The Association Between Lung Fluorodeoxyglucose Metabolism and Smoking History in 347 Healthy Adults

OBJECTIVE: This study aimed to evaluate the relationship between fluorodeoxyglucose metabolism and smoking history in healthy adults by analyzing lung standardized uptake value (SUV). METHODS: The (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) studies of 347 patients who did not show signs of having malignant diseases or lung inflammation were retrospectively evaluated. Four circular regions of interest (ROI) were manually drawn on the upper and lower lung regions. The averages of maximum SUV (SUVmax-avr) and mean SUV (SUVmean-avr) were calculated, and the mean values of each parameter for non-smokers, ex-smokers, and current smokers were compared. The correlation between SUVmax-avr and smoking history (tobacco burden and the duration of smoking cessation) was assessed based on present smoking status. The ex-smokers and current smokers were divided into three groups according to their tobacco burden, and the SUVmax-avrs of the two groups were compared. RESULTS: Both the mean values of SUVmax-avr and SUVmean-avr increased based on smoking history, with non-smokers having the lowest values and current smokers the highest. Tobacco burden had a positive correlation with SUVmax-avr in current smokers (r = 0.474, P< 0.001). However, neither tobacco burden (r = 0171, P = 0.162) nor duration of smoking cessation (r = 0.212, P = 0.082) had a significant correlation with SUVmax-avr in ex-smokers. The mean SUVmax-avr of current smokers was significantly higher than that of ex-smokers in patients with a medium or large tobacco burden (P = 0.012, P< 0.001, respectively). Although there was no significant difference between the mean SUVmax-avrs of ex-smokers and current smokers in patients with a small tobacco burden (P = 0.888), the mean SUVmax-avrs of both ex-smokers and current smokers with a small tobacco burden were significantly higher than that of non-smokers (P< 0. 001, P< 0.001, respectively). CONCLUSION: The findings indicate that lung SUV increases in current heavy smokers and partially decreases after the cessation of smoking, which is in line with previous reports studied by analyzingfluorodeoxyglucose (FDG) metabolism of lung specimens.