Medicina nuclear y radioterapia

The FDG-Uptake of Adipose Tissue is Higher in Individuals with Increased Blood Glucose Levels than in Individuals with Normal Levels

Abstract

Henry Lindholm, Per Grybäck, Alejandro Sánchez-Crespo, Fredrik Brolin and Hans Jacobsson

Abstract Objective: The influence of hyperglycaemia on the FDG uptake of regular adipose tissue at PET examinations was studied in clinical patients.

Methods: The report constitutes a sub-study of 500 consecutive clinical examinations evaluated in retrospect. The inclusion criteria comprised examinations with a normal, or a near normal FDG distribution. Patients who had been subjected to chemotherapy or radiotherapy <4 weeks prior to the examination were excluded. Otherwise, inclusion was made irrespective of concurrent diseases and/or therapy. In the current study, a sub-group of 62 patients with increased blood glucose levels (≥ 7.0 mmole/l) was compared with another 62 patients being paired with regard to age and gender and showing blood glucose levels within normal range (≤ 6.0 mmole/l). SUVmean of the axillary fat, perirenal fat, abdominal subcutis and gluteal fat were assessed. The gluteal fat was adequate for reliable evaluations. The other regions turned out more or less consistent for this because of the partial volume phenomenon, but were included because of the large number of observations, as well as no systematic influence on the outcome could be expected.

Results: There was a weak, but significantly higher FDG-uptake of all assessed adipose tissue depots in the patients showing increased blood glucose levels compared to the patients with normal blood glucose levels. The tracer uptake also varied between the different fat depots. This is in concordance with previous studies on insulinstimulated FDG-uptake showing differences of insulin resistance between various adipose tissue depots.

Conclusion: The uptake of FDG of adipose tissue is weakly increased in individuals with hyperglycemia compared to normal individuals. The differences are so small that they can be ignored in clinical practice.