Impact of noninsulin-dependent type 2 diabetes on carotid wall 18F-fluorodeoxyglucose positron emission tomography uptake

Abstract

Objectives: In this study, the impact of noninsulin-dependent type 2 diabetes mellitus on carotid wall (18)F-fluorodeoxyglucose (FDG) uptake in patients with documented or suspected cardiovascular disease was evaluated.

Background: Inflammation is a pivotal process in the progression of atherosclerosis, which can be noninvasively imaged by FDG positron emission tomography (FDG-PET).

Methods: Carotid artery wall FDG uptake was quantified in 134 patients (age 60.2 ± 9.7 years; diabetic subjects, n = 43). The pre-scan glucose (gluc) level corrected mean of the maximum standardized uptake value (SUV) values ((mean)SUV(gluc)), mean of the maximum target-to-background ratio ((mean)TBR(gluc)), and single hottest segment (SHS(gluc)) of FDG uptake in the artery wall were calculated. Associations between FDG uptake, the presence of risk factors for atherosclerosis, and diabetes were then assessed by multiple regression analysis with backward elimination.

Results: The study demonstrated a significant association between diabetes and FDG uptake in the arterial wall (diabetes (mean)SUV(gluc) β = 0.324, (mean)TBR(gluc) β = 0.317, and SHS(gluc) β = 0.298; for all, p < 0.0001). In addition, in diabetic patients, both body mass index ≥ 30 kg/m(2) ((mean)SUV(gluc) β = 0.4, (mean)TBR(gluc) β = 0.357, and SHS(gluc) β = 0.388; for all, p < 0.015) and smoking ((mean)TBR(gluc), β = 0.312; SHS(gluc), β = 0.324; for all, p < 0.04) were significantly associated with FDG uptake.

Conclusions: Type 2 diabetes was significantly associated with carotid wall FDG uptake in patients with known or suspected cardiovascular disease. In diabetic patients, obesity and smoking add to the risk of increased FDG uptake values.

Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1. Clinical Risk Factors of Carotid Vessel Wall Inflammation

This figure shows differences in meanSUVgluc values in patients with and without diabetes and with and without BMI values ≥ 30 kg/m2. Both variables were identified as significant (p < 0.05) independent predictors for carotid wall inflammation as depicted by meanSUVgluc values. Data is presented as median (bolded line), 25th - 75th percentile (box), 5th - 95th percentile (whiskers). Circles represent outliers. The p-value for each of the given independent predictors for carotid wall inflammation as depicted by meanSUVgluc values is adjusted for the other significant variable given in Table 2a (diabetes, BMI ≥ 30 kg/m2, and alcohol). Alcohol failed to show a statistical significant association (p < 0.05) with the meanSUVgluc values in the ENTER regression model and is therefore not shown as an independent predictor in this figure.

Figure 2. Clinical Risk Factors of Carotid Vessel Wall Inflammation

This figure shows differences in meanTBRgluc values in patients with and without diabetes, BMI ≥ 30 kg/m2, and alcohol. All variables were identified as significant (p < 0.05) independent predictors for carotid wall inflammation as depicted by the mean Target-to-Background-Ratio (meanTBRgluc). Family history is independently associated with a decreased risk of carotid wall inflammation as revealed by significantly lower meanTBRgluc values in patients with a family history of cardiovascular disease. Data is presented as median (bolded line), 25th - 75th percentile (box), 5th - 95th percentile (whiskers). Circles represent outliers. The p-value for each of the given independent predictors for carotid wall inflammation as depicted by meanTBRgluc values is adjusted for the other significant variables given in Table 2a (diabetes, BMI ≥ 30 kg/m2, alcohol, and family history of cardiovascular disease).

Figure 3. Clinical Risk Factors of Carotid Vessel Wall Inflammation

This figure shows differences in SHSgluc values in patients with and without diabetes, BMI ≥ 30 kg/m2, and alcohol. All variables were identified as significant (p < 0.05) independent predictors for carotid wall inflammation as depicted by the Single Hottest Segment (SHSgluc). Family history is independently associated with a decreased risk of carotid wall inflammation as revealed by significantly lower SHSgluc values in patients with a family history of cardiovascular disease. Data is presented as median (bolded line), 25th - 75th percentile (box), 5th - 95th percentile (whiskers). Circles represent outliers. The p-value for each of the given independent predictors for carotid wall inflammation as depicted by SHSgluc values is adjusted for the other significant variables given in Table 2a (diabetes, BMI ≥ 30 kg/m2, alcohol, and family history of cardiovascular disease).