Abstract 2949: Atherosclerotic Plaque Inflammation is Highly Correlated with Serum Inflammatory Biomarker Levels - An FDG-PET/CT Imaging Study
Introduction Atherosclerosis is a diffuse inflammatory condition, and FDG PET imaging can be used non-invasively to quantify inflammation within arteries. Plaque inflammation is greater in those at highest risk of future clinical events. Levels of arterial FDG uptake can differentiate symptomatic from asymptomatic lesions. We examined the relationship between arterial inflammation and circulating inflammatory biomarkers.
Methods We imaged 33 asymptomatic patients with either established vascular disease or risk factors for it. Subjects were scanned using GE Discovery LS PET/CT 90 minutes after 10mCi FDG. All 33 patients underwent carotid imaging. Additionally, 28 had aortic imaging, and 19 and 12 respectively had iliac and femoral arteries assessed. To estimate FDG uptake into vessel, standardized uptake values (SUV) were calculated using ROI applied to the PET/CT images and corrected for blood FDG activity. Blood for biomarker assays was drawn at the time of FDG injection.
Results Mean age was 64 years, with 73% males and 37% diabetic. There were significant correlations between MMP3 levels and descending aorta FDG uptake (r=0.45, p=0.043), MMP9 and carotid FDG uptake (r=0.42, p=0.019) and interleukin 18 was positively associated with aortic arch FDG uptake (r=0.49, p=0.024). Fibrinogen levels were positively correlated, though non-significantly, with FDG uptake in the aorta. There were significantly negative associations between adiponectin levels and FDG uptake in descending aorta (r = -0.52, p = 0.16), and between plasminogen activator inhibitor 1 (PAI-1) and carotid FDG uptake (r = -0.373, p = 0.05). There was no relationship between FDG uptake and any of the following biomarkers: interleukins 6 and 10, hsCRP, TNF alpha, MMP1 or lipid levels.
Conclusions We have shown significant positive correlations between arterial inflammation (quantified by FDG PET) and levels of several inflammatory serum biomarkers in patients with, or at risk of vascular disease. The negative relationships between vascular inflammation and adiponectin and PAI-1 suggest possible anti-inflammatory effects of these biomarkers. In the future, FDG PET could be used as part of a non-invasive vascular assessment to detect those patients at highest risk of clinical events.