CONTEXT: Outcome of acromegaly surgery is assessed by IGF-1 and glucose-suppressed GH, but whether the latter provide additional clinically relevant information when IGF-1 is normal is unclear. The role of GH suppression testing after surgery requires clarification. METHODS: We studied 97 acromegaly patients with normal IGF-1 after surgery by measuring GH after oral glucose longitudinally, initially at ≥ 3 months after surgery and repeated one or more times ≥ 1 year later. Nadir GH was categorized as normal or abnormal relative to the 97.5th percentile of nadir GH in 100 healthy subjects, which were ≤ 0.14 μg/L (DSL IRMA) or ≤ 0.15 μg/L(IDS iSYS). Signs and symptoms scores and insulin resistance were followed longitudinally. RESULTS: Of 68 patients with initial normal GH suppression 63(93%) remained in remission and of 29 with initial abnormal GH suppression, 9(31%) recurred. Recurrence was more common in patients with abnormal suppression (P
