Block B - cholesterol and statins Flashcards
(34 cards)
major factors for cornary risk ?
age, male gender, smoking and high blood pressure (hypertension) as well as Elevated cholesterol of LDL-C, low HDL-c and diabetes and family history (genetics)
minor factors ?
Minor factors include sedentary lifestyle, obesity, dietary saturated fats.
what are C reactive proteins a marker for ?
inflammation
primary prevention ?
Primary prevention has the aim of reducing formation and rate of progression in coronary and peripheral atherosclerosis from childhood to old age. The prevention of coronary events and strokes in apparently healthy persons at risk, particularly middle-aged and elderly. Furthermore, the prevention of heart attacks, strokes in persons with established atherosclerosis.
describe the liver ?
The liver is complex organ, located in the upper right corner of the abdomen in the thoracic cavity. It consists of two main lobes divided into right and left by the hepatic vein .The liver received approximately 15 ml of blood per minute from two major vessels: The hepatic artery supplies 25% of the total blood flow and provides most of the oxygen requirement. The portal vein drains most of the gastrointestinal tract (GI). It supplies 75% of the blood flow and transports the most recently absorbed material from the intestines to the liver. Drugs undergo first pass metabolism here , which can influence the amount of drug available.
what does the liver produce ?
Liver produces bio salts which act as an emulsion, these are stored in the gallbladder. Then following stimulation from the pancreas, it feeds bile into the duodenum to reduce the pH environment from the stomach. A key component of bile is cholesterol.
function of he liver ?
The liver stores glycogen, vitamins and iron.It contains an extensive reticuloendothelial system for the synthesis and breakdown of blood cells. The blood cells are then resynthesized with the heme (iron component) stored in the liver. Liver cells metabolize, detoxify and excrete through bile which moves through the small intestine, both endogenous and exogenous compounds by first pass metabolism. This is important in metabolism and execration of drugs and toxins.
ideal cholesterol level ?
target for cholesterol is 4-5 mmol/L and American expression is 200mg/dl-1.
target for HDL ?
The target for HDL ( good one) is around 1mmol/L
target for LDL ?
LDL ( bad one) is less than 2-3 mmol/L
target for triglycerides ?
Triglycerides are smaller than the LDL particles and a target for them is less than 1.7mmol/L.
ratio of HDL:LDL ?
The ratio of HDL:LDL is ideally less than 4.5mmol/L.
patient with high cholesterol , what will the ratio be ?
have a higher ratio of LDL compared to HDL. This means there is a lipid profile in the blood that would favour the development of atherosclerotic plaques. The oxidation of LDL and the immune cells such as macrophages and monocytes lead to the generation of the foam cell.
description of cholesterol ?
Cholesterol is a waxy , fat like substance that is a sterol , steroid alcohol. It is found in all cells of the body as it is part of the lipid bilayer. 75% of the cholesterol is synthesised in the liver due to resynthesis occurring and the other 25% comes from our diet , denovo.
cholesterol synthesis ?
cholesterol synthesis occurs primarily in the liver, cytoplasm and the Endoplasmic Reticulum in endothelial cells which involves over 30 enzymes. The HMG-CoA reductase reaction is the rate limiting step as it is at the start of the reaction. This stage is highly regulated and a target of pharmacological intervention. Statins target this step in cholesterol synthesis by blocking the enzyme HMG-coA reductase which in turn blocks the production of mevalonic acid and the further steps in cholesterol synthesis.
what is cholesterol in ?
Cholesterol is in the sex hormones such as testosterone and also by hormones released by the adrenal gland
why is synthesis of cholesterol important ?
It is also used in the production of bile acids which are used for neutralization. Vitamin D synthesis requires cholesterol to be present.
chylomicrons ?
Chylomicrons are small fat globules composed of protein and fat. There are different types as follows: Very low density lipoproteins (VLDL) , Intermediate-density lipoproteins (IDL) , Low density lipoproteins (LDL) and High density lipoproteins (HDL).
athersclerosis ?
Atherosclerosis is the formation of fatty plaques in the blood vessels and they can lead to heart attacks , strokes , angina and an increased risk of coronary heart disease. This is due to a narrowing of the artery and this causes an abnormal blood flow and oxygen delivery. A key factor here is the LDL molecules. The oxidation of LDL and the immune cells such as macrophages and monocytes lead to the generation of the foam cell. This foam cell undergoes apoptosis and forms a core for the ealry stage of a plawue.
Drug therapy for hyperlipidemia include bile sequestriants , what are these ?
sequester the bile which is excreted , this causes more of the available cholesterol to be used in producing bile and as a result the concentration of cholesterol decreases.
Niacin ?
B vitamins , important in synthesis , quite small not normally a large factor for reducing. Used for people which have liver diseases as an add on.
fibric acid derivitives ?
good for binding fat and cholesterol which is in our diet , so it is not absorbed by the GI tract.
why is the medditeranian diet good for ?
The Mediterranean diet is rich in plant oil , it is beneficial for having a good balance of lipids in the blood, as a result the ratio of LDL is lower , HDL is high and cholesterol is decreased.
Ezetimibe’s ?
Ezetimibe’s will reduce the fat being taken up from the gut
