Postprandial cholecystokinin secretion in elderly with protein-energy undernutrition.

OBJECTIVE: Malnutrition is currently observed in aged people, and cholecystokinin is an important peripheral satiety signal. The aim of this study was to examine the effect of aging and protein-energy malnutrition on postprandial cholecystokinin (CCK) release. DESIGN: Non-randomized, cross-sectional comparison by age group. SETTING: Gastroenterology section of a teaching hospital. PARTICIPANTS: Twenty-one human volunteers divided into three groups: young healthy subjects (Group 1: mean 29 years, n = 7), aged healthy subjects (Group 2, mean 80 years, n = 7), and aged subjects with an important degree of malnutrition (Group 3, mean 84.6 years, n = 7). INTERVENTION: Each subject ingested a standardized liquid meal after an overnight fast. MAIN OUTCOME MEASURES: Plasma cholecystokinin was measured using a sensitive bioassay before and after the ingestion of the liquid meal. RESULTS: Basal cholecystokinin levels were similar (0.9 to 1 pM equivalent CCK-8) in the three groups. Postprandial levels were significantly increased over basal (P less than 0.05). The maximal cholecystokinin value was lower in Group 1 (3.5 +/- 0.8 pM equivalent CCK-8) and Group 2 (3.3 +/- 0.77 pM equivalent CCK-8) than in Group 3 (8.3 +/- 2 pM equivalent CCK-8) (P less than 0.05). Integrated plasma cholecystokinin was also similar in Group 1 (171 +/- 38 pM.60 min), (P less than 0.05). CONCLUSION: The increase of postprandial maximal levels of cholecystokinin is more related to malnutrition than to aging.