Bone quality in beta-thalassemia intermedia: relationships with bone quantity and endocrine and hematologic variables

Bone quality is associated with fragility fracture in patients with hemoglobinopathies

BACKGROUND

Low bone mass, defined as a bone mineral density (BMD) Z-score ≤-2.0, is common in adults with thalassemia (Thal) and sickle cell disease (SCD), though disease-specific artifacts may contribute to inaccuracies in BMD assessment. Trabecular bone score (TBS), an indicator of bone quality, is not susceptible to these challenges and may improve fracture risk prediction.

METHODS

A retrospective chart review was conducted in patients with Thal or SCD who had at least one spine BMD scan by DXA in the past 10 years. The most recent scan was reanalyzed for bone quality with abnormal defined as TBS <1.2. Fracture prevalence was determined by patient report with medical record validation. Patients were compared to healthy controls who participated in previous research.

RESULTS

Data were abstracted from 126 patients with Thal (31.7 ± 11.9 yrs, 51 % Male), 170 with SCD (24.6 ± 13.5 yrs, 43 % Male), and 64 controls (25.9 ± 8.0 yrs, 17 % Male). Abnormal TBS was more common in Thal (26 %) or SCD (7 %) compared to controls (0 %, p < 0.001). Fracture prevalence was greater in Thal (36 %) compared to SCD (23 %) and controls (16 %, p = 0.005). Fragility fractures were not observed in controls but constituted 21 % of fractures in Thal and 15 % in SCD. After adjusting for age and hypogonadism, low bone mass was associated with an increased fracture prevalence (OR: 1.8, 95 % CI: 1.03, 3.23; p = 0.041), but not with fragility fracture. In contrast, abnormal TBS was strongly associated with fragility fracture after adjustment for age, sex, and BMI (OR: 11.4, 95 % CI: 2.2, 59.1, p = 0.004).

CONCLUSIONS

Bone quality by TBS may be a valuable tool in predicting the risk of fragility fractures in young adults with hemoglobinopathies and should be considered when making decisions for anti-resorptive therapy in those with low BMD naive to fracture or where disease-specific artifacts complicate accurate spine assessment by BMD alone.

Melatonin Supplementation Alleviates Bone Mineral Density Decline and Circulating Oxidative Stress in Iron-Overloaded Thalassemia Patients

Thalassemia patients often exhibit low bone mineral density (BMD). The iron overload associated with thalassemia elevates oxidative stress levels, leading to reduced BMD. Melatonin improves BMD in postmenopausal osteopenia, however, its effect on BMD in thalassemia patients with iron overload has not been investigated. A randomized controlled study was conducted at Hematology Clinic, Faculty of Medicine, Chiang Mai University. Thalassemia patients with osteopenia and iron overloaded condition, as indicated by BMD Z-score <-2 at l-spine, femoral neck, or total hip, and serum ferritin level > 500 μg/L were recruited in this study. Patients were randomized to receive either melatonin 20 mg/day or placebo at bedtime for 12 months. BMD was re-evaluated 12 months after interventions. Bone turnover markers (BTM), malondialdehyde (MDA as an oxidative stress marker), and pain scores were assessed at baseline, 6, and 12 months. The outcomes, including BMD, BTM, MDA, and pain scores, were evaluated in all patients. Forty-one thalassemia patients (18 males) were enrolled in the study and randomly assigned to either the melatonin group (n = 21) or the placebo group (n = 20). Characteristics of patients were not differences between groups. Mean age was 30.8 ± 6.2 years old. Thirty-three patients (80.4%) were transfusion-dependent patients. At 12 months, mean BMD at l-spine in melatonin group was not significantly different from placebo group (p = 0.069). However, l-spine BMD at 12 months in the melatonin group was significantly greater than baseline (p = 0.029). Serum levels of P1NP and MDA were significantly reduced at 6 months compared to baseline following melatonin treatment. The melatonin group experienced a notable decrease in back pain scores after 12 months compared to the initial measurements. 20 mg daily melatonin supplementation for 12 months alleviated l-spine BMD loss in iron-overloaded thalassemia with low BMD. Melatonin also significantly reduced circulating oxidative stress and mitigated back pain in these patients.

Bibliometric analysis of publications on trabecular bone score (TBS)

Purpose

Trabecular bone score (TBS), as a texture indicator of bone microarchitecture, predicts the risk of fracture. This study aims to explore the knowledge map of TBS.

Methods

We searched Scopus for "trabecular bone score" or "trabecular score" from the beginning to 2021. Our inclusion criteria were original articles and reviews that were related to TBS and our exclusion criteria were non-English articles, non-related to TBS, and document type other than original articles and reviews. and related documents were included for bibliometric analysis. Excel, VOS viewer, and Science of Science (Sci2) software were used for data synthesis.

Results

From 749 retrieved articles, 652 articles were included for analysis. These documents were cited 12,153 times and had an H-index of 56. The most productivity belonged to the USA (n = 130 documents), Switzerland (n = 101), and Italy (n = 67). "Osteoporosis International" (n = 80) had the highest participation in publishing. The research topics of interest were mainly related to the applicability of TBS for fracture risk assessment in chronic endocrine disorders such as osteoporosis and diabetes mellitus. Bursting analysis of the title and abstract revealed the initial focus of the discriminative power of TBS for osteoporotic fracture and the more recent focus on comparing bone mineral density (BMD) and TBS in a variety of chronic diseases.

Conclusion

The number of annual publications on TBS has increased, especially after 2016. These publications highlight the importance of in-depth knowledge of TBS in predicting fracture risk and also its strengths and limitations of treatment monitoring in different health conditions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01338-7.

Bone densitometry in Thalassemia major: a closer look at pitfalls and operator-related errors in a 10-year follow-up population

PURPOSE

Dual-energy X-ray absorptiometry (DXA) is the gold standard for measuring bone mineral density (BMD) with tolerable error rate, high precision, and excellent consistency. Our objective was to investigate the frequency and distribution of errors in a cohort of patients with Thalassemia major (TM).

METHODS

We reviewed the DXA examinations of 340 patients with β-TM followed by our institution, acquired in different imaging centers between 2009 and 2019. We collected sex and age at the time of the first examination and at the last visit, as well as BMD, T-score, and Z-score values. Errors were analyzed by anatomical site (lumbar spine, total hip, femoral neck).

RESULTS

Out of 5099 total DXA scans, 11.85% presented one or more errors. Specifically, the incorrect examinations were 315 out of 1707 (18.45%) at the lumbar spine level, 113 out of 1697 (6.66%) at the total hip, 176 out of 1695 (10.38%) at the femoral neck. Errors in vertebral inclusion were the most frequently registered (45.86%). A significant difference resulted from the comparison of the T-score and Z-score median values of all the lumbar spine DXA examinations and the correct ones (p value 0.037 and 0.0003, respectively).

CONCLUSION

Although not directly involved in the performance and interpretation of DXA, physicians interested in osteoporosis management should be familiar with the protocols to minimize errors and allow the proper use of bone densitometry. DXA obtained at the spine level is more frequently affected by errors in patients with TM, potentially influencing the diagnostic assessment of bone health status.

The influence of iron on bone metabolism disorders

Iron is a necessary trace element in the human body, and it participates in many physiological processes. Disorders of iron metabolism can cause lesions in many tissues and organs, including bone. Recently, iron has gained attention as an independent factor influencing bone metabolism disorders, especially the involvement of iron overload in osteoporosis. The aim of this review was to summarize the findings from clinical and animal model research regarding the involvement of iron in bone metabolism disorders and to elucidate the mechanisms behind iron overload and osteoporosis. Lastly, we aimed to describe the association between bone loss and iron overload. We believe that a reduction in iron accumulation can be used as an alternative treatment to assist in the treatment of osteoporosis, to improve bone mass, and to improve the quality of life of patients.

Inhibition of FGF23 is a therapeutic strategy to target hematopoietic stem cell niche defects in β-thalassemia

Clinical evidence highlights a relationship between the blood and the bone, but the underlying mechanism linking these two tissues is not fully elucidated. Here, we used β-thalassemia as a model of congenital anemia with bone and bone marrow (BM) niche defects. We demonstrate that fibroblast growth factor 23 (FGF23) is increased in patients and mice with β-thalassemia because erythropoietin induces FGF23 overproduction in bone and BM erythroid cells via ERK1/2 and STAT5 pathways. We show that in vivo inhibition of FGF23 signaling by carboxyl-terminal FGF23 peptide is a safe and efficacious therapeutic strategy to rescue bone mineralization and deposition in mice with β-thalassemia, normalizing the expression of niche factors and restoring hematopoietic stem cell (HSC) function. FGF23 may thus represent a molecular link connecting anemia, bone, and the HSC niche. This study provides a translational approach to targeting bone defects and rescuing HSC niche interactions, with potential clinical relevance for improving HSC transplantation and gene therapy for hematopoietic disorders.

Association of hepatic/pancreatic iron overload evaluated by quantitative T2* MRI with bone mineral density and trabecular bone score

BACKGROUND

Iron-overloaded patients are recognized as presenting an increased risk of osteoporosis. However, studies on the correlation between osteoporosis and organ iron overload are controversial or scarce. The aim of this study is to assess bone mineral density (BMD) and trabecular bone score (TBS) in correlation with hepatic and pancreatic iron overload.

METHODS

Forty-one patients diagnosed with hemoglobinopathies, were studied. BMDs of the lumbar spine (LS), femoral neck (FN), and total hip (TH) were analyzed by Dual-energy X-ray absorptiometry (DXA) scan. LS bone quality was derived from each spine DXA examination using the TBS analysis. Hepatic and pancreatic iron overload were obtained with a multi-echo gradient echo T2* technique.

RESULTS

Abnormal microarchitecture and abnormal bone mass were observed in 19/41 (46.3%) and 9/41 (22.0%) patients, respectively. For 26 males, BMD, T-score and Z-score of LS were significantly lower among subjects with moderate-severe hepatic iron-overload than their counterparts, as it is between no- and pancreatic iron-overload groups. For 15 females, patients with moderate-severe hepatic iron-overload had significantly lower BMD and T-score of FN and TH, and patients with pancreatic iron-overload had significantly lower BMD, T-score of FN, and lower BMD, T-score and Z-score of TH than their counterparts. Moreover, pancreatic T2*-value was positively correlated with BMD and T-score at all analyzed sites and Z-score at TH.

CONCLUSION

These data showed lower bone mass in patients with organ iron overload, particularly for LS in males, FN and TH in females. TBS may well represent a complementary tool for the evaluation of bone quality and the risk of fracture in iron-overloaded patients.

Impact of iron overload on bone remodeling in thalassemia

INTRODUCTION

Iron overload, a state with excessive iron storage in the body, is a common complication in thalassemia patients which leads to multiple organ dysfunctions including the bone. Iron overload-induced bone disease is one of the most common and severe complications of thalassemia including osteoporosis. Currently, osteoporosis is still frequently found in thalassemia even with widely available iron chelation therapy.

STUDY SELECTION

Relevant publications published before December 2019 in PubMed database were reviewed. Both pre-clinical studies and clinical trials were obtained using iron overload, thalassemia, osteoporosis, osteoblast, and osteoclast as keywords.

RESULTS

Increased ROS production is a hallmark of iron overload-induced impaired bone remodeling. At the cellular level, oxidative stress affects bone remodeling by both osteoblast inhibition and osteoclast activation via many signaling pathways. In thalassemia patients, it has been shown that bone resorption was increased while bone formation was concurrently reduced.

CONCLUSION

In this review, reports on the cellular mechanisms of iron overload-associated bone remodeling are comprehensively summarized and presented to provide current understanding this pathological condition. Moreover, current treatments and potential interventions for attenuating bone remodeling in iron overload are also summarized to pave ways for the future discoveries of novel agents that alleviate this condition.

Highly increased risk of fracture in patients with myeloproliferative neoplasm

The risk for hip and vertebral fracture was determined in 10,752 patients diagnosed with myeloproliferative neoplasms (MPN) in Sweden 1995-2015. The mean follow-up time were 6.34 years. Five percent developed hip fracture and 1.3% a vertebral fracture. There was a significant increased risk for fracture among the MPN patients compared with the Swedish population. The ratio of observed (obs) and expected (exp) number of hip fracture in all MPN patients, polycythemia vera (PV), essential thrombocythemia and MPN undetermined (MPNu) was 1.20 (95% confidence interval (CI): 1.10-1.31), 1.37 (95% CI: 1.19-1.58), 1.02 (95% CI: 0.87-1.19), and 1.28 (95% CI: 1.07-1.52), respectively. Corresponding figures for vertebral fractures were 1.94 (95% CI: 1.64-2.29), 2.09 (95% CI: 1.56-2.75), 1.50 (95% CI: 1.06-2.07) and 2.47 (95% CI: 1.77-3.35), respectively. Patients with MPN had an increased risk of hip and vertebral fracture, especially patients with PV and MPNu in comparison with the entire Swedish population.

Evaluation of the vitamin D and biomedical statuses of young children with β-thalassemia major at a single center in southern China

BACKGROUND

In young children, β-thalassemia major (β-TM) is associated with potentially severe clinical characteristics, including poor growth, feeding difficulties, hepatosplenomegaly, bone metabolic disorders, and skeletal abnormalities.

METHODS

In this study, we reviewed the demographic and clinical characteristics (e.g., age, sex, duration of blood transfusion and chelating therapy, and vitamin supplementation) and serum biomarker levels (e.g., iron accumulation, bone metabolism, liver, kidney, and thyroid function markers) of 32 patients that received regular blood transfusion at a single center in southern China with the aim of stratifying the risk of severe complications such as osteopenia, endocrinopathies, and multi-organ failures.

RESULTS

Although all patients exhibited moderately to strongly elevated serum ferritin levels, this biomarker was significantly higher in children older than ≥5 years, compared to younger children (*p < 0.05, 1512 ± 192.6 vs. 2337 ± 299.8 ng/ml, Mann-Whitney U test). Older children had a significantly lower 25-hydroxy vitamin D3 (25(OH)D3) level, compared to younger children (**p < 0.01, 34.25 ± 11.06 vs. 23.05 ± 9.95 ng/ml, Mann-Whitney U test). No age-related differences were observed in serum calcium, phosphorus, and PTH levels. Regarding liver function, the serum alanine aminotransferase (ALT) level was significantly increased in children older than ≥5 years, compared to younger children (*p < 0.05, 19.17 ± 2.44 vs. 43.45 ± 9.82I U/ml, Mann-Whitney U test). However, no age-related differences were observed in the serum levels of other liver or kidney and thyroid biomarkers.

CONCLUSIONS

Our results suggest that in older children, hepatic iron overload may be associated with a low serum concentration of 25(OH)D3, an indicator of vitamin D deficiency and altered bone metabolism. Iron accumulation may also be associated with a higher concentration of ALT, a sensitive marker of liver malfunction. These findings may provide important clinical indications of the need for intervention to prevent severe complications in children with β thalassemia.

Prevalence of abnormal glucose homeostasis in Chinese patients with non-transfusion-dependent thalassemia

Purpose: To determine the prevalence and underlying pathology of abnormal glucose homeostasis in Chinese patients with non-transfusion-dependent thalassemia (NTDT). Patients and methods: In this study, we enrolled 211 patients aged 4-63 years with NTDT, including 79 β thalassemia intermedia patients, 114 Hb H disease patients and 18 Hb E/β thalassemia patients. All had oral glucose tolerance test, serum ferritin (SF), homeostasis model assessment (HOMA) and liver iron concentration (LIC) measurement. One hundred and twenty healthy age-matched controls were also used for the comparative purpose. Iron load was assessed by using SF and hepatic load by LIC using validated MRI techniques. Results: The 211 patients were divided into three groups according to their fasting and 2 hrs postprandial blood glucose levels: hypoglycemic, normal glucose tolerance (NGT) and hyperglycemic groups. In this study, 149 patients had NGT, 33 had hypoglycemia, 4 had diabetes and 25 had impaired glucose tolerance (IGT). None had impaired fasting glucose. There was a significant correlation between 2 hrs postprandial blood glucose levels and age, PINS120, HOMA-IR, alanine aminotransferase and LIC (P<0.05). Risk factors for IGT in NTDT patients were older age (≥24 years) and SF concentration of ≥2,500 ng/mL. Conclusion: Age ≥24 years and SF ≥2,500 ng/mL of NTDT patients were at a greater risk for impaired glucose tolerance.

Rheumatic Manifestations of Haemoglobinopathies

PURPOSE OF THE REVIEW

To provide a clinically useful literature review on the rheumatic manifestations of haemoglobinopathies, critically analysing the literature from the past 5 years.

RECENT FINDINGS

There are limited new data to guide the management of rheumatic manifestations of haemoglobinopathies. Data further confirm the wide spectrum of potential rheumatic/MSK involvement in haemoglobinopathies, which poses both a diagnostic and therapeutic challenge. Inflammatory arthritis may be more common than previously believed. Steroid therapy by any route of administration can provocate a potential life-threatening vaso-occlusive crisis. Vitamin D deficiency is common. There are limited data to guide the drug treatment of reduced bone density in haemoglobinopathies. There have been a number of studies examining pain in sickle cell anaemia. Plasma levels of Klotho may represent a novel biomarker in patients with β-Thalassemia. There are little new data on the rheumatic manifestations in haemoglobinopathies and future high-quality research is needed.

Impact of bone disease and pain in thalassemia

Conventional treatment of thalassemia, namely regular blood transfusion and iron chelation, improves perspectives and quality of life; however, successful treatment leads to more time in which long-term complications such as bone disease can develop. Thalassemia bone disease (TBD) is unique: all aspects, from bone anatomy and bone quality to mineral density, may be affected, with important morbidity including osteoporosis, fractures, spinal deformities, nerve compression, and pain. Clinical presentations include growth impairment, rickets-like features, back pain, spinal deformities, any sign of nerve compression, severe osteoporosis, and fragility fractures. Age, history, physical examination, and diagnostic tests support orientation on risk factors. These include bone marrow expansion, toxicity from iron overload and iron chelation, endocrine dysfunctions (hypogonadism, hypohyperparathyroidism, hypothyroidism, growth hormone deficiency, diabetes), and vitamin (D, C, K) and zinc deficiencies. Several of these may coexist in an individual for a long time and at different degrees, making clarification of the relative contribution and selection of the best therapeutic options a challenge. Milestones for prevention of TBD are early and full inhibition of bone marrow hyperplasia and iron toxicity. Empowering patients' positive resources is key for achieving long-term healthy habits with regard to diet, physical activity, sunlight exposure, and lifestyle. Pain, related or unrelated to bone disease, is frequent in thalassemia. The most important targets for the hematologist include having an expert orientation on disease-related causes of pain, driving differential diagnosis, providing effective pain relief and, where feasible, removing the cause.