title: Ghrelin and PYY levels in adolescents with severe obesity: effects of weight loss induced by long-term exercise training and modified food habits.
abstract: This study investigated (a) changes in ghrelin and peptide YY (PYY) concentrations during a weight reduction programme and (b) baseline ghrelin and PYY levels as predictors of weight loss in 32 severely obese adolescents (BMI z score = 4.1). Subjects spent an academic year in an institution for childhood obesity. Fasting ghrelin and PYY, leptin, insulin levels and insulin resistance were measured at baseline (month 0) and during the programme (months 3, 6, 9). In addition, 15 normal-weight teenagers served as reference for the baseline assessments. At baseline, obese teenagers had lower ghrelin and PYY concentrations than normal-weight adolescents (P < 0.05). Moreover, they showed significantly higher leptin, insulin levels and homeostasis model assessment (HOMA) (P < 0.0001). During the lifestyle modification, there was a significant decrease in body weight among obese teenagers, associated with an increase in ghrelin (apparent from month 6; P < 0.05), a decrease in leptin (from month 3; P < 0.05) and a decrease in insulin and HOMA (from month 3; P < 0.0001), without any significant change in PYY. Anthropometrical changes were correlated neither with baseline ghrelin levels nor with changes in ghrelin and PYY after the lifestyle modification. However, higher baseline PYY tended to correlate with greater anthropometrical changes (P < 0.1). In adolescents with severe obesity, a long-term combination of supervised aerobic exercises and a balanced diet led to weight reduction and increased ghrelin concentrations, without any change in PYY concentrations. Moreover, baseline PYY concentrations might be considered as predictors of weight loss.
authors: Université de Franche-Comté, 25000 Besançon, France. carine.gueugnon@yahoo.fr
authors: Carine
authors: C
authors: Gueugnon
authors: Fabienne
authors: F
authors: Mougin
authors: Nhu Uyen
authors: NU
authors: Nguyen
authors: Malika
authors: M
authors: Bouhaddi
authors: Marie
authors: M
authors: Nicolet-Guénat
authors: Gilles
authors: G
authors: Dumoulin
mesh_terms: D000293:Adolescent; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D008019:Life Style; D008297:Male; D009767:Obesity, Morbid / Q000097:blood* / Q000178:diet therapy / Q000628:therapy; D019894:Peptide YY / Q000097:blood*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D054439:Ghrelin; D019894:Peptide YY