Dr. Alfonso Abizaid

• In-person event
• 4440Q, Carleton Technology and Training Centre, Carleton University
• 1125 Colonel By Drive, Ottawa, ON, K1S 5B6

• Contact
• Owen Rowland, owen.rowland@carleton.ca

Stress and Obesity: The Ghrelin Connection

Alfonso Abizaid, Dept. of Neuroscience, Carleton

Faculty Host: Owen Rowland

Obesity • Medical • Hormones • Brain
Obesity is, without a doubt, among the most pressing health issues facing Western societies. According to the United States Department of Health, levels of obesity have increased dramatically in the past 15 years so that, within the United States, about 60-65% of the population can be considered overweight (Body Mass Index [BMI] > 25%) and about 25-30% can be considered obese (BMI > 30%). Furthermore, it has been estimated that at the current rate, the costs of treating obesity will be over 50 billion dollars in the United States alone to treat all major chronic medical conditions related to or secondary to obesity. Given that obesity is linked to a variety of disorders that lead to early death, including cardiovascular malfunction, diabetes, cancer, respiratory ailments, renal failure, and dementia, it is not surprising that some have gone as far as predicting that life expectancy will decrease in the next fifty years as a direct result of current obesity rates. 

Obesity is related to a variety of pathologic conditions that include cancer, heart disease, diabetes, and renal insufficiency, all of which can lead to an early death and poor quality of life. In Canada, the rate of obesity and the health and economic issues associated with this condition have reached alarming levels. While it is clear that there are genetic factors that are closely associated with obesity, environmental factors also play an important role the behavioral and physiological responses that lead to body weight alterations and ultimately in obesity and metabolic syndrome. Stress, for example has been associated with a number of metabolic changes that ultimately can lead to obesity, insulin resistance, and cardiovascular disease. Interestingly, a number of symptoms that are seen following exposure to different types of stressors are also seen in animals exposed to chronically elevated levels of the hormone ghrelin. Ghrelin, a stomach derived hormone, is commonly associated with the stimulation of appetite and food intake (particularly the intake of high calorie foods), as well as the accumulation of body fat. Ghrelin appears to be released following exposure to stressors, and thus it is possible that the behavioral and metabolic alterations that are seen following chronic stress paradigms are mediated in part by ghrelin. In this presentation I show data that links the action of ghrelin on the brain to cause obesity and metabolic alterations