Plasma glucagon and insulin concentrations in acromegaly

Area of Science:

• Endocrinology
• Metabolic Disorders

Background:

• Acromegaly, a condition caused by excess growth hormone, is associated with glucose intolerance and diabetes.
• The specific patterns of insulin and glucagon secretion in acromegalic patients with and without diabetes require further elucidation.

Purpose of the Study:

• To investigate the distinct insulin and glucagon secretory profiles in patients with active acromegaly, differentiating between those with and without insulin-independent diabetes mellitus.

Main Methods:

• Studied sixteen patients with clinically active acromegaly, including four with insulin-independent diabetes mellitus.
• Administered glucose and arginine stimulation tests to assess insulin and glucagon responses.
• Compared hormonal responses to those of control subjects.

Main Results:

• Non-diabetic acromegalic patients demonstrated excessive insulin responses to both glucose and arginine.
• Acromegalic patients with diabetes showed markedly reduced insulin response to glucose but preserved response to arginine.
• Plasma glucagon concentrations did not significantly differ between diabetic and non-diabetic acromegalic groups, though a trend towards higher levels in the diabetic group was observed.

Conclusions:

• Acromegaly alters glucose metabolism, with distinct insulin secretion defects in patients who develop diabetes.
• Arginine may be a more robust stimulus for insulin secretion in acromegalic diabetic patients compared to glucose.