Does Early Overnutrition Differentially Alter Hypothalamic Neuropeptides That Regulate Food Intake In The Rat
Funder
National Health and Medical Research Council
Funding Amount
$346,250.00
Summary
In Australia the incidence of obesity, in particular childhood obesity, is increasing dramatically, and the possible long term consequences of this are of great concern. The brain regulates appetite through a number of chemical transmitters such as neuropeptide Y (NPY) which is present in the brains of mammals and causes increased food intake. The effects of overeating from a young age on these brain transmitters has been largely ignored although this may impact on subsequent eating behaviour. I ....In Australia the incidence of obesity, in particular childhood obesity, is increasing dramatically, and the possible long term consequences of this are of great concern. The brain regulates appetite through a number of chemical transmitters such as neuropeptide Y (NPY) which is present in the brains of mammals and causes increased food intake. The effects of overeating from a young age on these brain transmitters has been largely ignored although this may impact on subsequent eating behaviour. In addition to NPY we will study other transmitters in the brain that have profound effects on appetite, some increasing, and others decreasing, food intake. These may form useful therapeutic targets for new drugs for obesity. Key targets we will study include melanocortins, glucagon-like peptide 1, urocortin, melanin concentrating hormone, agouti related peptide, and NPY. We will determine whether overnutrition from birth to weaning leads to changes in these appetite regulating neurotransmitters in the brain, and monitor the hormonal signals that impact on their activity. We will also determine whether early overnutrition exacerbates the subsequent responses to a high fat diet by comparison with rats made obese as adults. We will measure brain concentrations of the neurotransmitters, the amount released from the brain, and determine whether the feeding responses to injections of these agents is altered in obese animals. We have evidence that these transmitters interact in a co-ordinated fashion to affect feeding; this project will examine whether these interactions are maintained in the various types of obesity. Rats are commonly used for this type of study as the processes regulating feeding are very similar to those in humans and these agents cause similar effects in rats and humans. It is hoped that this information will provide new insight into the way brain adapts to overnutrition, and provide potential treatments for obesity and other feeding disorders.Read moreRead less
This proposal is designed to test the protein leverage hypothesis (PLH) in humans: the idea that the level of food consumption in humans, like other animals, is adjusted to maintain a target protein intake. As the prevalence of overweight and obesity increases, with its attendant health problems, the need to identify which dietary components limit rather than exacerbate energy intake is imperative. According to the PLH, the consumption of a diet low in % protein and high in % fat and carbohydrat ....This proposal is designed to test the protein leverage hypothesis (PLH) in humans: the idea that the level of food consumption in humans, like other animals, is adjusted to maintain a target protein intake. As the prevalence of overweight and obesity increases, with its attendant health problems, the need to identify which dietary components limit rather than exacerbate energy intake is imperative. According to the PLH, the consumption of a diet low in % protein and high in % fat and carbohydrate, typical of many Western countries, inevitably requires the ingestion of additional energy to maintain protein intake constant, thus driving weight gain. Conversely, the consumption of a diet that is relatively high in % protein requires the ingestion of lower levels of energy, creating the potential for weight loss. Preliminary experimental and population-level nutritional survey data support the PLH, as does the finding that protein is more satiating than other macronutrients. If, as predicted, small changes in the proportion of protein in diets described in the current study are found to impact on total energy intake there will be significant implications for weight control strategies. Thus, if the PLH is confirmed, public health dietary recommendations and government policy settings for the food industry will need to change. Large-scale intervention studies aimed at demonstrating the longer term impact on body weight will also be required.Read moreRead less
A Cluster Randomised Controlled Trial Of Nurse And General Practitioner Partnership For Care Of COPD
Funder
National Health and Medical Research Council
Funding Amount
$449,377.00
Summary
Chronic Obstructive Pulmonary Disease (COPD) is a chronic disease that can progress to severe disability and use of hospital services. It is an important cause of both death and disability in Australia. Specifically it is the third leading cause of disease burden after heart disease and stroke. Smoking is the most important cause of the disease and there is strong evidence that smoking cessation will largely prevent progression of COPD. National evidence based guidelines for management of COPD w ....Chronic Obstructive Pulmonary Disease (COPD) is a chronic disease that can progress to severe disability and use of hospital services. It is an important cause of both death and disability in Australia. Specifically it is the third leading cause of disease burden after heart disease and stroke. Smoking is the most important cause of the disease and there is strong evidence that smoking cessation will largely prevent progression of COPD. National evidence based guidelines for management of COPD were published in 2003 but these need to be implemented in the community. General practice is well placed to have a key role in early intervention and evidence based management of COPD. There is evidence that specialised nurses working in collaboration with GPs can improve the care the chronic illnesses including COPD. Care Plans with input from health professionals from a range of disciplines have been recommended for COPD but there are barriers to implementing these in general practice. This project brings together nurse assistance and care planning in a model of care designed to deliver best practice management of COPD in the community. The aim of this research is to evaluate the impact of anurse and GP partnership for care of COPD. We will examine the effect on quality of care and health outcomes at 6 and 12 months follow up. Our hypothesis is that the use of a nurse to work as a team with the patient and GP to develop and implement a care plan based on clinical practice guidelines will improve the quality of care received and have a beneficial effect on the patients' respiratory and overall health. This research will be of major significance for improving COPD care in the community and will have far reaching implications for both policy and practice. It will also define a new role for nurses and GPs working in partnership.Read moreRead less
Exploration Of Exposures Associated With Bedding That Are Risks For Childhood Allergy And Asthma Symptoms
Funder
National Health and Medical Research Council
Funding Amount
$263,500.00
Summary
Asthma prevalence in Australia has doubled in the last 20 years, with 1 in 4 children now affected. House dust mites are probably the single most important allergen associated with asthma. The prevalence of mite allergy is linked to exposure, and such allergy when combined with high exposure, is a potent risk factor for asthma exacerbations. The current international advice for managing mite-allergic asthma, strongly advocates the use of bedding encasings as the best way to reduce exposure. Howe ....Asthma prevalence in Australia has doubled in the last 20 years, with 1 in 4 children now affected. House dust mites are probably the single most important allergen associated with asthma. The prevalence of mite allergy is linked to exposure, and such allergy when combined with high exposure, is a potent risk factor for asthma exacerbations. The current international advice for managing mite-allergic asthma, strongly advocates the use of bedding encasings as the best way to reduce exposure. However, three recent major trials using encasings and a meta-analysis of earlier trials all fail to show a clinical benefit. One of the applicants (ET) recently showed, using expertise in measuring personal exposure, that these encasings, as used, fail to significantly reduce aeroallergen exposure. By contrast, 3 recent Australian studies, involving the applicants, AK, ALP and NG showed that feather bedding compared to synthetic bedding, was strongly protective for asthma - the opposite of public advice. The suggested mechanisms involve reduced exposure to mite allergens, or altered exposure to bacterial endotoxin, but persuasive experimental support is lacking. We also propose a novel hypothesis that feather exposure may induce allergic 'tolerance'. Currently there is a lack of certainty about valid approaches to prevent asthma, and the Global Initiative for Asthma has described the need to understand mechanisms and improve interventions as urgent. This project is an ideal opportunity to combine the expertise of the CIA (ET) in measuring airborne exposures (mite, endotoxin, proteins) with that of the others who have expertise in children's asthma, and who are already involved in two large clinical trails involving different bedding and allergen avoidance. Our measurements of these bedding exposures and their clinical outcomes will provide, for the first time, a quantitative basis to refine public health allergen-based interventions to prevent and manage asthma.Read moreRead less