Patients often ask whether “high cholesterol”, “hyperlipidemia”, “hyperlipidemia” and “dyslipidemia” are the same thing. Are they the same thing? Prof. Ye Ping: There are many common names for dyslipidemia. For example, some patients will say that their cholesterol is high when they see only elevated cholesterol in the lipid test; and some doctors will habitually make the diagnosis of hyperlipidemia regardless of whether the patient has high cholesterol or high triglyceride levels. The four basic indicators of lipid testing include total cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol. In addition to increased cholesterol levels and increased triglyceride levels, there are also increased LDL cholesterol levels and decreased HDL cholesterol levels that occur with dyslipidemia, so the concept of hyperlipidemia is not comprehensive enough. At present, the medical profession has a unified name for this type of lipid problem – “dyslipidemia”. In other words, high cholesterol, hyperlipidemia and hyperlipidemia are actually aspects of dyslipidemia. So how do we determine dyslipidemia? What tests should be done? Prof. Ye Ping: To determine dyslipidemia, you need to go to the hospital to have a blood test, which includes – total cholesterol level, triglyceride level, HDL cholesterol, LDL cholesterol. There are also some hospitals that have different habits and test only total cholesterol and triglycerides, but this is not comprehensive. Because total cholesterol also includes HDL cholesterol and LDL cholesterol, if a person has a high LDL cholesterol and a low HDL cholesterol level, it is difficult to determine the exact type of dyslipidemia by testing only the total cholesterol level in this case, and it is not conducive to accurate drug selection. Therefore, standardized lipid tests in China usually include four indicators – total cholesterol level, triglyceride level, HDL cholesterol and LDL cholesterol. Some other hospitals will do more, including Apo A, Apo B, and Lipoprotein small A in addition to the above four items. If you have the conditions and are willing to do these items, you can also be tested for reference. Overall, the four basic items of current lipid testing in China can determine the type of dyslipidemia and guide the selection of therapeutic drugs and lifestyle interventions. What are the precautions to take before the lipid test? For example, should I fast or stop taking any medications? Is it necessary to stop strenuous exercise? Prof. Ye Ping: In the past, there were strict fasting requirements for lipid testing, but in recent years, some overseas expert consensus and recommendations have shown that strict fasting before lipid testing is not necessary. Because patients who fast for too long are prone to excessive hunger, which is not good for the body. In fact, the difference between fasting and non-fasting is mainly that fasting tests have a slight effect on triglycerides, but almost no effect on total cholesterol, HDL cholesterol, and LDL cholesterol. The increase in triglyceride levels caused by eating, which we do most of the day after meals, is a more accurate reflection of triglyceride levels, which is called “postprandial triglycerides”. If the true level of triglycerides needs to be very accurate, then strict fasting is required. In my opinion, if you just want to know your cholesterol level and you can’t tolerate fasting, you can do it without fasting, and whether you fast or not doesn’t have too much influence on the cholesterol level. Let’s talk about medications. Some patients stop taking all their lipid-lowering medications before they have their lipids tested. If you stop taking a meal, it is not a big problem, but if you stop taking lipids for a week, it will not reflect the lipid level after taking the medication, and it will not help the doctor to adjust the treatment plan according to the patient’s lipid level after taking the medication, so you should not just stop taking lipid-lowering medications, and you should not stop taking other medications. However, it should be noted that if the doctor requires strict fasting before the test, then lipid-lowering drugs should not be taken in the morning, while other drugs are not particularly contraindicated. Regarding the issue of exercise, because some patients are taking lipid-lowering drugs, if they do very strenuous exercise the night before the lipid test, there may be an increase in creatine kinase level in the blood, which makes it difficult to identify whether the increase in creatine kinase is caused by the adverse effect of taking lipid-lowering drugs or by exercise. Therefore, I advise patients not to drink alcohol or eat fat-rich foods the day before the lipid test, and not to exercise too vigorously, so as to ensure a relatively stable lipid level for the doctor to judge the efficacy of the lipid-lowering therapy and the drug adjustment plan. We often see in patient consultations that patients are not clear about hypercholesterolemia and hypertriglyceridemia, what is the difference between the two and what are the differences in prevention? Prof. Ye Ping: Hypercholesterolemia means that the total cholesterol level in the blood is higher than normal, and the ideal level of total cholesterol in China is less than 5.7 mmol/L in the Chinese Guidelines for the Prevention and Treatment of Adult Dyslipidemia. Hypercholesterolemia. The normal value of triglycerides should be less than 1.7 mmol/L. If it is higher than this value, the doctor will diagnose hypertriglyceridemia. The impact of these two diagnoses on atherosclerosis is very different and is now very clear. The most important component of total cholesterol is LDL cholesterol, which accounts for 60% of the total cholesterol. This elevated LDL cholesterol level is a very clear pathogenic factor for atherosclerotic cardiovascular disease. In the case of hypertriglyceridemia, it is generally accepted that increased triglyceride levels are a risk for the development of acute pancreatitis, and that a mild or moderate increase is also detrimental to atherosclerosis. Both require intervention, but the choice of intervention drugs and lifestyle depends on how many cardiovascular risk factors each person has, whether they have atherosclerotic cardiovascular disease, including the presence of stroke, coronary heart disease, atherosclerosis and other such factors, to decide whether to use drugs. Lifestyle intervention is the most important, for the treatment of hypertriglyceridemia, the most important is lifestyle intervention, including reducing fat intake, reduce alcohol consumption (in fact, Chinese people drink too much alcohol has the greatest impact on triglycerides, and is also a very important risk factor for the occurrence of acute pancreatitis). If you see an increase in triglyceride levels, it is very important to “keep your mouth shut” and reduce alcohol consumption as a way to lower triglycerides. Director Ye has just said that slightly elevated triglycerides are not a big problem, but some patients feel that the lower the triglycerides, the better, is that correct? Prof. Ye Ping: No, the ideal level of triglycerides should be lower than 1.7 mmol/L, but lower is not better. After all, triglycerides have important roles in our body: in energy metabolism, triglycerides release free fatty acids during the whole hydrolysis process, which are important for energy storage and energy utilization in peripheral organs and energy metabolism of the whole body; at the same time, cholesterol is also an important raw material for cell membrane and synthesis of corticosteroids. Triglycerides are a very important raw material for energy storage and metabolism in the body, so it is not better to have a lower triglyceride level. A triglyceride level of less than 1.7 mmol/L is ideal, but if it is slightly elevated, it is acceptable if it is below 2 mmol/L, but if it is above 2 mmol/L, you should “keep your mouth shut”. For cholesterol, is the lower the better? Prof. Ye Ping: I don’t think lower is better. This issue has been controversial in the cardiovascular community for many years, and there was a time when it was said that lower was better. There is now a consensus that lower cholesterol levels, especially LDL cholesterol, are better, and the question of how much lower is still being explored. But I believe in the saying that the body should be in balance, and if one substance is too low, there are unknown potential effects. So we are still conducting more clinical trials to demystify the effects of low cholesterol. In summary, I think that since cholesterol is a raw material for the synthesis of hormones in our body and an important raw material for cell membranes, although lower is better, it is still unknown to which level is our limit. Now that we know how to diagnose dyslipidemia, let’s understand some of the dangers associated with dyslipidemia. First of all, we would like to know what factors cause dyslipidemia? Prof. Ye Ping: The causes of dyslipidemia are divided into primary and secondary. Primary dyslipidemia is usually called familial hyperlipidemia, and the causes include genetic factors, such as familial hypercholesterolemia, familial hyperbeta lipoproteinemia, and familial hypertriglyceridemia, which are caused by the genetic inheritance of the family, and we call them familial hyperlipidemia or familial dyslipidemia. However, the majority of primary hyperlipidemia cannot be found. It is a combination of environmental and genetic factors, such as eating too much and exercising too little, plus some genetic background, such as parents with high lipid levels and their own children with high lipid levels. Now that life is better, hyperlipidemia or dyslipidemia will occur earlier if we do not pay attention to diet control. In fact, the majority of patients have primary dyslipidemia due to a combination of multiple genes, small variants and environmental factors, with no clear causative factors. The second type is secondary and the cause can be found. For example, patients with diabetes often have dyslipidemia, including increased triglyceride levels and decreased HDL cholesterol levels; for example, patients with nephrotic syndrome, hypothyroidism, and chronic renal insufficiency take medications that may cause increased cholesterol or triglyceride levels. These are called secondary dyslipidemia when they are caused by disease or medication. For secondary dyslipidemia, the most important thing is to remove the causative factors – patients with diabetes will improve their lipid level if they control their blood sugar well; patients with nephrotic syndrome will have to treat their kidneys in addition to lipid-lowering drugs; hypothyroidism will improve their lipid level after correcting the hypothyroidism. Nowadays, they say three highs, high blood pressure, high blood sugar and high blood lipid. Some patients with high blood pressure and diabetes ask on the website: do they need to measure blood lipid and will their blood lipid level rise? Prof. Ye Ping: Yes. Diabetic patients are at very high risk of cardiovascular disease, and diabetic patients must have their blood lipids checked, which is very important to determine the risk of atherosclerosis. In addition, hypertension is also closely related to dyslipidemia, and a large number of patients with metabolic syndrome (metabolic syndrome includes hypertension, hyperlipidemia, hyperglycemia, obesity) who are in the hospital every day have hypertension, combined with abnormal glucose metabolism, and also combined with dyslipidemia. So patients with hypertension and diabetes must have their blood lipid levels tested. I will extend this issue here, for diabetic patients, there are more or less some misunderstandings, because diabetic patients control blood sugar is actually mainly to prevent small vascular lesions, the so-called small vessels, microvascular lesions are renal lesions, retinal lesions and peripheral nerve lesions. However, the most important cause of cardiovascular events and death in diabetic patients is macrovascular disease caused by dyslipidemia. Dyslipidemia causes coronary artery and cerebral artery lesions, which lead to atherosclerosis and cardiovascular events, so patients with diabetes must have their blood lipids checked. Patients with dyslipidemia need lifestyle changes and lipid-lowering treatment to protect the large blood vessels and reduce the occurrence of atherosclerosis, cardiovascular disease and cardiovascular events. This is also true for hypertension. Are you saying that for hypertensive and diabetic patients, if the lipids are elevated it will be more harmful for them? Prof. Ye Ping: Yes. Does dyslipidemia cause any harm to the cardiovascular, cerebrovascular, kidney and lower extremities, and if so, what kind of symptoms do they usually have? Prof. Ye Ping: In fact, among the various types of dyslipidemia, the one that has the greatest impact on atherosclerosis is the increase in LDL cholesterol level, which is a pathogenic risk factor and can induce atherosclerotic cardiovascular disease. Atherosclerotic cardiovascular disease is a collective term for all medium and large arteries that are at risk of atherosclerosis: cerebral arteries, carotid arteries, coronary arteries that supply blood to the heart, etc. Plaque or atherosclerosis in the cerebral and carotid arteries can induce stroke and transient cerebral ischemia, while occlusion of the coronary arteries can cause myocardial infarction and acute cardiovascular events in patients. Renal artery is also a common site of atherosclerosis. Patients with renal artery stenosis caused by renal artery atherosclerosis will suffer from renal ischemia and renal function will be reduced. The presence of renal artery stenosis also leads to uncontrollable hypertension and a vicious circle – hypertension has serious cardiovascular and cerebrovascular effects, and renal artery stenosis causes renal hypofunction. Symptomatic treatment is required. Atherosclerosis of the arteries in the lower extremities is common, and the most common cause is “intermittent claudication”. What is intermittent claudication? When a patient walks fast or for a long time, the lower limbs become painful and the limp is relieved after rest. It is somewhat similar to angina pectoris, where there is no angina pectoris when there is no activity, but the symptoms of angina pectoris appear when there is a greater range of activity or when you run and walk up the stairs. In fact, the two are the same, occurring in the coronary artery atherosclerosis will appear angina, occurring in the lower limbs will appear intermittent claudication, which is a symptom of lower limb artery atherosclerosis. Many patients think that dyslipidemia is a chronic problem, for example, the blood lipid is very high now, but it does not cause obvious effects, so it can be ignored; it does not matter much if the blood lipid does not reach the standard, are these statements correct? Prof. Ye Ping: The treatment of asymptomatic dyslipidemia is the key point in the treatment of dyslipidemia in China, because patients with dyslipidemia are often asymptomatic, unlike hypertension which causes headaches. Many patients think that this kind of asymptomatic dyslipidemia does not need to be concerned, but in reality, the effect of this kind of dyslipidemia on atherosclerosis is subtle. Why do patients with familial hypercholesterolemia suffer from myocardial infarction or die prematurely at an early age? It is because the cholesterol level is high, but there are no symptoms and lack of related prevention and treatment, which often eventually leads to myocardial infarction, sudden death, and atherosclerosis. It is true that dyslipidemia is a chronic process, but the harm also exists implicitly. If the lipid level is high at the age of 30, there is not much effect yet, but after the age of 40 or 50, diseases such as atherosclerosis will follow. This is because with the increase of age, the arteries will have an aging change, and with the persistence of risk factors, the impact on the arterial wall will gradually increase. Therefore, patients with more severe dyslipidemia need to be treated aggressively, while in less severe cases, doctors will generally decide how to intervene based on risk stratification. It is important not to assume that because there are no symptoms, there will be no intervention or treatment. In fact, the rate of statin use in China is extremely low, and also the rate of statin discontinuation is extremely high even after patients are discharged from the hospital with acute coronary syndrome, because the public is not aware of the dangers of atherosclerotic disease. We have recently done a community-based MRI carotid plaque study, where some patients were not followed up after treatment, and when these patients were followed up again two years later, it was found that carotid atherosclerotic plaques grew in patients who had stopped taking the drug for two years, and that carotid atherosclerotic plaques shrank significantly in patients who continued to take the drug for two years. This shows the importance of statins in the treatment of atherosclerosis. However, some patients are far from knowing enough about statins and the dangers of dyslipidemia. China’s statin treatment and the treatment of dyslipidemia are far behind those in Europe and the United States, and I also hope that patients and friends can realize this exactly, and in order to reduce the risk of atherosclerosis and cardiovascular disease, they should actively cooperate with their doctors, actively change their lifestyles, and adhere well to their medication. Regarding the issue of achieving lipid standards, the current lipid standards are mainly graded according to the current “Guidelines for the Prevention and Treatment of Dyslipidemia in Chinese Adults”, and according to the “Recommendations of Chinese Experts on Dyslipidemia from the Chinese Cholesterol Education Program”, different lipid strata have different target values. Here I especially hope that our doctors will tell our patients when prescribing them what the LDL cholesterol level should be less than, and that they should review their lipid levels and LDL cholesterol levels after taking the medication to see if they meet the target values stated by the doctors. The standard can be achieved by close cooperation between the two aspects. Why is the issue of reaching the target mentioned? Many clinical trials have suggested that “according to the risk stratification, the higher the risk, the higher the risk, the lower the target value, so that LDL cholesterol will be lowered, the cardiovascular benefit will be greater, the ability to prevent cardiovascular events will be greater, and the future risk of cardiovascular events will be reduced. The lower the LDL cholesterol target, the greater the cardiovascular benefit, the greater the ability to prevent cardiovascular events, and the greater the risk of future cardiovascular events. Doctors see risk reduction as important. For example, if a patient with acute coronary syndrome has had one acute coronary syndrome myocardial infarction, there may be a second or even a third, so in order to prevent your risk of future cardiovascular events, you need to lower your lipid levels to standard levels to reduce your risk, and patients should recognize that – -Already had one cardiac event, then to not have a second event or to reduce the risk of having a second event, one should lower the lipid level and adhere well to medication.