Statins on Cardio-Vascular disease?

What /should they do? Are there other techniques to Cardio-Vascular disease. When were statins introduced?
My friend mentioned about the balance of HDL's/LDL's, why's it important? How many people take them?

Dyslipidemia is elevation of plasma cholesterol and/or TGs or a low HDL level that contributes to the development of atherosclerosis. Causes may be primary (genetic) or secondary. Diagnosis is by measuring plasma levels of total cholesterol, TGs, and individual lipoproteins. Treatment is dietary changes, exercise, and lipid-lowering drugs.
The statins (or HMG-CoA reductase inhibitors) form a class of hypolipidemic drugs used to lower cholesterol levels in people with or at risk of cardiovascular disease. They lower cholesterol by inhibiting the enzyme HMG-CoA reductase, which is the rate-limiting enzyme of the mevalonate pathway of cholesterol synthesis. Inhibition of this enzyme in the liver stimulates LDL receptors, resulting in an increased clearance of low-density lipoprotein (LDL) from the bloodstream and a decrease in blood cholesterol levels. The first results can be seen after one week of use and the effect is maximal after four to six weeks.
Lifestyle changes can help you prevent or slow the progression of coronary artery disease.
* Stop smoking. Smoking is a major risk factor for coronary artery disease. Nicotine constricts blood vessels and forces your heart to work harder, and carbon monoxide reduces oxygen in your blood and damages the lining of your blood vessels. If you smoke, quitting is the best way to reduce your risk of a heart attack.
* Control your blood pressure. Ask your doctor for a blood pressure measurement at least every two years. He or she may recommend more frequent measurements if your blood pressure is higher than normal or you have a history of heart disease. Normal blood pressure is below 120 systolic/80 diastolic as measured in millimeters of mercury (mm Hg).
* Check your cholesterol. Ask your doctor for a baseline cholesterol test when you're in your 20s and then at least every five years. If your test results aren't within desirable ranges, your doctor may recommend more frequent measurements. Most people should aim for an LDL level below 130 mg/dL. If you have other risk factors for heart disease, your target LDL may be below 100 mg/dL. If you're at very high risk for heart disease 鈥?if you've already had a heart attack or have diabetes, for example 鈥?you may need to aim for an LDL level below 70 mg/dL.
* Keep diabetes under control. If you have diabetes, tight blood sugar control can help reduce the risk of heart disease.
* Get moving. Exercise helps you achieve and maintain a healthy weight and control diabetes, elevated cholesterol and high blood pressure 鈥?all risk factors for coronary artery disease. With your doctor's OK, aim for 30 to 60 minutes of physical activity most days of the week.
* Eat healthy foods. A heart-healthy diet based on fruits, vegetables and whole grains 鈥?and low in saturated fat, cholesterol and sodium 鈥?can help you control your weight, blood pressure and cholesterol. One or two servings of fish a week are also beneficial.
* Maintain a healthy weight. Being overweight increases your risk of coronary artery disease. Weight loss is especially important for people who have large waist measurements 鈥?more than 40 inches for men and more than 35 inches for women 鈥?because people with this body shape are more likely to develop diabetes and heart disease.
* Manage stress. Reduce stress as much as possible. Practice healthy techniques for managing stress, such as muscle relaxation and deep breathing.
In addition to healthy lifestyle changes, remember the importance of regular medical checkups. Some of the main risk factors for coronary artery disease 鈥?high cholesterol, high blood pressure and diabetes 鈥?have no symptoms in the early stages. Early detection and treatment can set the stage for a lifetime of better heart health.
Also ask your doctor about a yearly flu vaccine. Coronary artery disease and other cardiovascular disorders increase the risk of complications from the flu.

HDL'S and LDL'S are cholesterol level's if they are high, you could have a heart attack or stroke.Lot's of people are on statin's to keep the level's down,along with a healthy diet.