I am a physiologist with expertise in endocrinology determining the roles of particular regulatory peptides in the normal functions of the gastrointestinal tract and in the development of gastrointestinal, renal and prostate cancers.
The Anorexia Of Ageing: Gastrointestinal Control Of Appetite And Feeding In The Elderly
Funder
National Health and Medical Research Council
Funding Amount
$190,500.00
Summary
On current projections, the proportion of the Australian population over 65 years will double to 25% in the next 25 years. Ageing is associated with a reduction in appetite and food intake, which has been called the anorexia of ageing. After about age 70, on average, this is associated with loss of body weight, mainly of muscle. The physiological anorexia and weight loss of ageing predispose to pathological weight loss and malnutrition, which is associated with increased morbidity and death rate ....On current projections, the proportion of the Australian population over 65 years will double to 25% in the next 25 years. Ageing is associated with a reduction in appetite and food intake, which has been called the anorexia of ageing. After about age 70, on average, this is associated with loss of body weight, mainly of muscle. The physiological anorexia and weight loss of ageing predispose to pathological weight loss and malnutrition, which is associated with increased morbidity and death rates. High rates of under-malnutrition have been reported among older institutionalised people in the USA and Australia, with lesser, but still substantial, numbers of community-dwelling older people also undernourished. We found recently that 43% of 250 older recipients of domiciliary care services living in their homes in Adelaide were either malnourished or at risk of malnutrition, and had significantly worse outcomes than their well-nourished counterparts over the following year, including increased falls and hospitalisations. Little research has been done to identify underlying causes and develop treatments for this problem. Recent studies, including ours, have shown that upper gastrointestinal (GI) factors (stomach mechanics, rate of gastric emptying, GI hormones including ghrelin, cholecystokinin [CCK] and amylin) have important effects on appetite and food intake, and are often affected by ageing in ways that reduce food intake The proposed studies will investigate this upper GI control of appetite and its contribution to the anorexia of ageing. We will investigate the effects of ageing on gastric factors, including ghrelin release, the satiating effects of CCK and amylin, and the appetite stimulating effects of ghrelin. The expected outcome of this project is a greater understanding of the causes of the anorexia of ageing, enabling the logical development of effective prevention and treatment strategies.Read moreRead less
Effects Of The Fatty Acid, Lauric Acid, On Energy Intake And Gut Motor And Hormonal Function In Health And Obesity
Funder
National Health and Medical Research Council
Funding Amount
$744,645.00
Summary
Obesity is largely due to energy intake exceeding energy expenditure, thus, strategies that reduce energy intake will result in weight loss. We discovered recently that the fatty acid, lauric acid, markedly reduces energy intake. Our studies will determine the effects of lauric acid on energy intake and body weight reduction in obese subjects. The research is a new initiative and explores the potential of lauric acid as a novel, nutrient-based and side-effect free approach to obesity management.
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 peop ....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.Read moreRead less
Effects Of Dietary Protein On Gastrointestinal Function: Implications For The Regulation Of Energy Intake In Obesity
Funder
National Health and Medical Research Council
Funding Amount
$677,157.00
Summary
Obesity is largely due to energy intake exceeding energy expenditure. The CI has reported that dietary protein markedly reduces energy intake but the mechanisms underlying this effect remain unknown. The proposed studies will determine whether gastrointestinal mechanisms are involved in the regulation of appetite and energy intake and how they relate to body weight reduction in obese subjects. The research represents a unique approach to the management of obesity and health.