What is Cardiovascular Disease?
Cardiovascular diseases include many heart and blood vessel problems. Often cardiovascular problems are due to atherosclerosis, which is when fatty substances build up in blood vessels resulting in the formation of plaques. These plaques can narrow or block the blood vessel leading to reduced blood flow to certain tissues. If this occurs in an extremity, severe pain and cramping occurs in the affected area. If this occurs in the brain, a stroke occurs. If this occurs in the heart tissue, a heart attack can occur. Other types of cardiovascular disease include heart failure (when the heart is not pumping enough blood around the body), arrhythmia (abnormal heart beat) and stenosis (when heart valves do not function correctly).
What Causes Atherosclerosis?
When an individual has too much LDL-cholesterol (“bad” cholesterol) in the bloodstream, it accumulates as fatty deposits, and stimulates extra cell growth within the blood vessels. These fatty deposits and extra cell growth narrow the blood vessels, restricting blood flow. Scars, known as atherosclerotic plaques, start to form as the fatty deposit grows. Plaques narrow the blood vessels even further and cause serious damage to the blood vessels. This clogging and narrowing of the arteries is known as atherosclerosis.
There are many factors that can contribute to elevated LDL-cholesterol levels. People with certain genotypes have an increased risk. These genetic variants include the APOE e4 allele (described and tested on this website) and mutations in LDLR, APOB and PCSK9 (causing familial hypercholesterolemia). Other factors that can affect LDL-cholesterol levels include gender (males generally have higher levels), age (older people have higher levels), excess alcohol consumption, high fat diet, low physical activity and overweight or obesity.
What Causes Hyperlipoproteinemia Type III?
Hyperlipoproteinemia type III occurs due to the diminished metabolism of cholesterol and triglycerides in the blood. These triglycerides and beta-very low-density lipoproteins accumulate in the blood, resulting in fatty deposits that restrict blood flow. Most people with hyperlipoproteinemia type III have two APOE e2 alleles. However, only a small proportion of people carrying this genotype actually develop hyperlipoproteinemia, so other genetic, environmental or hormonal factors are also thought to play a role. These other factors are likely to include factors that are similar to those that increase the risk of elevated LDL-cholesterol (e.g. obesity, age, diet and low physical activity). The presence of other disorders (e.g. diabetes) may also increase the risk of hyperlipoproteinemia.
Next, Cardiovascular Disease Symptoms »
Mozaffarian D, Benjamin EJ, Go AS, et al. (2015). Heart disease and stroke statistics—2015 update: a report from the American Heart Association. Circulation. 131: e29-322.
Song Y, Stampfer MJ, Liu S (2004). Meta-Analysis: Apolipoprotein E Genotypes and Risk for Coronary Heart Disease. Ann Intern Med. 141(2): 137-147.
What is Cardiovascular Disease? American Heart Association. (Reviewed 12/18/2014).
Heart Disease in Women. National Heart, Lung and Blood Institute (Updated 04/11/2014)