Abstract 5825: Association between Patterns of FDG Uptake and Arterial Wall Calcification on PET/CT and Atherogenic Risk Factors in Healthy Subjects

Abstract

Background: Augmented metabolic activity of macrophages leads to enough F-18 Fluorodeoxyglucose (FDG) uptake to allow visualization by positron emission tomography (PET). A large body of data, based on computed tomography (CT), has also accumulated concerning the relevance of vascular calcification to the atherosclerotic process. FDG PET/CT can localize both inflammatory changes and vascular calcification. The purpose of this study was to investigate risk factors contributing to these changes in the aorta in healthy subjects. Materials and Methods: A total of 66 consecutive healthy subjects (44 men, 22 women; age range, 30–82 years, mean age, 55.8 years) participating in a health check protocol including FDG PET/CT were evaluated retrospectively. We placed regions of interest on the arterial wall to measure FDG uptake by PET images. To assess arterial calcification, the calcium score of the aorta was measured on CT images. Results: FDG uptake was observed most commonly in proximal, followed by descending, thoracic, and abdominal segments. On the other hand, the most common site of vascular calcification was the descending thoracic aorta, followed by abdominal and, proximal segment. Whole aortic calcification (total calcium score of the whole aorta) was significantly correlated with age (r= 0.353, P= 0.004). On the other hand, FDG uptake (total SUV max of the whole aorta) was significantly correlated with systolic blood pressure (SBP) (r= 0.303, P= 0.013), triglyceride (TG) (r= 0.281, P= 0.022), fasting plasma glucose (FPG) (r= 0.317, P= 0.010), HbA1c (r= 0.433, P< 0.001), visceral abdominal fat area (r= 0.319, P= 0.005), and was negatively correlated with high density lipoprotein (HDL) (r= −0.317, P= 0.010), and adiponectin (r= −0.273, P= 0.029). Conclusions: Aortic calcification was significantly correlated with age. On the other hand, FDG uptake was significantly correlated with the components of metabolic syndrome such as SBP, TG, FPG, HbA1c, visceral adipose fat area and negatively correlated with HDL and adiponectin, but not with age. Our results may suggest that the components of metabolic syndrome and aging affect the progression of atherosclerosis differently.