Abstract 14785: The Influence of Haptoglobin Phenotype on Carotid Macroangiopathy in Patients With Type 2 Diabetes Mellitus
Background: Diabetes mellitus (DM) patients develop atherosclerosis. Intensive glycemic control therapy among Type 2 DM patients have failed to show preventive effects on cardiovascular events. One of reasons of this inconsistency is different unknown patient background. Hp gene in humans has 2 common alleles 1 and 2 resulting in 3 possible phenotypes (Hp1-1, Hp1-2, and Hp2-2). Hp2-2 phenotype produce a dysfunctional protein that dose not protect against oxidative damage, resulting in an independent risk factor for cardiovascular complications in DM patients. However, there are few reports on association of Hp phenotype with carotid macroangiopathy in DM patients.
Methods: This study included 83 consecutive patients aged 40-79 years with a <10 year, but at least 6-month history of type 2 diabetes. The exclusion criteria were insulin dependency, concomitant chronic diseases of the kidney and liver, recent acute illness, or a 3-month treatment change. HbA1c [(NGSP), mean glucose level marker], 1.5-AG (glycemic fluctuation marker) were sampled. Carotid maximum intima-media thickness (IMT) and the plaque score (PS) were determined by carotid ultrasonography.
Results: Patients were divided into 2 groups: Hp1 (Hp1-1 and 1-2, N=34) and Hp2 (Hp2-2, N=49). No significant differences in the HbA1c and 1.5-AG levels and clinical characteristics including age and medication were observed between groups. Only in Hp1, HbA1c level had significant positive correlation with max IMT and PS. Additionally, 1.5-AG level had significant negative correlation with PS. Based on HbA1c≥ 6.5 %, Hp1 was divided into 2 groups: Hp1(A) (HbA1c≥ 6.5%, N=18) and Hp1(B) (HbA1c<6.5%, N=16). Similarly, Hp2 was divided into 2 groups: Hp2(A) (HbA1c≥ 6.5%,N=22) and Hp2(B) (HbA1c<6.5%,N=27).
Only In Hp1(A), HbA1c level significantly correlated with max IMT and PS (R=0.52,P=0.02; R=0.43,P=0.04, respectively) but not in Hp1(B), Hp2(A) and Hp2(B). Similarly, only in Hp1(A), 1.5-AG level significantly correlated with PS (R=-0.44, P=0.04) but not in Hp1(B), Hp2(A) and Hp2(B).
Conclusion: Efficacy of glycemic control therapy for carotid macroangiopathy in type 2 diabetes patients may depend on the Hp phenotype and glycemic control.
- © 2013 by American Heart Association, Inc.