GH1 and functioning pituitary gland adenoma: As growth hormone (GH) and insulin-like growth factor-1 (IGF-1) play important roles in regulating the body metabolism, patients with growth hormone-secreting pituitary adenoma (GHPA) present with multiple metabolic abnormalities, such as diabetes (20 to 56%) and hyperlipidemia (13 to 51%) (22, –, 24).