Central modulation of the feeding response to amylin by leptin and insulin.

Central modulation of the feeding response to amylin by leptin and insulin.

ARTICLE IN PRESS 318 Abstracts / Appetite 49 (2007) 272–341 Effects of strength and aerobic training on metabolic syndrome, insulin, and testosteron...

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ARTICLE IN PRESS 318

Abstracts / Appetite 49 (2007) 272–341

Effects of strength and aerobic training on metabolic syndrome, insulin, and testosterone levels in dieting obese subjects

C.N. OCHNER, A. GELIEBTER, C.L. BAUER, S.A. HASHIM. New York Obesity Research Center, St. Lukes-Roosevelt Hospital, Columbia University, New York, NY, USA This study examined changes in hormones and risk factors associated with obesity across 3 groups: diet plus strength training (ST), diet plus aerobic training (AT), and diet only (DO). Eightyone (54f, 27 m) participants ranging in age from 19 to 48 (M=35.4 +7.2) years and BMI from 26 to 52 (M=33.8+5.9) kg/ m2 were randomized to ST, AT, or DO groups and lost weight on a formula diet over 8 weeks. Anthropometrics and fasting hormones were assessed pre and post-weight loss. All participants lost weight (M= 8.5+4.3 kg; F(2,78)=305, po0.001) with no difference between groups (ST: 7.5+4.0 kg; AT: 8.6+5.1 kg; DO: 9.2+3.3 kg). Improvements were found in metabolic syndrome risk factors (waist circumference, triglycerides, cholesterol, BP, glucose; all p’so0.03), with no difference between groups. Insulin levels improved (p=0.006) with a significant difference between AT ( 15.8+20.3 mU/mL, p=0.005) and ST (1.0+20.6 mU/mL, NS; F(2,46)=3.2, p=0.049) groups. Insulin resistance (HOMA) improvement (p=0.002) did not vary across groups. Testosterone (men only) increased more in the AT (0.7+0.1 ng/mL, NS), compared with both ST ( 0.07+0.7 ng/ mL, NS) and DO ( 0.37+0.3 ng/mL, NS; F(2,17)= 4.3, p=0.031), groups. Groups did not differ in reducing BMI or metabolic risk factors, however, aerobic exercise engendered a significant decrease in insulin and increase in testosterone while strength training showed the opposite effects. Further investigation into the differential effects of strength and aerobic training, during weight loss, on insulin and testosterone is warranted. 10.1016/j.appet.2007.03.150

Central modulation of the feeding response to amylin by leptin and insulin M. OSTO, P.Y. WIELINGA, B. ALDER, N. WALSER,

T.A. LUTZ. Institute of Veterinary Physiology, Vetsuisse Faculty University of Zurich, Switzerland Amylin is a pancreatic hormone, which is considered a satiating signal acting on neurons of the area postrema (AP). The orexigenic hormone ghrelin and the anorectic hormones leptin and insulin act on specific receptors on neurons in the arcuate nucleus (ARC) of the hypothalamus. These hypothalamic signals have been shown to modulate the effect of peripheral satiating hormones, like cholecystokinin (CCK). Because CCK’s anorectic effect depends on endogenous amylin, the aim of this study was therefore to evaluate a possible functional interaction between amylin and these hormones on short-term food intake in rats. The experiments were performed with male Wistar rats using a crossover design. Intracerebroventricular leptin (3.5 mg/5 ml) and intraperitoneal amylin (5 mg/kg) synergistically reduced 1h-food intake by 61% in chow-fed rats (amylin alone: 29%). Insulin administered into the third ventricle (i3vt) at a sub-threshold dose

(0.5mU/5 ml) significantly enhanced the response to peripheral amylin, reducing food intake by 69% versus 45% by amylin alone. In contrast, an i3vt injection of an orexigenic dose of ghrelin (5ng/5 ml) did not reverse the intraperitoneal amylin (5 mg/ kg)-induced inhibition of food intake, i.e. the difference in food intake between saline and amylin-injected animals was similar after ghrelin administration. The administration of a sub-threshold dose of ghrelin (3ng/5 ml) did not affect the anorectic action of peripheral amylin. These results indicate that an interaction between central ghrelin and peripheral amylin on food intake seems unlikely, but cannot be ruled out completely. By contrast the lipostatic signals leptin and insulin may synergize with amylin in reducing food intake. 10.1016/j.appet.2007.03.151

Objective sensory dimensions of food as predictor of nutrient intake in the elderly C. PAQUETa, C. HUETb, L. THIBAULTb. a

Faculty of Management, McGill University, Canada. School of Dietetics and Human nutrition, McGill University, Canada

b

This study aimed to measure sensory quality based on objective sensory dimensions (temperature, texture, appearance, flavour) that reflect their relationship with hedonic responses in order to predict food intake. This approach contrasts with institutional assessments based on individual liking self-reports. Sensory evaluation of 3776 food items was performed in a study on the determinants of food intake of hospitalized elderly patients. Sensory evaluation was conducted by trained evaluators using customized sensory profiles consisting in 7–8 sensory parameters judged relevant by experts to the sensory quality of the food item and measured using scales adapted from food manufacturing research and practice or constructed by the research team. Measurements of objective sensory dimensions were then transformed to reflect the hedonic quality of food item. To do so, we captured the relationship between these individual sensory parameters and the hedonic evaluation of the same food item. Sensory dimensions were considered among others as predictors of intake measures for energy and macronutrients. Our regression model showed that temperature could predict energy (r= 1,723, po0.01), protein (r= 0,089, po0.001) and lipid intake (r= 0,134, po0.0001). Texture of food could predict protein (r= 0,701, po0.0001) and lipid intake (r= 0,396, po0.05). Finally, flavour could only predict carbohydrate intake (r=2.973, p o0.05). Appearance wasn’t a significant predictor of any intake measure. The benefit of this approach is to provide uniform measures of sensory quality for a variety of food items that can be used to compare the sensory quality of such items or to obtain predictors of food intake based on sensory dimensions of food. 10.1016/j.appet.2007.03.152