VIENNA — A 2026 study presented at the Society of Nuclear Medicine and Molecular Imaging annual meeting in Vienna found that bariatric surgery induces coordinated metabolic changes across multiple organs, as revealed by whole-body PET/CT imaging. The research demonstrated that the procedure affects not only body weight but also the metabolic function of numerous tissues throughout the body.
The retrospective study included 32 patients with obesity who underwent either laparoscopic sleeve gastrectomy or one-anastomosis gastric bypass. Each participant received whole-body 18F-FDG PET/CT scans and comprehensive laboratory assessments both before surgery and one year afterward. Researchers measured 18F-FDG uptake in subcutaneous and visceral adipose tissue, liver, pancreas, spleen, adrenal glands, and skeletal muscle to evaluate metabolic activity.
Results showed that bariatric surgery led to synchronized metabolic shifts across fat, liver, pancreas, muscle, cardiovascular structures, bone-related tissues, and immune-endocrine organs. These changes correlated with improvements in glycemic, lipid, endocrine, and inflammatory markers. Network analysis further revealed stronger inter-organ connections after surgery, suggesting that metabolic processes became more integrated across the body.
Findings were compared with pre-surgery scans and with data from healthy control subjects to assess the scope of metabolic reorganization. Until now, clinicians have lacked a clear method to visualize how metabolism changes systemically after bariatric procedures, relying instead on weight measurements and blood tests.
"For patients, these findings suggest that metabolic recovery after bariatric surgery is a whole-body process," said Zeyang Wang, PhD candidate in the Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy at the Medical University of Vienna. "Molecular imaging may help show how different organs respond after surgery, beyond what can be measured by weight loss or blood tests alone. This work supports the use of whole-body PET/CT as a tool to map organ-level metabolic health."