GH1 and hypertensive disorder: Vitale and colleagues found that compared with age- and sex-matched nonacromegalic patients with hypertension, patients with acromegaly had lower systolic blood pressure than nonacromegalic hypertensive controls, while diastolic blood pressure was higher than nonacromegalic hypertension, which suggested that increased vascular resistance may be related to the excessive GH and IGF-1 induced growth of vascular smooth muscle cells (23), and it may also be related to water and sodium retention caused by GH and IGF-1 (24).