To investigate the impact of pituitary surgery on glucose metabolism and to identify predictors of remission of diabetes after pituitary surgery in patients with acromegaly.AIMTo investigate the impact of pituitary surgery on glucose metabolism and to identify predictors of remission of diabetes after pituitary surgery in patients with acromegaly.A national multicenter retrospective study of patients with acromegaly undergoing transsphenoidal surgery for the first time at 33 tertiary Spanish hospitals (ACRO-SPAIN study) was performed. Surgical remission of acromegaly was evaluated according to the 2000 and 2010 criteria.METHODSA national multicenter retrospective study of patients with acromegaly undergoing transsphenoidal surgery for the first time at 33 tertiary Spanish hospitals (ACRO-SPAIN study) was performed. Surgical remission of acromegaly was evaluated according to the 2000 and 2010 criteria.A total of 604 acromegaly patients were included in the study with a total median follow up of 91 months (interquartile range IQR 45-163). At the acromegaly diagnosis, 23.8% of the patients had diabetes mellitus (DM) with a median glycated hemoglobin (HbA1c) of 6.9% (IQR 6.4-7.9) 51.9 mmol/mol (IQR 46.4-62.8). In the multivariate analysis, older age (odds ratio OR 1.02, 95% CI 1.00-1.05), dyslipidemia (OR 5.25, 95% CI 2.81 to 9.79), arthropathy (OR 1.39, 95% CI 2.82 to 9.79), and higher IGF-I levels (OR 1.30, 95% CI 1.05 to 1.60) were associated with a greater prevalence of DM. At the last follow-up visit after surgery, 21.1% of the DM patients (56.7% of them with surgical remission of acromegaly) experienced diabetes remission. The cure rate of DM was more common in older patients (hazard ratio HR 1.77, 95% CI 1.31 to 2.43), when surgical cure was achieved (HR 2.10, 95% CI 1.01 to 4.37) and when anterior pituitary function was not affected after surgery (HR 3.38, 95% CI 1.17 to 9.75).RESULTSA total of 604 acromegaly patients were included in the study with a total median follow up of 91 months (interquartile range IQR 45-163). At the acromegaly diagnosis, 23.8% of the patients had diabetes mellitus (DM) with a median glycated hemoglobin (HbA1c) of 6.9% (IQR 6.4-7.9) 51.9 mmol/mol (IQR 46.4-62.8). In the multivariate analysis, older age (odds ratio OR 1.02, 95% CI 1.00-1.05), dyslipidemia (OR 5.25, 95% CI 2.81 to 9.79), arthropathy (OR 1.39, 95% CI 2.82 to 9.79), and higher IGF-I levels (OR 1.30, 95% CI 1.05 to 1.60) were associated with a greater prevalence of DM. At the last follow-up visit after surgery, 21.1% of the DM patients (56.7% of them with surgical remission of acromegaly) experienced diabetes remission. The cure rate of DM was more common in older patients (hazard ratio HR 1.77, 95% CI 1.31 to 2.43), when surgical cure was achieved (HR 2.10, 95% CI 1.01 to 4.37) and when anterior pituitary function was not affected after surgery (HR 3.38, 95% CI 1.17 to 9.75).Glucose metabolism improved in patients with acromegaly after surgery and 21% of the diabetic patients experienced diabetes remission; being more frequent in patients of older age, and those who experienced surgical cure and those with preserved anterior pituitary function after surgery.CONCLUSIONGlucose metabolism improved in patients with acromegaly after surgery and 21% of the diabetic patients experienced diabetes remission; being more frequent in patients of older age, and those who experienced surgical cure and those with preserved anterior pituitary function after surgery.