Statin Power
High Cholesterol
February 19, 2006
Cholesterol is a type of fat-like substance made by the liver and found in some of the foods we eat. Its carried in the blood in the form of lipoproteins (fat covered in proteins). There are two kinds of lipoproteins. Low-density lipoproteins (LDLs) tend to build up along the walls of the arteries. They are sometimes referred to as the "bad cholesterol" because high levels are associated with an increased risk for artery blockages.
High-density lipoproteins (HDLs) carry cholesterol from the body to the liver to be broken down and eliminated. Since HDLs help reduce cholesterol levels, they are often referred to as the "good cholesterol."
In some people, excess cholesterol builds up on the inside walls of the arteries. The waxy substance eventually can form into hardened plaque. In the heart, accumulation of plaque can interfere with the flow of blood to the heart muscle (coronary artery disease). The plaque can break open, or rupture, and release fat and cholesterol into the blood. A blood clot can form in the narrowed area of plaque and block the flow of blood. The part of the heart muscle fed by that artery is deprived of oxygen and dies. This is a heart attack, or myocardial infarction. A heart attack can also occur if the plaque builds up enough to close off the artery.
According to the American Heart Association, more than 99 million Americans have high cholesterol and may be at risk for heart disease. Ideally, total cholesterol levels should be less than 200 mg/dL of blood. LDL cholesterol (the bad cholesterol) should be less than 100 mg/dL. Since HDL cholesterol helps to keep LDL levels under control, higher HDL levels are advised. An HDL level of 60 mg/dL is considered to be protective against heart disease.
Statins to Reduce Cholesterol Levels
Statins are a group of drugs that have been prescribed to improve cholesterol levels. They work by blocking an enzyme in the liver (HMG C-A reductase) slowing down the bodys natural production of cholesterol. The drugs may also help the body remove LDL cholesterol that has accumulated on arterial walls.
Researchers say statins are now one of the most widely prescribed classes of medication in this country. Six statins are currently approved for use in the U.S.: LipitorŽ (atorvastatin), LescolŽ (fluvastatin), MevacorŽ (lovastatin), PravacholŽ (pravastatin), ZocorŽ (simvastatin) and CrestorŽ (rosuvastatin). The effects of the drugs vary somewhat. Some are better at lowering total cholesterol while others are better for lowering LDL cholesterol.
Research suggests, for some people, use of statins can reduce the risk of heart attack and stroke. However, there are some risks associated with the medications. The most common side effects can include nausea, diarrhea, gas, stomach upset and constipation. Some patients may experience headache, rash, dizziness or sleep problems.
About one percent of patients taking statins experience an increase in liver enzymes, which could be an indication of problems with liver function. In some cases, patients may need to discontinue use of statins.
Some patients taking statins develop muscle pain and tenderness. In very rare cases, muscle cells break down and release a protein, called myoglobin. This serious condition is known as rhabdomyolysis. The myoglobin protein can impair kidney function and lead to irreversible kidney failure and heart arrhythmias.
Other Uses for Statins
Research suggests statins may have benefits that go beyond controlling cholesterol and reducing the risk of heart attack and stroke. At the University of Alabama at Birmingham, investigators are studying the effects of a statin drug on Alzheimers disease. The theory is that cholesterol in brain cells may play a role in the brain changes that lead to Alzheimers.
In the 18-month study, Alzheimers patients will be randomized to receive a statin or placebo. At the end of the trial, doctors will compare the two groups to see if the statin medication was able to slow down the progression of Alzheimers deterioration.
Other studies have been conducted to determine if statins may have any benefit for conditions like macular degeneration, glaucoma, cancer, multiple sclerosis, hypertension, heart failure and rheumatoid arthritis.
Currently, there is still no solid evidence to show that statins will have any protective effect beyond their cholesterol-lowering benefits. Thus, those who arent currently taking the drugs shouldnt ask for them until more substantial evidence has been gathered.
AUDIENCE INQUIRY
For information about particular statin drugs:
LipitorŽ (Atorvastatin), http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a600045.html
LescolŽ (Fluvastatin), http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a694010.html
MevacorŽ (Lovastatin), http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a688006.html
PravacholŽ (Pravastatin), http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a692025.html
ZocorŽ (Simvastatin), http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a692030.html
CrestorŽ (Rosuvastatin), http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a603033.html
For information about high cholesterol,
American Heart Association, http://www.americanheart.org, or contact your local chapter
National Heart, Lung and Blood Institute, http://www.nhlbi.nih.gov
BIBLIOGRAPHY
Bleske BE, et al., "Neutral Effect on Markers of Heart Failure, Inflammation, Endothelial Activation and Function, and Vagal Tone after High-dose HMG-CoA Reductase Inhibition in Non-diabetic Patients with Non-ischemic Cardiomyopathy and Average Low-density Lipoprotein Level," Journal of the American College of Cardiology, January 17, 2006, Vol. 47, No. 2, pp. 338-341.
"Cholesterol," Dallas: American Heart Association, downloaded from website (http://www.americanheart.org), January 20, 2006.
Costenbader, Karen, M.D., and Jonathan Coblyn, "Statin Therapy in Rheumatoid Arthritis," Southern Medical Journal, May 2005, Vol. 98, No. 5, pp. 534-540.
Dale, Krista, Pharm.D., et al., "Statins and Cancer Risk," Journal of the American Medical Association, January 4, 2006, Vol. 295, No. 1, pp. 74-80.
Gotto, A., "Review of Primary and Secondary Prevention Trials with Lovastatin, Pravastatin and Simvastatin," American Journal of Cardiology, September 5, 2005, Vol. 96, No. 5A, pp. 34F-38F.
Hansen, Karen, M.D., et al.., "Outcomes in 45 Patients with Statin-Associated Myopathy," Archives of Internal Medicine, December 12/26, 2005, Vol. 165, No. 22, pp. 2671-2676.
"High Blood Cholesterol," Bethesda: National Heart, Lung and Blood Institute, downloaded from website (http://www.nhlbi.nih.gov), January 20, 2006.
Jones, Peter, M.D., "Statins: The Case for Higher, Individualized Doses," Cleveland Clinic Journal of Medicine, September 2005, Vol. 72, No. 9, pp. 811-816.
Kajinami, K., et al., "Pharmacogenomics of Statin Responsiveness," American Journal of Cardiology, November 7, 2005, Vol. 96, No. 9A, pp. 65K-70K.
McGwin, G., Jr., et al., "The Association Between Statin Use and Age Related Maculopathy," British Journal of Ophthalmology, September 2003, Vol. 87, No. 9, pp. 1121-1125.
McGwin, G., Jr., Ph.D., et al., "3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Inhibitors and the Presence of Age-Related Macular Degeneration in the Cardiovascular Health Study," Archives of Ophthalmology, January 2006, Vol. 124, No. 1, pp. 33-37.
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Pelat, M., and J. Balligand, "Statins and Hypertension," Seminars in Vascular Medicine, November 2004, Vol. 4, No. 4, pp. 367-375.
Sleijfer, S., et al., "The Potential of Statins as Part of Anti-Cancer Treatment," European Journal of Cancer, March 2005, Vol. 41, No. 4, pp. 516-522.
Sola S, et al., "Atorvastatin Improves Left Ventricular Systolic Function and Serum Markers of Inflammation in Nonischemic Heart Failure," Journal of the American College of Cardiology, January 17, 2006, Vol. 47, No. 2, pp. 332-337.
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"Statins in Rheumatology," The Journal of Rheumatology, January 2005, Vol. 32, No. 1, pp. 17-19.
Trubelja, N., "The Role of Statins in Preventing Stroke," Preventive Cardiology, Spring 2005, Vol. 8, No. 2, pp. 98-101.
Vasudevan, Abu, M.D., et al., "Safety of Statins," Cleveland Clinic Journal of Medicine, November 2005, Vol. 72, No. 11, pp. 990-1001.
Research compiled and edited by Barbara J. Fister
