Osteoporosis in β-Thalassemia: Clinical and Genetic Aspects

Bone mineral density in adult thalassaemias: a retrospective longitudinal study

OBJECTIVES

In this study, we aim to evaluate the long-term impact of thalassaemia on bone mineral density (BMD) through sequential analysis, compare changes in BMD values between male and female patients and find any correlation between BMD and biochemical markers in the adult thalassaemia group. BMD is a bone mineral density test using dual-energy X-ray to measure calcium hydroxyapatite per unit of bone, reflecting bone strength.

METHODS

We conducted a longitudinal retrospective observational cohort study to determine the changes in BMD values and biochemical parameters in adult thalassaemia patients. BMD was assessed at the lumbar spine (L1-L4) and proximal femora using Hologic's bone dual-energy X-ray absorptiometry. Five serial BMD values were retrieved from electronic records. Biochemical parameters, including serum calcium, phosphorus and 25-hydroxyvitamin D levels, were also assessed.

RESULTS

A total of 108 patients (47 males and 61 females; median age: 44 years) with thalassaemia major 71 patients, intermedia 20 patients, haemoglobin E disease 14 patients and thalassaemia-alpha three patients were included. The incidence of low BMD in patients with thalassaemia increased from 64 to 74% over three decades of analysis. Females and thalassaemia major patients had lower hip BMD values and corresponding Z-scores.

CONCLUSION

There is a progressive decline in BMD values in adult thalassaemia, which was apparent in female thalassaemia major patients. No changes in biochemical parameters, however, were observed over long-term assessments.

Endocrinopathies in beta thalassemia: a narrative review

Beta thalassemia is the most common genetic blood disorder, characterized by reduced production or complete absence of beta-globin chains. The combination of systematic red blood cell transfusion and iron chelation therapy is the most readily available supportive treatment and one that has considerably prolonged the survival of thalassemia patients. Despite this, the development of endocrine abnormalities correlated with beta thalassemia still exists and is mostly associated with iron overload, chronic anemia, and hypoxia. A multifactorial approach has been employed to investigate other factors involved in the pathogenesis of endocrinopathies, including genotype, liver disease, HCV, splenectomy, socioeconomic factors, chelation therapy, and deficiency of elements. The development of specific biomarkers for predicting endocrinopathy risk has been the subject of extensive discussion. The objective of the present narrative review is to present recent data on endocrinopathies in beta thalassemia patients, including the prevalence, the proposed pathogenetic mechanisms, the risk factors, the diagnostic methods applied, and finally the recommended treatment options.

Bone health in pediatric transfusion-dependent beta-thalassemia: Circulating osteoprotegerin and RANKL system

INTRODUCTION

While the mechanism of bone disease in thalassemia is multifactorial and still under investigation, the receptor activator of nuclear factor kappa B (RANK), receptor activator of nuclear factor kappa B ligand (RANKL), and osteoprotegerin (OPG) have pivotal roles in regulating bone metabolism. This study aimed to measure RANKL and OPG serum levels, and to detect the incidence of RANKL rs9533156, OPG rs2073618, and OPG rs2073617 genotypes in pediatric β-thalassemia patients and to assess their relation to bone mineral density.

METHODS

Sixty patients with transfusion-dependent β-thalassemia (TBT) patients ages 5 to 14 years were included, and 60 healthy, age- and sex-matched volunteers contributed as a control group. The patients were scanned for bone mineral density.

RESULTS

The mean of spine dual-energy X-ray absorptiometry (DXA) Z-score in patients was -1.66 ± 1.02 standard deviation (SD). Twenty-four of them had low spine DXA Z-scores. The patients showed significantly lower OPG levels and OPG/RANKLs ratios than the control group (3.28 ± 9.11 ng/ml and 11.38 ± 14.93 ng/ml, and 0.01 ± 0.03 and 0.07 ± 0.09, respectively). The RANKL SNP rs9533156 TC heterozygous genotype was detected more with statistical significance in patients than controls. The incidence of OPG rs2073618 and OPG rs2073617 genotypes were 2.3 times and 1.9 times more frequent in patients than controls, respectively.

CONCLUSION

The RANK/RANKL/OPG system may have an important role in regulating bone metabolism in TBT patients, although further studies are needed to clarify its role.

Extracellular Vesicle MicroRNA That Are Involved in β-Thalassemia Complications

Beta thalassemia major (βT) is a hereditary anemia characterized by transfusion-dependency, lifelong requirement of chelation, and organ dysfunction. MicroRNA (miRNA) can be packed into extracellular vesicles (EVs) that carry them to target cells. We explored EV-miRNA in βT and their pathophysiologic role. Circulating EVs were isolated from 35 βT-patients and 15 controls. EV miRNA was evaluated by nano-string technology and real-time quantitative polymerase chain reaction (RT-qPCR). We explored effects of EVs on cell culture proliferation, apoptosis, and signal transduction. Higher amounts of small EV (exosomes) were found in patients than in controls. The expression of 21 miRNA was > two-fold higher, and of 17 miRNA < three-fold lower in βT-EVs than control-EVs. RT-qPCR confirmed differential expression of six miRNAs in βT, particularly miR-144-3p, a regulator of erythropoiesis. Exposure of endothelial, liver Huh7, and pancreatic 1.1B4 cells to βT-EVs significantly reduced cell viability and increased cell apoptosis. βT-EV-induced endothelial cell apoptosis involved the MAPK/JNK signal-transduction pathway. In contrast, splenectomized βT-EVs induced proliferation of bone marrow mesenchymal stem cells (BM-MSC). In summary, the miR-144-3p was strongly increased; βT-EVs induced apoptosis and decreased endothelial, pancreatic, and liver cell survival while supporting BM-MSC proliferation. These mechanisms may contribute to βT organ dysfunction and complications.

Prevalence of Bone Density Reduction and Its Related Factors in Hemophilia Patients in South Khorasan Province in 2018

Background:

The present study aimed to determine the prevalence of bone density reduction and its associated factors in hemophilia patients in South Khorasan Province in 2018.

Materials and Methods:

This case-control study was conducted on all patients with hemophilia type A with medical records in Hemophilia center in South Khorasan province. A number of 57 eligible subjects who met the criteria were selected based on census method. Thereafter, 60 non-hemophilic individuals who were similar to hemophilic patients in terms of age and body mass index were selected by convenience sampling method. DXA device was used to measure bone mineral density (BMD) in two locations of femoral neck and lumbar vertebrae. Data were analyzed in SPSS software (version 19), using Chi-square, Fisher’s exact test, and independent t-test. A P-value less than 0.05 was considered statistically significant.

Results:

The prevalence rate of bone density reduction in spine bone in hemophilia patients was measured at 31.6% and 13.3% in non-hemophilia subjects (P=0.02); moreover, this rate in hip bone was reported as 7% and 5%, respectively (P=0.65). Relative frequency of bone density reduction in the spine and hip bone was not significantly different among hemophilia patients based on age, severity of hemophilia, vitamin D, hepatitis and smoking (P>0.05). However, a significant difference was detected in terms of body mass index (P<0.05).

Conclusion:

Based on the obtained results, the prevalence of bone density reduction in hemophilic patients was significantly higher, as compared to that of non-hemophilia patients. This necessitates the implementation of drastic preventive measures, prompt diagnosis, timely treatment, and appropriate therapeutic measures.

Bone mineral density in transfusion-dependent thalassemia patients and its associated factors in Southern Iran

Despite the significant improvements in the management of thalassemia, there are growing concerns regarding their long-term complications. We showed that low bone mass is one of the most prevalent complications among these patients. Insufficient physical activity and hypogonadism are the main possible associated factors followed by DM and insufficient sun exposure.

PURPOSE

Despite the significant improvements in the management of transfusion-dependent thalassemia (TDT), there are growing concerns regarding their long-term complications.

METHODS

This cross-sectional study included 615 TDT patients who were registered and followed in a comprehensive thalassemia clinic in Southern Iran. We measured serum biochemical tests and bone mineral density in all patients. We recorded physical activity and sun exposure subjectively, and an endocrinologist visited and examined all the patients. A group of age- and gender-matched healthy volunteers participated in the study as the control group.

RESULTS

The mean age of the studied population was 28.4 ± 7.7 years, and 55.8% were female. The prevalence of vitamin D deficiency was 45.6% and 54.4% in TDT patients and the control group. A portion of TDT patients suffered from different endocrinopathies, which included hypogonadism (49.8%), diabetes mellitus (17.2%), hypoparathyroidism (14.6%), and hypothyroidism (6.3%). The prevalence of low bone mass in patients with TDT was 48.3 and 74.6% in the femoral and lumbar bones, respectively. Low physical activity, insufficient sun exposure, diabetes mellitus, and hypogonadism were associated with low bone mass.

CONCLUSION

Low bone mass is highly prevalent among TDT patients in Southern Iran. Insufficient physical activity and hypogonadism are the main possible associated factors, followed by DM and insufficient sun exposure.

SAA1 gene polymorphisms in osteoporosis patients

Background: Serum amyloid A (SAA1) is an apolipoprotein that maintains glucose and lipid homeostasis. Its polymorphisms are associated with risks of myocardial infarction and coronary artery disease (CAD). Methods: However, little is known about the associations of these polymorphisms with susceptibility to osteoporosis, which we evaluated in this hospital-based case–control study involving 300 osteoporosis patients and 350 controls. Three single-nucleotide polymorphisms (SNPs) (rs183978373, rs12218, and rs10832915) were genotyped using MALDI TOF MS. Results: There were no differences in the rs183978373 and rs12218 polymorphisms between the osteoporosis group and controls. The SAA1 gene rs10832915 polymorphism increased the risk of osteoporosis in our Chinese population. The genotypes of the rs10832915 polymorphism were not significantly associated with clinical parameters (age, body mass index (BMI), high- and low-density lipoprotein (LDL), total cholesterol (TC), and T-score). Haplotype analysis revealed that the ATT haplotype had a significant correlation with a decreased risk of osteoporosis. Conclusion: In conclusion, the SAA1 rs10832915 polymorphism and its haplotypes are associated with osteoporosis, but this finding should be confirmed in large well-designed studies.

Health-related quality of life in pediatric and adolescent patients with transfusion-dependent ß-thalassemia in upper Egypt (single center study)

BACKGROUND

Thalassemia is a major health problem that disturbs the lifestyle of the affected patient. The aim of this work is to detect the impact of thalassemia on the quality of life regarding physical, social, emotional, psychological scored assessment.

METHODS

A case-control survey was conducted in Minia University children's hospital on 64 patients recruiting pediatric hematology outpatient clinic from July 2014 to February 2017. PedsQL™ 4.0 Generic Core Scale (Arabic version) was used to assess HRQOL in 64 thalassemia patients between 8 and 18 years of ages. Other related clinical data of the involved patients were collected from the pediatric hematology records.

RESULTS

Mean physical, emotional, social, school performance, psychological and total scores (- 36.9 ± 20.9, 49.4 ± 17, 47.2 ± 21.3, 38.5 ± 15.5, 45.3 ± 13.8, 47.9 ± 38.8 respectively) were significantly decreased compared with control (p = 0.001 for all). The younger age group had better scores regarding social, emotional, psychological and total scores compared to older ones (p = 0.01, 0.03, 0.01 and 0.009 respectively). Older age of starting transfusion was statistically significant protecting factor from poor physical QOL in thalassemia patients (OR = 0.96, p = 0.03). The presence of hepatomegaly was a statistically significant predictor for poor physical QOL (OR = 8.5, p = 0.02). Household income was the statistically significant predictor for poor emotional QOL (OR = 5.03, p = 0.04). High serum ferritin was the statistically significant predictor for poor social QOL (OR = 1.1, CI 95%=, p = 0.04). Regarding poor psychological QOL (OR = 0.94, p = 0.01) and total QOL (OR = 0.94, p = 0.01) scores, older age of starting transfusion was the statistically significant protecting factor.

CONCLUSION

Scheduled programs giving psychosocial help and a network connecting between the patients, school officials, thalassemia caregivers and the physician is required especially in developing countries where the health services are not integrated with social organizations. Special school services for thalassemia patients are required to deal with the repeated absence and anemia induced low mental performance of thalassemia children.

A contemporary therapeutic approach to bone disease in beta-thalassemia - a review

Homozygous beta-thalassemia represents a serious hemoglobinopathy, in which an amazing prolongation in the survival rate of patients has been achieved over recent decades. A result of this otherwise positive evolution is the fact that bone problems have become a major issue in this group of patients. Through an in-depth review of the related literature, the purpose of this study is to present and comment on the totality of the data that have been published to date pertaining to the prevention and treatment of thalassemia bone-disease, focusing on: the contribution of diet and lifestyle, the treatment of hematologic disease and its complications, the management of hypercalciuria, the role of vitamins and minerals and the implementation of anti-osteoporosis medical regimen. In order to comprehensively gather the above information, we mainly reviewed the international literature through the PubMed database, searching for the preventive and therapeutic data that have been published pertaining to thalassemia bone-disease over the last twenty-nine years. There is no doubt that thalassemia bone-disease is a complication of a multi-factorial etiopathology, which does not follow the rules of classical postmenopausal osteoporosis. Bisphosphonates have been the first line of treatment for many years now, with varied and usually satisfactory results. In addition, over the last few years, more data have arisen for the use of denosumab, teriparatide, and other molecules that are in the clinical trial phase, in beta-thalassemia.

Rheumatological complications of beta-thalassaemia: an overview

Beta-thalassaemia, an autosomal recessive haemoglobinopathy, ranks among the most frequent monogenetic diseases globally. The severe form of the disease, beta-thalassaemia major, is accompanied by progressive involvement of multiple organ systems as a result of the disease pathophysiology as well as iron overload from blood transfusions on a regular basis. Some of the manifestations might also be caused by medications used to manage iron overload. The purpose of this review is to highlight the rheumatological complications of beta-thalassaemia, which include musculoskeletal manifestations, such as arthritis and arthropathies, joint effusions, osteoporosis, bone fractures and myalgias, in addition to CTDs, such as pseudoxanthoma elasticum. Rheumatologists are strongly encouraged to take part in a multidisciplinary approach to the management of this debilitating disease.

Association between osteoprotegerin gene T950C polymorphism and osteoporosis risk in the Chinese population: Evidence via meta-analysis

Osteoporosis has been reported to be at least partially developed in response to functional polymorphisms of the osteoprotegerin (OPG). However, conflicting results have been found. This meta-analysis aimed to provide an assessment of the relationship between the risk for developing osteoporosis and OPG T950C polymorphism in the Chinese population. Studies to be analyzed were identified with the literature search in PubMed, Embase, Web of Science, the Cochrane Library, and the Chinese National Knowledge Infrastructure during May 2017. Seven case-control studies that included a total of 1850 osteoporosis cases and 3074 controls were assessed in this meta-analysis. Overall, no significant associations could be detected between OPG T950C polymorphism and osteoporosis when all included studies were pooled into this meta-analysis. In a subgroup analyses, OPG T950C polymorphism was significantly associated with the osteoporosis risk in South China (CC+TC vs. TT: OR = 1.34, 95% CI = 1.17-1.54; CC vs. TC+TT: OR = 0.79, 95% CI = 0.69-0.95) and for studies that included postmenopausal osteoporosis (CC vs. TC+TT: OR = 0.78, 95% CI = 0.64-0.94) or hospital-based controls (CC vs. TC+TT: OR = 0.81, 95% CI = 0.68-0.96). In conclusion, the results of this meta-analysis suggest that OPG T950C polymorphism might be associated with an increased osteoporosis risk in the Chinese population.

Evaluation of the Clinical and Laboratory Characteristics of Previously Followed-up Thalassemia Intermedia Patients to Provide Them Better Care in the Future

The increased awareness about the severity of complications in thalassemia intermedia patients led authorities to develop strategies for better management and follow-up of these patients. In this study, we aimed to define the clinical and laboratory characteristics in previously followed-up β-thalassemia intermedia patients and wanted to gain an insight about the follow-up of this patient population in a developing country to provide them better care in the future. The mean age at diagnosis was 4 years, and the mean hemoglobin was 7.13 g/dL. The mean age at the beginning of regular transfusion was 4.8 years. An overall 74% of patients were on a regular transfusion program. The mean ferritin values at diagnosis and the last follow-up were 487 and 1225 ng/mL, respectively. The most common mutations detected in patients were IVS-I-110, IVS-I-6, IVS-II-1, and FCS 8/9 in order of frequency. Complications were seen in 48% of patients. The most common complications were osteopenia/osteoporosis (34%), growth retardation (24%), hypogonadism (18%), and cardiomyopathy (13%). In conclusion, the relatively higher complication rate in our patients who were previously treated highlights once again the need for an increased effort for optimal management and follow-up of this specific group of patients.

Morbidity and mortality of adult patients with congenital dyserythropoietic anemia type I

Congenital dyserythropoietic anemia type I (CDAI) is a rare autosomal recessive disease characterized by macrocytic anemia, ineffective erythropoiesis, and secondary hemochromatosis. To better define the natural history of the disease among adult patients, we studied 32 Bedouin patients (median age 34 yr; range 21-60) all carrying the same CDAN1 founder mutation. Follow-up studies included complete blood count, blood chemistry, abdominal ultrasound, echocardiography, and T2*MRI. Main complications were due to anemia and ineffective erythropoiesis [osteoporosis (8/9, 89%), cholelithiasis (21/30, 70%), pulmonary arterial hypertension (PAH) (6/25, 24%)] and iron overload [hypothyroidism (9/24, 38%), and diabetes mellitus (6/32, 19%)]. T2* MRI revealed increased liver iron but no cardiac iron (13/13). Anemia improved in the majority of patients who underwent splenectomy (5/6). Three patients died (9%) at the age of 46-56 due to PAH (1) and sepsis (2). All previously underwent splenectomy. Analyzing both our patients and the 21 patients previously described by Heimpel et al. (Blood 107:334, 2006), we conclude that adults with CDA I suffer significant morbidity and mortality. Careful monitoring of iron overload and prompt iron chelation therapy is mandatory. Due to possible complications and inconsistent response to splenectomy α-interferon, transfusion therapy or stem cell transplantation should be considered as alternatives to this procedure in severely affected patients.

β-thalassemia patients and gynecological approach: review and clinical experience

Significant improvements in therapy and life expectancy of β-thalassemia patients in last decades result in the need of commitment for gynecologists and obstetricians as the complexity of organ impairment needs a specific multidisciplinary approach. After a review of clinical manifestations of β-thalassemia from a gynecologic point of view, we present the experience of a gynecologic center in treating β-thalassemia patients from more than 20 years.

Which pamidronate protocol is the best for treating osteoporosis in beta-thalassemia major?

One of the most common complications in thalassemia major patients is osteopenia and osteoporosis. In this study, we compare the therapeutic effect of two treatment protocols involving infusion of 45 mg of pamidronate injection every 6 weeks (P45) and 90 mg pamidronate infusion every 4 weeks (P90). Bone mineral density was measured using dual energy X-ray absorptiometry (DEXA). Z-score of lumbar vertebra (as L total) and the femoral head (as F total) were compared before and after administration of two protocols. Bone density between the two groups was compared by Student t test and by the paired t test before and after the intervention. Data were analyzed using SPSS (18). Ninety-one patients were treated with pamidronate 45 mg (P45), and 36 patients were treated with pamidronate 90 mg (P90). Ninety-one and 36 patients received P45 and P90 protocol, respectively. Mean age was 29.4 ± 8.1 and 30.9 ± 8.0 years old in P45 and P90 groups, respectively. Sixty-two and 58 % of P45 and P90 group were female. The means of F total were -1.73 ± 1.11 and -1.47 ± 0.92 before and after treatment in patients P45 (P = 0.01) and were -1.83 ± 0.75 and -1.57 ± 0.99 in group P90 (P = 0.005), respectively. Before treatment, the means of L total were -2.95 ± 0.81 and -2.92 ± 0.66 (P = 0.8) and after treatment were -2.53 ± 1.13 and 2.81 ± 0.98 (P = 0.1) in P45 and P90 groups, respectively. In P45, between the mean of L total was statistically significant difference before and after treatment (P < 0.0001); however, there was no significant difference in the P90 group (P = 0.3). The study showed effectiveness of both protocols. As the medication is expensive and should be administrated parenterally, we recommend P45 protocol which is less expensive with fewer injections.

Klotho, a new marker for osteoporosis and muscle strength in β-thalassemia major

Aim of this study was to compare plasma levels of the secreted protein Klotho in β-thalassemia major patients and in healthy controls. Also, we examined the existence of correlations between the protein level and osteoporosis, poor muscle strength and fractures. A total of 106 patients with β-thalassemia major and 95 healthy blood donors were enrolled. Klotho level in plasma was measured by mean of an ELISA test and the hand-grip strength using a dynamometer. Intact parathyroid hormone (PTH), 25-hydroxy vitamin D (Vitamin D), serum calcium (Ca), phosphate (P), total alkaline phosphatase (ALP), ferritin, creatinine were measured by standard clinical techniques. DXA was used to measure bone mineral density (BMD) at the lumbar spine (L2-L4), femoral neck and total hip. We found that the Klotho protein concentration was lower in the blood of patients with β-thalassemia major than in healthy controls, and it was directly correlated to the hand-grip strength. In β-thalassemia major patients, the secreted Klotho was lower than in healthy controls. The preliminary investigation into the correlation between markers of osteo- and sarcopenia and Klotho demonstrated a decreased Klotho concentration in β-TM patients and a higher probability of having had fragility fractures.

Spine bone texture assessed by trabecular bone score (TBS) to evaluate bone health in thalassemia major

Due to the increasing survival of thalassemic patients, osteopathy is a mounting clinical problem. Low bone mass alone cannot account for the high fracture risk described; impaired bone quality has been speculated but so far it cannot be demonstrated noninvasively. We studied bone quality in thalassemia major using trabecular bone score (TBS), a novel texture measurement extracted from spine dual-energy X-ray absorptiometry (DXA), proposed in postmenopausal and secondary osteoporosis as an indirect index of microarchitecture. TBS was evaluated in 124 adult thalassemics (age range 19-56 years), followed-up with optimal transfusional and therapeutical regimens, and in 65 non-thalassemic patients (22-52 years) undergoing DXA for different bone diseases. TBS was lower in thalassemic patients (1.04 ± 0.12 [range 0.80-1.30]) versus controls (1.34 ± 0.11 [1.06-1.52]) (p < 0.001), and correlated with BMD. TBS and BMD values correlated with age, indicating that thalassemia negatively affects both bone quality and quantity, especially as the patient gets older. TBS was 1.02 ± 0.11 [0.80-1.28] in the osteoporotic thalassemic patients, 1.08 ± 0.12 [0.82-1.30] in the osteopenic ones and 1.15 ± 0.10 [0.96-1.26] in those with normal BMD. No gender differences were found (males: 1.02 ± 0.13 [0.80-1.30], females 1.05 ± 0.11 [0.80-1.30]), nor between patients with and without endocrine-metabolic disorders affecting bone metabolism. Our findings from a large population with thalassemia major show that TBS is a valuable tool to assess noninvasively bone quality, and it may be related to fragility fracture risk in thalassemic osteopathy.

Bone disease in adult patients with β-thalassaemia major: a case-control study

Despite the extraordinary improvements carried out in diagnostic and therapeutic management of thalassaemia major over the past few decades, bone demineralization is still a common finding, even in optimally treated patients. The relationships between bone density and several clinical characteristics or hematological markers have been described, and many factors contributing to demineralization have been identified; among them endocrine complications seem to play an important role. Nevertheless, the complex etiological mechanisms of this heterogeneous osteopathy still remains incompletely clarified. While previous studies focused on the characteristics of thalassaemic patients affected from bone demineralization, we conducted a case-control study focused on thalassaemic patients free from bone disease, aimed to detect the distinctive characteristics and any possible protective feature. Among a large cohort of 150 adult patients with β-thalassaemia major, we enrolled 20 patients with normal bone mineralization and 20 patients with osteoporosis matched for gender, BMI, age at first transfusion, serum ferritin and pre-transfusional hemoglobin (Hb) levels. The differences in demographic, clinical and endocrinological profiles were investigated, correcting for physical and hematological features known as confounding variables. The comparison of the two groups for biochemical parameters and endocrine function showed a protective role of normal gonadic function and IGF-1 levels against osteoporosis, and a similar influence of hypoparathyroidism. Treatment-corrected hypothyroidism and diabetes seemed not to affect bone mineralization. In conclusion, from a different perspective our results corroborate the role of endocrinopathies in thalassaemic osteopathy, and once again underline the crucial importance of an early and multi-disciplinary intervention in preventing bone complications in thalassaemic patients.

Association between seven common OPG genetic polymorphisms and osteoporosis risk: a meta-analysis

Functional polymorphisms of the osteoprotegerin (OPG) gene are known to be involved in bone mineral density and the development of osteoporosis; however, some conflicting results have been reported. The aim of this meta-analysis is to provide a relatively comprehensive assessment of the relationship between seven common OPG genetic polymorphisms (T149C, A163G, G209A, T245G, T950C, G1181C, and C1217T) and osteoporosis risk. A literature search for eligible studies published before August 1st, 2013 was conducted in PubMed, Embase, Web of Science, Cochrane Library, and CNKI (China National Knowledge Infrastructure) databases. Pooled odds ratios and their corresponding 95% confidence intervals were used to evaluate the strength of the association under fixed- or random-effect models according to a heterogeneity test. All analyses were performed using the STATA software, version 12.0. Fourteen case-control studies with a total of 2383 osteoporosis cases and 2280 healthy controls were included in this meta-analysis. Among the seven polymorphisms, A163G and G1181C revealed significant associations with osteoporosis risk. For A163G (rs3102735), the combined results showed that the G allele of the A163G polymorphism may be associated with an increased risk of osteoporosis. Stratified analyses showed that the magnitude of the effect was similar in Caucasian and postmenopausal woman subgroups. For G1181C (rs2073618), however, we found that individuals with the C allele of the G1181C polymorphism had a decreased risk of osteoporosis, especially in Asian and postmenopausal woman subgroups. In summary, this meta-analysis indicated that the G allele of the OPG A163G polymorphism might increase osteoporosis risk in Caucasians, whereas individuals with the C allele of the G1181C polymorphism had a decreased risk of osteoporosis, especially in Asians. Both of these effects were observed in postmenopausal women. These polymorphisms could probably be used with other genetic markers together to identify individuals at a high risk of osteoporosis.

Dual-energy X-ray absorptiometry with serum ferritin predicts liver iron concentration and changes in concentration better than ferritin alone

Accurate assessment of liver iron concentration (LIC) is critical for optimal monitoring of iron toxicity in multitransfused patients. Serum ferritin is the most widely used although its association to LIC is only modest. We studied if a liver-specific measure using dual-energy X-ray absorptiometry (DXA) systems could improve LIC estimates over ferritin alone in Thalassemia (Thal) patients. Thirty-seven patients with Thal (19.2 ± 9.0 yr, 20 male) were studied and 10 had multiple visits. Height, weight, ferritin, whole-body DXA, and hepatic superconducting quantum interference device (SQUID) were measured within 5 wk. DXA hepatic density was measured using right rib, whole liver, and multiple subliver regions. The best agreement to SQUID LIC was found using a combination of ferritin, weight, DXA subliver region 3 bone mineral content (BMC), and right rib BMC. DXA with ferritin improved the ferritin alone correlation from R(2)=0.35 to R(2)=0.62. Serial LIC changes using DXA were associated with serial SQUID changes (r=0.73, p=0.02). Changes in ferritin alone were not significant (p=0.06). We conclude that the addition of whole-body DXA measures and body weight substantially increased the accuracy of LIC and change in LIC estimates over the use of ferritin alone and could be useful when magnetic resonance imaging or SQUID is not available.

Evaluation of osteopathy in thalassemia by bone mineral densitometry and biochemical indices

OBJECTIVE

To evaluate osteopathy in thalassemia by bone mineral densitometry (BMD) and biochemical indices.

METHODS

Prospective review analysis with no follow up from 2006 to 2007 of 42 regularly transfused thalassemics aged 10-25 years (27 boys, 15 girls) was done. Anthropometry, pubertal stage and symptomatology were noted. Urinary C-terminal cross-linked telopeptide of type-1 collagen (Crosslaps) by ELISA; serum 25-OH vitamin D and osteocalcin by RIA; parathyroid hormone (PTH) and ferritin by chemiluminescence and IGF-1 by Enzyme immunoassay were evaluated. Dual Energy X-ray Absorptiometry (DEXA) of lumbar spine and femur was done on Lunar prodigy system. Data was entered and analyzed using the SPSS for Windows software. Mean comparisons were done by ANOVA 1 and data was compared using Chi-square test and p value < 0.05 was taken as significant.

RESULTS

Of 42 patients, 81% had osteoporosis by Z-score of DEXA. Urinary crosslaps was high in 55%; 36% had increased osteocalcin; 62% had low vitamin D levels; 38% had high parathyroid levels and IGF-1 was low in 52%. Mean serum ferritin level was 5344 ± 2855 ng/dl. There was statistical significance (p = 0.046) between chronological age and BMD. All 42 cases were divided into two groups: Group-1 (Normal DEXA), Group-2 (Abnormal DEXA) and analysis of biochemical indices between two groups showed no significant difference in any of the biochemical parameters.

CONCLUSION

This study revealed majority of thalassemics with inadequate chelation have bone resorption with advancing chronological age and BMD should be evaluated regularly for early diagnosis to prevent morbidity.

Osteoporosis syndrome in thalassaemia major: an overview

Osteoporosis in thalassaemia major (TM) represents a prominent cause of morbidity. The mechanism of pathogenesis of bone disease (BD) in TM is multifactorial and complicated. Peak bone mass is achieved shortly after completion of puberty and normally remains stable until the third decade of life when age-related bone mass begins. Growth hormone (GH) and sex steroids play a crucial role in bone remodeling and in the maintenance of skeletal architecture during adult life. GH and insulin growth factors (IGFs) have anabolic effect in bone formation. Sex steroids act probably by increasing the expression of RANKL by osteoblastic cells and alterations in the RANK/RANKL/OPG system in favor of osteoclasts. Impaired GH secretion and lack of sex steroids in thalassemic patients due to pituitary damage, contribute to failure of achieving optimal peak bone mass. Other endocrine complications such as hypoparathyroidism and vitamin D deficiency have also a detrimental role on bones in TM. It is still questionable whether the international criteria for defining osteopenia and osteoporosis are relevant to patients with TM; also a question arises for the diagnostic methods such as DEXA scan and management of osteoporosis with known treatment protocols, in the thalassaemic patient.

Bone disease in thalassemia: a frequent and still unresolved problem

Adults with beta thalassemia major frequently have low BMD, fractures, and bone pain. The purpose of this study was to determine the prevalence of low BMD, fractures, and bone pain in all thalassemia syndromes in childhood, adolescence, and adulthood, associations of BMD with fractures and bone pain, and etiology of bone disease in thalassemia. Patients of all thalassemia syndromes in the Thalassemia Clinical Research Network, > or =6 yr of age, with no preexisting medical condition affecting bone mass or requiring steroids, participated. We measured spine and femur BMD and whole body BMC by DXA and assessed vertebral abnormalities by morphometric X-ray absorptiometry (MXA). Medical history by interview and review of medical records, physical examinations, and blood and urine collections were performed. Three hundred sixty-one subjects, 49% male, with a mean age of 23.2 yr (range, 6.1-75 yr), were studied. Spine and femur BMD Z-scores < -2 occurred in 46% and 25% of participants, respectively. Greater age, lower weight, hypogonadism, and increased bone turnover were strong independent predictors of low bone mass regardless of thalassemia syndrome. Peak bone mass was suboptimal. Thirty-six percent of patients had a history of fractures, and 34% reported bone pain. BMD was negatively associated with fractures but not with bone pain. Nine percent of participants had uniformly decreased height of several vertebrae by MXA, which was associated with the use of iron chelator deferoxamine before 6 yr of age. In patients with thalassemia, low BMD and fractures occur frequently and independently of the particular syndrome. Peak bone mass is suboptimal. Low BMD is associated with hypogonadism, increased bone turnover, and an increased risk for fractures.

Survival and Complications in Thalassemia

The life expectancy of patients with thalassemia major has significantly increased in recent years, as reported by several groups in different countries. However, complications are still frequent and affect the patients' quality of life. In a recent study from the United Kingdom, it was found that 50% of the patients had died before age 35. At that age, 65% of the patients from an Italian long-term study were still alive. Heart disease is responsible for more than half of the deaths. The prevalence of complications in Italian patients born after 1970 includes heart failure in 7%, hypogonadism in 55%, hypothyroidism in 11%, and diabetes in 6%. Similar data were reported in patients from the United States. In the Italian study, lower ferritin levels were associated with a lower probability of experiencing heart failure and with prolonged survival. Osteoporosis and osteopenia are common and affect virtually all patients. Hepatitis C virus antibodies are present in 85% of multitransfused Italian patients, 23% of patients in the United Kingdom, 35% in the United States, 34% in France, and 21% in India. Hepatocellular carcinoma can complicate the course of hepatitis. A survey of Italian centers has identified 23 such cases in patients with a thalassemia syndrome. In conclusion, rates of survival and complication-free survival continue to improve, due to better treatment strategies. New complications are appearing in long-term survivors. Iron overload of the heart remains the main cause of morbidity and mortality.