[Health in the 100-Year Life Era] Why Medication Is Necessary Even When Cholesterol Levels Are Low

Management for Preventing Atherosclerosis
Medication Recommended Regardless of Levels Based on Blood Pressure, Diabetes, and Smoking Status

One of the common questions patients ask in the consultation room is, “Is my cholesterol level normal?” Patients often expect a quick answer, but from a doctor's perspective, it is often difficult to immediately respond with “It is normal/high” or “You need to take medication/You don’t need medication.” This is because whether the level is normal or abnormal does not depend solely on the LDL level but varies according to the patient’s overall vascular condition and the level of atherosclerosis risk factors. For example, if a woman in her 40s who does not drink or smoke and has no hypertension or diabetes visits with an LDL cholesterol level of 180, it is slightly high but may not yet require medication. On the other hand, if a man in his 60s with a long history of smoking and diabetes has an LDL cholesterol level of 105, medication may be recommended. Health checkup results often use a general reference value of 130 mg/dL without considering individual risk factors, which can sometimes cause confusion.

The reason for managing cholesterol is to prevent atherosclerosis. Arteries are blood vessels that supply blood to our body. If blood is not supplied to important vessels such as those in the heart or brain, problems arise immediately, leading to diseases like myocardial infarction and stroke. These two are the second leading causes of death after cancer, and combined, they cause more deaths than cancer. LDL cholesterol, commonly called “bad cholesterol,” accumulates in the vascular endothelium and causes inflammation, which progresses to atherosclerosis and narrows the vascular lumen. Once atherosclerosis develops, it cannot be removed even if cholesterol is later lowered, so it is important to prevent it by lowering LDL cholesterol beforehand. If you have previously experienced vascular narrowing diseases such as myocardial infarction or angina, it is recommended to manage LDL cholesterol to be below 55 mg/dL. Additionally, those with other vascular diseases such as stroke, peripheral artery disease, or abdominal aortic aneurysm are advised to control LDL cholesterol below 70 mg/dL. This level usually requires medication for most people.

If you have diabetes, it is recommended to keep LDL cholesterol below 100 mg/dL, and especially for those with diabetes for more than 10 years, below 70 mg/dL is advised. For people without diabetes, the decision is made by considering risk factors such as age (men over 45, women over 55), family history of myocardial infarction, hypertension, smoking, and low HDL cholesterol (<40 mg/dL). Usually, if there are two or more risk factors, the goal is to lower LDL to below 130 mg/dL. Otherwise, the target is LDL cholesterol below 160 mg/dL, and if LDL cholesterol is 190 mg/dL or higher, medication is recommended regardless of other conditions.

Healthy diet and exercise do not affect cholesterol levels as much as the general public might think. For example, reducing saturated and trans fats through a healthy diet lowers cholesterol by only about 5?10%. Aerobic exercise reduces LDL cholesterol by 3?4 mg/dL, which is a level that can vary slightly each time it is measured. Therefore, when cholesterol is quite high, it is often difficult to sufficiently reduce cholesterol with diet and exercise alone. However, healthy eating and exercise must be combined because they reduce cardiovascular disease and provide other health benefits beyond lowering cholesterol. Mediterranean-style dietary patterns including whole grains, beans, nuts, fruits, vegetables, and olive oil help manage cholesterol, while excessive consumption of snacks, fried foods, ice cream, and processed foods should be avoided.

Cholesterol levels are greatly influenced by genetics. Especially in women, levels often rise sharply during menopause. Medication primarily involves drugs that inhibit the enzyme producing cholesterol in the liver, which can reduce LDL cholesterol by 30?50%. Combining drugs that inhibit cholesterol absorption in the intestines helps lower cholesterol further. If triglycerides are high, triglyceride-lowering drugs may also be necessary. Cholesterol medications are among the drugs with the fewest side effects and have shown the most reliable effects in preventing cardiovascular disease. If cholesterol is high, rather than having vague fears such as “I have to take medication for life” or “Long-term medication will be harmful,” it is recommended to take it with the mindset that it is the most reliable preventive medicine to reduce the risk of sudden death or disability. For reference, health supplements like policosanol have not been proven to prevent cardiovascular disease and are best avoided.

Dongwook Shin, Professor, Department of Family Medicine, Samsung Medical Center