Surrogate Markers of Subclinical Atherosclerosis and Its Associated Factors in Patients with β-Thalassemia Major

Abstract

β-Thalassemia major (β-TM) is a severe genetic hemoglobin (Hb) disorder with cardiovascular complications such as atherosclerosis due to transfusion-dependent iron overload. We aimed to determine the associated factors with surrogate markers of subclinical atherosclerosis in these patients. Sixty subjects with β-TM referred to the Thalassemia Clinic of the Iranian Blood Transfusion Organization (IBTO) were included in our study. The blood samples were collected for laboratory measurements. The carotid intima-media thickness (CIMT), was measured by ultrasonography, and ankle-brachial index (ABI) was calculated. The multivariate linear analysis was performed to determine the appropriate indicators of subclinical atherosclerosis in β-TM. There was no significant difference in baseline characteristics between the study groups. In multivariate linear analysis, age and systolic blood pressure (SBP) were negatively associated with inverse-transformed CIMT [unstandardized β coefficient (B): −0.024, 95% confidence interval (95% CI): −0.032- −0.010, p < 0.001; B: −0.009, 95% CI: −0.017- −0.001, p 0.031, respectively]. There was also a significant correlation between the serum level of high-density lipoprotein cholesterol (HDL-C) and insulin with higher ABI, after adjustment for confounding variables (B: 0.003; 95% CI: 0.000–0.005; p = 0.030, and B: 0.004, 95% CI: 0.000–0.009, p = 0.037, respectively). Our results show that advancing age and increased SBP, HDL-C and insulin, associated with higher CIMT or ABI, are appropriate indicators of subclinical atherosclerosis in β-TM patients.

Keywords:

• Atherosclerosis
• ankle brachial index (ABI)
• β-thalassemia (β-thal)
• carotid intima-media thickness (CIMT)

Acknowledgements

The authors thank all the participants and the staff of the thalassemia clinic of the Iranian blood transfusion organization. This study was a part of an MD thesis by Dr. Elaham Mahmoudi and supported by the Tehran University of Medical Sciences.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.