Abnormal glucose tolerance in Egyptian beta-thalassemic patients: possible association with genotyping

Investigation of Pancreatic Sonography Findings in Patients With Beta-Thalassemia Major

Objective:

Some structural abnormalities have been reported on sonography of pancreas in patients with beta-thalassemia which can indicate that the patient is developing diabetes. In this study, the aim was to investigate the findings of pancreatic sonography in patients, with beta-thalassemia major.

Methods:

This cross-sectional study included information extracted from the medical record and entered into an information form. A cohort of 190 people were split into case and control groups, retrospectively. The required data were extracted from patient’s documents. Data were analyzed with SPSS software, version 22; with the chi-square statistical tests. A P value of < .05 was considered statistically significant.

Results:

This study consisted of 33 males and 61 females in the case group and 32 males and 64 females in the control group. The most common echogenicity observed during pancreatic sonography, in the control group, was an isoechoic feature (72.3%), followed by hyper and hypoechogenicity (18.1% and 9.6%, respectively). The prevalence of an isoechoic texture in the patient case group was 58.3%, while hyper and hypoechogenicity were seen in 26% and 2.1%, respectively ( P = .070). There was a poor negative correlation between diabetes and pancreatic echogenicity ( P = .002 and r = −.226). Also, there was a poor positive correlation between fasting serum glucose levels and pancreatic echogenicity ( P = .034, n = 96 and r = .217).

Conclusion:

This study demonstrates, in this patient group, that there was a poor relationship between pancreatic head size with serum ferritin levels and pancreatic echogenicity with diabetes. These results may suggest using sonography to diagnose early stages of diabetes in patients with thalassemia.

Elevated Prevalence of Abnormal Glucose Metabolism and Other Endocrine Disorders in Patients with β-Thalassemia Major: A Meta-Analysis

Background

Endocrinopathies are common in patients with β-thalassemia major despite parenteral iron chelation therapy with deferoxamine. Prevalence of abnormal glucose metabolism in previous studies was controversial. The aim of this study was to discuss the prevalence of abnormal glucose metabolism in β-thalassemia major based on a meta-analysis.

Methods

PubMed, ScienceDirect, Springerlink, Ovid, Web of Science, MEDLINE, Wanfang database, and Chinese National Knowledge Internet were searched for relevant articles. Two authors selected the articles according to the inclusion criteria and then extracted the data. The prevalence of diabetes mellitus (DM) in β-thalassemia major was defined as the primary outcome. The prevalence with the 95% confidence interval (95%CI) was used to evaluate the proportion of abnormal glucose metabolism and other endocrine disorders in patients with β-thalassemia major. Subgroup analyses were applied to explore the prevalence in different regions. Sensitivity analysis and publication bias assessment were also conducted.

Results

A total of 44 studies with 16605 cases were included in this analysis. Diabetes mellitus was present in 6.54% (95% CI: 5.30%-7.78%). The fixed subgroup study revealed that the region with the highest prevalence was the Middle East (prevalence= 7.90%, 95% CI: 5.75%-10.05%). The accumulated meta-analysis revealed that the prevalence of DM in β-thalassemia major was relatively steady in each year. The prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and other endocrine disorders in β-thalassemia major was 17.21% (95% CI: 8.43%-26.00%), 12.46% (95% CI: 5.98%-18.94%), and 43.92% (95% CI: 37.94%-49.89%), respectively. Sensitivity analysis showed that the pooled results were robust; publication bias assessment revealed that there was no significant evidence that the pooled results were influenced by publication bias.

Conclusion

High prevalence of endocrine disorders involving abnormal glucose metabolism was detected in β-thalassemia major. Treatment and prevention measurements may be necessary to prevent growth and endocrine problems.

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.

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.

Impact of genotype on endocrinal complications in β-thalassemia patients

In β-thalassemia, certain mutations cause a complete absence of β-globin chain synthesis, termed β⁰-thalassemia, while others may allow certain β-globin production and are termed β⁺- or β⁺⁺-thalassemia. The homozygous state results in severe anemia, which requires regular blood transfusion. By contrast, frequent blood transfusion can in turn lead to iron overload, which may result in several endocrinal complications. The present study aimed to investigate the impact of genotype on the development of endocrine complications in β-thalassemia patients. A cross-sectional study was conducted on 100 thalassemia patients >10 years. A data abstraction form was designed to capture the appropriate information from the individual medical records, including full clinical, laboratory, transfusion and chelation data. The genotype of the patients was identified by the DNA sequencing technique. Growth retardation and hypogonadism were the most prominent endocrinal complications (70 and 67%, respectively) followed by hypothyroidism, diabetes mellitus and hypoparathyrodism (8, 8 and 7%, respectively). The most common mutations identified were IVS-1-110, IVS-1-1 and IVS-1-6 (63, 47 and 41%, respectively). Patients with the β⁰β⁰ genotype had a significantly higher prevalence of growth retardation, hypogonadism, hypothyroidism and hypoparathyrodism compared to those with the β⁰β⁺ and β⁺β⁺ genotypes (P<0.001, P<0.001, P<0.001 and P=0.037, respectively). Patients with the homozygous IVS-11-745 mutation had a significantly higher prevalence of diabetes (P=0.001). The underlying genetic defect in thalassemia patients is a contributing factor for the development of endocrinal complications, as patients with the more severe defects have a greater rate of iron loading through higher red cell consumption.

Insulin resistance, impaired glucose tolerance and alpha-thalassemia carrier state

BACKGROUND

This study was designed to determine relationship between the glucose metabolism disorder (the insulin resistance and the impaired glucose tolerance) and α-thalassemia.

METHODS

In this historical cohort study, 80Alpha-thalassemia carriers and 80 healthy people were enrolled. The participants had no diabetes familial history and the waist circumference and blood pressure were in normal range (waist circumference of less than 102 cm in men, 88 cm in women and blood pressure <120/80 mmHg). The serum insulin level, fasting blood glucose (after 12 hours fasting) and two-hour plasma glucose during an oral glucose tolerance test (2-h OGTT) were measured. Insulin resistance was estimated according to homeostasis model assessment method (HOMA). Chi-square test, independent sample t-test and the relative risk were used for data analysis.

RESULTS

According to FBS and OGTT results, the percentage of diabetes mellitus and pre-diabetes were 1.3% and 33.8% in Alpha-thalassemia carriers, respectively. The control group showed 2.5% diabetic and 13.8% pre-diabetic cases as well. The relative risk for the glucose tolerance impairment (diabetes and pre-diabetes) was 2.78 (95% CI: 1.31-5.88, P = 0.07).Six and a half percent of the Alpha-thalassemia group and 2.5% in the control group had 2.25 ≤ HOMAIR ≤ 3.59 (an intermediate state of Insulin sensitivity) p = 0.443. In the study, there was no subject with insulin resistance (HOMAIR >3.59).

CONCLUSIONS

The possibility of risk enhancement of the impaired glucose tolerance (pre-diabetes and diabetes mellitus) in patients with α-thalassemia is almost three times greater than the normal population without relationship with insulin resistance. Diabetic and pre-diabetic Alpha-thalassemia carrier state is younger than the general population suffering of these disorders.

Endocrinopathies, metabolic disorders, and iron overload in major and intermedia thalassemia: serum ferritin as diagnostic and predictive marker associated with liver and cardiac T2* MRI assessment

INTRODUCTION

Endocrinopathies and metabolic disorders-characterized β thalassemic (βT) patients and the prevention and treatment of these comorbidities are important targets to be achieved. The aim of the study was to analyze the diagnostic and prognostic role of ferritin for endocrinopathies and metabolic disorders in βT patients. The ability of iron chelators to treat iron overload and to prevent or reverse metabolic disorders and endocrinopathies was also evaluated.

PATIENTS AND METHODS

Seventy-two βT patients were treated with different chelation strategies during the study. Receiver operating characteristics analysis was employed to calculate the area under the curve for serum ferritin to find the best cutoff values capable of identifying endocrine dysfunction in thalassemic patients. Kaplan-Meier curves were generated to assess the incidence of endocrinopathy. Adjusted risk estimates for endocrinopathy were calculated using univariate followed by multivariate Cox proportional hazard regression analysis.

RESULTS

High ferritin levels were observed in patients with hypothyroidism [1500 (872.5-2336.5) μg/L], hypogonadism [878 (334-2010) μg/L], and in patients with hypoparathyroidism or osteoporosis [834 (367-1857) μg/L]. A strict correlation between ferritin and T2* magnetic resonance imaging of heart (r = -0.64; P:0.0006) and liver (r = -0.40; P:0.03) values was observed. Patients with ferritin values above 1800 μg/L experienced a significantly faster evolution to hypothyroidism [log-rank (χ(2) ):7.7; P = 0.005], hypogonadism [log-rank (χ(2) ):10.7; P = 0.001], and multiple endocrinopathies [log-rank (χ(2) ):5.72; P = 0.02]. Ferritin predicted high risk of endocrine dysfunction independently of confounding factors (HR:1.23; P < 0.0001). The intensification of chelation therapy led to an amelioration of hypothyroidism.

CONCLUSIONS

Ferritin represents a prognostic marker for βT patients and a predictive factor for progression to endocrine dysfunctions. Intensive chelation therapy allows the reversibility of hypothyroidism.

Effect of long-term transfusion therapy on the glycometabolic status and pancreatic Beta cell function in patients with Beta thalassemia major

BACKGROUND

Diabetes mellitus is a major complication of iron overload in patients with beta thalassemia major.

DESIGN

This is a descriptive study conducted in a Tertiary Care Teaching Hospital to analyze beta cell function and insulin resistance, and their relation to iron overload status in beta thalassemia major. Fasting glucose, two-hour post load glucose, fasting insulin, alanine amino transaminase (ALT), and ferritin were used as outcome measures. The homeostatic model assessment (HOMA model) was used to calculate the beta cell function and insulin resistance index.

RESULTS

Of the 30 cases, 20% had impaired fasting glucose, 3.3% had impaired glucose tolerance, and none had diabetes. Fasting glucose was not significant between the cases and controls (P = 0.113). Fasting insulin (P = 0.001), ferritin (P = 0.001), and ALT (P = 0.001) levels were significantly high in the cases. Insulin resistance index was significantly higher in the cases (P = 0.001) as also the beta cell function (P = 0.001). With increase in age and the number of units transfused there is a decline in beta cell function, fasting insulin, and insulin resistance after attaining the maximum level. This suggests that initial insulin resistance is followed by insulin depletion due to loss of beta cell function, leading to diabetes mellitus.

CONCLUSION

Impaired glucose tolerance (IGT) and insulin resistance precede the onset of insulin-dependent diabetes and adequate chelation therapy is essential for delaying the onset or for prevention of diabetes.

Glucose homeostasis in Egyptian children and adolescents with β-Thalassemia major: Relationship to oxidative stress

BACKGROUND

Oxidative stress in children with β-thalassemia may contribute to shortened life span of erythrocytes and endocrinal abnormalities.

AIM

This study was aimed to evaluate glucose homeostasis in Egyptian children and adolescents with β-thalassemia major and its relation to oxidative stress.

MATERIALS AND METHODS

Sixty children and adolescents with β-thalassemia major were studied in comparison to 30 healthy age and sex-matched subjects. Detailed medical history, thorough clinical examination, and laboratory assessment of oral glucose tolerance test (OGTT), serum ferritin, alanine transferase (ALT), fasting insulin levels, plasma malondialdehyde (MDA) as oxidant marker and serum total antioxidants capacity (TAC) were performed. Patients were divided into two groups according to the presence of abnormal OGTT.

RESULTS

The prevalence of diabetes was 5% (3 of 60) and impaired glucose tolerance test (IGT) was 8% (5 of 60). Fasting blood glucose, 2-hour post-load plasma glucose, serum ferritin, ALT, fasting insulin level, homeostatic model assessment for insulin resistance index (HOMA-IR) and MDA levels were significantly elevated while TAC level was significantly decreased in thalassemic patients compared with healthy controls (P < 0.001 for each). The difference was more evident in patients with abnormal OGTT than those with normal oral glucose tolerance (P < 0.001 for each). We also observed that thalassemic patients not receiving or on irregular chelation therapy had significantly higher fasting, 2-h post-load plasma glucose, serum ferritin, ALT, fasting insulin, HOMA-IR, oxidative stress markers OSI and MDA levels and significantly lower TAC compared with either those on regular chelation or controls. HOMA-IR was positively correlated with age, serum ferritin, ALT, MDA, and negatively correlated with TAC.

CONCLUSIONS

The development of abnormal glucose tolerance in Egyptian children and adolescents with β--thalassemia is associated with alteration in oxidant-antioxidant status and increase in insulin resistance.

RECOMMENDATION

1- Glucose tolerance tests, HOMA-IR, and MDA should be an integral part of the long-term follow-up of children and adolescents with β-thalassemia major. 2- Regular iron chelation and antioxidant therapy should be advised for thalassemic patients to improve glucose hemostasis.

The epidemiology of hepatitis C virus in Egypt: a systematic review and data synthesis

BACKGROUND

Egypt has the highest prevalence of hepatitis C virus (HCV) in the world, estimated nationally at 14.7%. Our study's objective was to delineate the evidence on the epidemiology of HCV infection among the different population groups in Egypt, and to draw analytical inferences about the nature of HCV transmission in this country.

METHODS

We conducted a systematic review of all data on HCV prevalence and incidence in Egypt following PRISMA guidelines. The main sources of data included PubMed and Embase databases. We also used a multivariate regression model to infer the temporal trend of HCV prevalence among the general population and high risk population in Egypt.

RESULTS

We identified 150 relevant records, four of which were incidence studies. HCV incidence ranged from 0.8 to 6.8 per 1,000 person-years. Overall, HCV prevalence among pregnant women ranged between 5-15%, among blood donors between 5-25%, and among other general population groups between 0-40%. HCV prevalence among multi-transfused patients ranged between 10-55%, among dialysis patients between 50-90%, and among other high risk populations between 10% and 85%. HCV prevalence varied widely among other clinical populations and populations at intermediate risk. Risk factors appear to be parenteral anti-schistosomal therapy, injections, transfusions, and surgical procedures, among others. Results of our time trend analysis suggest that there is no evidence of a statistically significant decline in HCV prevalence over time in both the general population (p-value: 0.215) and high risk population (p-value: 0.426).

CONCLUSIONS

Egypt is confronted with an HCV disease burden of historical proportions that distinguishes this nation from others. A massive HCV epidemic at the national level must have occurred with substantial transmission still ongoing today. HCV prevention in Egypt must become a national priority. Policymakers, and public health and medical care stakeholders need to introduce and implement further prevention measures targeting the routes of HCV transmission.

Relationship between beta-globin gene carrier state and insulin resistance

Objective

To assess the relationship between being beta globin gene carrier and developing insulin resistance.

Methods

This study was conducted on 164 subjects including 82 healthy ones and 82 patients with beta thalassemia minor (microcytosis (MCV <80 fl) and hypochromia (MCH <25 pg) and HbA2 ≥ 3.5% using HPLC). Fasting blood glucose (FBS) values of 100–125 mg/dl were considered as impaired fasting glucose, and above 125 mg/dl as diabetes mellitus. Two hours After 75 gram glucose load(GTT), blood sugar level of 140–199 mg/dl was considered as impaired glucose tolerance and above 199 mg/dl as diabetes mellitus. Insulin resistance was diagnosed based on homeostasis model assessment method (HOMA).

Results

According to FBS and BS2hPG values, the percentages of diabetes mellitus, pre diabetes, and normal glucose tolerance in case group was 8.5%, 9.8% and 81.7%, respectively. There was no case of diabetes mellitus in control group and 6.1% of this group were pre diabetic and 93.9% of them had normal glucose tolerance test (P = 0.02). Relative risk for diabetes mellitus and insulin resistance in the cases with minor thalassemia was 2 (95% CI: 1.8-2.5) and 2.02 (95% CI: 1.7-2.4), respectively.

Conclusion

The risk of developing diabetes and insulin resistance in patients with thalassemia minor is two times greater than the general population. Considering the high serum levels of CRP in these cases, the inflammation noted in liver cells could be considered as the underlying cause of insulin resistance, impaired glucose tolerance and diabetes in these patients.

Gradient-echo magnetic resonance imaging study of pancreatic iron overload in young Egyptian beta-thalassemia major patients and effect of splenectomy

BACKGROUND

Thalassemic patients suffer from diabetes mellitus secondary to hemosiderosis.

AIMS

The study aimed to evaluate pancreatic iron overload by T2*-weighted Gradient-echo magnetic resonance imaging (MRI) in young beta-thalassemia major patients and to correlate it with glucose disturbances, hepatic hemosiderosis, serum ferritin and splenectomy.

METHODS

Forty thalassemic patients (20 non diabetic, 10 diabetic, and 10 with impaired glucose tolerance) were recruited from Pediatric Hematology Clinic, in addition to 20 healthy controls. All patients underwent clinical assessment and laboratory investigations included complete blood count, liver function tests, serum ferritin and oral glucose tolerance test (OGTT). A T2*-weighted gradient-echo sequence MRI was performed with 1.5 T scanner and signal intensity ratio (SIR) of the liver and the pancreas to noise were calculated.

RESULTS

Significant reduction in signal intensity ratio (SIR) of the liver and the pancreas was shown in thalassemic patients compared to controls (P < 0.0001), Thalassemic patients with abnormal glucose tolerance; including diabetics and thalassemics with impaired glucose tolerance; displayed a higher degree of pancreatic and hepatic siderosis compared to thalassemics with normal glucose tolerance or controls (P < 0.001, P < 0.0001). Splenectomized thalassemic patients had significantly lower SIR of pancreas compared to non splenectomized patients (P < 0.05). A strong correlation was present between hepatic and pancreatic siderosis in studied patients (P < 0.001).

CONCLUSIONS

pancreatic siderosis can be detected by T2* gradient-echo MRI since childhood in thalassemic patients, and is more evident in patients with abnormal glucose tolerance. After splenectomy, iron deposition may be accelerated in the pancreas. Follow up of thalassemic patients using pancreatic MRI together with intensive chelation therapy may help to prevent the development of overt diabetes.

Growth and endocrine function in thalassemia major in childhood and adolescence

BACKGROUND

Thalassemia major is an inherited hemoglobin disorder characterized by chronic anemia and iron overload due to transfusion therapy and gastrointestinal absorption. Iron overload causes most of the associated mortality and morbidity and frequently involves the endocrine glands.

AIM

To review the most pertinent literature on the topic.

METHODS

One hundred and twenty-three papers were evaluated.

RESULTS

Disproportionate short stature is frequent and becomes more evident at puberty because of the lack of growth spurt. Later on, partial height recovery may occur. Long-term treatment with recombinant human GH seems ineffective to improve final height. Pubertal development is characterized by a clinical spectrum ranging from hypogonadism to a simple delay in starting and developing of puberty. Hormonal replacement is mandatory in cases of absent or arrested puberty. Pancreatic beta-cells function may be impaired during adolescence or later on. Its impairment ranges from hyperinsulinemia, secondary to insulin resistance, with normal glucose tolerance to beta-cells failure with insulin-dependent diabetes mellitus. Primary hypothyroidism may affect thalassemic patients from the second decade of life. The thyroid dysfunction may be reversible (if an intensive chelation therapy regimen is started in the precocious phase), stationary, or slowly progressive. Central hypothyroidism is less common and autoimmune thyroiditis absent.

CONCLUSION

Despite the improvement of the treatment, the involvement of the endocrine system still burdens the life of these patients. Further therapeutic improvement would reasonably reduce morbidity and, hopefully, mortality of thalassemic patients and make the endocrine disorders easier to treat.

Organ-specific hemosiderosis and functional correlation in Chinese patients with thalassemia intermedia and hemoglobin H disease

We performed MRI assessment in 37 adult Chinese patients with thalassemia intermedia and hemoglobin H disease. Despite abnormal ferritin and liver T2*, only 5% of patients had cardiac hemosiderosis. The two patients with reduced ejection fraction had normal cardiac T2*. Half of the cases showed pituitary and pancreatic iron loading. Subclinical endocrine abnormalities (HOMA, insulin growth factor) showed correlation with pancreatic, pituitary, and cardiac MRI values. Prospective data with serial functional and imaging monitoring is needed to verify the utility for chelation to improve cardiac and endocrine function in this group of patients.

A cross-sectional study of metabolic and endocrine complications in beta-thalassemia major

BACKGROUND AND OBJECTIVES

Iron overload is a major problem in patients with beta-thalassemia major, and it has many structural and metabolic consequences. The aim of this study was evaluation of endocrine disturbances in patients with beta-thalassemia major who were older than 10 years of age.

PATIENTS AND METHODS

In this cross-sectional study, investigators collected demographic data and medical histories, as well as menstrual history in females, from the medical records of 56 patients with beta-thalassemia major. Patients were examined to determine their pubertal status and the standard deviation score for height for evaluation of short stature. For evaluation of glucose tolerance, a fasting blood glucose and oral glucose tolerance test were performed. Evidence for diabetes mellitus was based on American Diabetes Association and World Health Organization criteria. Serum levels of calcium, phosphorous, thyroid-stimulating hormone, free thyroxin, luteinizing hormone and follicular-stimulating hormone, and estradiol in girls and testosterone in boys were measured.

RESULTS

The mean and standard deviation for age in the 56 patients (36 males and 20 females) was 15.62+/-4.44 years. Diabetes mellitus was present in 5 patients (8.9%), impaired fasting glucose was found in 16 patients (28.6%) and an impaired glucose tolerance test was found in 4 patients (7.1%). Short stature (standard deviation score <-2) was seen in 25 (70%) boys and 14 (73%) girls. Impaired puberty was found in 40 patients (71%). Hypocalcaemia and primary overt hypothyroidism were present in 23 (41%) and 9 patients (16%), respectively.

CONCLUSION

Despite therapy with deferoxamine to treat iron overload, the risk of secondary endocrine dysfunction remained high. Hypogonadism was one of the most frequent endocrine complications. Impaired glucose tolerance, short stature, hypocalcemia, subclinical and overt hypothyroidism are also frequent.

Age- and body mass index-dependent relationship between correction of iron deficiency anemia and insulin resistance in non-diabetic premenopausal women

BACKGROUND

No prospective studies have evaluated the effects of correction of iron deficiency anemia on insulin resistance in non-diabetic premenopausal women. We investigated this relationship in 54 non-diabetic premenopausal women with iron deficiency anemia.

SUBJECTS AND METHODS

All patients were treated with oral iron preparations. Insulin resistance was calculated with the Homeostasis Model Assessment formula. All patients were dichotomized by the median for age and BMI to assess how the relationship between iron deficiency anemia and insulin resistance was affected by age and BMI.

RESULTS

Although the fasting glucose levels did not change meaningfully, statistically significant decreases were found in fasting insulin levels following anemia treatment both in the younger age (<40 years) (P=0.040) women and in the low BMI (<27 kg/m2) (P=0.022) subgroups but not in the older age (>or=40 years) and the high BMI (>or=27 kg/m2) subgroups. Post-treatment fasting insulin levels were positively correlated both with BMI (r=0.386, P=0.004) and post-treatment hemoglobin levels (r=0.285, P=0.036). Regression analysis revealed that the factors affecting post-treatment insulin levels were BMI (P=0.001) and post-treatment hemoglobin levels (P=0.030).

CONCLUSION

Our results show that following the correction of iron deficiency anemia, insulin levels and HOMA scores decrease in younger and lean non-diabetic premenopausal women.

Evolution of OGTT in patients with beta-thalassaemia major in relation to chelation therapy

Glucose metabolism disturbances are frequently reported among patients with beta-thalassaemia major on conventional treatment consisted of regular blood transfusions and adequate chelation treatment. Aim of this study was to evaluate the evolution of oral glucose tolerance test (OGTT) in thalassaemic patients in relation to their chelation treatment. Data from two OGTTs performed with an interval of 2 years were studied retrospectively. Patients considered eligible for this study were those who maintained unchanged chelation treatment and did not receive any anti-diabetic agent during the last 2 years. Thirty-one patients (16 M and 15 F) were enrolled with a mean age of 23.73+/-4.23 years at the end of the study. Patients were divided into three groups concerning chelation treatment. First group was receiving deferoxamine (DFO) by an 8-hourly subcutaneous infusion five-six times a week, second group was chelated with deferiprone (DFP) at a daily dose of 75 mg/kg orally and the third group was receiving combined therapy with DFO (3 days/week) and DFP (daily). At the time of the first OGTT, 26 patients (84%) were found to have normal OGTT; three of them showed an impaired glucose tolerance during second test (one was chelated with DFP and two were receiving combined therapy). None of the five patients with impaired glucose metabolism during the first test became diabetic. On contrary, one patient receiving combined therapy managed to normalize his second OGTT. In contrast with the overall trend of a deteriorating glucose tolerance in the whole patient series, the group receiving combined therapy managed to increased beta-cell function index and decreased insulin resistance index, although not statistically significant when compared to other groups. Further studies are needed to support these preliminary results.

Reduced insulin secretion in normoglycaemic patients with beta-thalassaemia major

AIMS

To assess insulin sensitivity and secretion in the fasting state in regularly transfused patients with beta-thalassaemia major with normal glucose response during an oral glucose tolerance test and to estimate its possible relation to iron overload.

METHODS

We measured fasting glucose, insulin and C-peptide levels in 24 patients with beta-thalassaemia major and 18 control subjects matched for age and body mass index. Insulin sensitivity and insulin release index were calculated according to the homeostasis model assessment (HOMA). Correlations with age, body mass index and serum ferritin were also calculated.

RESULTS

Fasting glucose levels in patients were increased compared with control subjects (5.5 +/- 0.12 vs. 4.7 +/- 0.13 mmol/l, mean +/- SEM, P < 0.001). Pancreatic B-cell insulin secretion in the fasting state (estimated by SC(HOMA)) was lower in thalassaemic patients (SC(HOMA) 88.5 +/- 11.11 vs. 184.3 +/- 23.72 in control subjects, P < 0.001). Patients were then divided into those with impaired (IFG) and normal (NFG) fasting glucose. SC(HOMA) was higher in the patients with NFG compared with those with IFG patients (110.6 +/- 17.63 vs. 66.3 +/- 10.88, respectively, P < 0.05) but estimated insulin sensitivity (ISI(HOMA)) was similar. Plasma values of C-peptide correlated positively with ferritin (r = 0.42, P = 0.04) and SC(HOMA) (r = 0.45, P = 0.02) and negatively with ISI(HOMA) (r = -0.43, P = 0.03).

CONCLUSIONS

These results support the concept that impaired B-cell function, as reflected by a reduction in the insulin secretion index, is present in beta-thalassaemic patients with normoglycaemia before changes in oral glucose tolerance tests are apparent.

Carotid body dysfunction: The possible etiology of non-insulin dependent diabetes mellitus and essential hypertension

Carotid bodies are monitors of oxygen and glucose delivery to the brain. Faced with the threat of hypoxia or hypoglycemia carotid bodies initiate responses to counter the threat. General corrective action is to improve the perfusion by increasing the arterial blood pressure. Specific corrective actions are to stimulate ventilation to improve oxygen availability or to induce insulin resistance to raise blood glucose levels. Inappropriateness of response caused by misreading of hypoxia as hypoglycemia and hypoglycemia as hypoxia is observed experimentally and clinically. The response to all four types of hypoxia, namely, hypoxic, anemic, histotoxic and ischemic (or stagnant) hypoxia, is stimulation of ventilation and elevation of blood pressure. Ischemia produced by narrowing of the artery to the carotid body activates the carotid bodies. The activation produces hypertension, stimulation of ventilation and insulin resistance that manifests as non-insulin dependent diabetes mellitus. There is epidemiologic and necropsy evidence for the onset of atherosclerotic changes in childhood. Early atherosclerotic changes occurring in the region of carotid arteries and their bifurcation narrows the lumen of the arteries to the carotid bodies and produce hypo-perfusion of the carotid bodies. This ischemic hypoxia is a causative, or at least a permissive factor for hypertension and/or non-insulin dependent diabetes mellitus. It is suggested that neither non-insulin dependent diabetes mellitus causes hypertension nor hypertension causes diabetes mellitus, but both are caused by dysfunctional carotid bodies.