[Fat Bear Science] I’ve drunk milk, but this is the first time I’ve heard of “milk blood”!

Mr. Liu, 55 years old, came to the hospital for a physical examination a few days ago. One hour after his blood sample was drawn, the doctor in the laboratory department called to tell him that his blood was chylosing and the test result was inaccurate. The sample was returned and Mr. Liu was asked to eat a light diet for a few days and come back for a fasting blood test again.

Mr. Liu was puzzled. What exactly is chylosing? How could he have chylosing when he was healthy? What harm does chylosing do to the body? Director Wu Lixiang of the Medical Laboratory Department of Chongqing Cancer Hospital and Chongqing University Affiliated Cancer Hospital tells everyone about chylosing.

Wu Lixiang, Director of Medical Laboratory Department of Chongqing Cancer Hospital, Chief Technician. Graduated from the Department of Medical Laboratory of Chongqing Medical University, postgraduate degree. Vice Chairman of the Laboratory Committee of Chongqing Hospital Association, Vice Chairman of the Laboratory Committee of Chongqing Traditional Chinese Medicine Association.

Yu Yao, Chief Technician of Medical Laboratory Department, Chongqing Cancer Hospital and Affiliated Cancer Hospital of Chongqing University, graduated from Chongqing Medical University with a master's degree. He has been engaged in laboratory work for 6 years and actively participated in the promotion of medical science knowledge as the corresponding author of the department. In 2015-2016, he was responsible for a science popularization project of the Science and Technology Commission of Sha District as the person in charge, and the project has been completed. In 2016-2017, he participated in a science popularization project of the Science and Technology Commission of Sha District as the second participant. He wrote the paper "Empirical Research on Various Science Popularization Models in Community Health Education" and won the third prize in the essay solicitation activity of the Chongqing Science Popularization Work Theory Seminar in 2016.

Q1What is chylomicronemia?

Chyle, commonly known as "milk blood", is blood containing a high amount of fat. After the blood is centrifuged or has been stationary for a period of time, the upper layer of plasma can be seen to be milky white or turbid.

The fat ingested by the human body is transformed into tiny chylomicrons and enter the blood after being digested and absorbed. When the number of chylomicrons reaches a certain level, the serum changes from a clear and transparent light yellow liquid to a milky white viscous liquid, which is medically called chyle blood.

Q2Why is there a high level of fat in the blood?

Chyleemia is a special physiological and pathological phenomenon caused by abnormal lipid metabolism and lymphatic vessel obstruction. The fat in the food is emulsified into chylomicrons after digestion and absorption in the small intestine and enters the lymphatic vessels and blood circulation.

Normally, the concentration of chylomicrons in the blood increases 30 minutes after a meal, especially a heavy meal, and usually returns to normal after 1-2 hours. However, if the lipid metabolism is abnormal or the triglyceride level is particularly high, the chylomicron phenomenon will last longer, possibly 3 to 4 hours.

Chylorrhea may be the result of a high-fat diet or it may be caused by abnormal lipid metabolism, i.e. hyperlipidemia.

Q3Who is prone to developing chylosing blood?

People who have an unreasonable diet, often overeat, and eat high-fat, high-protein foods

The occurrence of chylomicronemia is significantly related to the time of consuming high-fat foods. The shorter the time between consuming high-fat foods and blood collection, the higher the incidence of chylomicronemia. Therefore, it is not advisable to consume high-fat foods within at least 24 hours before blood collection.

In addition, the diet is nutritionally unbalanced, such as excessive intake of saturated fatty acids (butter, cream, pastries, fried foods) and insufficient intake of trace elements and vitamins.

The weather is cold in winter, and friends have the habit of winter tonic and often eat high-calorie, high-protein foods. Therefore, the proportion of chylous blood in blood collection in winter is much higher than in other seasons.

Overweight or obese people

Obesity is closely related to chylosing. In blood sample examination, chylosing is more common in overweight people, especially those with abdominal obesity. Some obese people start eating a light diet a week before blood drawing and still have chylosing.

Older people

The incidence of chylosing blood is closely related to age. The older the age, the higher the incidence of chylosing blood, which may be related to the body's functional metabolism.

However, in recent years, epidemiological surveys have found that the incidence of chylothorax is becoming younger and younger, which should be given sufficient attention.

Office workers who lack exercise, are stressed, anxious, or sit for long periods of time

In addition, long-term alcoholism and smoking are more likely to cause chylosing blood.

People with certain diseases should also pay attention

Patients with diabetes, hypothyroidism, and nephrotic syndrome are also prone to increased blood fat.

Long-term use of certain medications can also easily lead to chylosing, such as tamoxifen, oral contraceptives, raloxifene, diuretics, etc. Chylosing is also more common in pregnant women, especially in the late stages of pregnancy.

Q4What harm does chylosing blood have on the human body?

Chylolyticemia is also known as hyperlipidemia in medicine, and is also called the "silent killer" and the "source of many diseases."

Occasional high blood lipids have little effect on the body, but long-term hyperlipidemia greatly increases the risk of thrombosis and can easily cause symptoms such as headaches and dizziness. It is a risk factor for stroke, coronary heart disease, myocardial infarction, and sudden death.

Many patients with hyperlipidemia may not show obvious symptoms, and it takes a certain amount of time for hyperlipidemia to develop into coronary heart disease and stroke. The direct damage of hyperlipidemia is to accelerate systemic atherosclerosis, because all important organs in the body rely on arteries for blood and oxygen supply. Once the arteries are blocked by atherosclerotic plaques, it will lead to a series of serious consequences.

When the amount of fat accumulated on the blood vessel wall reaches a certain level, the corresponding organs supplied by the blood vessels will develop lesions due to ischemia. In the heart, it can cause coronary heart disease and acute myocardial infarction; in the cerebral arteries, it can cause cerebral insufficiency and cerebral infarction; in the kidneys, it can cause renal artery sclerosis and even stenosis, renal failure, uremia, etc.

High blood lipids can cause liver damage. Long-term high blood lipids can lead to fatty liver, which will gradually develop into cirrhosis and seriously damage liver function. Therefore, many patients experience symptoms of elevated alanine aminotransferase.

In addition, hyperlipidemia is also an important risk factor for hypertension, impaired glucose tolerance, and diabetes. It can also lead to cholelithiasis, pancreatitis, retinal hemorrhage, and even blindness and peripheral vascular disease.

Q5How to determine the severity of chylosing blood?

First, the degree of turbidity of the plasma layer can be assessed visually after centrifugation of the specimen, but this is not accurate enough and is generally divided into mild, moderate and severe.

The serum of patients with chylosing carries a large amount of low-density lipoprotein (LDL), very low-density lipoprotein (VLDL) and chylomicrons, which are mainly composed of triglycerides (TG) and cholesterol (CHO). In particular, the higher the concentration of VLDL and chylomicrons, which are mainly composed of TG, the more serious the chylosing degree of the serum sample. Currently, the chylosing degree of the sample is mainly described by measuring the concentration of TG in the sample, which can make the research more accurate.

Q6Why is the test of chylous blood sample inaccurate?

The liquid part of the blood floating on the surface of the chylous blood sample is like floating "white oil" (animal fat). The "white oil" will interfere with the results of the blood test, causing a false positive reaction and failing to truly reflect the patient's physical condition.

Chyle blood specimens can have a certain impact on the patient's clinical test results. Chyle blood is characterized by high fat content in the blood, which is very common in the blood of patients with hyperlipidemia. After the human body ingests a large amount of fat, chylomicrons will appear in the blood. The main components of chylomicrons are lipoprotein, cholesterol and triglycerides, which are key factors affecting the test.

Chyle blood affects related indicators such as WBC, PLT, Hb, MCHC, MPV and MCH in routine blood tests. In addition, it also affects blood rheology, coagulation and some biochemical items. Severe chyle blood still significantly interferes with some biochemical indicators, such as alanine aminotransferase, aspartate aminotransferase and urea, which cannot be measured.

Therefore, when you need to undergo a blood test, you must eat a light diet, have a regular work and rest schedule in the next week, and draw blood on an empty stomach on the day of the test. For patients who have received fat emulsion, they need to stop for 2 days before drawing blood on an empty stomach.

Q7How to prevent chylosing blood?

Adjust the dietary structure and eat a reasonable diet. From the blood lipid analysis, it can be concluded that blood lipids are triglycerides, total cholesterol, lipoproteins and carrier proteins. Among them, triglycerides are related to diet and are called variable fats, while total cholesterol is fixed fat and has little to do with diet. If the triglyceride single item is high, one of the best ways is to control diet.

Eat more whole grains, adjust the nutritional structure of your diet, eat less sugary foods and drinks (canned fruits, sugary drinks); eat less foods high in saturated fatty acids, such as sausages, bacon, fat, chicken feet, animal offal, etc.; eat more foods high in unsaturated fatty acids, such as fish, especially salmon, eel, white pomfret, etc., which are high in unsaturated fatty acids.

Strengthen exercise and control weight. With the improvement of living standards, people take in excessive nutrients, which leads to obesity. Obesity can also cause blood chyle. Therefore, according to personal physique, do appropriate exercise and control weight, such as running, swimming, gymnastics, etc.

Live a regular life, do not drink alcohol or smoke for a long time. Do not drink excessively, because the heat generated by alcohol metabolism will turn into triglycerides if it cannot be consumed. In addition, you should also keep a regular schedule and maintain a good attitude.

Regular follow-up and appropriate drug treatment. For people who previously had high blood lipids, it is especially important to control them, and at the same time, conduct regular follow-up examinations to observe changes in blood lipids. If the blood lipid level is high and difficult to reduce to normal levels, it is necessary to take some blood lipid-lowering drugs under the guidance of a doctor.

Text/ Fat Bear Picture/ Online Review/ Wu Lixiang Yu Yao

Original article, no reproduction without authorization

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Chongqing Science and Technology Commission Science Popularization Funding Project