Albumin in the blood is a marker of the rate of aging and mortality risk

Basic information

Albumin is synthesized in liver cells (up to 15 g per day). For the body, it is the main reserve protein (a source of amino acids), i.e., during periods of prolonged fasting, it is consumed first.

Albumin maintains circulating blood volume. It determines oncotic (colloid-osmotic) pressure by 80%, since due to the small size of its molecules it is contained in fairly large quantities in the serum. Albumin ensures the transport of important chemical compounds: bilirubin, urobilin, cholesterol, calcium, bile salts, fatty acids, exogenous substances (penicillin, sulfonamides, hormones, mercury and some drugs).

In addition to the oncotic and transport functions, albumin has a wide range of other important physiological functions, such as immunocorrection, endothelial stabilization, and antioxidant effects.

Important! One “taxi molecule” of albumin is capable of binding and transporting up to 25-50 molecules of bilirubin, for example. Therefore, hypoalbuminemia increases the concentration of free (unbound) biologically active components. This fact must be taken into account when selecting the dosage of drugs, because against the background of low albumin concentrations, the activity of drugs, and, accordingly, their therapeutic effect, can change, even becoming toxic.

In young children, pregnant women (especially in the 3rd trimester) and lactating women, as well as smokers, the content of albumin in the blood serum is slightly lower than in other groups of patients.

Deviation from normal levels of albumin in the blood occurs under the influence of both internal and external factors. Therefore, to make an accurate diagnosis, additional studies are prescribed to help determine the onset of the pathological process and its cause, as well as take all necessary measures to eliminate the disease.

Detailed description of the study

Albumin is a representative of the plasma protein fraction. It accounts for about 55-65% of the total number of protein molecules in the blood. Albumin is synthesized in the liver and is almost completely excreted into the bloodstream. On average, the amount of protein produced is 10-15 grams per day.

The main function of albumin in the body is to regulate the oncotic pressure of blood plasma. This pressure maintains the physiological exchange of fluid between blood vessels (capillaries) and the extravascular space (various tissues and organs).

Another important function of albumin is the transport of organic and inorganic substances. These include various biochemical molecules - bilirubin, fatty acids, hormones, calcium ions and heavy metals - and medicinal molecules - many antibiotics, analgesics, diuretics and other drugs. Also, if there is insufficient protein intake with food, albumin can act as a source of essential amino acids for the human body.

Low serum albumin levels are of key importance in medical practice. This condition is called hypoalbuminemia. It is accompanied by a decrease in oncotic pressure, as a result of which fluid leaves the bloodstream and accumulates in tissues and organs, so-called “hungry” (protein-free) edema is formed.

This clinical symptom is often observed in patients with liver cirrhosis due to disruption of the synthesis of albumin and other plasma proteins, as well as excess pressure in the portal vein. Edema is predominantly detected in the abdominal area (ascites), and as the disease progresses, it can be observed throughout the body. Albumin concentration is an important indicator in the Child-Pugh score, the main tool for classifying the severity of liver cirrhosis.

The following conditions and diseases can also be considered as factors for the development of hypoalbuminemia:

1. Low protein diet;
2. Accelerated breakdown of albumin due to oncological, infectious, endocrine diseases and injuries;
3. Reduced absorption of proteins in the intestine due to inflammation (celiac disease, Crohn's disease), resection of the small intestine;
4. Kidney diseases with a high level of albumin excretion in the urine;
5. III trimester of pregnancy.

The latter condition is a physiological feature and is explained by the fact that during pregnancy a woman’s circulating plasma volume increases, but the level of albumin (and other proteins) remains the same - relative hypoalbuminemia develops.

Elevated levels of serum albumin in the blood (hyperalbuminemia) are usually of no clinical significance. The exception is situations with severe dehydration due to various diseases or conditions.

The best material for determining albumin concentration is venous blood. For this laboratory analysis, capillary blood (from a finger) is used. Indications for this diagnostic method may be:

1. Large area burns;
2. Small/hard-to-reach veins;
3. Excessive obesity;
4. Proven tendency to thrombus formation in venous vessels;
5. Age up to 7 years.

In the absence of the above conditions, it is strongly recommended to examine the albumin level in venous blood. This laboratory test is recommended to determine liver and/or kidney function and assess nutritional status—the adequacy of the diet. Also, the study of serum albumin makes it possible to dynamically evaluate the effectiveness of treatment in patients with edema due to hypoalbuminemia.

Indications

The study is prescribed and its results are interpreted by a general practitioner, therapist, pediatrician, cardiologist, nephrologist, gastroenterologist, surgeon, hepatologist, resuscitator, nutritionist, hematologist.

An albumin test is prescribed for the following conditions:

• Chronic liver and kidney diseases;
• Oncopathology;
• Extensive burns and severe injuries;
• Rheumatic diseases;
• Malabsorption syndrome (impaired absorption of nutrients in the small intestine).
• Assessment of protein-synthetic liver function;
• Nutritional status assessment;
• Differential diagnosis of edematous syndrome.

If you complain of the following symptoms, an albumin test may also be prescribed:

• Jaundice,
• Pathological long-term fatigue,
• Sudden or long-term weight loss
• Prolonged diarrhea
• Symptoms of nephrotic syndrome (swelling around the eyes, legs, ascites).

To assess kidney function, the test can be performed in conjunction with blood nitrogen, blood urea and creatinine tests.

When should you take an Albumin test?

1. Diagnosis of liver diseases with impaired synthetic function;
2. Assessment of the severity of liver cirrhosis (Child-Pugh scale);
3. Detection of kidney pathologies;
4. Irrational diet, insufficient consumption of protein foods, fasting (assessment of nutritional status);
5. Malabsorption of proteins in the intestine: short bowel syndrome, Crohn's disease;
6. Identifying the cause of local or widespread edema;
7. Condition after burns, to assess albumin loss;
8. Infectious, rheumatological, oncological and endocrine diseases that may be associated with hypoalbuminemia.

Reference values ​​for albumin in blood

Important! Standards may vary depending on the reagents and equipment used in each particular laboratory. That is why, when interpreting the results, it is necessary to use the standards adopted in the laboratory where the analysis was carried out. You also need to pay attention to the units of measurement.

Normal values ​​of albumin in blood serum according to the independent laboratory Invitro:

Helix laboratory standards:

Important! The interpretation of the results is always carried out comprehensively. It is impossible to make an accurate diagnosis based on only one analysis.

Complexes with this research

Anti-aging diagnostics in postmenopause Control of age-related changes during the postmenopausal period 12,630 ₽ Composition
Advanced anti-aging diagnostics in postmenopause Advanced control of age-related changes during the postmenopause 29,230 ₽ Composition

Male anti-aging diagnostics Monitoring of basic indicators in men aged 40+ 13,300 ₽ Composition

IN OTHER COMPLEXES

• Biochemistry of blood. 13 indicators 3,490 ₽
• Preventive check-up 6,300 ₽
• Women's check-up No. 1 RUB 19,290
• For those at risk of COVID-19 RUB 4,510
• Advanced women's anti-aging diagnostics RUB 28,680

Lowering values

In European practice, it is customary to distinguish the following conditions in which albumin values ​​can be reduced:

• Ascites;
• Extensive burns and injuries;
• Glomerulonephritis;
• Liver diseases, hepatitis,
• cirrhosis,
• carcinoma,
• hepatic encephalopathy;

In Russian laboratories (Invitro and Helix), the interpretation of low albumin includes, in addition to the above conditions, the following:

• The presence of exudates and transudates (edematous fluid of an inflammatory and non-inflammatory nature, respectively);
• Condition after blood transfusion and severe bleeding;
• Increased catabolism (energy metabolism) of proteins: febrile syndrome;
• infections, sepsis (blood poisoning);
• endocrine disorders (thyrotoxicosis);
• some cancers;
• rheumatic lesions;
• increase in circulating blood volume (hyperhydration);
• analbuminemia (hereditary pathology characterized by a critical decrease in the amount of albumin in the blood);
• heart failure with congestion;
• treatment with hormonal drugs, amiodarone, taking high doses of steroid hormones, growth hormone, insulin;
• pregnancy.

Albumen

Material for research: blood serum.

Albumin is the main blood protein produced in the human liver. Albumins are classified into a separate group of proteins - the so-called protein fractions. Changes in the ratio of individual protein fractions in the blood often provide the doctor with more significant information than just total protein. The determination of albumin is used to diagnose liver and kidney diseases, rheumatic diseases, and oncological diseases.

It accounts for more than half of all blood proteins. Synthesized in the liver, the half-life is 17 days. Since albumin molecules take part in binding water, when its level drops below 30 g/l, part of the water moves from the vascular bed to denser tissues, causing edema.

Functions of albumins:

1. Maintaining oncotic pressure of blood plasma. Therefore, when the albumin content in the plasma decreases, the oncotic pressure drops, and the fluid leaves the bloodstream and enters the tissue. “Hungry” edema develops. Albumin provides about 80% of the oncotic pressure of plasma. It is albumins that are easily lost in the urine during kidney disease. Therefore, they play a large role in the drop in oncotic pressure in such diseases, which leads to the development of edema.
2. Albumin is a reserve of free amino acids in the body, formed as a result of the proteolytic breakdown of these proteins.
3. Transport function. Albumin transports many substances in the blood, especially those that are poorly soluble in water: free fatty acids, fat-soluble vitamins, steroids, hormones (thyroxine, triiodothyronine, cortisol), metabolites (uric acid, bilirubin), some ions (Ca2+, Mg2+). To bind calcium, the albumin molecule contains special calcium-binding centers. In combination with albumin, many drugs are transported, for example, acetylsalicylic acid, penicillin.

A biochemical blood test for albumin may show a slight decrease in protein levels in the blood of a pregnant woman, during lactation, and in those who smoke. Increased albumin in the blood occurs due to dehydration, loss of fluid from the body. Albumin provides about 80% of the oncotic pressure of plasma. It is albumins that are easily lost in the urine during kidney disease. Therefore, they play a large role in the drop in oncotic pressure in such diseases, which leads to the development of edema.

The level of albumin in the blood is an indicator of the well-being of the body.

Increased albumin levels: almost never occur, and if detected, it usually causes a decrease in water content, which leads to dehydration.

Decreased albumin levels (hypoalbuminemia): Observed with insufficient protein intake from food (fasting, cachetsia), impaired absorption of protein breakdown products through the gastrointestinal mucosa (enteritis, removal of part of the stomach, oncology); decreased synthesis of vitamin A; chronic liver diseases (hepatitis, cirrhosis, atrophy, carcinoma); malabsorption syndrome (gastroenteropathy) and gastrointestinal pathology; chronic renal pathology; thermal burns; tissue injuries; after bleeding; in the postoperative state, as well as in sepsis and infectious diseases; thyrotoxicosis, rheumatic diseases.

Preparation for the study: blood sampling is performed strictly on an empty stomach.

Preparing for analysis

A laboratory test for serum albumin is performed as part of a blood chemistry test. The training requirements are standard; a detailed description of them is given here.

However, given the high ability of protein to bind, it would not be amiss to recall that a few days before the procedure it is necessary to stop taking any medications, and to exclude fatty, fried foods and alcohol from the diet.

Sources:

• Spinella R, Sawhney R. Albumin in chronic liver disease: structure, functions and therapeutic implications. - Hepatology International, Sep 2015.
• Data from the independent laboratory Invitro.
• Data from Helix laboratory.
• Sridevi Devaraj. Albumin. — Medscape, Jan 2015.

Low albumin levels may predict poor outcome in patients with COVID-19

The COVID-19 pandemic has claimed more than four hundred thousand lives worldwide, and Spain is one of the worst affected countries. At the time of writing this article, there have already been more than 25,000 deaths due to COVID-19 in Spain. The article's authors explain that despite this, little information is available regarding the underlying characteristics and risk factors for patients at risk of hospitalization due to infection. This study included 48 patients admitted with COVID-19.

The scientists explained that it was necessary to identify factors on the basis of which an unfavorable prognosis for a particular patient can be made. The team said many studies show that there is suppression of the immune system during infection. This may be a key factor that leads to the progression of a mild infection to a more severe and ultimately life-threatening condition in the patient. Because inflammation plays a key role, factors that influence inflammation may be important in the progression of the disease.

Albumin is a protein produced in the liver and found in the blood. People with low albumin levels may have liver and kidney problems. Low albumin levels are also seen in patients with malnutrition, severe infection, thyroid disease, and inflammatory bowel disease.

The study involved 52 patients hospitalized due to complications of COVID-19 until March 31, 2020. Of these patients, 48 ​​had severe acute respiratory syndrome due to SARS-CoV-2. They all tested positive for the virus. Data were collected between 15 and 31 March 2021. The aim of the study was to describe the clinical characteristics and epidemiological features of severely and critically ill patients.

Among the 48 patients, 21 were admitted to intensive care and 27 were not. All of these patients were residents of the island of Mallorca in Spain. Their average age was 66 years, and 67% were men. The age distribution was similar among patients. The following conclusions were made:

before hospitalization included fever (all patients), cough (85% of patients), difficulty breathing (76% of patients), diarrhea (42% of patients, and weakness (21%)).

The main reason for hospitalization among patients was low blood oxygen levels (SpO2 below 90%) and the presence of pneumonia in both lungs (94% of cases).

Among all patients, 70% had high blood pressure, 62% had high cholesterol and 30% had heart disease.

Those admitted to the intensive care unit (ICU) had more difficulty breathing.

Acute respiratory syndrome (ARDS) developed in all patients admitted to the ICU.

All 48 participants required oxygen therapy.

Laboratory tests showed that intensive care unit patients had low lymphocyte counts and low blood albumin levels.

Among patients admitted to the ICU, there was a significant increase in inflammatory markers such as lactate dehydrogenase (LDH), C-reactive protein (CRP), and procalcitonin compared with those not admitted to the ICU.

Lower blood albumin levels were significantly associated with worse outcome and longer hospital stay. The risk of death was also higher among people with lower blood albumin levels.

In red blood cell studies, mean corpuscular volume of red blood cells was lower among patients who died from infection and its complications.

At the end of the study (April 28, 2021), the mortality rate was 21%: 8 patients in intensive care units and 2 in other units died from infection.

At the end of the study, all non-ICU patients were discharged from the hospital. While among the intensive care unit patients, one third remained in hospital at the end of the study (5 in the intensive care unit and 2 transferred to general wards).

Conclusions and implications

People with influenza A (H1N1) and human immunodeficiency virus infection (HIV) also had a poorer outcome if they had lower albumin levels, the paper's authors reported. Among patients with influenza, the need for respiratory support increased with low albumin levels, and among patients with HIV, low albumin levels meant a greater risk of inflammation and atherosclerosis.

This was a relatively small study that showed that certain laboratory parameters may be important in characterizing the severity of illness in patients with COVID-19. “Lower albumin levels were associated with worse outcomes in patients with COVID-19. Albumin may be important because of its association with disease severity and mortality in patients infected with SARS-CoV-2."

The scientists added: “This small case series provides the first steps towards a comprehensive clinical characterization of severe and critical adult patients with COVID-19 in Spain.”

Expert opinion

: Of course, based on such a small study, no final conclusions can be drawn. But now any additional information can adjust the forecasts for patients with COVID-19. Moreover, determination of albumin level is included in the list of standard laboratory tests.

Anemia, hypertension, hypovitaminosis D: are your kidneys okay?

Not many people know, but the kidneys are not only an excretory organ. It is “here” that vitamin D is transformed into its active form. Erythropoietin is synthesized here, which maintains the level of red blood cells. Renin is formed here, which indirectly affects the “width” of the vessels and, thereby, determines the pressure. And kidney disease has many more signs and consequences than is commonly believed.

"Non-standard" and "classic"

Symptoms of kidney disorders, as already noted, are not only about “urine” and lower back pain. After all, they appear exclusively at the time of acute inflammation in the organ.

In other cases, changes can be much more inconspicuous, the identification of which is possible only through screening. A special, distinctive feature of such disorders is resistance to traditional therapy.

Signs may include:

1. Jumps in blood pressure that are difficult to correct.

After all, renal renin activates angiotensin, which sharply constricts blood vessels and increases blood pressure.

Among other things, angiotensin irritates the thirst center in the brain, literally “forcing” you to drink more, thereby increasing the volume of the liquid part of the blood and contributing to an even greater increase in pressure.

And this “pressure” does not decrease after taking “conventional” medications, creating the risk of a critical increase.

2. Persistent anemia (deficiency of red blood cells)

due to a lack of renal erythropoietin, which stimulates the bone marrow to synthesize red blood cells. At the same time, the level of iron, vitamins B12 and B9, the deficiency of which is the main cause of anemia, remains normal.

3. Symptoms of D-deficiency and calcium disorders.

Decreased immunity, distorted immune reactions, caries, osteoporosis, rickets, muscle cramps, weakened memory and concentration, mood instability with a tendency to depression and other symptoms occur against the background of normal levels of total vitamin D and its fractions (25-hydroxyergocalciferol and 25-hydroxycholecalciferol) .

And a decrease in the level of 1,25-dihydroxycholecalciferol (calcitriol), the only active form of vitamin D, which is formed in the kidneys under the influence of parathyroid hormone and has all the effects inherent in the vitamin, can “give away” the renal origin of the symptoms.

Of course, kidney problems can also manifest themselves with more “classical” signs, such as urinary problems, swelling and general weakness. Indeed, with renal failure, toxic metabolic products accumulate in the body, as well as metabolites of drugs and other “harmful” substances.

Simple and affordable

Kidney screening, in addition to a urine test, should also include some blood parameters, including:

1. Creatinine and urea are products of protein metabolism, a slight increase in the level of which is acceptable during active physical activity and during fasting. Whereas a significant increase is a sign of developing renal failure;
2. Uric acid is a breakdown product of purine bases (DNA, RNA), an increase in which leads to the accumulation of urates and the development of gout. And the reason for the increase may be a violation of the excretory function of the kidneys, as well as a number of serious diseases;
3. Albumin is one of the protein fractions synthesized in the liver, which is normally unable to penetrate the kidney filter. Therefore, a lack of albumin in the blood may be an early sign of kidney pathologies. However, such an analysis must be evaluated in combination with other indicators, as well as a blood test (the appearance of protein);
4. Clinical blood test with leukocyte formula - helps to identify renal inflammation (which in the early stages may not have clinical signs), as well as a lack of red blood cells (anemia). Which, as already noted, may be a consequence of erythropoietin deficiency.