IGF1 and acromegaly: compared the blood of 13 patients with acromegaly and 12 sex- and age-matched normal blood pressure controls and found that the NO concentration decreased in platelets of patients with acromegaly, which was mainly related to the decreased expression of endothelial NO synthase, and the internal NO concentration was negatively correlated with GH/IGF-1 levels and the duration of acromegaly (34).