Effects of age and weight on the metabolic activities of the cervical, thoracic and lumbar spines as measured by fluorine-18 fluorodeoxyglucose-positron emission tomography in healthy males

This study aimed to explore the age and weight-related metabolic trends in the spines of healthy male subjects using fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) imaging.Forty three healthy male subjects (age 23-75 years, weight 50-145kg) were selected from the CAMONA study. A global assessment methodology was applied to the subjects' 18F-FDG 180 minute scans, where each region of the spine (cervical, thoracic and lumbar) was individually encapsulated in a single region of interest, and standardized uptake value (SUVmean) was calculated per respective region.SUVmean increased significantly with weight in both the thoracic spine (Slope=0.0066, P=0.001) and lumbar spine (Slope=0.0087, P<0.0001), but not the cervical spine. There were no significant correlations between age and SUVmean in all three regions. The cervical spine (average SUVmean=1.84±0.31) illustrated elevated activity when compared to the thoracic (average SUVmean=1.46±0.27, P<0.0001) and lumbar (average SUVmean=1.41±0.28, P<0.0001) spines.This study illustrated the ability of 18F-FDG PET to assess metabolic processes in the spine. The data provided evidence of weight dependent metabolic activity, likely related to inflammation. This study offers a methodological precedent that can be applied to studies in populations with back pain.