Relation of Carotid Artery ¹⁸F-FDG Uptake to C-Reactive Protein and Framingham Risk Score in a Large Cohort of Asymptomatic Adults

Abstract

We investigated the relation of carotid 18 F-FDG uptake to high-sensitivity C-reactive protein (hsCRP) and Framingham risk score (FRS) in a large cohort of asymptomatic adults. Methods: Carotid artery 18 F-FDG uptake was measured on the PET/CT scans of 1,181 asymptomatic subjects, and maximum target-to-background ratio (M-TBR) and intima-media thickness (IMT) were compared with clinical risk factors and hsCRP. The estimated 10-y risk for general cardiovascular disease was calculated by FRS. Results: FRS increased from 11.5% 6 7.8% to 14.8% 6 10.5% in subjects with an M-TBR $ 1.7, compared with , 1.7, and the odds ratio for an FRS $ 10% was 1.9 (95% confidence interval [CI], 1.4-2.5). Adjusting for age confirmed a significant association of M-TBR and IMT with FRS. Independent determinants of high M-TBR were abdominal fat (b coefficient [B], 1.1040; P , 0.0001), low-density lipoprotein (LDL) (B, 0.0006; P , 0.05), and FRS (B, 0.0025; P , 0.05) for subjects , 50 y and abdominal fat (B, 0.9740; P , 0.0001), age (B, 0.0040; P 5 0.0001), LDL (B, 0.0008; P 5 0.0001), and IMT (B, 0.1097; P , 0.01) for subjects $ 50 y. Although hsCRP also stratified subjects for FRS-based risk, no correlation was found between hsCRP and M-TBR or IMT, suggesting that they may have different inferences. Importantly, in the low-hsCRP (14.2% 6 9.7% vs. 11.3% 6 7.4%) and high-hsCRP groups (18.8% 6 14.3% vs. 13.3% 6 10.2%), FRS was significantly greater for subjects with high M-TBR than for those with low M-TBR. The odds ratio for FRS $ 10% between subjects with high and low M-TBR was 1.20 (95% CI, 0.90-1.60; P 5 0.209) in the low-hsCRP group and 2.95 (95% CI, 1.48-5.86; P 5 0.002) in the high-hsCRP group. Conclusion: High carotid 18 F-FDG uptake in asymptomatic adults is associated with increased clinical risk factors and FRS. Furthermore, it appears to reflect aspects of atherosclerotic inflammation distinct from hsCRP concentration and may offer incremental information regarding cardiovascular risk.

Oxidized Low-Density Lipoprotein Stimulates Macrophage 18F-FDG Uptake via Hypoxia-Inducible Factor-1α Activation Through Nox2-Dependent Reactive Oxygen Species Generation

“…PET using 18 F-FDG provides noninvasive imaging of atherosclerotic plaque inflammation (2). In human subjects, 18 F-FDG uptake in atherosclerotic lesions is increased in a manner that correlates to cardiovascular risk (3,4) and is reduced after drug treatment or risk modification (5,6). Thus, 18 F-FDG PET holds promise for monitoring disease progression and therapeutic response.…”

Joint Effect of Carotid Plaque and C‐Reactive Protein on First‐Ever Ischemic Stroke and Myocardial Infarction?

“…In this scenario, CRP and carotid plaques should represent the same underlying risk factor (ie, unstable plaques), and a more substantial attenuation of the risk estimates would be expected on adjustment for CRP. In line with these findings, it is not firmly established that CRP correlates to vulnerable plaque characteristics 49, 50, 51…”

Metabolic and Molecular Imaging of Atherosclerosis and Venous Thromboembolism

“…To assess relationships between cardiac risk factors and 18 F-FDG PET, Noh et al measured 18 F-FDG carotid plaque uptake in 1,181 asymptomatic subjects, and correlated the results with 10-y Framingham risk score (FRS) (mean 6 SD, 12.3% 6 8.7%, indicating intermediate risk) (1). The authors determined that an elevated carotid plaque 18 F-FDG uptake (mean target-to-background ratio $ 1.7) increased the chance of having an elevated FRS of 10% or more (odds ratio, 1.9).…”