Is ghrelin a signal of decreased fat-free mass in elderly subjects?
OBJECTIVE: Aging is associated with appetite decline, weight loss, reduced fat-free mass (FFM), and increased fat mass (FM). Ghrelin and leptin are short- and long-term determinants of energy balance respectively, whose dysregulation could alter food intake. We evaluate the relationship of circulating ghrelin and leptin responses to standardized oral mixed nutrient load (SOMNL) with body composition, daily food intake, and insulin sensitivity in healthy elderly subjects (ES). DESIGN AND METHODS: Twenty-six ES (12/14 M/F, 69+/-4 years) and ten young healthy controls (LY) (5/5 M/F, 27+/-3 years) were studied at the International Center for the Assessment of Nutritional Status (Milan, Italy) with air plethysmography, dual energy X-ray absorptiometry, indirect calorimetry, and dietary intake assessment. Basal and postprandial ghrelin, leptin, testosterone, glucose, insulin and C-peptide concentrations, and insulin resistance (homeostasis model assessment (HOMA-R)) and sensitivity (quantita
