Relation of haptoglobin phenotype to early vascular changes in patients with diabetes mellitus.
Haptoglobin (Hp) is an antioxidant protein and the major susceptibility gene for atherosclerosis in diabetic patients. The effect of Hp phenotype on arterial compliance and metabolic and inflammatory parameters was investigated. Patients were divided into 3 groups according to Hp phenotype of Hp 2-2, Hp 2-1, and Hp 1-1. Arterial elasticity of large and small arteries was evaluated using the pulse-wave contour analysis method. The large-artery elasticity index (LAEI) was lower in patients with Hp 2-2 compared with Hp 1-1 (8.4 +/- 2.3 vs 12.6 +/- 4.1 ml/mm Hg x 100; p <0.0001). The difference in LAEIs between the Hp 2-1 and Hp 1-1 groups was also significant (9.9 +/- 2.6 vs 12.6 +/- 4.1 ml/mm Hg x 100; p = 0.025). The Hp 2-2 and Hp 2-1 groups did not differ from one another. The small-artery elasticity index (SAEI) was significantly lower in patients with Hp 2-2 compared with Hp 1-1 (2.8 +/- 1.0 vs 4.4 +/- 1.9 ml/mm Hg x 100; p = 0.004). Differences in SAEIs between patients with Hp 2-1 and Hp 1-1, as well as those with Hp 2-1 and Hp 2-2, were not detected. Systemic vascular resistance differed significantly across groups, driven by the difference between patients with Hp 2-2 and Hp 1-1. In conclusion, LAEI and SAEI were significantly lower and systemic vascular resistance was higher in homozygotes for the 2 allele (Hp 2-2) compared with patients with Hp 2-1 or Hp 1-1 phenotypes. Differences in arterial elasticity were detected despite the lack of by-phenotype differences in glycemic control, blood pressure, or presence of cardiovascular risk factors.
Shor
Marina
M
Department of Internal Medicine, E. Wolfson Medical Center, Tel Aviv University, Tel Aviv, Israel.
Boaz
Mona
M
Gavish
Dov
D
Wainshtein
Julio
J
Matas
Zipora
Z
Shargorodsky
Marina
M
D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics*; D003925:Diabetic Angiopathies / Q000235:genetics*; D004548:Elasticity; D005260:Female; D006242:Haptoglobins / Q000235:genetics*; D006439:Hemodynamics; D018056:Hemorheology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D013997:Time Factors; D014655:Vascular Resistance / Q000235:genetics
D006242:Haptoglobins