Genotyping and phenotyping of Haptoglobin gene polymorphisms and their correlation with cardiovascular disease and biochemical parameters in Iranian patients with type 2 diabetes mellitus

Purpose We aimed to examine genotyping and phenotyping of Haptoglobin (Hp) gene polymorphisms and their correlation with cardiovascular disease and biochemical parameters in Iranian patients with type 2 diabetes mellitus. Methods We analyzed the phenotype (by polyacrylamide gel electrophoresis and peroxidase labeling), genotype (by extracting DNA), and biochemical characteristics to determine the relationship of Hp polymorphisms with premature CVD and its severity in 148 patients with T2DM, 150 patients with both CVD and T2DM, and 130 healthy controls at Afshar Hospital in Yazd city, Iran. Results After adjustment for age and gender, the Hp2–1 and Hp2–2 genotypes and phenotypes were related to an elevated risk of CVD in diabetic participants compared to the control group (OR = 10.35, 95% CI: 3.39–31.59, p = 0001and OR = 9.25, 95% CI: 2.29–28.59, p = 0001, respectively). Such an association was significantly observed in patients with diabetes compared to the control group (OR = 1.06, 95% CI: 0.25–4.20, p = 0.956); however, the frequency of Hp2–1and Hp2–2 genotypes in patients with both diabetes and CVD was not significantly different in comparison with diabetic individuals (OR = 1.65, 95% CI: 0.40–6.83, p = 0.484). After adjusting for age, sex, and disease, we also discovered that the Hp polymorphisms are correlated with low density lipoprotein cholesterol (LDL) and triglyceride (TG) levels. Conclusion Based on what we found, the genotypes and phenotypes of Hp2–2 and Hp2–1 are thought to be risk factors for type 2 diabetes. In addition, these polymorphisms might play an important role in increasing LDL and TG levels.