Bone Mineral Density and Vitamin D Receptor Genetic Variants in Egyptian Children with Beta Thalassemia Major on Vitamin D Supplementation

Endocrinopathies in Hemoglobinopathies: What Is the Role of Iron?

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

Bone mineral density in primarily preadolescent children with hemoglobin E/β-thalassemia with different severities and transfusion requirements

BACKGROUND

Children with β-thalassemia major and β-thalassemia intermedia frequently have low bone mass. However, studies of bone mineral density (BMD) in children with transfusion-dependent (TD) or non-transfusion-dependent (NTD) hemoglobin (Hb) E/β-thalassemia are scarce.

OBJECTIVES

To determine the prevalence of low bone mass among mostly preadolescent children with NTD and TD Hb E/β thalassemia and the related factors.

METHODS

We investigated the BMD of the lumbar spine (LSBMD) and total body (TBBMD), measured by dual-energy X-ray absorptiometry, of 59 children with NTD Hb E/β-thalassemia and 50 with TD Hb E/β-thalassemia.

RESULTS

The median age of the patients was 10.4 (6.2-13.5) years in the NTD group and 10.3 (5.9-14.1) years in the TD group. These children had a relatively low prevalence of low bone mass (NTD: 1.7%-10.2%; TD: 4%-14%). The values varied with the bone site measured and the BMD size-adjustment method used (height age vs. bone age). The NTD group had significantly lower TBBMD Z-scores (adjusted for height age) than the TD group. The proportion of patients with low lumbar spine bone mass (adjusted for bone age) was significantly higher for the TD group than for the NTD group.

CONCLUSIONS

Our study demonstrates that most children with either disease had normal BMD. Patients with the NTD form had a lower TBBMD than those with the TD form. Low bone mass affected the lumbar spine of patients with TD Hb E/β-thalassemia more than those with the NTD form.

Identification of osteopenia and osteoporotic changes in pediatric thalassemia patients at thalassemia center, Misan city, Iraq; An intervention study

Background: Thalassemia syndrome is a heterogeneous group of hereditary disorders affecting the synthesis of globin chains of adult hemoglobin's, leading to ineffective erythropoiesis, hemolysis, and moderate to severe anemia. To identify the incidence of osteopenia and osteoporosis and it is relation to some of the probable risk factors of decreasing BMD among thalassemia patients attended Misan thalassemia center in Misan city in Iraq. Methods: A randomized cross-sectional study, applied through a period from September 2020 to September 2021, on 50 thalassemia patients attended thalassemia Center Amarah, Misan, Iraq. 24 were males and 26 were females, we divided them in to two groups according to age (10-14) years, (>14-18) years. They were scanned for bone mineral density (BMD) at lumbar spine. Results: 90% of patients had reduction in BMD patients mostly among THM patients. 40% had positive family history of thalassemia, Vitamin D3 level were low in (80%) of patients & DEXA studies were mostly between [(-1) -(-2.5)] before treatment that slightly improved after therapy in ranges of osteopenia but not in osteoporosis which increase severity as well. Conclusions:  Most thalassemia patient had severe anemia, corrected by frequent blood transfusion are complicated by increasing serum ferritin level and decreasing level of vitamin D3 in association with reduction in bone density mass in ranges of osteopenia and osteoporosis which correlates positively with increasing ages, early age at diagnosis and female gender  this altered bone mass density  require family awareness for better nutrition and optimum medical therapy and compliance to improve outcomes.     

Hops extract and xanthohumol ameliorate bone loss induced by iron overload via activating Akt/GSK3β/Nrf2 pathway

INTRODUCTION

Osteoporosis is closely related to iron metabolism. This study aimed to investigate whether hops extract (HLE) and its active component xanthohumol (XAN) could ameliorate bone loss caused by iron overload, and explored its potential mechanism.

MATERIALS AND METHODS

Iron overload mice induced by iron dextran (ID) were used in vivo, and were treated with HLE and XAN for 3 months. Bone micro-structure and bone morphology parameters were determined by Micro-CT and TRAP staining. Bone metabolism markers and oxidation indexes in serum and bone tissue were evaluated. For in vitro experiment, bone formation indexes were determined. Moreover, the expression of key proteins in protein kinase B (Akt)/glycogen synthetase kinase 3β (GSK3β)/nuclear factor E2-related (Nrf2) pathway was evaluated by Western blotting.

RESULTS

HLE and XAN effectively improved the bone micro-structure of the femur in mice, altered bone metabolism biomarkers, and regulated the expression of proteins related to bone metabolism. Additionally, they significantly promoted cell proliferation, runt-related gene 2 (Runx2) expression, and increased ALP activity in ID-induced osteoblasts. Moreover, HLE and XAN markedly inhibited the increase of oxidative stress caused by iron overload in vivo and in vitro. Further studies showed that they significantly up-regulated the expression of p-Akt, p-GSK3β, nuclear-Nrf2, NAD(P)H: quinone oxidoreductase 1 (NQO1), and heme oxygenase-1 (HO-1) in ID-induced osteoblasts.

CONCLUSION

These findings indicated hops and xanthohumol could ameliorate bone loss induced by iron overload via activating Akt/GSK3β/Nrf2 pathway, which brought up a novel sight for senile osteoporosis therapy.

Nutrition in Thalassemia: A Systematic Review of Deficiency, Relations to Morbidity, and Supplementation Recommendations

BACKGROUND

Reports of nutritional deficiencies in patients with thalassemia (Thal) are common. Despite its importance, however, nutritionally focused research in Thal has been limited by inadequate sample size, inconsistent methodology, a lack of control comparisons, and few interventional trials. Due to these limitations, clinicians lack evidence-based nutrition recommendations to support clinical decision-making. This systematic review summarizes observed relationships between nutrition and morbidity in Thal published in the last 3 decades.

METHODS

PubMed, Web of Science, and Embase were screened for articles pertaining to nutrition in Thal using comprehensive search terms. Studies performed in humans, written in English, and published between 1990 and 2020 were included. Over 2100 manuscripts were identified, from which 97 were included.

RESULTS

Patients with Thal were most often deficient in vitamins A, C, D, selenium, and zinc. Prevalence of nutritional deficiency was positively correlated with age and iron overload. Evidence to support the role of vitamin D and zinc for bone health was observed; zinc was also found to improve glucose metabolism.

CONCLUSIONS

Due to the risk for multinutrient deficiency, nutritional status should be assessed annually in patients with Thal with prompt nutrient replacement when deficiency is detected. Routine supplementation with vitamin D and zinc is recommended.

Vitamin D and bone health status in beta thalassemia patients-systematic review

Thalassemia is a chronic congenital disease characterized by a combination of endocrine and metabolic disorders. Bone disease is a very common complication related to the poor absorption of calcium, the secondary chronic renal disease with low vitamin D, as well as multiple endocrine risk factors. The aim of this systematic review was to estimate the prevalence of vitamin D deficiency in thalassemia, as well as its association with osteoporosis/low bone mass. A systematic review was carried out using PubMed/Medline, Cochrane, and EBSCO databases. The methodological quality of the included studies was assessed with the validated Newcastle-Ottawa Quality Assessment Scale adapted for cross-sectional studies and cohort studies respectfully and the Cochrane Collaboration for clinical trials. After application of predetermined exclusion criteria compatible with the PICOS process, a total of 12 suitable articles were identified. The prevalence of vitamin D deficiency varied considerably. Only five of the reviewed studies examined the correlation between vitamin D levels and BMD of which just three showed a statistically significant positive association of mild/moderate grade. Vitamin D deficiency is a common comorbidity in patients with thalassemia. However, both its prevalence and its severity vary considerably in different populations, and existing evidence is insufficient to conclude whether vitamin D supplementation is also associated with BMD improvement in this special population group.

Is CONUT score a predictor of morbidity in patients with adult transfusion dependent beta thalassemia?

OBJECTIVE

Increased life span with regular transfusion and iron chelator treatments enhances the importance of nutrition in beta thalassemia. Controlling Nutritional Status (CONUT) score is a nutritional index calculated on serum albumin, total cholesterol and lymphocyte count. We aim to evaluate need for transfusion and the clinical conditions which cause morbidity with CONUT score in patients with adult transfusion dependent beta thalassemia (BTD).

METHOD

We conducted a retrospective study at the Denizli Thalassemia Center. We used Mann Whitney Utest for comparing. We applied logistic regression analysis and ROC analysis to evaluate CONUT score and clinical effects.

RESULTS

A total of 102 patients with BTD were included. 89 were beta thalassemia major and 13 were transfusion dependent thalassemia intermedia (44 male,58 female). The median age was 26. The mean follow up period was 26 months. The median of CONUT score was 3.0 (min: 0-max: 6). CONUT score of 54 patients (52.9%) was high (≥3). We found significant difference with CONUT score ≥3 (median:32 units) and CONUT score of <3 (median:26.5 units) in terms of annual erythrocyte transfusion amount (p = 0.001). Low bone mass, vitamin D deficiency / insufficiency and hypogonadism were found to be more common with high CONUT score (≥3) (p = 0.001). CONUT score is a distinguishing parameter for hypogonadism (p = 0.001; AUC = 0.922) and low bone mass (p = 0.001; AUC = 0.867).

CONCLUSION

CONUT score can be used as a predictor to evaluate need for transfusion and morbidity of patients with BTD. If nutritional status is closely followed with CONUT score and nutritional deficiency is corrected, cost and complications will be decreased and expanctancy of life can be increased.

Vitamin and mineral supplementation for β-thalassemia during COVID-19 pandemic

AIM

Low levels of immune-related micronutrients have been identified in β-thalassemia samples. Moreover, the excess amount of iron, contributing to oxidative stress in the pathogenesis of the disease, alters the immune system in β-thalassemia, which is important during the COVID-19 pandemic.

MATERIALS & METHODS

Searches of PUBMED and EMBASE were conducted to identify the level and supplementation of micronutrients in β-thalassemia, published from 2001-May 2020.

RESULTS

The review found six observational and five interventional studies supporting the importance of supplementing vitamins and minerals among patients with β-thalassemia.

CONCLUSION

Supplementation of immune-related vitamins and minerals might bring benefits to the immune system, especially in reducing oxidative stress in β-thalassemia.

Association of VDBP rs4701 Variant, but not VDR/RXR-α Over-Expression with Bone Mineral Density in Pediatric Well-Chelated β-Thalassemia Patients

Background

The reduced rate of bone formation despite the availability of vitamin D has been reported in β-thalassemia. Genetic factors, together with environmental ones, could be implicated in this condition. Since vitamin D binding protein (VDBP) maintains bioavailability of vitamin D which binds to vitamin D receptor (VDR)-retinoid X receptor alpha (RXRA) heterodimer to exert its molecular actions, we speculated that vitamin D metabolic-axis expression signature and variants could be potential molecular candidates for bone turnover/disease in thalassemia. To this end, this study aims to analyze VDR/RXRA expression signature, and two VDBP variants in a pilot sample of Egyptian β-thalassemia children in correlation with bone mineral density (BMD).

Patients and methods

Forty-four well-chelated β-thalassemia children and 40 unrelated controls were enrolled. The serum bone chemistry profile was measured. Peripheral blood mononuclear cells (PBMN) VDR/RXRA expression levels were quantified by Real-Time quantitative reverse transcription-polymerase chain reaction (qRT-PCR). VDBP rs7041 and rs4588 variants were identified by Real-Time allelic discrimination assay. All patients were subjected to lumbar-spine Dual-energy X-ray absorptiometry (DEXA).

Results

VDR/RXRA expressions were significantly higher in β-thalassemia children compared to controls (P = 0.001 and <0.001, respectively) and showed higher values in β-thalassemia major relative to β-thalassemia intermedia. Expression levels of both genes were not associated with sex or BMD. However, VDBP rs4701 genotyping revealed lower BMD-L4 and a higher frequency of osteoporosis.

Conclusions

β-Thalassemia children had higher expression levels of PBMN VDR/RXRA. VDBP rs4701 variant was associated with osteoporosis in our β-thalassemia patients on vitamin D supplementation. Further large-scale studies in other ethnic populations are warranted.

Vitamin D Status in Russian Children and Adolescents: Contribution of Genetic and Exogenous Factors

Background: The problem of vitamin D deficiency is particularly relevant for the entire territory of Russia, since most parts of the country are located above the 42nd geographical latitude and the residents are therefore at risk of vitamin D deficiency. Despite the urgency of the problem, a comprehensive study of the molecular and genetic mechanisms and exogenous factors of vitamin D deficiency in children living in various geographical areas of the Russian Federation has not been conducted. Different variants in the loci of the genes responsible for the synthesis, hydroxylation, and transport of vitamin D (such as DHCR7, CYP2R1, CYP24A1, and GC), as well as VDR gene polymorphisms may also be associated with the risk of vitamin D deficiency. The aim of this study was to analyze the influence of exogenous factors on the blood levels of 25-hydroxyvitamin D (25(OH)D) in children of three regions of the Russian Federation, as well as the relationship of blood 25(OH)D levels with polymorphic variants of cytochrome P450 genes and VDR gene. Methods: We conducted blood 25(OH)D level analysis in 333 healthy children and adolescents in three regions located in different geographical zones of the Russian Federation. We studied the polymorphic variants c.1075A>C (I359L, rs1057910, CYP2C9 ^* 3) and c.430C>T (R144C, rs1799853, CYP2C9 ^* 2) in the CYP2C9 gene, c.1334T>C (M445T, rs4986910, CYP3A4 ^* 3), and CYP3A4 ^* 1B (c.-392C>T, rs2740574) in the CYP3A4 gene, 1846G>A, (rs3892097, CYP2D6 ^* 4) in the CYP2D6gene, TaqI (NM_000376.2: c.1056T>C; rs731236), FokI (NM_000376.2:c.2T>C; (rs2228570), and BsmI (NM_000376.2: c.1024+283G>A; rs1544410) in the VDR gene. We also analyzed the influence of exogenous factors on the level of 25(OH)D in children of the three study regions, as well as the relationship of the level of 25(OH)D with variants CYP2C9 ^* 2 (c.430C>T; R144C), CYP2C9 ^* 3 (c,1075A>C; I359L), CYP2D6 ^* 4 (1846G>A), CYP3A4 ^* 3 (c.1334T>C), and CYP3A4 ^* 1B (c.-392C>T) and rs731236, rs2228570 and rs1544410 in the VDR gene. Results: We found that the blood level of 25(OH)D depended on the geographical location and the number of sunny days per year. The average blood level of 25(OH)D in adolescent boys was statistically significantly lower than in girls of this age group. The level of 25(OH)D also significantly depended on the prophylactic dose of cholecalciferol administered to the subjects. In the study, it was shown that a dose of cholecalciferol ≥1,000 IU per day can achieve a normal level of 25(OH)D in healthy children. We found no statistically significant association between single-nucleotide polymorphic variants of cytochrome P450 genes (CYP2C9 ^* 3, CYP3A4 ^* 3, CYP2C9 ^* 2, CYP2D6 ^* 4, and CYP3A4 ^* 1B) and blood level of 25(OH)D in the subjects. We also did not find a relationship between the TaqI, FokI, and BsmI polymorphisms of the VDR gene and serum 25(OH)D concentration. Conclusion: Exogenous factors (time of year, place of residence, and prophylactic administration of cholecalciferol), as well as endogenous factors (age and sex), play a determining role in the development of vitamin D deficiency and insufficiency; in contrast to genetic factors-polymorphic variants of the genes of xenobiotic phase 1 enzymes (CYP2C9, CYP2C19, CYP2D6, and CYP3A4) and the VDR gene-which do not play such role. This study shows the need to create a diagnostic algorithm for Vitamin D deficiency based on the age, season of the year, and prophylactic dose of cholecalciferol.