Dr. Nabili received his undergraduate degree from the University of California, San Diego (UCSD), majoring in chemistry and biochemistry. He then completed his graduate degree at the University of California, Los Angeles (UCLA). His graduate training included a specialized fellowship in public health where his research focused on environmental health and health-care delivery and management.
Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.
Homocysteine is an amino acid that is produced by the body, usually as a
byproduct of consuming meat. Amino acids are naturally made products, which are
the building blocks of all the proteins in the body.
Why is it important to monitor homocysteine levels?
In 1969, Dr. Kilmer S. McCully reported that children born with a genetic
disorder called homocystinuria, which causes the homocysteine levels to be very
high, sometimes died at a very young age with advanced atherosclerosis in their
arteries. However, it was not until the 1990's that the importance of
homocysteine in heart disease and stroke was appreciated.
What are the possible symptoms or features of elevated homocysteine levels?
Theoretically, an elevated level of homocysteine in the blood
(hyperhomocysteinemia) is believed to cause narrowing and hardening of the
arteries (atherosclerosis). This narrowing and hardening of the vessels is
thought to occur through a variety of ways involving elevated homocysteine. The
blood vessel narrowing in turn leads to diminished blood flow through the
affected arteries.
Elevated levels of homocysteine in the blood may also increase the tendency
to excessive blood clotting. Blood clots inside the arteries can further
diminish the flow of blood. The resultant lack of blood supply to the heart
muscles may cause heart attacks, and the lack of blood supply to the brain
causes strokes.
Elevated homocysteine levels also have been shown to be associated with
formation of blood clots in veins (deep vein thrombosis and
pulmonary
embolism). The mechanism is complex, but it is similar to the way that they
contribute to atherosclerosis. In some studies, even moderate levels of
homocysteine level showed higher rates of repeated incidence of blood clot
formation. (1,2)
A stroke results from impaired oxygen delivery to brain cells via the bloodstream. A stroke is also referred to as a CVA, or cerebrovascular incident. Symptoms of stroke include: sudden numbness or weakness of the face, arm or leg. Sudden confusion, trouble speaking or understanding. Sudden trouble seeing in one or both eyes, sudden trouble walking, dizziness, or loss of balance, and/or sudden severe headache with no known cause. A TIA, or transient ischemic attack is a short-lived temporary impairment of the brain caused by loss of blood supply. Stroke is a medical emergency.
A pulmonary embolism occurs when a piece of a blood clot from deep vein thrombosis (DVT) breaks off and travels to an artery in the lung where it blocks the artery and damages the lung. The most common symptoms of a pulmonary embolism are shortness of breath, chest pain, and a rapid heart rate.
Deep vein thrombosis (DVT) is a blood clot in a vein located deep in the muscles of the legs, thighs, pelvis (lower torso), or arms. The most common symptoms of a deep vein thrombosis are swelling and pain in the leg that has the blood clot. A DVT is difficult to diagnose without specific tests in which the deep vein system can be examined.
Cholesterol is naturally produced by the body, and is a building block for cell membranes and hormones. Low-density lipoprotein (LDL) cholesterol is the "bad" cholesterol, conversely, high-density lipoprotein (HDL) cholesterol is the "good" cholesterol. High cholesterol treatment includes lifestyle changes (diet and exercise), and medications such as statins, bile acid resins, and fibric acid derivatives.
Heart attack happens when a blood clot completely obstructs a coronary
artery supplying blood to the heart muscle. A heart attack can cause chest pain, heart failure, and electrical
instability of the heart.
Alcoholism is a disease that includes alcohol craving and continued drinking despite repeated alcohol-related problems, such as losing a job or getting into trouble with the law.
Heart disease (coronary artery disease) is caused by a buildup of cholesterol deposits in the coronary arteries. Risk factors for heart disease include smoking, high blood pressure, heredity, diabetes, peripheral artery disease, and obesity. Symptoms include chest pain and shortness of breath. There are a variety of tests used to diagnose coronary artery disease. Treatment includes life-style changes, medications, procedures, or surgery.
Smoking is an addiction. More than 430,000 deaths occur each year in the U.S. from smoking related illnesses. Secondhand smoke or "passive smoke" also harm family members, coworkers, and others around smokers. There are a number of techniques available to assist people who want to quit smoking.
Vitamins are organic substances that are essential for the proper growth and functioning of the body. Calcium is a mineral essential for healthy bones and is also important for muscle contraction, heart action, and normal blood clotting.
Heart attacks are the major causes of unexpected, sudden death among men and women. A heart attack is also a significant cause of heart failure. Learn the risk factors for heart attack such as high blood pressure, diabetes, and other heart conditions. Lowering your risk factor, lifestyle changes, and in some cases medication are the most effective way of preventing a heart attack.
A heart attack is a layperson's term for a sudden blockage of a coronary artery. This photo essay inlcudes graphics, pictures, and illustrations of diseased heart tissue and the mechanisms that lead to coronary artery disease, and possible heart attack.
Cholesterol occurs naturally in the body. High blood cholesterol levels increase a person's risk of developing heart disease, heart attacks, strokes, TIAs, and more. In addition to medication (fibrates, statins, bile acid sequestrants, and niacin), lifestyle changes can be made to lower blood cholesterol levels
Vitamins and exercise can lower your risk for heart attack and heart disease. Folic acid, vitamins, and homocysteine levels are interconnected and affect your risk for heart disease or heart attack. Antioxidants and exercise also play a key role in heart attack and heart disease prevention. Lower your risk factors for heart disease and heart attack by lowering cholesterol, lowering blood pressure, diabetes prevention, and smoking cesssation.
The lungs are a pair of organs in the chest that are primarily responsible
for the exchange of oxygen and carbon dioxide between the air we breathe and blood. The lung is composed of clusters of small air sacs (alveoli) divided by
thin, elastic walls (membranes). Capillaries, the tiniest of blood vessels, run
within these membranes between the alveoli and allow blood and air to come near each
other. The distance between the air in the lungs and the blood in the
capillaries is very small, and allows molecules of oxygen and carbon dioxide to
transfer across the membranes.
The exchange of the air between the lungs and blood are through the arterial
and venous system. Arteries and veins both carry and move blood throughout the
body, but the process for each is very different.