lecture 13 Flashcards
cardio-metabolic risk
is a condition in which the possibilities of developing atherosclerotic cardiovascular disease and diabetes mellitus are significantly enhanced
the first law of fuel metabolism
energy must be stored before it can be released and utilized
metabolic flexibility
ability to switch rapidly between substrates
the second law of fuel metabolism
the brain must be continuously supplied with glucose….it cant metabolize proteins or fatty acids.
the liver
needed to maintain adequate blood glucose levels. First stores glucose in the form of glycogen (glycogenesis).
What happens to the liver when circulating levels of glucose fall too low?
the liver will break down glycogen and release it back into the bloodstream as glucose (glycogenolysis) causing the rise of blood sugar.
Insulin
storage hormone secreted by beta cells of the pancreas. Release of insulin is stimulated by a rise in blood sugar. Its role is to lower blood sugar by increasing glucose uptake by the muscles.
Glucagon
secreted by alpha cells in the pancreas in response to low blood sugar (hypoglycemia). Glucagon secretion causes a rise in blood glucose and free fatty acids by stimulating glycogenolysis in the liver.
Epinephrine
stimulated by immediate stress and by exercise. Role is to suppress insulin secretion and promote glucagon secretion. Increases glycogenolysis, gluconeogenesis, and fat mobilization. in order to increase circulating levels of glucose and fatty acids.
cortisol
– stimulated by chronic stress. Similar to epinephrine in that it increases circulating levels of substrates and ensures the mobilization of fuels necessary to adapt to long-term stress.
subsistence efficiency
refers to the amount of food intake needed to support the work necessary to obtain that food. Over 100,000 years ago, people consumed approximately 3,000 calories per day and expended about 1,000 calories per day in work activity …subsistence efficiency ratio (SER) of 3:1.
The combination of overfeeding and inadequate amounts of work activity is the precursor to what?
metabolic dysregulation at the cellular level
How does the body adapt to overfeeding?
The body adapts to overfeeding and chronic oversupply of fuel by getting bigger…increased body mass will burn more energy at rest.
Those carrying a variant of the FTO gene tend to be..
heavier than those without it. There is an obesity risk associated with the FTO gene
What occurs when the body consumes more energy than it expends?
there is a build up of substrate within the cell
What is the consequence of the build up of substrate?
the buildup of ROS, a small and highly reactive molecule. Leads to oxidative stress.
Excess ROS is associated with which conditions?
metabolic disregulation leading to type 2 diabetes and the dysfunction of insulin action within the cell.
What happens if the liver becomes too fatty?
it leads to disfunction of the insulin signals that will shut down glucose production resulting in high blood sugar.
Insulin resistance
precursor to type 2 diabetes
what happens in the body when one has type 2 diabetes?
The excess blood sugar in diabetes can wreak havoc on blood vessels all over the body and cause complications. It can severely damage the eyes, kidneys, nerves, and other body parts; cause sexual problems; and double the risk of heart attack and stroke.
type 1 diabetes
considered an autoimmune disease and is characterized by a deficiency in insulin production and secretion by the beta cells of the pancreas.
Used to be termed “juvenile-onset” or “insulin-dependent” diabetes.
type 2 diabetes
considered a lifestyle disease and is defined by reduced insulin sensitivity in target tissue (primarily muscle, fat, and liver).
Was referred to as “adult-onset” or “non-insulin dependent” diabetes.
Three biologic factors increase cardiometabolic risk
hypertension, hyperglycemia, and dyslipidemia.
cardiometabolic risk reductions
weight loss
high ration of body fat to lean mass
