Reversal of vascular F-18-FDG uptake with plasma high-density lipoprotein elevation by atherogenic risk reduction

Abstract

Vascular F-18-FDG uptake marker represents inflammation in atherosclerotic lesions, but whether inflammation can be reversed by risk-modifying interventions has not, to our knowledge, been demonstrated. In this study, we evaluated the change of vascular F-18-FDG uptake in response to lifestyle intervention on serial PET/CTscans and further assessed how the findings relate to atherogenic risk reduction. Methods: A total of 60 healthy adults underwent F-18-FDG PET/CT scans and atherogenic risk-factor assessment at baseline and again after 17.1 +/- 8.3 mo of practicing lifestyle modification. The PET/CT images were evaluated for the presence of vascular F-18-FDG lesions, and vessel-to-blood-pool F-18-FDG ratios were measured. Indices from summed ratios of positive lesions were compared and correlated to atherogenic risk factors. Results: At follow-up, significant reductions in diastolic blood pressure (P < 0.05), total cholesterol (P < 0.05), and low-density lipoprotein level (P < 0.05) and an increase in high-density lipoprotein (HDL) level (P < 0.0001) were demonstrated. On the initial PET/CT scan, 50 of 60 subjects showed 1 or more F-18-FDG-positive lesions (5.9 +/- 5.0/subject), leading to a total of 352 vascular sites. On follow-up, F-18-FDG-positive lesions were significantly reduced to 2.1 +/- 2.2 sites per subject (P < 0.0001) and a total of 124 sites (64.8% reduction). Follow-up F-18-FDG-positive rates were significantly reduced for the aorta and iliac arteries. In addition, significant reductions in the whole-body F-18-FDG index from 1.39 +/- 1.23 to 0.53 +/- 0.59 (P < 0.0001) and carotid F-18-FDG index from 0.08 +/- 0.16 to 0.03 +/- 0.06 (P = 0.01) were shown. The whole-body F-18-FDG index correlated with total cholesterol (P < 0.05) and HDL level (P < 0.05), and the magnitude of reduction in the F-18-FDG index closely correlated to the amount of increase in plasma HDL level (P = 0.005). Conclusion: Our study demonstrated that vascular F-18-FDG uptake is reversed in response to atherogenic risk reduction by lifestyle intervention and that the magnitude of improvement correlates to increases in plasma HDL levels. Thus, serial F-18-FDG PET/CT may be useful for monitoring improvements in the inflammatory component of atherosclerotic lesions in response to risk modification.