Cholesterol Explained
Cholesterol can't dissolve in the blood. It must be transported through your bloodstream by carriers called lipoproteins, which got their name because they’re made of fat (lipid) and proteins.
The two types of lipoproteins that carry cholesterol to and from cells are low-density lipoprotein, or LDL, and high-density lipoprotein, or HDL. LDL cholesterol and HDL cholesterol, along with one fifth of your triglyceride level, make up your total cholesterol count, which can be determined through a blood test.
LDL (Bad) Cholesterol
LDL cholesterol is considered the “bad” cholesterol because it contributes to plaque, a thick, hard deposit that can clog arteries and make them less flexible. This condition is known as atherosclerosis. If a clot forms and blocks a narrowed artery, heart attack or stroke can result. Another condition called peripheral artery disease can develop when plaque buildup narrows an artery supplying blood to the legs.
HDL (Good) Cholesterol
HDL cholesterol is considered “good” cholesterol because it helps remove LDL cholesterol from the arteries. Experts believe HDL acts as a scavenger, carrying LDL cholesterol away from the arteries and back to the liver, where it is broken down and passed from the body. One-fourth to one-third of blood cholesterol is carried by HDL. A healthy level of HDL cholesterol may also protect against heart attack and stroke, while low levels of HDL cholesterol have been shown to increase the risk of heart disease.
Triglycerides
Triglycerides are another type of fat, and they’re used to store excess energy from your diet. High levels of triglycerides in the blood are associated with atherosclerosis. Elevated triglycerides can be caused by overweight and obesity, physical inactivity, cigarette smoking, excess alcohol consumption and a diet very high in carbohydrates (more than 60 percent of total calories). Underlying diseases or genetic disorders are sometimes the cause of high triglycerides. People with high triglycerides often have a high total cholesterol level, including a high LDL cholesterol (bad) level and a low HDL cholesterol (good) level. Many people with heart disease or diabetes also have high triglyceride levels.
Lp(a) Cholesterol
Lp(a) is a genetic variation of LDL (bad) cholesterol. A high level of Lp(a) is a significant risk factor for the premature development of fatty deposits in arteries. Lp(a) isn't fully understood, but it may interact with substances found in artery walls and contribute to the buildup of fatty deposits.
BLOOD PRESSURE
Blood pressure is typically recorded as two numbers, written as a ratio like this:
Systolic
The top number, which is also the higher of the two numbers, measures the pressure in the arteries when the heart beats (when the heart muscle contracts).
Diastolic
The bottom number, which is also the lower of the two numbers, measures the pressure in the arteries between heartbeats (when the heart muscle is resting between beats and refilling with blood).
Which number is more important, top (systolic) or bottom (diastolic)?
Typically more attention is given to the top number (the systolic blood pressure) as a major risk factor for cardiovascular disease for people over 50 years old. In most people, systolic blood pressure rises steadily with age due to increasing stiffness of large arteries, long-term build-up of plaque, and increased incidence of cardiac and vascular disease.
A complete fasting lipoprotein profile will show the following for:
Total blood (or serum) cholesterol
Your total cholesterol score is calculated using the following equation: HDL + LDL + 20 percent of your triglyceride level. A total cholesterol score of less than 4.65mmol/L is considered optimal.
HDL (good) cholesterol
With HDL cholesterol, higher levels are better. Low HDL cholesterol puts you at higher risk for heart disease. People with high blood triglycerides usually also have lower HDL cholesterol. Genetic factors, type 2 diabetes, and certain drugs, such as beta-blockers and anabolic steroids, also lower HDL cholesterol levels. Smoking, being overweight and being sedentary can all result in lower HDL cholesterol.
LDL (bad) cholesterol
A low LDL cholesterol level is considered good for your heart health. However, your LDL number should no longer be the main factor in guiding treatment to prevent heart attack and stroke, according to new guidelines from the American Heart Association. For patients taking statins, the guidelines say they no longer need to get LDL cholesterol levels down to a specific target number. A diet high in saturated and trans fats raises LDL cholesterol.
Triglycerides
Triglyceride is the most common type of fat in the body. Normal triglyceride levels vary by age and sex. A high triglyceride level combined with low HDL cholesterol or high LDL cholesterol is associated with atherosclerosis, the buildup of fatty deposits in artery walls that increases the risk for heart attack and stroke
ANGINA
Angina is chest pain or discomfort caused when your heart muscle doesn't get enough oxygen-rich blood. It may feel like pressure or squeezing in your chest. The discomfort also can occur in your shoulders, arms, neck, jaw, or back. Angina pain may even feel like indigestion.But, angina is not a disease. It is a symptom of an underlying heart problem and is usually a symptom ofcoronary heart disease (CHD).There are many types of angina, including acute coronary syndrome, angina pectoris, chest pain, coronary artery spasms, microvascular angina, Prinzmetal's angina, angina inversa, stable or common angina, unstable angina and variant angina. View an animation of angina.Angina occurs when the heart muscle does not get the blood it needs to function properly. This usually happens because one or more of the coronary arteries is narrowed or blocked, also called ischemia.Angina can also be a symptom of coronary microvascular disease (MVD). This is heart disease that affects the heart’s smallest coronary arteries and is more likely to affect women than men. Coronary MVD also is called cardiac syndrome X and non-obstructive CHD. Learn more about angina in women.Depending on the type of angina you have, there are many factors that can trigger angina pain. The symptoms also vary based on the type of angina you have.Types of Angina - Knowing the types of angina and how they differ is important.
Stable Angina / Angina Pectoris
It occurs when the heart muscle doesn't get as much blood as it needs. This usually happens because one or more of the heart's arteries is narrowed or blocked, also called ischemia.
Unstable Angina
Unstable angina or sometimes referred to as acute coronary syndrome causes unexpected chest pain, and usually occurs while resting. The most common cause is reduced blood flow to the heart muscle because the coronary arteries are narrowed by fatty buildups (atherosclerosis) which can rupture causing injury to the coronary blood vessel resulting in blood clotting which blocks the flow of blood to the heart muscle.
Variant (Prinzmetal) Angina
Unlike typical angina – which is often triggered by exertion or emotional stress - Prinzmetal’s angina almost always occurs when a person is at rest, usually between midnight and early morning. These attacks can be very painful.
Pinzmetal’s angina is rare, representing about two out of 100 cases of angina, and usually occurs in younger patients than those who have other kinds of angina.The pain from variant angina is caused by a spasm in the coronary arteries (which supply blood to the heart muscle).
Microvascular Angina
This type of angina may be a symptom of coronary microvascular disease (MVD). Coronary MVD is heart disease that affects the heart’s smallest coronary artery blood vessels.
Causes of microvascular angina: Spasms within the walls of these very small arterial blood vessels causes reduced blood flow to the heart muscle leading to a type of chest pain referred to as microvascular angina.
