Haptoglobin genotype and endothelial function in diabetes mellitus: a pilot study.
Endothelial function (EnF) is impaired in patients with diabetes mellitus (DM) due in large part to an increase in oxidative stress. Haptoglobin (Hp) is a potent antioxidant protein which is encoded by two different alleles (1 and 2) with the Hp 1 protein being a superior antioxidant to the Hp 2 protein. We hypothesized that DM individuals with the Hp 2-2 genotype would have greater endothelial dysfunction as compared to DM individuals with the Hp 1-1 genotype. We studied EnF in 16 Hp 2-2, 14 Hp 1-1 DM individuals and 14 healthy subjects. DM patients' groups were matched in terms of age, cardiovascular risk factors and metabolic characteristics. EnF was assessed using post-ischemic reactive hyperemia and strain gauge plethysmography and expressed either as the maximal flow after the ischemic period or as the area under the flow-time curve (AUC). We showed that EnF indices, AUC and maximal flow, were also higher in the healthy and Hp 1-1 groups compared with Hp 2-2 genotype group (615 +/- 60 and 600 +/- 40 vs. 450 +/- 50 ml dl(-1), 29 +/- 2.6 and 25 +/- 3 vs. 14 +/- 1.8 ml min(-1) dl(-1), P < 0.003 and P < 0.05, for AUC and maximal flow, one-way ANOVA, respectively). We concluded that Hp 2-2 diabetic patients had a worse EnF than controls and Hp 1-1 diabetic subjects.
Dayan
Lior
L
J. Recanati Autonomic Dysfunction Center, Medicine A, Technion-Israel Institute of Technology, Rambam Medical Center, PO Box 9602, 31096, Haifa, Israel. l_dayan@rambam.health.gov.il
Levy
Andrew P
AP
Blum
Shany
S
Miller-Lotan
Rachel
R
Melman
Uzi
U
Alshiek
Jonia
J
Jacob
Giris
G
D001783:Blood Flow Velocity; D003920:Diabetes Mellitus / Q000503:physiopathology*; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D006242:Haptoglobins / Q000235:genetics*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D014664:Vasodilation / Q000235:genetics*
D006242:Haptoglobins