Weight-Reducing Dietary Intervention Increases the Ability of Hyperinsulinemia to Suppress Serum Ghrelin Concentration in Individuals with Obesity

Abstract

BackgroundGhrelin is an orexigenic peptide secreted mainly by the stomach. Serum ghrelin concentrations are suppressed after a meal, probably due to insulin release. Individuals with obesity are characterized by a lower fasting serum ghrelin and a lower ghrelin decrease after a meal. The effect of weight loss on the ability of insulin to suppress serum ghrelin concentration remains unknown. ObjectiveThe aim of the present study was to analyze the effect of weight-reducing dietary intervention on the ability of hyperinsulinemia to suppress serum ghrelin concentration in young individuals with uncomplicated obesity. MethodsWe examined 38 individuals with marked overweight or obesity, who underwent a 12-wk dietary intervention program. Serum ghrelin concentration was measured before and after a 2-h hyperinsulinemic–euglycemic clamp, both pre- and post-intervention. Twenty normal-weight individuals served as a control group and were examined at baseline only. ResultsIndividuals with overweight/obesity were characterized by a lower fasting serum ghrelin concentration than normal-weight individuals (P = 0.006). Insulin decreased serum ghrelin concentration in both groups (P < 0.001); however, this decrease was markedly lower in individuals with overweight/obesity than in normal-weight individuals (99.70 ± 136.37 vs. 215.45 ± 250.28 pg/mL; P = 0.026). Fasting serum ghrelin concentration increased after the intervention. After weight-reducing dietary intervention, the decrease in serum ghrelin concentration after the clamp was significantly greater than the pre-intervention value (99.70 ± 136.37 vs. 221.82 ± 228.75 pg/mL; P = 0.002). ConclusionsWeight-reducing dietary intervention restores the ability of hyperinsulinemia to suppress serum ghrelin concentration. It may suggest an enhanced feeling of satiety after moderate weight loss in individuals with overweight/obesity.