Characterisation of the anorexia of ageing [ 2000 - 2002 ]

Research Grant

Researchers: Prof Ian Chapman (Principal investigator)

Brief description Human ageing is characterised by reduced appetite and food intake, so that average body weight decreases after 70-75 years. This physiological anorexia predisposes to pathological weight loss and malnutrition, worsening of other illnesses, and increased mortality. This project aims to identify causes of this anorexia of ageing, with a view to developing prevention and treatment strategies. We hypothesise that (1) Satiety signals are overactive in the elderly. We will determine whether older people are more sensitive to gastric distension, which reduces appetite and food intake, by measuring perceptions (fullness, hunger, etc), gastric compliance and food intake during intragastric balloon inflation. This will also be done during nutrient infusion into the small intestine, to assess the interaction between gastric and intestinal satiety factors. The contribution of age-related slowing of gastric emptying to the anorexia of ageing will be assessed and the possibility that reduced energy intake worsens the anorexia of ageing will be examined in a nutrient supplementation study. We will have shown that the release of the satiety hormone cholecystokinin (CCK) is greater in older than young adults and that CCK administration causes a greater suppression of food intake in older people, suggesting that increased CCK activity may be a cause of the anorexia of ageing. We will pursue these findings by attempting to increase appetite and food intake in the lderly by administration of a CCK antagonist (blocker). We will also measure the satiating effects of two other probable satiety hormones, amylin and glucagon like peptide 1 in older and young people. (2) The feeding drive is reduced in the elderly Opioids stimulate feeding. In animals this effect is reduced by ageing. To determine whetther this is also so in humans, the suppressive effect of the opioid antagonist naloxone on feeding will be assessed in young and older subjects.

Funding Amount $AUD 173,380.55

Funding Scheme NHMRC Project Grants

Notes Standard Project Grant