Increased prevalence of high Body Mass Index in patients presenting with pituitary tumours: severe obesity in patients with macroprolactinoma

Prolactinoma has been associated with obesity. As opposed to ACTH- and GH-secreting adenoma, the mechanism by which macroprolactinoma causes obesity has not been fully understood. Having seen patients with both prolactinoma and obesity and more recent literature on brain dopamine, dopamine 2 receptors and obesity, we re-evaluated the potential relationship between prolactinoma and obesity. Data of patients with pituitary adenomas were collected retrospectively over a period of 20 years. 399 patients with well-documented pituitary adenomas and information about pre-treatment body mass index (BMI), age, sex, and tumour type were analysed. Elevated BMI (> or = 30 kg/m2) was observed in 8/36 patients (22.2%) with ACTH-producing tumours, in 15/70 (21.4%) with GH-producing tumours, in 25/100 (25%) with macroprolactinoma, in 8/81 (9.9%) with microprolactinoma, and in 18/105 (17.1%) with inactive macroadenomas. Macroprolactinoma patients had a mean BMI value (27.5 +/- 7.7 kg/m2) similar to that of patients with Cushing's disease (27.2 +/- 5.9 kg/m2) and acromegaly (27.4 +/- 4.4 kg/m2) and on average a significantly higher BMI value compared to that of patients with inactive macroadenomas (25.8 +/- 4.4 kg/m2) (95% CI 1.2, 4.4; p-value or = 30 kg/m2 in patients with macroprolactinoma was significantly higher (95% CI 0.1, 0.29; p-value