Parathyroid hormone in pediatric patients with β-thalassemia major and its relation to bone mineral density; a case control study

An In-Depth Analysis of Variable Dynamics Influencing Bone Mineral Density in Transfusion-Dependent Thalassemia Patients

The survival of patients with transfusion-dependent thalassemia has increased with optimal blood transfusion. In adult patients with thalassemia, iron toxicity due to repeated blood transfusion is the main contributing factor causing decreased bone density and leads to mechanical disruption in the bone structure. This study aimed to analyze the variables affecting bone mineral density (BMD) in patients with thalassemia major. We enrolled patients with transfusion-dependent thalassemia who visited the Hasan Sadikin Hospital Bandung outpatient clinic. Participants underwent anthropometric measurement, laboratory, and BMD examination. Bivariate analysis was performed to determine the correlation between clinical data and BMD by Pearson or Rank-Spearman depending on data distribution. Multivariate analysis was performed to determine the most influential variables using linear regression analysis. p < 0.05 was considered statistically significant. Overall, 59 participants were included. BMD was significantly correlated with body mass index (BMI), sex, average pre-transfusion hemoglobin level, blood transfusion volume, and vitamin D, with coefficient r values of 0.47, 0.34, - 0.27, and - 0.28 (p < 0.05), respectively. BMI was the variable that most influenced BMD, with 0.39 coefficient value, an adjusted coefficient value of 0.32 (0.01-0.04), and p = 0.04. Receiver operating characteristic analysis showed BMI had the highest area under the curve (AUC) in all examination areas, especially in the hip area, with 0.800 AUC. 77.8% sensitivity, and 71.7% specificity. BMD was correlated with BMI, sex, average pre-transfusion hemoglobin level, blood transfusion volume, and vitamin D, with BMI being the most influential factor affecting BMD.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12288-024-01864-1.

Assessment of serum vitamin D levels in Egyptian children with beta-thalassemia major

Background

Beta-thalassemia major patients are at increased risk of complications including endocrinopathies and bone disease due to iron overload. So, this study aimed to assess the growth parameters, serum levels of 25-OH-vitamin D, calcium, and phosphorous in children with beta-thalassemia major. This was a case-control study that included 55 children with beta-thalassemia major compared with 30 sex- and age-matched healthy children that served as a control group. All enrolled children were subjected to full history taking, clinical examination including anthropometric measurements, and laboratory investigations including complete blood count, serum ferritin, levels of serum calcium, phosphorus, and 25-OH-vitamin D.

Results

Body mass index was statistically significantly lower in the thalassemic group (P < 0.001). It was observed that vitamin D levels were significantly lower in thalassemic patients than in controls (P value < .0001). The mean serum 25-OH-vitamin D levels were 19.84 ± 5.79 ng/ml and 44.98 ± 5.77 ng/ml, respectively; 22 cases (40%) had insufficient vitamin D, and 5 cases (9%) had deficient vitamin D. Regarding serum calcium and phosphorous, there was no significant difference between the thalassemic and control groups.

Conclusion

Children with beta-thalassemia major had low body mass index and metabolic abnormality in the form of lower serum levels of vitamin D that signify the importance of therapeutic interventions.

An Evaluation of Bone Health Parameters in Regularly Transfused Beta-Thalassemia Major Patients

As beta-thalassemia major patients need regular blood transfusions due to the severe hemoglobin deficiency, the occurrence of related bone defects with simultaneous fluctuations in the biochemical and hematologic parameters is seen. The hospital-based cross-sectional observational study was done to determine and correlate the bone mineral density (BMD) with biochemical parameters and hematologic parameters in 50 regularly transfused beta-thalassemia major patients of older than 6 years of age. Descriptive statistics were analyzed with SPSS version 20.0 software. A P<0.05 was considered as statistically significant. The prevalence of suboptimal BMD at lumbar spine was 86% and at femur neck was 74%. A statistically significant correlation of BMD was found with mean pretransfusion hemoglobin values, serum calcium levels, and serum vitamin D levels (P<0.05). It was concluded that continuous monitoring of the BMD, biochemical, and hematologic parameters in regularly transfused beta-thalassemia major patients may help assess the ongoing deficiencies; helping to maintain timely and regular blood transfusions with supplementation of calcium, vitamin D to ensure good bone health.

Effect of serum fibroblast growth factor receptor 2 and CAPS proteins on calcium status in β-thalassaemia major patients who are free from overt inflammation

Bone disorders and disturbed calcium (Ca) homeostasis are common disorders in β-thalassaemia major (β-TM). In the present study, two bone related markers are studied in β-TM patients with negative C-reactive protein for the first time; fibroblast growth factor receptor 2 (FGFR2) and CAPS protein. Another goal is to estimate the correlation between the recent parameters and bone biomaterials as a function of iron status parameters in β-TM patients. The results revealed that, in patients with β-TM serum FGFR2, CAPS, alkaline phosphatase (ALP) and Mg significantly increased while serum Ca levels were low as compared with controls. Ca status is correlated with iron overload in β-TM. A significant correlation was present between CAPS and FGFR2. In conclusion, FGFR2 and CAPS associated with Ca status and subsequent bone disturbances in β-TM patients. Their level can be predicted from the equation: CAPS =0.001ALP +0.48FGFR2-1.26Ca - 3.95Pi +12.76 with acceptable applicability.

Intestinal calcium transport and its regulation in thalassemia: interaction between calcium and iron metabolism

Osteoporosis and derangement of calcium homeostasis are common complications of thalassemia. Despite being an important process for bone and calcium metabolism, little is known about intestinal calcium transport in thalassemia. Recent reports of decreases in both intestinal calcium transport and bone mineral density in thalassemic patients and animal models suggested that defective calcium absorption might be a cause of thalassemic bone disorder. Herein, the possible mechanisms associated with intestinal calcium malabsorption in thalassemia are discussed. This includes alterations in the calcium transporters and hormonal controls of the transcellular and paracellular intestinal transport systems in thalassemia. In addition, the effects of iron overload on intestinal calcium absorption, and the reciprocal interaction between iron and calcium transport in thalassemia are elaborated. Understanding the mechanisms underlining calcium malabsorption in thalassemia would lead to development of therapeutic agents and mineral supplements that restore calcium absorption as well as prevent osteoporosis in thalassemic patients.