Blood Fats Explained
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Blood Fats Explained HEART UK – The Cholesterol Charity providing expert support, education and influence 2 | Fats in the blood At risk of cardiovascular disease? | 3 Fats in the blood At risk of cardiovascular disease? Fats that circulate in the blood are called lipids. Very low density lipoproteins (VLDL) transport Cardiovascular disease (CVD) is the medical Blood pressure is a measure of the resistance Cholesterol and triglycerides are both lipids. mainly triglycerides made by the liver to where name for circulatory diseases such as coronary to the flow of blood around your body. It is They have essential roles in the body. In excess they are either used to fuel our muscles or stored heart disease (CHD), stroke, mini stroke (transient measured in millimetres of mercury (mmHg). Your they are harmful. for later use. ischaemic attack or TIA), angina and peripheral doctor or nurse will measure both your systolic vascular disease (PVD). You are more likely to (upper figure) and diastolic (lower figure) blood Cholesterol is needed to build cell walls and Low density lipoproteins (LDL) carry most of the develop CVD the more risk factors you have. pressure. About a third of adults have high blood to make hormones and vitamin D. Some of our cholesterol in our body from the liver to the cells pressure. If untreated it increases the risk of cholesterol comes from the food we eat; but most that need it. The cholesterol that is carried on LDLs There are two types of risk factors: heart attack and stroke. High blood pressure is is made in the liver. When broken down cholesterol is called LDL-cholesterol or bad cholesterol. Fixed risk factors – these include your age, usually diagnosed when a number of readings are is used to make bile acids which help us to digest High density lipoprotein (HDL) plays a vital family history and being a man. You cannot do made above 140/90mmHg. our food. role in taking excess cholesterol, away from cells anything to change these risk factors. Type 2 diabetes can affect your heart health. Triglycerides are fats which are found in and artery walls, back to the liver for disposal and Risk factors you can change: This is because it can affect the quantity and our food. When we eat, any fat in our food is recycling. Having healthy HDL levels means less quality of fats (cholesterol and triglycerides) absorbed by our gut (intestine). It is then moved cholesterol will build up in the artery wall. • Unhealthy cholesterol (and triglyceride) levels in your blood. Usually people with type 2 around the body, in our blood, as triglycerides. The cholesterol that is carried on HDLs is called in the blood diabetes have increased triglyceride levels (due The liver also makes triglycerides. They provide HDL-cholesterol or good cholesterol. • Smoking to an increase in VLDLs), low levels of HDL the energy that is needed by our muscles and We also refer to intermediate density • High blood pressure and smaller sized LDL particles. This pattern organs and help keep us warm. lipoprotein (IDL) in this booklet. These are • Type 2 diabetes increases the risk of developing heart disease. cholesterol and triglyceride rich particles. • A large waistline What are lipoproteins? A large waistline is a sign that you are storing fat Cholesterol and triglycerides cannot circulate Unlike chylomicrons the levels of VLDL, LDL, There is a lot you and your doctor can do to lower inside and around your vital organs. Doctors know loosely in the blood, so they travel in “round HDL, IDL and cholesterol change very little after your risk from these. this fat can increase your risk of diabetes and heart a meal. The levels of these lipoproteins usually problems. We talk more about this on page 5. parcels” called lipoproteins. Lipoproteins contain Stopping smoking can make a big difference reflect longer term diet and lifestyle habits. a special mix of fats and proteins which allow to both your short and long term health. People them to flow freely in the blood. Apolipoprotein B is the key protein for who smoke are more likely to have a stroke, heart APOLIPOPROTEIN A The are four main lipoproteins (sometimes called chylomicrons, VLDL and LDL. attack or breathing problems when compared to someone with the same risk factors who does PHOSPHOLIPID apolipoproteins). They vary in size, content and Apolipoprotein A is the key protein for HDL. not smoke. On average smokers die 15 years CHOLESTERYL how tightly they are packed (density). ESTER Lipoprotein (a) or Lp(a) is a large “sticky” earlier than non-smokers. Toxins in cigarette Chylomicrons are the largest. They carry lipoprotein particle made in the liver. The amount smoke put a bigger strain on the heart - making TRIGLYCERIDE triglycerides from the intestine to the tissues of Lp(a) in our blood is largely decided by our it beat faster, increasing the risk of blood clots UNESTERIFIED where they are needed as a source of energy. genetic makeup. Doctors are interested in Lp(a) and damaging the inside of your blood vessels CHOLESTEROL The number of chylomicrons in the blood because high levels increase the risk of heart and (arteries). Smoking also lowers your protective increases after a meal and then slowly decreases. circulatory disease. HDL-cholesterol. You can cut your risk of CHD in half, in just one year, by stopping smoking. The HDL lipoprotein Words in red are featured in our glossary on page 14. Cholesterol and triglycerides have essential roles in the body. Having a healthy diet, not smoking, being active and keeping your waistline in check are Lipoproteins - like LDL and HDL - carry cholesterol and triglycerides around in the blood good for everyone and can help you keep healthy. 4 | How your heart works Why your liver is important | 5 How your heart works Why your liver is important The heart RIGHT CORONARY ARTERY The liver plays a central role in controlling the LEFT CORONARY amount of fat in your blood. The heart, blood vessels and blood make up our ARTERY circulatory system. The heart is a muscle which Liver cells have special “hooks” on them that can never stops beating, it pumps blood around the CIRCUMFLEX remove LDL cholesterol from the blood. These body. The left side pumps oxygen and nutrient ARTERY are called LDL receptors. rich blood to the brain, muscles, organs, and Most of our cholesterol is made in the liver. every cell in the body. The right side of the heart The liver is also the major site for changing is slightly smaller and returns blood to the lungs to excess sugars, proteins and alcohol into fatty be topped up with oxygen. acids and triglycerides, which are then either used The heart has its own blood supply which comes for energy or stored for later. from the coronary arteries. These divide many Any fat that builds up in the liver, can damage it. times to provide oxygen and nutrients to every MARGINAL Fatty liver can be caused by drinking too much part of the heart muscle to help keep it healthy ANTERIOR ARTERY INTERVENTRICULAR alcohol or by eating too much. It is common and pumping normally. ARTERY POSTERIOR INTERVENTRICULAR ARTERY in people who carry too much fat around their waistline. If you have too much fat in your liver Heart disease The heart and the coronary arteries it won’t work as well as it should - a sign could Problems occur when any one of these arteries be too much cholesterol, triglycerides or sugar in become narrowed due to the slow build-up of What is atherosclerosis? your blood. Most people won’t know they have a fatty material (called plaque or atheroma). (ather-o-scler-o-sis) fatty liver. This process - called atherosclerosis - causes Atheroslcerosis is a very slow process, coronary heart disease (CHD). Sometimes BRAIN an artery can become so narrow it cannot deliver happening over many years. It can start very enough blood. This results in warning symptoms early in life and results in the build up of fatty TONSIL material in the linings of your blood vessels. such as chest pain – we call this stable angina. THYROID When these fatty deposits become very large These fatty deposits start when the blood vessel or extended they may burst. Just like when you lining becomes damaged. This makes it easier for graze your knee, a blood clot and then scarring cholesterol (carried on lipoproteins like LDL) to LUNGS forms over the damaged area. Over time this stick on and build up more rapidly. HDL lipoproteins HEART can remove cholesterol from these deposits. damage may partly or completely block the artery. STOMACH When this happens it is called acute coronary Reducing your LDL cholesterol, increasing your HDL LIVER SPLEEN syndrome (ACS), unstable angina or heart cholesterol and reducing other risk factors can help KIDNEY attack. A heart attack is sometimes referred to slow down the process of atherosclerosis. as a myocardial infarction or MI. Major organs in the body Heart facts • Your coronary arteries supply your heart muscle with oxygen and nutrients • Your liver controls the amount and type of fat in your blood • A heart attack happens when one of these arteries become blocked • Fatty liver happens when your body stores fat inside your liver 6 | Lipid clinics How blood fats cause heart disease | 7 Lipid clinics How blood fats cause heart disease Lipid clinics provide specialist help and advice Checking your blood fat levels Having enough cholesterol and triglycerides is to those who have raised blood lipids such as vital for health. But sometimes we have too much Your doctor can check the amount of cholesterol cholesterol and triglycerides and who may have, cholesterol, triglycerides, and the lipoproteins that and triglycerides in your blood.