Abstract
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Objectives: We aimed to determine the relationship between coronary vascular function, carotid intima thickness (IMT) and coronary artery calcification (CAC) in asymptomatic individuals with normotensive or hypertensive type 2 diabetes mellitus (NDM and HDM).
Methods: MBF was measured in ml/g/min with N-13 ammonia and PET at rest, during CPT and during adenosine-induced pharmacologic vasodilation in 32 healthy controls, 23 NDM and 13 HDM. Carotid IMT and CAC were measured using high-resolution vascular ultrasound and electron beam tomography (EBT).
Results: Compared to controls, endothelium-related change in MBF to CPT (ΔMBF)progressively declined in NDM and HDM groups that was also mirrored by corresponding changes of coronary vascular resistance (ΔCVR)(Table). The adenosine-related CVR (accounting for possible differences in coronary driving pressure)was significantly less in controls than in NDM and HDM (Table). Carotid IMT did not differ significantly between controls and NDM, but was significantly higher in the HDM group. Further, although the CAC was higher in NDM and HDM as compared to controls, no significant differences among the groups were found. On regression analysis carotid IMT did not correlate with CAC (r=0.18, p=0.25). Also, there was no relation between carotid IMT, CAC and ΔMBF, respectively (r=-0.19, p=0.24 and r=-0.14, p=0.24) or ΔCVR (r=0.02, p=0.08 and r=0.09, p=0.73) nor when compared to adenosine-stimulated MBFs (r=0.11, p=0.51 and r=-0.15, p=0.23) or corresponding CVR (r=0.09, p=0.85 and r=0.12, p=0.58).
Conclusions: These findings suggest that in asymptomatic type 2 diabetic patients an impairment of coronary circulatory function precedes structural alterations in the arterial wall. The lack of any association between between measures of coronary vascular function, carotid IMT and CAC indicates these surrogates to measure different aspects and stages of early vascular disease in diabetic patients.
- Society of Nuclear Medicine, Inc.