Gastrointestinal peptides, gastrointestinal motility, and anorexia of aging in frail elderly persons

Abstract

The mechanisms involved in anorexia in frail elderly people remain unclear. The objective of this study was to establish whether fasting and postprandial levels of gastrointestinal peptides, gastrointestinal motility, and hunger are modified by age and frailty. Three groups of subjects were studied: (a) frail elderly (>70 years) persons, (b) non-frail elderly (>70 years) persons, and (c) healthy adults (aged 25-65 years). After an overnight fast, participants ingested a 400 Kcal liquid meal and appetite, hormonal, and gastrointestinal responses were monitored during early (0-60 min) and late (60-240 min) postprandial periods. Frail persons showed poor nutritional status, sarcopenia, and almost absence of hunger during fasting and postprandial periods. Older persons presented higher levels of glucose and insulin during fasting, enhanced postprandial CCK release in early postprandial period and postprandial hyperglycemia and hyperinsulinemia, but similar ghrelin levels than younger adults. Ultrasound scan showed that the fasting antral area was higher and antral compliance lower in old persons. The paracetamol absorption test showed enhanced postprandial gastric emptying in the frail. Non-gallbladder contractors showed no CCK peak in younger and non-frail groups, but the same high CCK peak as contractors in the frail. Frailty was associated with anorexia, risk of malnutrition, and sarcopenia. Frail persons showed impaired gastric motility (larger antral area at rest, impaired antral compliance, and enhanced postprandial emptying), impaired gallbladder motility, and fasting and/or postprandial alterations in CCK, glucose, and insulin release. Further studies are needed to determine if these factors may contribute to anorexia of aging in frail persons.