As the third major killer affecting human health, diabetes is the most common endocrine disorder disease in the clinic, and with the improvement of human living standards, the incidence rate is increasing year by year. The following is to introduce the β of diabetes-related indicators - oxybutyric acid.
β-hydroxybutyric acid related knowledge
Ketone bodies are collectively referred to as β-oxybutyric acid, acetoacetic acid and acetone (of which β-oxybutyric acid accounts for about 78%, acetacetic acid accounts for about 20%, and acetone accounts for about 2%), which is a unique intermediate metabolite of fatty acids when decomposing and oxidation in the liver. Because diabetic patients can not use glucose oxidation normally for energy, so the body fat decomposition increases, liver fatty acid decomposition is correspondingly vigorous, resulting in a large number of ketone bodies in the body, resulting in ketosis and ketoacidosis.
Ketoacidosis is the most common severe acute complication of diabetes and is the leading cause of death in people with diabetes. In order to judge the condition in a timely and accurate manner, there is a great need for a highly sensitive and specific indicator, and the determination of β-hydroxybutyric acid meets the above requirements.
What is diabetic ketoacidosis (DKA)
The ketone body is composed of β-oxybutyric acid, acetoacetic acid and acetone, all of which are acidic substances, and when the accumulation of acidic substances in the body exceeds the body's compensatory capacity, the PH value of the blood will decrease (<7.35), and metabolic acidosis will occur in the body, which is what we usually call diabetic ketoacidosis.
Detection advantages
Clinical testing of urine ketones is often used to diagnose diabetic ketoacidosis, which is simple and easy, but when the patient is urinary or has severe damage to renal function, renal blood circulation disorders, glomerular filtration is reduced, and urinary ketones can be reduced or disappeared, it cannot be diagnosed by urine. In addition, conventional methods of detecting ketones cannot detect β-oxybutyric acid. In the case of hypoxia when diabetic ketoacidosis occurs, the urine ketone body is mainly composed of β-hydroxybutyric acid, so the urine ketone body result is false negative. The American Diabetes Association believes that quantitative detection of blood β-oxybutyric acid is a reliable and useful method for the diagnosis or monitoring and treatment of ketoacidosis instead of urine ketone body testing, and it plays an important role in the accurate judgment of the disease and the observation of efficacy. The main reasons are as follows:
1. β-oxybutyric acid is the main component of ketone bodies in the blood, which can reflect the situation of ketone bodies in the body and the real situation of acidosis.
2. In ketoacidosis, the increase in the level of β-oxybutyric acid is much greater than that of acetone and acetoacetic acid, so it is a more sensitive marker of ketoacidosis.
3. β-hydroxybutyric acid is the most stable in the ketone body (4 °C can be stable for 7 days), while acetone and acetoacetic acid are unstable, which can affect the results if not analyzed in time.
Why is blood β-oxybutyric acid high?
Poorly controlled blood sugar in people with diabetes may lead to increased levels of β-hydroxybutyric acid in the blood. However, for non-diabetic patients, if the diet is high in sugar, staying up late, drinking alcohol, etc., it will also lead to an increase in β-oxybutyric acid, so if there is an increase in β-hydroxybutyric acid, it is also necessary to check other indicators to determine whether it is diabetes. If diabetes is ruled out and your diet and living habits improve, you will basically return to normal.
1. Physiological blood ketones are elevated:
Fasting, high-fat diet, strenuous exercise
Newborns and pregnant women may be slightly taller
2. Pathological increase in blood ketones:
Diabetic ketoacidosis
Diabetic Pregnancy
Malnutrition, prolonged fasting
3. Medication:
Biguanides, salicylic acids, etc
4. Factors affecting test results:
Biguanides: false positives
Diabetic nephropathy, with a decreased or elevated renal threshold
summary
Β-oxybutyric acid can be used to monitor the onset of ketoacidosis in people with diabetes, such as severe illness, nervousness, pregnancy, and persistent blood glucose levels in excess of 13.4 mmol/L. In addition, when insulin therapy, the β-oxybutyric acid in the blood drops earlier than the decrease in blood glucose by 2h, and timely measurement of blood β-oxybutyric acid levels can better evaluate the efficacy of diabetic patients.
The application of enzymatic analysis has made the detection of β-oxybutyric acid more and more clinical attention, as a highly sensitive and specific index, it has gradually become an important means for the early diagnosis and treatment of ketoacidosis.
Source: Department of Clinical Laboratory, Shanghai Chest Hospital
Editor: Ren Mileage Reviewer: Xiao Ran