LDL cholesterol level x time risk of cardiovascular disease
Diseases in which cholesterol clogs blood vessels, such as cerebral infarction and myocardial infarction, are called arterial effective disease (ASCVD). These diseases occur over time when bad cholesterol in the blood sticks to the walls of blood vessels, forming fatty lumps called atheroma on the walls of blood vessels. Bad cholesterol is transported through the blood in a ball called low-density lipoprotein cholesterol (LDL-C). This sticks to the walls of blood vessels and drops fat components onto the walls of blood vessels. I explain to patients that atheroma is a condition where the skin is covered with oil, similar to acne. When blood vessels are exposed to high concentrations of bad cholesterol, fat accumulates in them (Figure 1).
Since the level of bad cholesterol and the time taken are proportional to the risk of cerebral infarction or myocardial infarction, it is important to keep it low and for a long time.
This is a diagram showing that the more LDL cholesterol x time, the higher the risk of cardiovascular disease. Blue, then red, then black, then purple means that you have been exposed to high LDL cholesterol for a long period of time.
Domanski, M.J. et al.JACC.2020;70(13):1507-16
Figure 1 Time × LDL-C area and cardiovascular disease risk
Medicines to lower bad cholesterol (+diet)
When I tell patients that they should take medicine because they have high bad cholesterol, many of them say, ``It's okay. I don't need medicine, I'll take care of it with my diet, not with medicine.'' In fact, 30% of bad cholesterol is influenced by diet, and about 70% is synthesized by the liver, so it is often not possible to lower LDL cholesterol sufficiently through diet alone. However, this does not mean that you should binge eat and drink (Table 1).
| For the purpose of lowering LDL cholesterol, it is recommended to limit the mortality energy ratio under appropriate total energy intake. | Evidence level: 1, Recommended level A |
| It is recommended for obese people to reduce their weight and modify and limit their fat intake with an appropriate energy intake, and for non-obese people to improve serum lipids and potentially suppress the onset of arteriosclerotic disease. | Evidence level: Consensus, Recommendation level A |
| For secondary prevention of coronary artery disease, we recommend drug therapy with the maximum tolerated dose of strongstatin as the first choice from early onset, regardless of the LDL cholesterol level before the start of treatment. Furthermore, drug therapy will be strengthened to achieve LDL cholesterol management targets, taking into account individual risks. | Evidence level: 1+, Recommendation level: A |
In particular, a low target value of 70 mg/dL has been set for secondary prevention for patients who have experienced a single myocardial infarction. The concept of "lower the better" is gaining popularity, and doctors recommend lowering LDL cholesterol as much as possible.
Medications called statins are effective in lowering bad cholesterol. The management goal is to evaluate the patient's risk and strengthen the medication to reach the management target value, which is effective in preventing arteriosclerotic disease.