INS and vasculitis: Metformin increases intestinal glucose uptake, insulin (but also exercise-induced insulin secretion) results in elevated [18F]FDG uptake in physiological tissues (e.g., muscles), antibiotics (>7 days) are associated with a lower chance of revealing an infection focus, and corticosteroids (>10 days) reduce the sensitivity for diagnosing inflammation (e.g., vasculitis) (17).