Growth and Endocrine Function in Tunisian Thalassemia Major Patients

Iron overload disorders: Growth and gonadal dysfunction in childhood and adolescence

Hemochromatosis (HC) is characterized by the progressive accumulation of iron in the body, resulting in organ damage. Endocrine complications are particularly common, especially when the condition manifests in childhood or adolescence, when HC can adversely affect linear growth or pubertal development, with significant repercussions on quality of life even into adulthood. Therefore, a timely and accurate diagnosis of these disorders is mandatory, but sometimes complex for hematologists without endocrinological support. This is a narrative review focused on puberty and growth disorders during infancy and adolescence aiming to offer guidance for diagnosis, treatment, and proper follow-up. Additionally, it aims to highlight gaps in the existing literature and emphasizes the importance of collaboration among specialists, which is essential in the era of precision medicine.

Clinical Complications and Their Management

The diversity of disease-related complications among patients with β-thalassemia is complicated by the wide spectrum of genotypes and clinical risk factors. The authors herein present the different complications seen in patients with β-thalassemia, the pathophysiology underlying these complications and their management.

Hypothyroidism in children with Hb E/β-thalassemia compared between those who received regular transfusion and those who underwent hematopoietic stem cell transplantation

The studies of hypothyroidism in children with transfusion-dependent hemoglobin E/β-thalassemia (TDT), especially in those who underwent hematopoietic stem cell transplantation (HSCT) are limited. We performed a longitudinal retrospective analysis of thyroid function test (TFT) results among TDT patients aged <25 years who received regular transfusion compared to those who underwent HSCT in Faculty of Medicine Siriraj hospital, Thailand during October 2003 to March 2019. Fifty patients (23 TDT, 27 HSCT) were included. The mean age at the last follow-up was 20.1 ± 2.8 vs. 14.5 ± 4.61 years, respectively. The median age at HSCT was 6 (range: 1.9-13.7) years. The prevalence of hypothyroidism among TDT and post-HSCT was 47.8% and 52.2%, respectively. No study patients showed symptoms or signs of hypothyroidism. Subclinical hypothyroidism was the most common type (63.6% of TDT, and 100% of post-HSCT). We found persistent hypothyroidism in 30.4% of TDT, and in 22.2% of post-HSCT. Thyroxine was given in 1 TDT patient with overt hypothyroidism, and in 3 of 6 post-HSCT patients with persistent subclinical hypothyroidism. The ex-thalassemia patients who underwent HSCT after the age of 10 years had a significantly higher risk of post-HSCT hypothyroidism compared to those who underwent HSCT at the age ≤10 years (hazard ratio: 12.01, 95% confidence interval: 1.65-87.41; p = 0.014). In conclusion, hypothyroidism was found to be common in both TDT and post-HSCT patients. Subclinical hypothyroidism without symptoms and signs was the most common type, and was diagnosed only by TFT screening. Long-term regular surveillance of TFT should be performed in both groups of patients.

Relationship between serum ferritin and growth status of pediatric transfusion dependent thalassemia

Background

Growth retardation is a long-term complication in pediatric transfusion-dependent thalassemias (TDTs), presented as short-stature and upper body segment shortening. The cause of this condition was chronic hypoxia, iron overload, endocrinopathy, inadequate transfusion, and iron chelation. We analyze the relationship between ferritin level and growth status of pediatric TDTs.

Methods

This was a cross-sectional study on pediatric TDTs aged 2-18 years old at Dr. Soetomo General Academic Hospital Surabaya, Indonesia conducted in 2020. They required blood transfusion every 2-4 weeks. We evaluated the ratio of upper/lower body segments, weight for age Z-score (WAZ), height for age Z-score (HAZ), and body mass index (BMI) Z-score, based on CDC growth chart as growth status parameters. Serum ferritin was checked every three months to determine iron overload and iron chelation (deferiprone, deferasirox and deferoxamine). We used Spearman correlation and Mann-Whitney U test to analyze between variables (α=0.05).

Results

We enrolled 15/29 males with median age 10.5 years. Serum Ferritin had negative correlation with the ratio of upper/lower body segments (rho=-0.552; P=0.002), but not for HAZ (rho=-0.078; P=0.694), WAZ (rho=-0.186; P=0.342), BMI Z-score (rho=-0.089; P=0.653) especially if serum ferritin was above 2500 µ/L. In deferiprone group (n=8), the WAZ (P=0.034) and BMI Z-score (P=0.031) were lower; but the ratio of upper/lower body segments was greater (P=0.039) than the deferasirox group.

Conclusion

Growth retardation was more visible in pediatric TDTs with high ferritin and in deferiprone group. The height and the ratio of upper/lower body segments of the body were more affected.

New Entity-Thalassemic Endocrine Disease: Major Beta-Thalassemia and Endocrine Involvement

Beta-thalassemia (BTH), a recessively inherited haemoglobin (Hb) disorder, causes iron overload (IO), extra-medullary haematopoiesis and bone marrow expansion with major clinical impact. The main objective of this review is to address endocrine components (including aspects of reproductive health as fertility potential and pregnancy outcome) in major beta-thalassemia patients, a complex panel known as thalassemic endocrine disease (TED). We included English, full-text articles based on PubMed research (January 2017–June 2022). TED includes hypogonadism (hypoGn), anomalies of GH/IGF1 axes with growth retardation, hypothyroidism (hypoT), hypoparathyroidism (hypoPT), glucose profile anomalies, adrenal insufficiency, reduced bone mineral density (BMD), and deterioration of microarchitecture with increased fracture risk (FR). The prevalence of each ED varies with population, criteria of definition, etc. At least one out of every three to four children below the age of 12 y have one ED. ED correlates with ferritin and poor compliance to therapy, but not all studies agree. Up to 86% of the adult population is affected by an ED. Age is a positive linear predictor for ED. Low IGF1 is found in 95% of the population with GH deficiency (GHD), but also in 93.6% of persons without GHD. HypoT is mostly pituitary-related; it is not clinically manifested in the majority of cases, hence the importance of TSH/FT4 screening. HypoT is found at any age, with the prevalence varying between 8.3% and 30%. Non-compliance to chelation increases the risk of hypoT, yet not all studies confirmed the correlation with chelation history (reversible hypoT under chelation is reported). The pitfalls of TSH interpretation due to hypophyseal IO should be taken into consideration. HypoPT prevalence varies from 6.66% (below the age of 12) to a maximum of 40% (depending on the study). Serum ferritin might act as a stimulator of FGF23. Associated hypocalcaemia transitions from asymptomatic to severe manifestations. HypoPT is mostly found in association with growth retardation and hypoGn. TED-associated adrenal dysfunction is typically mild; an index of suspicion should be considered due to potential life-threatening complications. Periodic check-up by ACTH stimulation test is advised. Adrenal insufficiency/hypocortisolism status is the rarest ED (but some reported a prevalence of up to one third of patients). Significantly, many studies did not routinely perform a dynamic test. Atypical EM sites might be found in adrenals, mimicking an incidentaloma. Between 7.5–10% of children with major BTH have DM; screening starts by the age of 10, and ferritin correlated with glycaemia. Larger studies found DM in up to 34%of cases. Many studies do not take into consideration IGF, IGT, or do not routinely include OGTT. Glucose anomalies are time dependent. Emerging new markers represent promising alternatives, such as insulin secretion-sensitivity index-2. The pitfalls of glucose profile interpretation include the levels of HbA1c and the particular risk of gestational DM. Thalassemia bone disease (TBD) is related to hypoGn-related osteoporosis, renal function anomalies, DM, GHD, malnutrition, chronic hypoxia-induced calcium malabsorption, and transplant-associated protocols. Low BMD was identified in both paediatric and adult population; the prevalence of osteoporosis/TBD in major BTH patients varies; the highest rate is 40–72% depending on age, studied parameters, DXA evaluation and corrections, and screening thoracic–lumbar spine X-ray. Lower TBS and abnormal dynamics of bone turnover markers are reported. The largest cohorts on transfusion-dependent BTH identified the prevalence of hypoGn to be between 44.5% and 82%. Ferritin positively correlates with pubertal delay, and negatively with pituitary volume. Some authors appreciate hypoGn as the most frequent ED below the age of 15. Long-term untreated hypoGn induces a high cardiovascular risk and increased FR. Hormonal replacement therapy is necessary in addition to specific BTH therapy. Infertility underlines TED-related hormonal elements (primary and secondary hypoGn) and IO-induced gonadal toxicity. Males with BTH are at risk of infertility due to germ cell loss. IO induces an excessive amount of free radicals which impair the quality of sperm, iron being a local catalyser of ROS. Adequate chelation might improve fertility issues. Due to the advances in current therapies, the reproductive health of females with major BTH is improving; a low level of statistical significance reflects the pregnancy status in major BTH (limited data on spontaneous pregnancies and growing evidence of the induction of ovulation/assisted reproductive techniques). Pregnancy outcome also depends on TED approach, including factors such as DM control, adequate replacement of hypoT and hypoPT, and vitamin D supplementation for bone health. Asymptomatic TED elements such as subclinical hypothyroidism or IFG/IGT might become overt during pregnancy. Endocrine glands are particularly sensitive to iron deposits, hence TED includes a complicated puzzle of EDs which massively impacts on the overall picture, including the quality of life in major BTH. The BTH prognostic has registered progress in the last decades due to modern therapy, but the medical and social burden remains elevated. Genetic counselling represents a major step in approaching TH individuals, including as part of the pre-conception assessment. A multidisciplinary surveillance team is mandatory.

Differences in longitudinal growth patterns of children and adolescents with transfusion-dependent hemoglobin E/β-thalassemia and those achieving successful hematopoietic stem-cell transplantation

BACKGROUND

Short stature is a very common endocrinopathy among children with transfusion-dependent (TD) thalassemia. Hematopoietic stem-cell transplantation (HSCT) is the only effective curative treatment for TD thalassemia. This study aimed to identify and compare the longitudinal growth patterns of children with TD hemoglobin E (Hb E)/β-thalassemia against those of children successfully undergoing HSCT.

MATERIALS AND METHODS

We reviewed the medical records of 39 patients with TD Hb E/β-thalassemia receiving regular blood transfusions, and 39 post-HSCT patients. Longitudinal weight and height Z-scores at each year of age were recorded for TD patients, and longitudinal weight and height Z-scores at each year before and after HSCT were obtained for post-HSCT patients.

RESULTS

The mean weight and height Z-scores of TD patients decreased gradually and were lowest at age 13. However, post-HSCT subjects saw significant improvement in their mean weight and height Z-scores 6 and 3 years after HSCT, respectively, relative to pre-HSCT baseline values.

CONCLUSIONS

Longitudinal growth patterns differed between patients successfully undergoing HSCT and children and adolescents with TD Hb E/β-thalassemia. HSCT significantly improved height outcomes of children and adolescents with TD Hb E/β-thalassemia.

Insulin-Like Growth Factor -1 (IGF-1) and Glucose Dysregulation in Young Adult Patients with β-Thalassemia Major: Causality or Potential Link?

BACKGROUND

Insulin-like growth factor-1 (IGF-1) has been shown to lower blood glucose through stimulating glucose transport to fat and muscle and inhibiting hepatic glucose output. Although previous cross-sectional reports reported an association between low circulating concentrations of IGF-1 and glucose dysregulation (GD), its role is still debated.

AIMS OF STUDY

The present retrospective study was designed to assess the circulating IGF-1 levels in β-thalassemia major (β -TM) patients with normal oral glucose tolerance test (NGT-OGTT) and (GD) referred for an endocrine evaluation to explore the potential link between low IGF-1 and GD.

STUDY DESIGN AND METHODS

Our study included 34 young adult patients with β-TM; 12 patients with NGT after OGTT, 7 with impaired glucose tolerance (IGT), 9 with impaired fasting glucose (IFG) plus IGT, and 6 patients with β-TM-related diabetes mellitus (β-TM- DM).

RESULTS

Twenty-two β-TM patients with GD or β-TM- DM and 1 patient with NGT had IGF-1 levels below the 2.5th percentile. Correlation of IGF-1 with fasting plasma glucose, HOMA-IR (homeostatic model assessment for insulin resistance) and OGIS (oral glucose insulin sensitivity) was found. Moreover, a negative correlation was documented between ALT and the Insulinogenic Index (IGI) and a positive correlation between serum ferritin and PG 2-h after OGTT.

CONCLUSION

This study reports for the first time an association between low levels of IGF-1 and GD in β-TM patients. Despite some limitations, our study can serve to generate proposals for more convenient and efficient methods to identify and treat early GD in patients with β-TM, and to conduct more extensive studies. www.actabiomedica.it).

The Prevalence of Hypothyroidism among Patients With β-Thalassemia: A Systematic Review and Meta-Analysis of Cross-Sectional Studies

As a cause of chronic blood transfusions, iron overload is an important issue in β-thalassemia (β-thal) patients that leads to multiple organ dysfunctions. This is an updated meta-analysis conducted to summarize the existing evidence of the prevalence of hypothyroidism (HT) among patients with transfusion-dependent (TDT) and non transfusion-dependent β-thal (NTDT) and for the first time we meta-analyzed the relationship between ferritin level and HT. This systematic review and meta-analysis were done according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. We searched databases including Web of Science (ISI), Scopus, PubMed, Embase, and Scholar. The quality of the included studies was assessed based on the Newcastle-Ottawa scale (NOS) checklist. Meta-analysis was done using Stata statistical software. The pooled prevalence of total HT, subclinical HT, and overt HT among β-thal patients was 13.25 [95% confidence interval (95% CI): 10.29-16.21; 11.84, 95% CI: 8.43-15.25 and 12.46, 95% CI: 1.05-23.87], respectively. The prevalence of total HT was 16.22% (95% CI: 12.36-20.08) in TDT and 7.22% (95% CI: 3.66-10.78) in NTDT patients. Serum ferritin (SF) levels were significantly lower in euthyroid compared to hypothyroid patients [standard mean difference (SMD) -2.15 (95% CI: -3.08, -1.21, p value <0.001]. The prevalence of HT was higher in TDT compared to NTDT patients. Moreover, our results showed a significant association of high serum ferritin (SF) levels with hypothyroidism in β-thal patients. Both of these findings highlight the importance of prevention measures and timely diagnosis and management of iron overload in β-thal patients.

A Systematic Review and Meta-Analysis of Stature Growth Complications in β-thalassemia Major Patients

Background

Blood transfusion is a traditional treatment for β-thalassemia (β-thal) that improves the patients' anemia and lifespan, but it may lead to iron overload in parenchymal tissue organs and endocrine glands that cause their dysfunctions as the iron regulatory system can't excrete excess iron from the bloodstream.

Objective

To evaluate the prevalence of iron-related complications (short stature, growth retardation, and growth hormone deficiency) in β-thalassemia major (βTM) patients.

Methods

We performed an electronic search in PubMed, Scopus, and Web of Sciences to evaluate the prevalence of growth hormone impairment in β-thalassemia major (βTM) patients worldwide. Qualities of eligible studies were assessed by the Joanna Briggs Institute checklist for the prevalence study. We used Comprehensive Meta-Analysis (Version 2) to calculate the event rate with 95% CIs, using a random-effects model for all analyses.

Findings

Seventy-four studies were included from five continents between 1978 and 2019; 70.27% (Asia), 16.21% (Europe), 6.75% (Africa), 2.70% (America), 1.35% (Oceania), and 2.70% (Multicenter). The overall mean age of the participants was about 14 years. The pooled prevalence of short stature (ST) was 48.9% (95% CI 35.3-62.6) and in male was higher than female (61.9%, 95% CI 53.4-69.7 vs. 50.9%, CI 41.8-59.9). The pooled prevalence of growth retardation (GR) was 41.1% and in male was higher than in female (51.6%, 95% CI 17.8-84 vs. 33.1%, CI 9.4-70.2). The pooled prevalence of growth hormone deficiency (GHD) was 26.6% (95% CI 16-40.8).

Conclusion

Our study revealed that near half of thalassemia patients suffer from growth impairments. However, regular evaluation of serum ferritin levels, close monitoring in a proper institute, suitable and acceptable treatment methods besides regular chelation therapy could significantly reduce the patients' complications.

Endocrinopathies complicating transfusion-dependent hemoglobinopathy

OBJECTIVES

To investigate the prevalence and significance of different endocrinopathies in children and adolescents with transfusion-dependent thalassemia and sickle-cell anemia.

METHODS

This is a descriptive, retrospective study between January 2010 and July 2018 in King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Data was collected through reviewing electronic hospital medical records then filling out data collection sheets and was interpreted through the IBM SPSS Statistics for Windows version 20.0 (IBM Corp, Armonk, NY, USA). Results: The total sample size was 119 patients, gender equality was almost achieved with 55.5% being male and 45.5% being female. The most common endocrinopathies were identified in the following order of short stature (39.5%), diabetes mellitus (29.4%), hypogonadism (12.6%), osteopenia (12.6%), osteoporosis (9.2%), hypothyroidism (9.2%), hypocortisolism (3.4%), and hypoparathyroidism (2.5%). All of which were statistically significant in their relationship to hemoglobinopathies with the exception of osteopenia and osteoporosis. Hypogonadism and hypocortisolism were found to be statistically significant in their relationship to a positive history of splenectomy at p=0.026 and p=0.012. Short stature was found to be statistically significant in its relationship to the male gender with a p=0.001. Conclusion: Endocrinopathy is a frequent complication of hemoglobinopathies, for which the most common were found to be short stature, diabetes mellitus,  and low bone mineral density.

Prevalence of endocrine disorders and their associated factors in transfusion-dependent thalassemia patients: a historical cohort study in Southern Iran

PURPOSE

Transfusion-dependent beta-thalassemia (TDT) patients suffer from various endocrinopathies. The main contributing factor associated with these complications is iron overload, secondary to frequent blood transfusions. To improve patients' quality of life, we evaluated the prevalence of endocrine disorders while considering the associated factors for further assessment.

METHODS

Seven hundred thirteen transfusion-dependent thalassemia patients with age range 10-62 years were enrolled in this study. Serum calcium, phosphorous, fast blood sugar, ferritin, 25-OH vitamin D, free thyroxin, thyroid-stimulating hormone and parathyroid hormone were assessed. Bone mineral density was measured by dual-energy X-ray absorptiometry.

RESULTS

In total, 86.8% of the TDT patients suffered from at least one endocrinopathy. The prevalence of endocrinopathies in descending order of frequency was low bone mass (72.6%), hypogonadism (44.5%), diabetes mellitus (15.9%), hypoparathyroidism (13.2%), and hypothyroidism (10.7%). Age, body mass index and splenectomy were significantly associated with most of the endocrine disorders.

CONCLUSION

Endocrine complications are frequently observed in TDT patients. Splenectomy is a major risk factor and should be generally avoided unless it is highly indicated. Periodic surveillance of endocrine function and proper management of iron overload are advised.