[Medical Q&A] What does increased or decreased cholesterol mean?

Author: Jia Mei, Chief Physician, Peking University People's Hospital

Reviewer: Jin Mei, Chief Physician, Beijing Anzhen Hospital, Capital Medical University

Increased cholesterol in the blood is related to coronary heart disease, diabetes, hypertension, nephrotic syndrome, hypothyroidism, smoking, drinking, etc.; decreased cholesterol is relatively rare in clinical practice, such as liver disease, hyperthyroidism, anemia, severe infection, and malnutrition, which can cause decreased cholesterol.

Low-density lipoprotein combines with cholesterol to form low-density lipoprotein cholesterol. Low-density lipoprotein is synthesized by the liver or converted from very low-density lipoprotein. Increased levels of low-density lipoprotein are associated with atherosclerosis, and lowering low-density lipoprotein cholesterol is beneficial for preventing coronary heart disease and atherosclerosis. However, the lower the low-density lipoprotein cholesterol, the better. Too low a level of low-density lipoprotein cholesterol can lead to cholesterol transport disorders, which in turn leads to malnutrition. Increased low-density lipoprotein cholesterol can cause cerebrovascular and cardiovascular atherosclerosis, leading to cardiovascular and cerebrovascular events. In nephrotic syndrome, diabetes, and pregnancy, low-density lipoprotein cholesterol can also increase; malnutrition, chronic anemia, trauma, decreased liver function, etc. can cause a decrease in low-density lipoprotein cholesterol.

High-density lipoprotein cholesterol is a combination of cholesterol and high-density lipoprotein. High-density lipoprotein cholesterol is an indicator of anti-atherosclerosis and has a protective effect on blood vessels. High levels of high-density lipoprotein cholesterol reduce the risk of coronary heart disease. Long-term exercise can increase high-density lipoprotein cholesterol, but high-density lipoprotein cholesterol can also increase in smokers and obese people.