evaluate the role of T2* MRI of pancreatic iron overload and its relation with the diabetic state in thalassemic patients.

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.

R2*-relaxometry of the pancreas in patients with human hemochromatosis protein associated hereditary hemochromatosis

PURPOSE

To evaluate pancreatic iron in patients with human hemochromatosis protein associated hereditary hemochromatosis (HHC) using R2* relaxometry.

MATERIALS AND METHODS

81 patients (58 male, 23 female; median age 49.5, range 10-81 years) with HHC were retrospectively studied. All underwent 1.5T magnetic resonance imaging (MRI) of the abdomen. A fat-saturated multi-gradient echo sequence with 12 echoes (TR=200ms; TE-initial 0.99ms; Delta-TE 1.41ms; 12 echoes; flip-angle: 20°) was used for the R2* quantification of the liver and the pancreas. Parameter maps were analyzed using regions of interest (3 in the liver and 2 in the pancreas) and R2* values were correlated.

RESULTS

59/81 patients had a liver R2*≥70 1/s of which 10/59 patients had a pancreas R2*≥50 1/s. No patient presented with a liver R2*<70 1/s and pancreas R2*≥50 1/s. All patients with pancreas R2* values≥50 1/s had liver R2* values≥70 1/s. ROC analysis resulted in a threshold of 209.4 1/s for liver R2* values to identify HFE positive patients with pancreas R2* values≥50 1/s with a median specificity of 78.87% and a median sensitivity of 90%.

CONCLUSION

In patients with HHC R2* relaxometry of the pancreas should be performed when liver iron overload is present and can be omitted in cases with no sign of hepatic iron.

Breath-hold spin echosequence for assessing liver iron content

OBJECTIVE

To compare a multiple breath-hold, multiecho, multiplanar spin-echo (BHMEMPSE) magnetic resonance (MR) sequence with a TR of 300ms with a traditional multiecho, multiplanar spin-echo (MEMPSE) MR sequence for assessing liver iron content.

MATERIALS AND METHODS

This study was approved by the institutional review board; informed consent was waived. Liver R2 measurement was derived from the mono-exponential model by BHMEMPSE and MEMPSE MR sequences of a 1.5T MR machine in 30 thalassemia patients (9men, 21women, aged 27.7±6.8years). Hepatic iron contents were estimated using Ferriscan in all patients. The inter- and intra-observer agreement of the 2 MR sequences was also evaluated.

RESULTS

MEMPSE R2 values significantly correlated with Ferriscan iron content values (r=0.895, p<0.001) and serum ferritin concentration (r=0.661, p<0.001). BHMEMPSE R2 values significantly correlated with Ferriscan values (r=0.914, p<0.001) and serum ferritin concentration (r=0.608, p<0.001). The distribution of MEMPSE R2 values against BHMEMPSE R2 values revealed an excellent linear relationship (r=0.978, p<0.001). The inter- and intra-observer agreement of the 2 MR sequences was excellent, with an interclass correlation coefficient exceeding 0.9. The distribution of Ferriscan against BHMEMPSE R2 values revealed a curvilinear relationship (r=0.935, p<0.001).

CONCLUSIONS

The BHMEMPSE sequence exhibited comparable estimation for assessing liver iron content, comparable repeatability and a shorter acquisition time compared with the MEMPSE sequence. The BHMEMPSE sequence can serve as an adjunctive sequence to assess liver iron content.

Anti-Thyroid Peroxidase Antibodies and Male Gender Are Associated with Diabetes Occurrence in Patients with Beta-Thalassemia Major

BACKGROUND

Intensive transfusion schedule and iron-chelating therapy prolonged and improved quality of life in patients with β-thalassemia (β-T) major. However, this led to an increased risk of developing impaired glucose tolerance or diabetes. In this study we analyzed variables associated with the occurrence of impaired glucose tolerance or diabetes in patients with β-T major.

METHODS

388 Sardinian patients were included. Age, gender, duration of chelation therapy, body mass index, and markers of pancreatic and extrapancreatic autoimmunity were analyzed.

RESULTS

Multiple logistic regression analysis showed that anti-thyroid peroxidase (TPO) antibodies (Ab) (OR = 3.36; p = 0.008) and male gender (OR = 1.98; p = 0.025) were significantly associated with glucose impairment, while the other variables were not. Ferritin levels were significantly higher in TPOAb positive compared to TPOAb negative patients (4870 ± 1665 μg/L versus 2922 ± 2773 μg/L; p < 0.0001).

CONCLUSIONS

In patients with β-T major a progressive damage of insulin-producing cells due to secondary hemosiderosis appears to be the most reasonable mechanism associated with glucose metabolism disorders. The findings need to be confirmed with additional well designed studies to address the question of whether TPOAb may have a role in the management of these patients.

Reduced beta-cell reserve and pancreatic volume in survivors of childhood acute lymphoblastic leukaemia treated with bone marrow transplantation and total body irradiation

BACKGROUND

Impaired glucose tolerance (IGT) and diabetes mellitus (DM) occur more frequently after bone marrow transplantation and total body irradiation (BMT/TBI), but the mechanism is unclear. This study investigates insulin sensitivity, β-cell reserve and pancreatic volume in adult survivors of childhood acute lymphoblastic leukaemia (ALL).

METHOD

Survivors (aged 16-26 years) of ALL treated with BMT/TBI (10-14·4 Gy) Group 1 (n = 20, 10 m) were compared with a chemotherapy-only Group 2 (n = 28, 11 m). Participants underwent assessments of insulin sensitivity by whole body composite-insulin-sensitivity-index (ISIcomp ) from oral glucose tolerance tests (OGTTs); first (AIRarg , AIRg , AUCin10 ) and second (AUC in second phase ) phase insulin responses from arginine-intravenous glucose tolerance tests; and pancreatic volume by abdominal magnetic resonance imaging (MRI). Data were analysed by odds ratio, Chi-square or Fisher's exact tests, Student's t-tests, analysis of covariance (ancova) and Pearson's or partial correlations (5% significance).

RESULTS

Abnormal OGTTs were documented in Group 1 (DM = 2, IGT = 7). Insulin secretion adjusted for insulin sensitivity was lower in Group 1 than Group 2 as a whole [LogAIRarg (P = 0·008), logAIRg (P = 0·013) and logAUCin10 (P = 0·014)] and after exclusion of those with abnormal glucose tolerance [logAIRarg (P = 0·011), logAIRg (P = 0·007) and logAUCin10 (P = 0·006)]. Group 1 had lower pancreatic volume than Group 2 [52·0 (14·2) vs 72·8 (23·5), P = 0·001] cm(3) , and results were consistent after adjustment for size by body surface area (P = 0·019). Pancreatic volume correlated with logAIRarg adjusted log ISIcomp (partial correlation = 0·34, P = 0·025).

CONCLUSIONS

Adult survivors of childhood BMT/TBI for ALL demonstrated reduced β-cell reserve and smaller pancreatic volume, both likely additional aetiological factors, with reduced insulin sensitivity, in their increased risk of diabetes.

Transition of Thalassaemia and Friedreich ataxia from fatal to chronic diseases

Thalassaemia major (TM) and Friedreich’s ataxia (FA) are autosomal recessive inherited diseases related to the proteins haemoglobin and frataxin respectively. In both diseases abnormalities in iron metabolism is the main cause of iron toxicity leading to increased morbidity and mortality. Major efforts are directed towards the prevention of these diseases and also in their treatment using iron chelation therapy. Both TM and FA are endemic in Cyprus, where the frequency per total population of asymptomatic heterozygote carriers and patients is the highest worldwide. Cyprus has been a pioneering nation in preventing and nearly eliminating the birth of TM and FA patients by introducing an organized health structure, including prenatal and antenatal diagnosis. Effective iron chelation therapy, improved diagnostic methods and transfusion techniques as well as supportive therapy from other clinical specializations have improved the survival and quality of life of TM patients. Despite the tiresome clinical management regimes many TM patients are successful in their professional lives, have families with children and some are now living well into their fifties. The introduction of deferiprone led to the elimination of cardiac failure induced by iron overload toxicity, which was the major cause of mortality in TM. Effective combinations of deferiprone with deferoxamine in TM patients caused the fall of body iron to normal physiological ranges. In FA different mechanisms of iron metabolism and toxicity apply to that of TM, which can be targeted with specific iron chelation protocols. Preliminary findings from the introduction of deferiprone in FA patients have increased the hopes for improved and effective therapy in this untreatable condition. New and personalised treatments are proposed in TM and FA. Overall, advances in treatments and in particular of chelation therapy using deferiprone are transforming TM and FA from fatal to chronic conditions. The paradigm of Cyprus in the prevention and treatment of TM can be used for application worldwide.