Adiponectin | Laboratory research

Adiponectin is a hormone and adipokine protein produced mainly by adipose tissue and involved in metabolic processes that increase insulin sensitivity and anti-inflammatory activity.

Low concentrations of adiponectin are associated with conditions such as obesity, type II diabetes, metabolic syndrome, and atherosclerosis.

How is adiponectin produced?

White adipocytes in subcutaneous, visceral, and bone marrow adipose tissue produce the majority of adiponectin.

In addition, striated skeletal muscle cells, heart muscle and endothelial cells, vascular endothelial cells have the ability to produce adiponectin.

Adiponectin control pathways

Insulin is an important factor involved in the synthesis of adiponectin.

Insulin-like growth factor (IGF-1) and growth hormone (GH) regulate adiponectin production in adipose tissue. Leptin (another adipokine) may also play an important role in regulating adiponectin turnover.

function

Adiponectin plays an important role in cellular and metabolic processes.

The sensitivity of cells to insulin ensures that the body uses it efficiently. The higher the sensitivity to insulin, the easier it is used by the body and maintains a normal level of sugar in the blood.

Insulin resistance is the opposite of insulin sensitivity, where liver, muscle, and fat cells do not respond to insulin. At this time, the pancreas secretes extra insulin to overcome resistance and regulate blood glucose levels.

Adiponectin plays an important role in insulin sensitivity, namely:

Increases the release of insulin by the pancreas

Enhances glucose uptake by fat cells

Increases the sensitivity of liver and skeletal muscle cells to insulin

It inhibits the new formation of glucose in the liver

It helps to oxidize fatty acids

Promotes accumulation processes in subcutaneous adipose tissue (and not in the liver, skeletal muscles and interorgan-visceral spaces), which reduces the amount of visceral fat and improves fat and glucose metabolism

The inflammatory process develops in response to an invading agent from the environment, during the release of "fighter" cells by the immune system. There are two types of inflammation:

Acute inflammation – a necessary immediate response to injury to the body, eg cuts, lacerations. The immune system sends immune cells to the wound to protect the body from invading microbes from the wound.

Chronic inflammation is a condition where, despite the fact that the causative agent no longer exists, the immune system continues to release immunocompetent cells and the inflammatory process continues. Examples of this are rheumatoid arthritis, type II diabetes, Alzheimer's disease, tumors, and more.

Adiponectin reduces the number of macrophages and inflammatory processes in endothelium, muscle cells, epithelium, which protects these tissues from chronic inflammatory damage.

What is the difference between leptin and adiponectin?

Leptin and adiponectin are both adipokines produced and secreted by adipose tissue. Leptin increases metabolism and suppresses appetite.

Inadequate levels of adiponectin and leptin are associated with obesity, with the only difference being that in obesity there is an increase in the amount of leptin and a decrease in the amount of adiponectin.

When is adiponectin tested?

Adiponectin research is done in venous blood. Determining its value is important in the diagnostics of metabolic disorders, such as type II diabetes, metabolic syndrome, and others. Along with the basic diagnostic studies of metabolic disorders, sometimes these studies are also important.

The norm of the amount of adiponectin can be different, with different methods, when conducting research in different laboratories. Also, the normal rate depends on the condition of the human reproductive organs and the body mass index.

Body mass index (BMI) is the ratio of height to weight. It is calculated as the ratio of the square of the weight (in kilograms) to the height (in meters). Fatigue cannot be diagnosed by calculating the BMI in isolation. His data are discussed in context with other studies that reflect metabolic status.

Average normal values ​​of adiponectin:

> 10 – low risk indicator

7-10 – average risk indicator

4-7 – high risk indicator

< 4 very high risk

Conditions that cause changes in adiponectin:

fattening

weight loss

Insulin resistance

Atherosclerosis

Lipodystrophy

Adiponectin and atherosclerosis

Atherosclerosis is a condition in which lipid plaques form on the inner surface of blood vessels, narrowing the lumen and making the vessel wall rigid (inelastic). Foil is a mass of sticky consistency that contains cholesterol, calcium and other substances.

Because adiponectin has an anti-inflammatory effect, it prevents the formation of plaques. Its deficiency is one of the factors in the mechanism of atherosclerosis development.

Adiponectin and insulin resistance

Because adiponectin increases insulin sensitivity, its deficiency contributes to the development of resistance. In insulin resistance, the cells do not respond to the doses of insulin produced, resulting in the production of even more insulin (hyperinsulinemia) and metabolic disorders (prediabetes, type 2 diabetes, obesity).

Adiponectin and lipodystrophy

Lipodystrophy is a group of rare syndromes, when the distribution of fat on the body is disturbed - some areas are cachexically hypotrophic (thin), and some areas have a very large amount of fat. This type of fat accumulation is observed in internal organs, including the liver, which hinders its functioning.

Lipodystrophy can be congenital or acquired. Congenital and human immunodeficiency virus-associated lipodystrophy is associated with adiponectin deficiency.

Adiponectin and obesity

People with excess body weight have a deficiency of adiponectin. However, adiponectin levels are quite high in people with anorexia and very low body mass. Hence the conclusion that the more adipose tissue in the body, the lower the level of adiponectin.

Is there a treatment for adiponectin deficiency?

Adiponectin deficiency can be corrected by weight loss and physical activity.

Medicines - metformin and thiazolidine group - which are prescribed to correct diabetes and metabolic syndrome, help to increase the concentration of adiponectin in the body.