HNF 461 1st Edition Lecture 22 Outline of Last Lecture I General functions of LDL and HDL II Structure of LDL and HDL III LDL Transport into Cells IV Synthesis of Cholesterol from Acetyl CoA V HDL Synthesis and Transport VI Exchange of TG and CE Between VLDL LDL and HDL VII Cholesterol Homeostasis Outline of Current Lecture I Cholesterol Homeostasis II Blood Lipids and Cardiovascular Disease CVD III Formation of Plaque IV Desirable Blood Cholesterol Levels V Obesity and CVD VI Exercise and CVD VII Dietary Fatty Acids and Carbohydrates VIII Dietary Cholesterol IX Dietary n 6 n 3 Fatty Acid Ratio X MyPlate XI Dietary Guidance XII Specific Dietary Recommendations Current Lecture Blood Lipid Recommendations 1 Cholesterol Homeostasis a Peripheral Cells These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute i Take in cholesterol from LDL can make their own cholesterol and by selfregulation ii Lose cholesterol by transport to HDL b Organ Level Liver i Take in cholesterol from HDL LDL IDL dietary cholesterol chylomicron remnants and can make its own cholesterol ii Loses cholesterol by formation of bile acids salts synthesized from cholesterol and by production of VLDL recycling process because VLDL will become IDL LDL which is reabsorbed by the liver 2 Blood Lipids and Cardiovascular Disease CVD a Unhealthy diets account for 30 of CVD b Total Cholesterol high cholesterol increases chances for heart disease c HDL want higher amount of cholesterol in HDL d Non HDL not desired especially LDL because it is very susceptible to being oxidized e Total Cholesterol HDL ratio want to be low f Total triglycerides want to be low g Particle numbers size want to be low small h Each individual apolipoproteins 3 Formation of Plaque a Nascent LDL passes in out of the endothelial cell layer Occasionally when under the cell layer can be oxidized which attracts macrophages macrophages take up oxidized LDL become lipid engorged foam cells which lose function Platelets are attracted to the endothelial cells which cause a proliferation of the smooth muscle cells Smooth muscle cells take up oxidized LDL and become foam cells Process continues until the proliferation of foam smooth muscle cells form plaque If the plaque becomes big enough will block blood flow and will cause a heart attack 4 Desirable Blood Cholesterol Levels a LDL Cholesterol 100 mg dl or below is desired b Total Cholesterol 200 mg dl or below is desired 240 mg dl is high c HDL a higher level is better i For Men Levels below 40 mg dl is low 60 mg dl is optimal ii For Women different due to estrogen 50 mg dl is optimal iii Triglycerides 100 mg dl is optimal 5 Obesity and CVD a Obesity correlated to CVD and plaque disease b Accumulation of fat tissue fat tissue produces cytokines which causes systematic inflammation attracts more macrophages i Shows CVD and plaque buildup is caused not only by nutritional status but also by immune function 6 Exercise and CVD a Exercise can lower risk of CVD because can reverse the buildup of large fat droplets large fat droplets are metabolically less active b Fat in muscle is bad because can cause insulin resistance and therefore will cause a buildup of glucose 7 Dietary Fatty Acids and Carbohydrates a Total Cholesterol HDL ratio does not change when replace carbohydrates for saturated FAs in the diet b Total cholesterol HDL ratio will decrease when trans FAs are replaced by unsaturated FAs and carbohydrates Removing trans fats from the diet has the largest impact in lowering ratio c Replacing fat with carbohydrates will increase the total triglyceride level during the fasting state 8 Dietary Cholesterol a Source animal products b Recommendation 300 mg day c If dietary intake is high then cells can compensate by decreasing self production of cholesterol to maintain balance 9 Dietary n 6 n 3 Fatty Acid Ratio a The ratio between the two matters in decreasing the risk of CVD 10 MyPlate a Focuses on foods b Balances calories and avoids oversized portions 11 Dietary Guidance a Overall healthy eating patterns b Appropriate body weight c Desirable blood cholesterol profile d Desirable blood pressure accurate sodium intake is key for maintenance 12 Specific Dietary Recommendations a 5 servings of fruits vegetables each day b 6 servings of grains c 2 servings of fish per week d 25 g fiber each day e Maintain healthy body weight f Physical activity 30 60 min activity on most all days of the week