5 - Health & Diabetes
Glycemic Index
Measure of how much blood glucose levels rise.
5. List health issues that are common in people with poorly controlled type 2 diabetes.
- feeling constantly thirsty (as the kidneys excrete the extra glucose through urine) - blurred vision (extra glucose enters the eye) - weight loss (due to low insulin levels and muscle cells relying on burning fat for energy) - Damage to cells and organs creates long-term problems in the heart, blood vessels, kidneys, eyes, and nerves. - Excess glucose causes blood vessels to thicken and lose some elasticity, making inds more prone to heart attacks and stroke. Can lose vision and even lose limbs.
Glycemic Load
(Food's GI x food's gram of carbs) / 100 - Adding lipids and proteins can lower blood sugar rise.
Q: Patients in the lifestyle treatment ...
Lost more weight, increased physical activity, reduced risk by 58%.
2. Explain what happens when sensitivity to insulin is impaired.
TYPE I DIABETES the pancreatic cells that secrete insulin are destroyed by the body's immune system, leading to a major deficiency of insulin that typically progresses to its complete absence - not preventable, and between 5% and 10% of individuals with diabetes have type 1 - extremely low levels of insulin limit the body's ability to use glucose. To minimize the breakdown of muscle protein for energy, fatty acids are released from adipose tissue. - Since the brain cannot use fatty acids effectively for energy, the liver converts some of these fatty acids into KETONE BODIES, an energy source the brain can use. - KETOACIDOSIS: If left untreated, over time these ketones build up in the bloodstream and increase the acidity of blood.
Diagnosing insulin resistance
Test blood glucose levels after fasting.
Type II diabetes is a growing problem
7th leading cause of death. - Women, AA, pacific islanders, etc at higher risk than white males - unhealthy body weight + being very sedentary increases risk.
Q: What stimulates the pancreas to secrete insulin?
Elevated blood glucose levels
Q Insulin dependent diabetics who inject the wrong amount of insulin can go into "insulin shock," a condition characterized by dizziness and fainting. Insulin shock is treated by giving the diabetic patient sugar. Insulin shock is probably produced by injecting too _________ insulin, which causes most of the blood's glucose to ________________ the blood. The____ blood sugar levels cause fainting.
-Too much insulin -Too much blood glucose removed from blood -Low blood sugar levels cause fainting.
Gestational Diabetes
1) Pregnancy hormones cause insulin resistance 2) Blood glucose levels rise and cross placenta, exposing the infant to excess glucose 3) In response to glucose exposure, baby produces excess insulin 4) The extra fuel and excess glucose causes the baby to grow larger and accumulate excess body fat RISK FACTORS Overweight prior to pregnancy, had gestational diabetes w/ previous pregnancy, aged 25+, family history of Type 2, prediabetic. 18% of pregnancies!
1. Describe how the amount of glucose in the blood is regulated. 3. Explain the roles of two hormones, insulin and glucagon (glycogen?), in regulating blood glucose levels.
1. After we eat, blood glucose levels go up 2. This stimulates pancreas to secrete INSULIN, which stimulates the cells in the skeletal muscle, cardiac muscle, and adipose tissue to take up glucose from the blood. - excess glucose stored for later use as GLYCOGEN (many glucose molecules bonded together). - after limit reached, rest is converted to fat 3. Hours after you eat and blood glucose levels go down, the pancreas secretes GLUCAGON, which signals liver cells to release glucose into the blood to maintain blood glucose levels. - The liver produces and exports this glucose by breaking down glycogen and synthesizing new glucose molecules from amino acids.
Q: What sx is linked to which type?
1. Reduced insulin production => Type I 2. Insulin resistance => Type II and Gestational 3. Rapid disease onset => Type I 4. Being overweight or obese => 2 and Gest.
Type I Diabetes
Autoimmune Disorder. The pancreas doesn't secrete enough insulin in response to an increase in blood sugar => must inject insulin. RISK FACTORS - genetics, ethnicity (high prevalence in whites) TREATMENT - Insulin injections, insulin pump - Glucose monitoring with meter - Track food choices and activity *** No way to prevent it. Nobody knows what triggers the immune system to attack the beta islet cells.
Chronic, excessive high levels of blood glucose ...
Cause damage to cells, fuk up nerve cells, your eyes, numbness in fingers + toes - Increase risk of stroke, death by pneumonia - Kidney failure!!! - Erectile dysfunction - Damage to small blood vessels - Gum disease, tooth decay - Increased risk of heart disease - Poor healing of wounds, amputations
Q: What symptom is common to Gestational, Type 1 and Type 2 diabetes?
Elevated blood glucose levels
Q: What stimulates the pancreas to secrete glucagon?
Decreased blood glucose levels.
Resistant starches
Don't get digested, reduce blood sugar levels, increases insulin sensitivity => LOWER GI! - Like brown rice in comparison to white rice.
Gestational Diabetes consequences
For Mother: - Higher incidence of C-section - High blood pressure during pregnancy - Increased risk of developing Type 2 For Baby: - Risk of shoulder injury during birth - Higher risk of breathing problems - Increased risk of becoming an obese child - Increased risk of Type 2 as an adult
6. Describe how gestational diabetes differs from type 1 or type 2 diabetes. How are they similar? How do they differ? Can we cure any of these forms of diabetes?
Gestational Diabetes: decreased insulin sensitivity due to pregnancy. Obese women have higher risk. - Low glycemic-index diet can keep blood glucose levels at healthy levels. 1) Hormones produced during pregnancy can cause insulin resistance, and sometimes diabetes 2) Glucose levels in mother's blood increases, and the infant is exposed to the excess glucose. 3) In response to the high glucose, the baby produces excess insulin. 4) The extra fuel and high insulin concentrations cause the infant to grow larger and accumulate excess body fat.
Blood Glucose Homeostasis
Homeostasis: Process where organisms regulate internal conditions within a range suitable for survival. Target for blood glucose: 70-99 mg of glucose per 100 ml of blood between meals.
Insulin
Hormone (short protein) that is produced by the pancreas. - Stimulates cells to take up glucose from blood - Stimulate the liver to take up glucose and convert to glycogen * Red blood cells preferentially use insulin for energy. Skeletal muscle and brain cells use for energy too. Adipose tissues can take up excess glucose.
So, what goes wrong during diabetes?
Hyperglycemia: too much sugar in the blood. Early sx: increased thirst, urination, fatigue, tingling in toes and fingers, unexpected weight loss Can lead to: pregnancy complications, high blood pressure, heart disease and stroke, kidney failure, blindness, amputations, death
More Type I Diabetes
Hyperglycemia: when the pancreas becomes unable to produce insulin, muscle and adipose tissues cannot appropriately take up glucose, and blood glucose levels skyrocket - Then, glucose enters urine faster than the kidneys can transport it back into the blood and the excess glucose "spills over" into urine. This loss of glucose in urine deprives the body of a many of the calories consumed throughout the day. The presence of all this glucose in urine also draws additional water into the urine causing increased urine volume and rapid rates of water loss CURE: Purified insulin injections
During starvation,
Ketone bodies are synthesized to prevent muscular loss.
**
Not all insulin resistant individuals have diabetes. 35% of Americans are insulin resistant!
4. Explain the difference between diabetes and prediabetes.
Prediabetes: a condition in which blood glucose levels are moderately elevated above levels that are considered normal. - after fasting for eight hours, the blood glucose levels of someone with prediabetes would measure 100 mg to 125 mg per 100 ml blood, which is elevated but still less than the fasting level of at least 126 mg per ml that is required for a diagnosis of diabetes. - after ingesting glucose as part of an oral glucose tolerance test (OGTT), the same person would have elevated blood glucose levels in the 140 mg to 199 mg per 100 ml range—just under the 200 mg/100 ml diagnostic level for diabetes
7. Describe factors that increase risk for type 2 and gestational diabetes and those that protect against it and understand how these factors relate to diet
Pro-diabetes factors Excess calories Low intake of whole grains High intakes of refined carbohydrates, sugar-sweetened beverages + trans fat, sat fat Low activity level Anti-diabetes factors Lean body and physical activity Diet rich in whole grains, beans, healthy fats and oily fish
Diabetes Reversal Study
Severe caloric restrictions worked too (?)
Glucose Homeostasis
Stimulus: HIGH BLOOD GLUCOSE 1. Beta islet cells release insulin from pancreas 2. Cells take up glucose, LIVER converts glucose to glycogen 3. Adipose (fat) tissues stimulated to take up glucose 4. Glucose levels drop Stimulus: LOW BLOOD GLUCOSE 1. Alpha islet cells release glucagon from pancreas, which signals liver to increase glucose production 2. LIVER breaks down glycogen into glucose 3. Glucose levels rise
Type 2 Diabetes
The pancreas secretes plenty of insulin, but the cells don't respond to the signal. RISK FACTORS - Being overweight, aged 45+ - Sedentary lifestyle (sedentary 3 days a week!) - Ethnicity (all but white)
Diabetes Prevention Program
Tracked people at risk for Type II diabetes. 3 treatments 1) Intensive Lifestyle Modification (diet, weight loss, personal trainer w/ exercise) 2) Given special drug 3) Given placebo FINDINGS: onset of Type II preventable/slowed by diet, exercise and weight loss.
New Study with Dogs
Transplant healthy pancreatic cells w/collagen solution (to help sneak past immune system) to replace damaged ones. Works well with dogs!
For every 2 additional hours of watching TV,
Type II Diabetes risk up 20% and heart disease risk up 15%
Type II Diabetes
occurs when cells are less sensitive to the effects of insulin, even if the pancreas is able to produce normal amounts - Normal insulin sensitivity: insulin signals total glucose transporter activity to increase, and blood glucose levels decrease as glucose enters muscles and fat cells. - Poor insulin activity: insulin signal is weak, so the muscles and fat cells do not effectively take up glucose, causing blood glucose levels to remain high. => => How/why does this happen? Excess adipose tissue produces hormone-like substances that circulate through the body and interfere with the insulin signals that typically stimulate glucose uptake. => => => The pancreas then produces more insulin to help glucose enter cells. => => Insulin resistance also blocks insulin's ability to suppress liver glucose production, contributing to even higher blood glucose levels. (Type I is when cells are less sensitive to the effects of insulin, even if the pancreas is able to produce normal amounts)