IGF1 and acromegaly: Compared to patients with a purely GH-secreting adenoma, acromegalic patients with HPRL present an earlier onset of the disease, but with less expressive physical characteristics of acromegaly.(15) Therefore, whenever possible, we recommend screening patients with prolactinoma for acromegaly at the time of diagnosis by measuring insulin-like growth factor type 1 (IGF-1) without the need for routine measurements in the follow-up of these individuals.