Lecture 4 Flashcards
What are dyslipidaemias?
Disorders in abnormal blood lipids, and/or lipoproteins
- Increased cholesterol and/or triglycerides
Play a important role in the development of hypercholesterolemia
Genetics
Hypercholesterolemia is associated with
gene mutations of proteins involved in cholesterol metabolism
- LDL receptor (LDLr), & proprotein convertase subtilisin-like kexin type 9 (PCSK9)
Basic causes of atherosclerosis
The role of lipoproteins:
In atherosclerosis
VLDL has
large quantities of TGs, less cholesterol & phospholipids
Lipoproteins circulate in blood – lipoprotein lipase walls of tissue capillaries (adipose tissue) – hydrolyses large portion of triglycerides
Control of intracellular [cholesterol]
When [chol] inside cell is great
The cell slows down on its LDL receptor production
Reduce LDL being absorbed
Treating FH
Lifestyle changes, such as exercising & eating a healthy low-fat diet, are the first line of defence against high cholesterol.
Treating FH
Specific recommendations include
Reducing the amount of saturated fat in your diet to <30% of daily calories.
Consuming 10-20g of soluble fibre a day (oats, peas, beans, apples, citrus fruits & carrots).
Increasing physical activity.
Maintaining a healthy body weight.
With FH - recommend take medication to help lower your LDL cholesterol levels.
Specific medication depend on various factors, including your risk factors, your age, your current health & possible side effects.
Pharmacological Treatment
Statins.
Bile-acid-binding resins.
Cholesterol absorption inhibitors.
Combination cholesterol absorption inhibitor and statin.
Injectable medications.
Statins.
Statins — among the most commonly prescribed medications for lowering cholesterol — block a substance the liver needs to make cholesterol. This causes the liver to remove cholesterol from the blood. Statins may also help the body reabsorb cholesterol from built-up deposits on artery walls, potentially reversing coronary artery disease. Choices include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Altoprev), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin (Crestor) & simvastatin (Zocor).
Bile-acid-binding resins.
The liver uses cholesterol to make bile acids, a substance needed for digestion. The medications cholestyramine (Prevalite), colesevelam (Welchol) & colestipol (Colestid) lower cholesterol indirectly by binding to bile acids. This prompts the liver to use excess cholesterol to make more bile acids, which reduces the level of cholesterol in the blood.
Cholesterol absorption inhibitors.
The small intestine absorbs the cholesterol from the diet & releases it into the bloodstream. The drug ezetimibe (Zetia) helps reduce blood cholesterol by limiting the absorption of dietary cholesterol. Zetia can be used in combination with any of the statin drugs.
Combination cholesterol absorption inhibitor and statin.
The combination drug ezetimibe-simvastatin (Vytorin) decreases both absorption of dietary cholesterol in the small intestine and production of cholesterol in the liver. It’s unknown whether Vytorin is more effective in reducing heart disease risk than taking simvastatin by itself.
Injectable medications.
A new class of drugs can help the liver absorb more LDL cholesterol — lowers concentration of cholesterol circulating in your blood.
Alirocumab (Praluent) & evolocumab (Repatha) for people who have a genetic condition that causes very high levels of LDL. These drugs may also be used for people who have had heart attacks or strokes & need additional lowering of their LDL levels. These injectable drugs are administered at home one or two times a month.
Medications for high triglycerides
Fibrates.
Niacin.
Omega-3 fatty acid supplements.
Fibrates.
The medications fenofibrate (Tricor) & gemfibrozil (Lopid) decrease TGs by reducing the liver’s production of very-low-density lipoprotein (VLDL) cholesterol & by speeding up the removal of TGs from the blood. VLDL cholesterol contains mostly TGs.
