Glossary

Acute coronary syndrome (ACS)

Adverse coronary events, such as unstable angina and acute myocardial infarction, in which the primary culprit is atherosclerosis.

Albumin

A major plasma protein synthesized in the liver that serves as a transport for fatty acids, bilirubin, and some drugs. Decreased serum albumin occurs in renal disease.

Angiotensin

A group of polypeptide vasosuppressor hormones formed by renin; angiotensin II stimulates aldesterone secretion and serves as a neurotransmitter. Raising blood pressure and reduces renal fluid loss through blood flow constriction.

Angiotensin-converting enzyme (ACE) inhibitor

Commonly used to treat high blood pressure, this drug class blocks the action of angiotensin-converting enzymes. It reduces the constriction of the blood vessels, veins, and arteries, resulting in the lowering of blood pressure.

Ankle-brachial index (ABI)

A measurement designed to diagnose intermittent claudication in the legs caused by peripheral artery disease (PAD). The lower the index, the greater the risk for heart attack, stroke, or other serious circulatory or heart events. An index of .41 to .90 suggests PAD. Measurements less than .40 indicate severe blockage in the leg arteries.

Atherogenic

Substances that have the capacity to start or accelerate the process of atherogenesis or the formation of lipid deposits in the arteries.

Atherosclerosis

A narrowing of a blood vessel due to the accumulation of plaque, resulting in a restriction of blood flow. Plaque comprises irregular deposits of cholesterol and other debris deposited within the intima and media of large and medium-sized arteries.

ATP III (see NCEP)

The ATP III (Third Adult Treatment Panel) evidence-based guidelines include nearly 1,000 references and represent a synthesis of all the data from major clinical trials. By elaborating further on previous reports, ATP III provides for more intensive lipid-lowering treatment in a larger population of patients, with special emphasis on those with multiple risk factors.

Bile-acid sequestrants

These lipid-regulating agents bind with cholesterol-containing bile acids in the intestines and prevent them from being absorbed into the bloodstream. They bind bile acids in the small intestine and carry them out of the body, causing the body to use more cholesterol to make more bile acids. This results in lower cholesterol levels. Bile-acid sequestrants also prevent absorption of some dietary cholesterol.

Body mass index (BMI)

A frequently employed index of obesity, expressed as weight in kilograms (kg) divided by the square of height in meters (m²); BMI = kg/m².

Calcium channel blocker (CCB)

A drug that reduces spasm of the blood vessels, lowers blood pressure, and controls angina; acts by selectively blocking the uptake of calcium by the cells.

Cardiovascular disease (CVD)

Any disease of the heart and/or blood vessels, including peripheral, coronary and cerebrovascular diseases.

Carotid artery disease

A progressive disease involving the buildup of fatty material and plaque in the carotid arteries; can lead to a stroke.

Cerebrovascular disease

Any disease affecting the blood vessels of the brain.

Cholesterol

A sterol, or fat-like substance, contained in foods of animal origin, and a precursor of bile acids and steroid hormones. Cholesterol is produced by the liver and is essential for making cell membranes. It plays a significant role in the pathogenesis of atherosclerosis. There are several types, including HDL-C, LDL-C, VLDL-C. Each kind of cholesterol is transported in plasma by specific lipoproteins.

Chronic kidney disease (CKD)

Level of renal insufficiency determined by overall kidney damage (pathological abnormalities or markers of damage in blood and urine tests or imaging) and glomerular filtration rate of <60 mL/min/1.73m² for ≥ 3 months.

Coronary artery bypass graft (CABG)

A surgery to bypass atherosclerosis in the coronary arteries. The process detours blood around the blockage and restores the supply to the heart muscle.

Coronary artery disease (CAD)

A disease characterized by a narrowing or blockage of the arteries that supply blood to the heart, which may result in angina pectoris, myocardial infarction, or sudden cardiac death.

Coronary heart disease (CHD)

An acute or chronic disease affecting the blood vessels of the heart, and involving an insufficient supply of oxygenated blood to the myocardium. This condition is most often a consequence of arterial narrowing, but can also be due to increased oxygen demand or diminished blood oxygen transport. Also referred to as ischemic heart disease (IHD).

Creatinine

Anhydride of creatine excreted in the urine and used as a marker for measuring kidney function.

Creatinine clearance

Clearance in the kidney of endogenous creatine; estimated glomerular filtration rate.

Diabetes (type 1 and type 2)

A condition characterized by hyperglycemia resulting from the body's inability to use blood glucose for energy.

• Type 1 diabetes: also called insulin-dependent diabetes mellitus (IDDM). In type 1 diabetes, the pancreas makes little or no insulin because the insulin-producing β cells have been destroyed. This type of diabetes usually appears suddenly and most commonly in people younger than 30 years of age. Treatment consists of insulin administrated by injection or pump, a planned diet, regular exercise, and daily self-monitoring of blood glucose.
  
• Type 2 diabetes: also called non–insulin-dependent diabetes mellitus (NIDDM). Type 2 diabetes is associated with insulin resistance and impaired β cell function. Its management includes diet, exercise, and monitoring of glucose levels. Sometimes oral antihyperglycemic agents or insulin injections are needed. Type 2 diabetes accounts for 90%–95% of diabetes cases.

Diabetic nephropathy

Kidney disease that accompanies later stages of diabetes, usually characterized by hyperfiltration at first and progressing, in most serious cases, to end-stage renal disease.

Diuretic

Also known as a water pill, this therapy helps rid the body of excess fluids and salt. Usually used in the treatment of high blood pressure and heart failure.

Dyslipidemia

An abnormal concentration in the blood of one or more lipids, such as an elevated LDL-C level or a depressed HDL-C level.

End-stage renal disease (ESRD)

The final stages of chronic kidney disease, where renal function has been compromised anywhere from 80%–95%. Most common cause is diabetes; usually treated by dialysis or kidney transplantation.

Fibric acids

Also known as fibrates, these lipid-regulating agents speed up the chemical breakdown of triglyceride-rich lipoproteins that circulate in the body. Fibrates increase lipolysis and eliminate triglyceride-rich particles from plasma by activating lipoprotein lipase and reducing apoprotein C-III production.

Glomerular filtration rate (GFR)

In the kidney, the volume of fluid filtered from the renal glomerular capillaries into Bowman's capsule per unit time. Most closely determines renal function.

Glucose (blood)

The main sugar that the body makes from the three elements of food—proteins, fats, and carbohydrates—but mostly from carbohydrates. Glucose with insulin is the major source of energy for living cells and is carried to each cell through the bloodstream.

Hemoglobin A_1c (HbA_1c)

Hemoglobin carries oxygen to the red blood cells and sometimes joins with the glucose in the bloodstream. A_1c is a test that measures a person's average blood glucose level over 2 to 3 months. The test shows the amount of glucose that adheres to the red blood cell, which is proportional to the amount of glucose in the blood.

High-density lipoprotein (HDL)

A lipoprotein that protects against the development of coronary heart disease through a process known as reverse cholesterol transport. HDL transports cholesterol from the body cells to the liver, where it is excreted in bile. Elevated blood plasma levels of HDL-cholesterol (HDL-C) are negatively correlated with coronary heart disease risk. HDL-C is often called the "good" cholesterol.

HMG-CoA reductase inhibitors (statins)

These lipid-regulating agents (3-hydroxy-3-methylglutarylcoenzyme A reductase inhibitors), commonly referred to as statins, inhibit HMG-CoA reductase in the liver. By inhibiting the formation of mevalonate, the amount of cholesterol produced in the body is reduced. The resulting decrease of cholesterol leads to an increase in the number of hepatic LDL receptors, which results in increased clearance of LDL from the blood.

Hypercholesterolemia

A condition in which blood plasma cholesterol levels are elevated.

Hyperglycemia

High blood sugar which occurs when the body does not have enough insulin or when the body cannot use insulin properly.

Hyperlipidemia

A condition in which any or all lipid levels are elevated, including hypertriglyceridemia and hypercholesterolemia.

Hypertension

The force of blood through and against the walls of arteries causes blood pressure (BP) to rise and fall during the day. If BP remains elevated, it is diagnosed as high blood pressure or hypertension. A consistent blood pressure reading of 140/90 mm Hg or higher is considered hypertension.

Hypertriglyceridemia

A condition in which blood plasma triglyceride levels are elevated.

Impaired fasting glucose (IFG)

A measure of fasting plasma between 100 and 125 mg/dL; considered a prediabetic state.

Infarction

Death of cells resulting from decreased blood supply to tissue; usually a result of ischemia.

Inflammation

The body's response to injury; blood clotting is often part of that response. Blood clots can slow or stop blood flow in the arteries, which can cause heart attacks and strokes.

Insulin resistance

A basic metabolic abnormality underlying type 2 diabetes. Insulin resistance describes reduced insulin sensitivity of cells to the action of insulin.

Intermittent claudication (IC)

A symptom of arterial insufficiency, IC is a form of vascular disease. Lack of blood flow due to atherosclerosis will result in lower leg pain.

Ischemia

A decrease of blood flow to tissue due to constriction or obstruction of a blood vessel, which can lead to cell death. Myocardial ischemia (decreased blood supply to the heart) results from a constriction or obstruction of the coronary arteries.

Lipids

Fats, oils, and waxes that serve as building blocks and energy sources for the body. Compound lipids include the glycolipids (lipid-sulfur combinations), lipoproteins (lipid-protein combinations), and phospholipids (lipid-phosphate combinations).

Lipoprotein

Protein-covered fat particles that facilitate cholesterol and triglyceride transport throughout the body. The four basic classes are high-density, low-density, and very low-density lipoproteins, and chylomicrons.

Low-density lipoprotein (LDL)

A lipoprotein that is formed in the circulation and transports cholesterol from the liver to other body tissues. Elevated blood plasma levels of LDL-cholesterol (LDL-C) are positively correlated with coronary heart disease risk. LDL-C is often called the "bad" cholesterol.

Lumen

The channel or cavity through which blood flows within blood vessels. Atherosclerotic plaque buildup will often narrow this tubular passage, restricting blood flow.

Metabolic syndrome

According to ATP III guidelines, patients at high-risk for heart disease are diagnosed when three or more of these risk factors are present: Abdominal obesity (waist circumference) men >40 inches, women >35 inches; TG >150 mg/dL; HDL-C, men <40 mg/dL, women <50 mg/dL; blood pressure ≥130/≥85 mm Hg; fasting glucose ≥110 mg/dL. Weight loss enhances LDL-C lowering and reduces all risk factors. Exercise reduces very–low-density lipoprotein cholesterol levels, increases HDL-C levels, and, in some persons, decreases LDL-C levels. It also can reduce blood pressure and insulin resistance. Treatment of hypertension, elevated TG, and low HDL-C will reduce CHD risk.

Myocardial infarction (MI)

Cell death of the myocardium resulting from inadequate blood or oxygen supply. Myocardial infarction is almost always a result of atherosclerosis of the coronary arteries and is associated with thrombosis. Also referred to as a heart attack.

National Cholesterol Education Program (NCEP)

Launched in 1985 by the National Heart, Lung, and Blood Institute, the NCEP educates health professionals and the public on the importance of high blood cholesterol as a risk factor for coronary heart disease. In 1988, the Adult Treatment Panel (ATP) issued recommendations for detecting, evaluating, and treating high blood cholesterol in adults, identifying LDL-C as the primary target for lipid intervention. In 1993, the second Adult Treatment Panel (ATP II) issued revised guidelines stressing that elevated blood cholesterol, high blood pressure, and obesity as well as smoking are important modifiable risk factors for cardiovascular disease. In 2001, ATP III provided for more intensive lipid-lowering treatment in a larger population, with special emphasis on those with multiple risk factors.

Nephron

The functional unit of the kidney, consisting of a variety of tubules and the loop of Henle. The number of nephrons in each kidney varies but is in the thousands.

Nicotinic acid

Also known as niacin, this water-soluble derivative of vitamin B works in the liver by reducing production of triglycerides and VLDL. There are three types of nicotinic acid: immediate release, timed release, and extended release.

Non–HDL-C

Total cholesterol minus HDL-C. Non–HDL-C goals are set 30 mg/dL higher than LDL-C goals for each risk category in ATP III. Non–HDL-C goal is recommended for persons with high TG levels (>200 mg/dL).

Omega-3 fatty acids

Unsaturated fatty acids that are present in marine animal fats and some vegetable oils. These fatty acids can increase the ratio of high-density to low-density lipoproteins while lowering overall plasma lipid levels, particularly TG. Research has shown that omega-3 fatty acids decrease risk of arrhythmias, thrombosis, TG levels, the growth rate of atherosclerotic plaque, and the risk for arrhythmias and thrombosis. They also improve the health of arteries and may slightly lower BP.

Percutaneous coronary intervention (PCI)

A medical procedure that reduces the amount of constriction, or narrowing, in a coronary artery due to plaque formation.

Peripheral artery disease (PAD; see PVD)

Damage to or narrowing of the blood vessels that transport blood away from the heart to arms, legs, or organs.

Peripheral vascular disease (PVD; see PAD)

Damage to or blockage in the veins that transport blood from the arms and legs back to the heart.

Placebo

A dummy treatment administered to the control group in a clinical trial so the specific and nonspecific effects of the experimental treatment can be distinguished. The experimental treatment must produce better results than the placebo in order to be considered effective.

Plaque

Atherosclerotic plaque is composed of a lipid-rich core and a fibrous cap that separates the core from the artery's plasma compartment. Plaque buildup may cause the intimal layer of the vessel's wall to protrude into the lumen, thus narrowing the passageway for blood. Many plaques grow abluminally and may not decrease lumen size.

Primary prevention

Any form of intervention to reduce risk and/or prevent the development of coronary heart disease in individuals with no existing history of the disease.

Renin-angiotensin system (RAS)

The pathway responsible for the regulation of sodium balance, fluid volume, and blood pressure in the body, via renal secretions.

Risk factor

Cardiac risk factors comprise modifiable and non-modifiable factors that predispose an individual to the development of heart disease. Although there are different guidelines for assessing risk, commonly accepted risk factors include elevated LDL-C, depressed HDL-C, elevated triglycerides, smoking, diabetes, family history of heart disease, obesity, sedentary lifestyle, high blood pressure, elevated lipoprotein(a), elevated homocysteine level, and being a male over 45 or a postmenopausal female not on hormone replacement.

Secondary prevention

Any form of intervention to reduce risk and/or prevent the reoccurrence of a cardiac event in individuals with an existing history of the disease.

Statin

A general term for an HMG-CoA reductase inhibitor.

Stenosis (aortic)

Narrowing of the aorta or of the heart's aortic orifice.

Stent

A wire mesh tube used to open an artery recently cleared by angioplasty. It is collapsed to a small diameter and surrounds a balloon catheter. When the balloon is inflated the stent expands, locks in place, and forms a scaffold holding the artery open. It improves blood flow to the heart muscle and relieves symptoms.

Stroke

Occurs when blood flow to the brain is interrupted, preventing oxygen and nutrients from reaching brain tissue. Without the nourishment, brain cells begin to die, leading to a loss of abilities controlled by the affected area of the brain.

• Embolic stroke: Occurs when a blood clot or small piece of plaque or vegetation travels through the bloodstream to the brain and lodges in one of the smaller cerebral arteries, blocking blood flow.
• Hemorrhagic stroke: Caused by various disorders affecting the cerebral blood vessels, including chronic hypertension and aneurysms. This type accounts for 17% of all strokes.
• Ischemic stroke: Develops when a clot blocks an artery supplying blood to the brain. This artery usually has been narrowed and hardened by plaque. This type accounts for 83% of all strokes.
• Thrombotic stroke: Develops when a blood clot forms in an area of atherosclerosis in a carotid, vertebral, or cerebral artery and blocks blood flow to or within the brain.
• Transient ischemic attack (TIA): also reffered to as a "mini-stroke." Occurs when the blood supply to part of the brain is briefly interrupted. TIA symptoms are similar to those of a stroke but do not last as long. Most symptoms disappear within an hour, although they may persist for up to 24 hours.

Total cholesterol (TC)

The total amount of cholesterol carried in the blood, whether by HDL, LDL, or another carrier.

Triglycerides (TG)

Fat made by the liver or ingested through the diet. Elevated blood plasma levels of triglycerides are positively correlated with coronary heart disease risk.

Urinary albumin:creatinine ratio (UACR)

A useful measure of renal function used in diabetic renal disease; measured using the first morning urine sample where practicable.

Very–low-density lipoprotein (VLDL)

A class of lipoproteins that transports triglycerides from the intestine and liver to the adipose and muscle tissues. They are synthesized by the liver and primarily contain triglycerides in their lipid cores.