Relationship between beta-globin gene carrier state and insulin resistance

OBJECTIVE To assess the relationship between being beta globin gene carrier and developing insulin resistance. METHODS This study was conducted on 164 subjects including 82 healthy ones and 82 patients with beta thalassemia minor (microcytosis (MCV <80 fl) and hypochromia (MCH <25 pg) and HbA2 ≥ 3.5% using HPLC). Fasting blood glucose (FBS) values of 100-125 mg/dl were considered as impaired fasting glucose, and above 125 mg/dl as diabetes mellitus. Two hours After 75 gram glucose load(GTT), blood sugar level of 140-199 mg/dl was considered as impaired glucose tolerance and above 199 mg/dl as diabetes mellitus. Insulin resistance was diagnosed based on homeostasis model assessment method (HOMA). RESULTS According to FBS and BS2hPG values, the percentages of diabetes mellitus, pre diabetes, and normal glucose tolerance in case group was 8.5%, 9.8% and 81.7%, respectively. There was no case of diabetes mellitus in control group and 6.1% of this group were pre diabetic and 93.9% of them had normal glucose tolerance test (P = 0.02). Relative risk for diabetes mellitus and insulin resistance in the cases with minor thalassemia was 2 (95% CI: 1.8-2.5) and 2.02 (95% CI: 1.7-2.4), respectively. CONCLUSION The risk of developing diabetes and insulin resistance in patients with thalassemia minor is two times greater than the general population. Considering the high serum levels of CRP in these cases, the inflammation noted in liver cells could be considered as the underlying cause of insulin resistance, impaired glucose tolerance and diabetes in these patients.