Glucose intolerance in thalassemia major is related to insulin resistance and hepatic dysfunction

The clinical characteristics, biochemical parameters and insulin response to oral glucose tolerance test (OGTT) in 25 transfusion dependent β-thalassemia (TDT) patients recently diagnosed with diabetes mellitus (DM)

BACKGROUND

Patients with transfusion dependent β-thalassemia (TDT) are at high risk for developing, over the time, a form of diabetes distinct from type 1 and type 2 diabetes, but with similarities to both.

AIMS OF STUDY

The aim of this study is to describe the clinical and laboratory data, and the insulin secretion and sensitivity, in TDT patients , recently diagnosed with diabetes mellitus (DM).

MATERIALS AND METHODS

The medical records of 25 TDT patients with DM, diagnosed by standardized oral glucose tolerance test (OGTT) and insulin secretion, were analysed; data were compared to TDT patients without diabetes and to a group of healthy subjects. Natural history of glucometabolic status before the diagnosis of DM was also reviewed.

RESULTS

On average, the TDT patients with DM were younger compared to TDT patients without diabetes. The mean age at diagnosis of  DM in female and male TDT patients was 24.0 ± 7.1 years and 31.9 ± 5.6 years, respectively (P: 0.007). Serum alanine aminotransferase values, basal insulin levels and prevalence of hypogonadism were consistently higher in TDT patients with DM compared to those without diabetes. Decreased insulin secretion and increased insulin resistance was observed in patients with DM.

CONCLUSION

The natural history of glucometabolic status in TDT patients is characterized by a deterioration of glucose tolerance over time. Iron overload and liver dysfuction are the main factors responsible for glucose disturbances (GD) in TDT patients. The therapeutic approach must be individualized and followed by a multidisciplinary team.

Glucose Homeostasis and Effect of Chelation on β Cell Function in Children With β-Thalassemia Major

OBJECTIVE

To assess the prevalence of impaired glucose tolerance in β-thalassemia major and correlate it with chelation therapy.

MATERIALS AND METHODS

Sixty-seven subjects with β-thalassemia major, aged 1 to 20 years, were enrolled in our prospective cohort. Clinical details were recorded. Baseline oral glucose tolerance test, serum insulin, C peptide, and insulin resistance were measured. The biochemical profile was repeated after 6 months.

RESULTS

The mean age of subjects was 7.43±4.48 years. Eight (11.9%) subjects had impaired fasting glucose, 7 (10.4%) had impaired glucose tolerance, and 1 (1.4%) subject had diabetes at baseline. Subjects with abnormal glucose profile had longer disease duration (95% confidence interval [CI] of difference=-6.64 to -0.68; P=0.019) and higher fasting blood glucose (95% CI of difference=-32.1 to -10.5; P=0.001) and serum ferritin (95% CI of difference=-219.8 to -3.4; P=0.001) than normoglycemic subjects. Insulin resistance and serum ferritin showed significant increase at 6 months (P<0.001 and P=0.001, respectively). Patients on deferiprone alone significantly improved glucose homeostasis on follow-up than those on desferrioxamine or combination therapy of desferrioxamine and deferiprone (P<0.05).

CONCLUSIONS

Prolonged disease duration and higher serum ferritin adversely affects glucose homeostasis in thalassemic children. Deferiprone was the most effective chelator to improve glucose homeostasis in chronically transfused thalassemics.

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.

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.

Glucose metabolism in the Belgrade rat, a model of iron-loading anemia

The iron-diabetes hypothesis proposes an association between iron overload and glucose metabolism that is supported by a number of epidemiological studies. The prevalence of type 2 diabetes in patients with hereditary hemochromatosis and iron-loading thalassemia supports this hypothesis. The Belgrade rat carries a mutation in the iron transporter divalent metal transporter 1 (DMT1) resulting in iron-loading anemia. In this study, we characterized the glycometabolic status of the Belgrade rat. Belgrade rats displayed normal glycemic control. Insulin signaling and secretion were not impaired, and pancreatic tissue did not incur damage despite high levels of nonheme iron. These findings suggest that loss of DMT1 protects against oxidative damage to the pancreas and helps to maintain insulin sensitivity despite iron overload. Belgrade rats had lower body weight but increased food consumption compared with heterozygous littermates. The unexpected energy balance was associated with increased urinary glucose output. Increased urinary excretion of electrolytes, including iron, was also observed. Histopathological evidence suggests that altered renal function is secondary to changes in kidney morphology, including glomerulosclerosis. Thus, loss of DMT1 appears to protect the pancreas from injury but damages the integrity of kidney structure and function.

Pancreatic iron and glucose dysregulation in thalassemia major

Pancreatic iron overload and diabetes mellitus (DM) are common in thalassemia major patients. However, the relationship between iron stores and glucose disturbances is not well defined. We used a frequently sampled oral glucose tolerance test (OGTT), coupled with mathematical modeling, and magnetic resonance imaging (MRI) to examine the impact of pancreatic, cardiac, and hepatic iron overload on glucose regulation in 59 patients with thalassemia major. According to OGTT results, 11 patients had DM, 12 had impaired glucose tolerance (IGT), 8 had isolated impaired fasting glucose (IFG), and 28 patients had normal glucose tolerance (NGT). Patients with DM had significantly impaired insulin sensitivity and insulin release. Insulin resistance was most strongly associated with markers of inflammation and somatic iron overload, while disposition index (DI) (a measure of beta cell function) was most strongly correlated with pancreas R2*. Patients with DM and IGT had significantly worse DI than those with NGT or IFG, suggesting significant beta cell toxicity. One-third of patients having elevated pancreas R2* had normal glucose regulation (preclinical iron burden), but these patients were younger and had lower hepatic iron burdens. Our study indicates that pancreatic iron is the strongest predictor of beta cell toxicity, but total body iron burden, age, and body habitus also influence glucose regulation. We also demonstrate that MRI and fasting glucose/insulin are complementary screening tools, reducing the need for oral glucose tolerance testing, and identify high-risk patients before irreversible pancreatic damage.

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.

Insulin-related metabolism following hematopoietic stem cell transplantation in childhood

OBJECTIVES

To assess insulin-related metabolism following hematopoietic stem cell transplantation (HSCT) in childhood.

STUDY DESIGN

Thirty-four patients who underwent HSCT were compared with 21 patients with similar diseases who were not transplanted. Median follow-up was 3.6 yr after HSCT. Anthropometric parameters, fasting plasma glucose and insulin levels, hemoglobin A(1c) (HbA(1c)) and lipid profile were measured and compared.

RESULTS

HbA(1c) was significantly higher (p = 0.001) in the study group. Two (5.8%) patients in the study group developed type 2 diabetes mellitus. Among thalassemic patients, significantly lower insulin resistance indices (p = 0.05) and fasting plasma insulin levels (p = 0.033) were found in the study group compared with the control group.

CONCLUSIONS

Attentive follow-up of insulin-related metabolism following HSCT in children is needed. The significance of the higher HbA1c values in the study group remains to be evaluated in a larger cohort of patients.

Evaluation of glucose homeostasis in transfusion-dependent thalassemic patients

Diabetes is an important problem encountered in thalassemic patients. The severity and type of glucose disturbances vary greatly in different studies. Also the pathogenesis seems to be complex; either insulin deficiency or insulin resistance may mediate the glucose disturbances. In a group of thalassemic patients glucose homeostasis was evaluated. Diabetes prevalence was 1.8%. Forty patients were investigated both with an oral glucose tolerance test and first-phase insulin response. Three patients had impaired fasting glucose, 1 patient had impaired glucose tolerance, and 2 patients had hyperinsulinism. Nineteen of 40 patients who were tested had low first-phase insulin response (47.5%) with below 10th centile. Age, BMI, height SDS, age at diagnosis, age at first blood transfusion, number of blood transfusions in a year, percentage of elevated liver enzyme, and hemoglobin and ferritin levels were not different between patients with low first-phase insulin response to patients with normal first-phase insulin response. Four patients are HCV infected, and only 1 of them had low first-phase insulin response. The study group showed a high rate of impairement in insulin secretion by first-phase insulin response to glucose overload, despite the low rate of insulin resistance. Defect of insulin secretion in thalassemic patients may develop earlier than insulin resistance, and then be accompanied by insulin resistance. Increasing insulin resistance with age and the occurrence of additional factors could lead to detoriation of glucose metabolism.

Prevalence of impaired glucose metabolism in beta-thalassemic children receiving hypertransfusions with a suboptimal dosage of iron-chelating therapy

A cross-sectional study of impaired glucose metabolism was carried out in 48 beta-thalassemic patients receiving hypertransfusions. An oral glucose tolerance test (OGTT) was performed using the method and criteria of the American Diabetes Association (ADA). Diabetes mellitus was diagnosed in two patients, and impaired glucose tolerance was found in four patients, giving a prevalence of impaired glucose metabolism of 12.5% in our patient population. The significant clinical characteristics associated with the diagnosis of impaired glucose metabolism were wasting (-2.15/-0.86 SDS, p = 0.025), stunting (-2.69/-1.22 SDS, p = 0.03), higher ferritin levels (8679/4710 microg/L, p = 0.005), splenectomy (50/9.5%, p = 0.012), and lower area under curve (AUC) of insulin secretion after OGTT (40.0/77.7, p = 0.002). The significant decrease of AUC insulin in thalassemic patients with an impaired glucose tolerance test suggests that the pathogenesis may originate from pancreatic beta-cell damage rather than from insulin resistance. In conclusion, the prevalence of impaired glucose tolerance in our population of thalassemic patients receiving hypertransfusions with suboptimal iron chelating therapy was 12.5%. The clinical characteristics of thalassemic patients who developed impaired glucose tolerance were wasting, stunting, higher ferritin levels, splenectomy, and lower AUC insulin.

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.

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.

Effect of enhanced iron chelation therapy on glucose metabolism in patients with beta-thalassaemia major

Recently introduced chelation regimens that combine deferoxamine (DFO) and deferiprone have been shown to have greater efficacy in promoting iron excretion than either chelator alone and have been associated with rapid reduction of the iron load in the heart and liver, and with reversal of cardiac dysfunction. It is unclear whether this combined therapy could be associated with a reduction in iron load or decline in the severity of iron-induced endocrinopathies. Starting in January 2001, 42 patients with beta-thalassaemia major, previously maintained on subcutaneous DFO only, were switched to combined treatment with DFO and deferiprone. The primary endpoint was to investigate the effects of this therapy on the glucose metabolism characteristics of this population. Combination therapy markedly decreased ferritin levels (638 +/- 1345 vs. 2991 +/- 2093 microg/l, P < 0.001). Glucose responses were improved at all times during an oral glucose tolerance test, particularly in patients in early stages of glucose intolerance. Glucose quantitative secretion also decreased significantly with combined therapy, while no significant change occurred in insulin levels in any group. Insulin secretion, according to the homeostasis assessment model, markedly increased in all groups, while overall reduction in insulin sensitivity did not reach statistical significance. This study showed that the combination of DFO and deferiprone was associated with an improvement in liver iron deposition and glucose intolerance.

A relationship between serum ferritin and the insulin resistance syndrome is present in non-diabetic women but not in non-diabetic men

BACKGROUND

Previous studies have suggested that serum ferritin is one of the components of the insulin resistance syndrome in Caucasians. Because serum ferritin levels differ significantly between men and women, variation in the role of ferritin in insulin resistance between the sexes, particularly in Asian populations, is still unknown.

OBJECTIVE

To examine whether the association between serum ferritin and insulin resistance differs between men and women in randomly selected non-diabetic Chinese subjects.

DESIGN

A retrospective study.

PATIENTS

Four hundred and seventeen non-diabetic Chinese subjects (140 men and 277 women) were studied.

MEASUREMENTS

Fasting plasma glucose, insulin, lipoproteins and serum ferritin concentrations, as well as plasma glucose and insulin responses to a 75-g oral glucose test (n = 219), were determined.

RESULTS

Fasting serum ferritin concentrations (mean +/- SEM) were significantly higher in men than in women (504 +/- 33 vs. 242 +/- 18 pmol/l, P < 0.001). In women, fasting serum ferritin concentrations correlated significantly with age, body mass index (BMI), amount of body fat, fasting plasma glucose, insulin, cholesterol, triglyceride concentrations, glucose response to an oral glucose load, and homeostasis model assessment (HOMA) of insulin resistance but not with blood pressure, high density lipoprotein (HDL) cholesterol levels and insulin response to oral glucose. On the contrary, none of the above anthropometric and metabolic variables was related to fasting serum ferritin levels in men. HOMA insulin resistance increased progressively across three different tertiles for measured serum ferritin concentrations in women (P < 0.003). In men, HOMA insulin resistance levels were not different among three differing measured serum ferritin levels (P = 0.424). Adjustment for age, BMI and menopause status did not change the significant relationship between HOMA insulin resistance and serum ferritin in women.

CONCLUSIONS

We observed that a relationship between serum ferritin levels and insulin resistance exists in women but not in men. This sexual dimorphism merits further investigation.

Insulin sensitivity and beta-cell secretion in thalassaemia major with secondary haemochromatosis: assessment by oral glucose tolerance test

Diabetes mellitus in patients with thalassaemia major is caused by secondary haemochromatosis due to transfusional iron overload. The pathogenetic mechanisms leading from siderosis to diabetes are still poorly understood. This study aimed at assessing the influence of insulin resistance and insulin deficiency on that process. Glucose, insulin and C-peptide levels during oral glucose tolerance tests (OGTT) from 36 thalassaemic patients with normal ( n=23), impaired ( n=6), or diabetic glucose tolerance ( n=7) and 32 control subjects were examined. Insulin secretion and insulin sensitivity were assessed by established calculated indices. Fasting, 2h and integrated glucose concentration were significantly increased in thalassaemic patients with normal glucose tolerance compared to controls (5.01/4.59 mmol/l, 6.33/5.17 mmol/l, and 844.2/739.3 mmol/l per min, respectively; all P<0.03). Patients with impaired glucose tolerance presented hyperinsulinaemia and delayed peak insulin during OGTT. The C-peptide/insulin ratio was decreased in patients with abnormal glucose tolerance compared to controls (5.85/7.33 x 10(3)pmol/l per min, P<0.03). It was negatively correlated with age in patients ( r=-0.45, P<0.01), but positively in controls ( r=0.43, P<0.03). Insulin sensitivity was significantly reduced in patients with impaired glucose tolerance or diabetes compared to controls. In addition, a significant decrease in patients with normal glucose tolerance was shown by two insulin sensitivity indices (all P<0.05). In thalassaemia patients, insulin sensitivity was negatively correlated with age. Insulin secretion capacity according to the homeostasis assessment model was significantly reduced in patient groups compared to controls (Kruskal-Wallis-test, P<0.004).

CONCLUSION

Insulin resistance is of central importance for the development of diabetes mellitus in patients with secondary haemochromatosis. An additional early defect in beta-cell secretion cannot be excluded.

Three-year prospective evaluation of glucose tolerance, beta-cell function and peripheral insulin sensitivity in non-diabetic patients with thalassemia major

The aim of this prospective study was to evaluate the evolution of glucose tolerance (GT), insulin secretion and peripheral insulin sensitivity during a 3-yr follow-up in a homogenous population consisting of fourteen non-diabetic adults with thalassemia major (TM). All the patients underwent 2 OGTTs with a 3-yr interval and random measurements of fasting glycemia during the entire follow-up. At the time of both OGTTs, peripheral insulin sensitivity was assessed by both homeostatic model assessment (HOMA) index and a novel index derived from the OGTT. At the second OGTT patients exhibited both significantly higher fasting glucose concentrations and enhanced glycemic responses, with greater average glucose areas. GT deterioration over time was accompanied by a reduction of insulin sensitivity, with no concomitant change of insulin secretion. No patient developed diabetes mellitus (DM) during follow-up. To conclude, the natural history of glycometabolic status in TM adults seems to be characterized by a GT deterioration over time, which may probably reflect an increase of insulin resistance. GT deterioration is more evident in patients with the highest responses to the 1st OGTT and particularly in those with pre-existing impaired GT.

Endocrine complications of thalassemia

Growth, sexual development, fertility, bone mineral density, diabetes mellitus, hypothyroidism, hypoparathyroidism, and hypoadrenalism are the main issues to be addressed in the long-term follow-up of patients with thalassemia. During childhood, growth may be affected by anemia, and other potential endocrine complications. Puberty is the stage of the maximal growth insult. Beta thalassemia is associated with bone abnormalities characterized by bone marrow expansion of the medullary cavity, and osteopenia with cortical thickening and trabecular coarsening. Good nutrition with adequate vitamins and trace elements intake, along with calcium and vitamin D supplementation, can increase bone density and prevent bone loss. Endocrine abnormalities should be monitored carefully and a thorough endocrine evaluation should be carried out yearly in every patients to detect subclinical endocrinopaties.

Ultrasonography of the pancreas, as a function index, in children with beta-thalassemia

Increased echogenicity of the pancreas, due to hemosiderosis, is a frequent laboratory finding in children and adolescents with beta-thalassemia. The aim of this study was to investigate whether increased echogenicity of the pancreas is associated with dysfunction. The ultrasonic image of the pancreas was examined in 34 children aged 12+/-3.8 years old and was compared to the endocrine and exocrine functioning of the gland. Oral glucose tolerance test (OGTT) was performed with simultaneous measurement of insulin and serum trypsin. Twenty-six of the 34 patients (76.5%) presented increased echogenicity, while 8 (23.5%) had a normal ultrasonic pancreatic image. 77% of the patients with increased echogenicity had abnormal OGTT, 46%, with subnormal or increased insulin values, and 32.5% manifested low levels of trypsin. Among the patients with normal ultrasound, 25% had abnormal OGTT and 37.5% abnormal insulin values. Statistical analysis with Student's t-test revealed that patients with increased echogenicity had significantly higher glucose values on OGTT at 60: 7.6 +/- 1.8 mmol/l (137.3 +/- 33.7 mg/dl) as compared to the patients with normal ultrasound: 6.1 +/- 1.2 mmol/l (110.75 +/- 21.72 mg/dl) (p<0.05). Insulin values were significantly affected at 30, 60, and 90 min: 570+/-301, 332+/-156, 294+/-158 pmol/l (79.54 +/- 42, 46.4 +/- 21.8, 41.04 +/- 22 mU/l) respectively in patients with increased echogenicity in comparison to those with normal ultrasonographic image of the gland: 301 +/- 170, 192 +/- 52, 135 +/- 63 pmol/l (42 +/- 23.7, 26.85 +/- 7.36, 18.9 +/- 8.8 mU/l) (p<0.05). No statistical significance was observed between the two groups regarding trypsin levels, even though abnormal values were observed in more children with increased echogenicity than in patients with a normal ultrasound. The above findings confirm that increased echogenicity of the pancreas is associated with disturbance of its function. This simple imaging method could be used as a rough early index of detection of an increased risk for developing diabetes mellitus in patients with beta-thalassemia.