Modulating the GIP System in Patients With Acromegaly Due to a Pituitary Tumor

Aim: To determine the importance of the GIP system in patients with acromegaly who has paradoxical growth hormone secretion during an oral glucose tolerance test (OGTT) using a GIP antagonist (GIP-A).

Thirty participants (age 18-75 years) with normal kidney and liver parameters and hemoglobin levels will be included in a placebo-controlled cross-over study. The study consists of two study days with concomitant infusions of A) GIP-A or B) saline (placebo).

A paradoxical growth hormone secretion to an OGTT is here defined as an increase in plasma growth hormone levels of ≥30% from baseline based on a mean value of the definitions in the literature.

Regazzo et al. (2017) European Journal of Endocrinology 176, 543-553 Mukai et al. (2018) The Journal of Clinical Endocrinology and Metabolism 104(5), 1637-1644 Hage et al. (2019) The Journal of Clinical Endocrinology and Metabolism 104(5), 1777-1787 Scaroni et al. (2019) J Clin Endocrinol Metab 104(3), 856-862

Inclusion criteria

• Patients under clinical investigation of acromegaly disease with normal kidney function, liver function and hemoglobin levels.

Exclusion criteria

• Medication for acromegaly, adenectomy, liver disease, uncontrolled anemia, severe heart disease, uncontrolled high blood pressure (>170/100 mmHg), current pregnancy