Circulating ghrelin levels in basal conditions and during glucose tolerance test in acromegalic patients

Ghrelin exerts a wide range of metabolic functions. In contrast to the body of information accumulated on the role of ghrelin on energy balance, the possible relevance of the peptide on GH secretion in physiological and pathological conditions has so far been poorly investigated. The aim of the present study was to evaluate circulating ghrelin levels in acromegalic patients in basal conditions and in response to oral glucose tolerance test (OGTT). Serum ghrelin, insulin and leptin levels were measured in 31 healthy normal weight subjects as controls, 25 patients with simple obesity and 17 non-diabetic acromegalic patients. Ghrelin and insulin response to OGTT was evaluated in six controls, four obese and six acromegalic patients. The acromegalic patients showed ghrelin levels lower than those observed in normal weight subjects (201+/-20 vs 329+/-32 pmol/l, P