IGF1 and acromegaly: Uncontrolled secretion of growth hormone (GH) from the hypophysis is the key feature of acromegaly, whereas elevated levels of insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 and calcitriol, and the presence or absence of secondary gonadal insufficiency are important factors that influence the bone metabolism in these patients (1).