Haptoglobin genotype is associated with increased endothelial dysfunction serum markers in type 1 diabetes

BackgroundTo evaluate the genotype-driven effect of haptoglobin (Hp) in patients with type 1 diabetes without clinical cardiovascular (CV) disease, considering endothelial dysfunction (ED) and arterial stiffness (AS). Material and methodsAbout 137 patients with type 1 diabetes (duration 5years) and 68 age- and sex-matched controls were evaluated for the following: (i) smoking, alcohol intake, BMI, blood pressure, fasting plasma glucose, HbA(1c) and lipid profile; (ii) microvascular complications; (iii) serum markers of ED (ICAM-1, VCAM-1 and E-selectin); (iv) AS, assessed as aortic pulse wave velocity (aPWV); and (v) Hp genotype. ResultsThe prevalence of the 1/1, 2/1 and 2/2 Hp genotypes was 285%, 467% and 248% in patients with type 1 diabetes and 209%, 388% and 403% in controls, respectively. No differences were found in classical CV risk factors between patients homozygous for allele 2 and the remaining genotypes, both in patients with type 1 diabetes and controls. Patients with type 1 diabetes carrying the Hp2/2 genotype had higher concentrations of ICAM-1 (651 (567-760) ng/mL vs. 590 (517-693) ng/mL; P=0033) and sVCAM-1 (11331 (8846-14586) ng/mL vs. 9564 (7385-12061) ng/mL; P=0040) than those without it. The Hp2/2 genotype remained independently associated with ED after adjusting for CV risk factors (P=0038). No significant differences were found for aPWV between Hp genotypes. ConclusionsEndothelial dysfunction may be influenced by Hp2/2 genotype in patients with type 1 diabetes with independence of classical CV risk factors.