Vitamin D deficiency and its relationship with cardiac iron and function in patients with transfusion-dependent thalassemia at Chiang Mai University Hospital

ABSTRACT

Background: Vitamin D deficiency is common in patients with thalassemia. Vitamin D deficiency could be related to cardiac dysfunction. Increased parathyroid hormone (PTH) is also known to be associated with heart failure. Objectives: To determine the prevalence of Vitamin D deficiency and to explore the impact of Vitamin D deficiency on cardiac iron and function in patients with transfusion-dependent thalassemia. Method: A cross-sectional study in patients with Transfusion-dependent thalassemia was conducted. Patients with liver disease, renal disease, type 1 diabetes, malabsorption, hypercortisolism, malignancy, and contraindication for MRI were excluded. Calcium, phosphate, PTH, vitamin D-25OH were measured. CardiacT2^* and liver iron concentration (LIC) and left ventricular ejection fraction (LVEF) were determined. Results Sixty-one (33M/28F) patients with Transfusion-dependent thalassemia were enrolled. The prevalence of Vitamin D deficiency was 50.8%. Patients with cardiac siderosis had tendency for lower D-25OH than those without siderosis (15.9 (11.7–20.0) vs. 20.2 (15.85–22.3) ng/mL); p = 0.06). Serum calcium, phosphate, PTH, LIC, cardiac T2^*, and LVEF were not different between the groups with or without Vitamin D deficiency. Patients with Vitamin D deficiency had significantly lower hemoglobin levels compared to those without Vitamin D deficiency (7.5 (6.93–8.33) vs. 8.1 (7.30–8.50) g/dL; p = 0.04). The median hemoglobin in the last 12 months was significantly correlated with D-25OH. Cardiac T2^* had significant correlation with PTH. Conclusion: Vitamin D deficiency is prevalent in patients with Transfusion-dependent thalassemia. Vitamin D level is correlated with hemoglobin level. Vitamin D status should be routinely assessed in these patients. Low PTH is correlated with increased cardiac iron. This study did not demonstrate an association between Vitamin D deficiency and cardiac iron or function in patients with Transfusion-dependent thalassemia.

KEYWORDS:

• Cardiac iron
• cardiac function
• transfusion-dependent thalassemia
• Vitamin D

Acknowledgements

The authors would like to thank pediatric cardiology nurses for assistance and the patients who volunteered to participate in this study.

Disclosure of potential conflicts of interest

The authors have no conflicts of interest to report. The authors confirm that the research presented in this article met the ethical guidelines, including adherence to the legal requirements, of [Thailand] and received approval from the [Ethic committee at the Faculty of Medicine, Chiang Mai University].

Additional information

Funding

This project was fully supported by Thailand Research Fund grant (RSA5680014) and Faculty of Medicine Research Fund from the Faculty of Medicine of Chiang Mai University, Chiang Mai, Thailand.