Effect of heterozygous β-thalassaemia trait on coronary atherosclerosis via coronary artery disease risk factors: a preliminary study

BACKGROUND Thalassaemia is considered the most common genetic disorder worldwide. An association between the heterozygous beta-thalassaemia trait and myocardial infarction has previously been observed. However, the relationship between heterozygous beta-thalassaemia and atherosclerosis, considering other coronary artery disease (CAD) risk factors, has remained unclear. METHODS A case-control study was conducted to evaluate the hypothesis that thalassaemia minor affects the likelihood of atherosclerotic plaque formation. Blood counts and blood chemistry data as well as traditional risk factors from 1,363 patients referred to heart centres for coronary angiography were recorded. Heterozygous beta-thalassaemia was diagnosed by the presence of hypochoromic-microcytic anaemia, ferritin levels > 12 ng/ml and haemoglobin-A2 levels > 3.5. RESULTS Chi-squared analysis showed that the prevalence of heterozygous beta-thalassaemia was not significantly different between patients with and without CAD (p > 0.05). Multivariate logistic regression analysis using CAD as the dependent variable and traditional risk factors, haematocrit, ferritin levels and heterozygous beta-thalassaemia as independent variables, did not show any significant difference either. Independent two-tailed student's t-tests showed that haematocrit levels were statistically different (p = 0.000) between CAD(+) and CAD(-) groups, but low-density lipids (LDL), high-density lipids (HDL), triglycerides (TG), total cholesterol and serum ferritin levels were not statistically different (p > 0.05). CONCLUSION The prevalence of heterozygous beta-thalassaemia in the case group was not significantly different from the control group. This case-control study did not support the hypothesis that thalassaemia minor affects the likelihood of atherosclerotic plaque formation.