Differential regulation of plasma obestatin and ghrelin by meal intake and the cholinergic system in lean, but not obese individuals.

Author(s): Maier C, Riedl M, Vila G, Wolzt M, Clodi M, Ludvik B, Luger A

Affiliation(s): Department of Clinical Endocrinology and Metabolism, University Clinics of Medicine III, Medical University of Vienna, Vienna, Austria. Christina.maier@meduniwien.ac.at

Publication date & source: 2010-10, J Clin Endocrinol Metab., 95(10):E214-8. Epub 2010 Jul 21.

Publication type: Randomized Controlled Trial

CONTEXT: Obestatin is cosecreted with and stemming from the same precursor as ghrelin and is apparently involved in energy metabolism. Relatively little is known about the regulation of obestatin release. OBJECTIVE: The regulation of obestatin release and obestatin-to-ghrelin ratios by meal intake and the cholinergic system were studied in lean and obese subjects. DESIGN, PARTICIPANTS, AND SETTING: We conducted a randomized, double-blind, placebo-controlled, crossover study with 4 study days in eight obese (body mass index >30 kg/m(2)) and eight matched lean (body mass index <25 kg/m(2)) healthy subjects (two males and six females per group) at a University Clinical Research Unit. INTERVENTIONS: Atropine (1 mg iv) was administered alone and in combination with breakfast (550 kcal) intake, or placebo (isotonic saline) alone and in combination with breakfast. MAIN OUTCOME MEASURES: We measured plasma obestatin and obestatin/ghrelin ratios. RESULTS: Both obestatin and ghrelin/obestatin ratios decreased significantly from baseline by either atropine or meal intake in lean individuals, with the two effects adding up on the combined atropine/breakfast day. In contrast, there were no statistically significant differences in obese subjects, who also showed significantly greater association between ghrelin and obestatin values than their lean counterparts. CONCLUSIONS: Obestatin and ghrelin release is differentially regulated by meal intake and the cholinergic system in lean individuals. This regulation is impaired in obesity.