1. ^*Obesity and Diabetes Clinical Research Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Phoenix, Arizona
2. ^†Division of Neurosciences, Oregon National Primate Research Center, Oregon Health Sciences University, Beaverton, Oregon
3. ^‡Genetic Epidemiology & Clinical Research Group, Department of Medicine, Institute of Public Health & Clinical Medicine, Umeå University Hospital, Umeå, Sweden

Correspondence: Yan Guo Obesity and Diabetes Clinical Research Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 4212 North Sixteenth Street, Phoenix, AZ 85016. E-mail: yanguo@phx.niddk.nih.gov

^*The costs of publication of this article were defrayed, in part, by the payment of page charges. This article must, therefore, be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Received 12 July 2005; Accepted 19 June 2006.

Abstract

Objective: To explore the potential role of the endogenous peptide YY (PYY) in the long-term regulation of body weight and energy homeostasis.

Research Methods and Procedures: Fasting and postprandial plasma PYY concentrations were measured after an overnight fast and 30 to 180 minutes after a standardized meal in 29 (21 men/8 women) non-diabetic subjects, 16 of whom had a follow-up visit 10.8 1.4 months later. Ratings of hunger and satiety were collected using visual analog scales. Resting metabolic rate (RMR) (15-hour RMR) and respiratory quotient (RQ) were assessed using a respiratory chamber.

Results: Fasting PYY concentrations were negatively correlated with various markers of adiposity and negatively associated with 15-hour RMR (r = - 0.46, p = 0.01). Postprandial changes in PYY (area under the curve) were positively associated with postprandial changes in ratings of satiety (r = 0.47, p = 0.01). The maximal PYY concentrations achieved after the meal (peak PYY) were negatively associated with 24-hour RQ (r = - 0.41, p = 0.03). Prospectively, the peak PYY concentrations were negatively associated with changes in body weight (r = - 0.58, p = 0.01).

Discussion: Our data indicate that the endogenous PYY may be involved in the long-term regulation of body weight. It seems that this long-term effect was not exclusively driven by the modulation of food intake but also by the control of energy expenditure and lipid metabolism.