24-Hour profiles of circulating ghrelin and peptide YY are inversely associated in normal weight premenopausal women

• Published in: Peptides (New York, N.Y. : 1980) N.Y. : 1980), 2012-11, Vol.38 (1), p.159-162
• Main Authors: Hill, Brenna R., Souza, Mary Jane De, Wagstaff, David A., Sato, Rino, Williams, Nancy I.
• Format: Article
• Language: English
• Subjects: Adolescent; blood; body fat; body mass index; carbohydrates; Circulating; Female; food intake; Ghrelin; Ghrelin - blood; Human; Humans; hypothalamus; Ideal Body Weight; Mathematical models; Peptide YY; Peptide YY - blood; Peptides; premenopause; Premenopause - blood; radioimmunoassays; secretion; Secretions; Snacks; Statistical analysis; Statistical methods; women; Young Adult
• ISSN: 0196-9781; 1873-5169
• DOI: 10.1016/j.peptides.2012.08.017

► Circulating PYY was a significant predictor of ghrelin over 24h in humans. ► Increases in circulating PYY were associated with decreases in circulating ghrelin. ► PYY may be modulating ghrelin secretion in normal weight women over a 24h period. ► Findings substantiate experimental inferences that PYY modulates ghrelin secretion. Peptide YY (PYY) and ghrelin (GHR) may modulate one another's actions within the hypothalamus. Peripheral infusion of PYY in humans acutely suppresses circulating concentrations of GHR. Whether an association between PYY and GHR exists in the peripheral circulation of humans over 24h is unknown. The purpose of this study was to determine if circulating concentrations of PYY and GHR were significantly associated over 24h in humans. Participants (n=13) were normal weight, moderately active, women ages 18–24 yr. Blood samples were obtained q10min for 24h and assayed using RIA for total PYY and total GHR hourly from 0800 to 1000h and 2000 to 0800h and q20min from 1000 to 2000h. Dietary intake during the 24h procedure was comprised of 55% carbohydrates, 30% fat, and 15% protein (three meals and a snack). Statistical analyses included linear mixed-effects modeling to test whether PYY predicted GHR concentrations over 24h. Participants weighed 57.0±1.5kg and had 26.1±1.5% body fat (15.0±1.1kg), 42.1±1.1kg fat free mass, a BMI of 21.3±0.5kg/m2 and RMR of 1072±28kcal/24h. Visually, PYY and GHR exhibited an inverse association over nearly the entire 24h period. Statistically, circulating concentrations of 24h PYY predicted 24h GHR (ghrelin=1860.51–2.14*PYY; p=0.04). Circulating concentrations of PYY are inversely associated with GHR over 24h. These data provide evidence that PYY may contribute to the modulation of the secretion of GHR in normal weight, premenopausal women over a 24h period and supports similar inferences from experimental studies in animals and humans.