What is adiponectin?
Adiponectin has the genders GBP-28, AdipoQ and Acrp30 and is one of the adipokines (adipose tissue hormones). The body forms it using the gene APMI on the chromosome 3q27. The production of adiponectin always takes place when the fat cells are only slightly filled.
The tissue hormone composed of 247 amino acids has a collagen-like structure and is responsible for the regulation of sugar and lipid metabolism. Certain conditions, such as chronic insulin regulatory dysfunction associated with persistently elevated insulin levels, cause less adiponectin to be produced in adipose tissue.
Adiponectin administration can accelerate the breakdown of adipose tissue - a method that could be helpful in the future for the unwilling patient. In persons with normal adiponectin levels, its share of the total protein present in the blood serum is only 0.01 percent. The adiponectin concentration in the blood is determined by the ELISA method.
Function, effect & tasks
Adiponectin regulates glucose metabolism together with leptin, insulin and other hormones. It changes the effect of insulin on the fat cells. Therefore, it is also referred to as immune modulator. If the adiponectin content in the blood is low, the effect of insulin is also weakened.
Since overweight people and insulin-resistant patients have a low adiponectin level, their risk of getting Type 2 diabetes is significantly higher than that of people of normal weight. Adiponectin acts on the receptors AdipoR1 and AdipoR2. AdipoR1 is located in skeletal muscle, adipoR2 in liver tissue. In people with a normal adiponectin level in the blood serum, the hormone increases the sensitivity to insulin and counteracts insulin resistance. It is increasingly released when the insulin level rises in the short term and promotes fat storage in the fat cells.
As an antagonist of the inflammation-promoting hormones produced in the abdominal fat tissue, adiponectin has an anti-inflammatory (anti-inflammatory) effect. Therefore, people with a normal adiponectin level also have a low risk of getting atherosclerosis. In people with obesity who additionally suffer from coronary heart disease, however, the too low level causes even greater damage to the vascular system. In animal experiments it could be shown that animals with too low a concentration of adiponectin in the blood, more often on a blood poisoning died than animals with normal adiponectin blood values.
Additional doses of tissue hormone drastically reduced this risk. In addition, it inhibits the formation of new glucose (glucose) in the liver, stimulates the oxidation of fatty acids in the liver, stimulates glucose uptake into the muscle and causes the formation of insulin.
Education, occurrence, properties & optimal values
Adiponectin is formed in the adipocytes (fat cells) of the body. However, their production is only stimulated if the adiponectin concentration in the blood serum is too low. Adiponectin, like the other adipose-derived hormone leptin, has an effect on glucose and lipid metabolism.
If it is present in sufficient quantity in the blood, it inhibits inflammatory processes in the body, such as the vessel walls and cell membranes. People with a normal adiponectin level have a lower risk of developing type 2 diabetes. Scientists are now assuming that in the future the doctor will be able to use the adiponectin blood level to make a statement as to whether the patient in question has an increased diabetes risk or not. The researchers also found that patients with a genetic variant of the hormone have a significantly higher risk of developing diabetes mellitus than those with "normal" adiponectin.
In recent clinical studies, it has been possible to increase the adiponectin content in the blood with the administration of certain medications. Another way to normalize blood levels is, according to the physicians, to reduce the excess weight and change the diet.
Diseases & Disorders
A pathologically low level of adiponectin in the blood causes the body to make insufficient use of the fatty acids stored in the adipose tissue. People with obesity have not only permanently (too) low adiponectin blood levels, but also increased leptin levels.
Leptin is the other hormone that is produced in adipose tissue. It usually causes an inhibition of appetite. However, since obesity blocks this positive effect of leptin, insulin resistance develops. The too high leptin concentration leads to oxidative stress and therefore to increased inflammatory parameters. People with this dysfunction are at greater risk of developing diabetes type 2, arteriosclerosis, coronary heart disease and heart attack. In her blood can be found to high triglyceride levels and low levels of HDL cholesterol.
Also the total cholesterol value is more or less increased. To counteract this, physicians recommend to reduce the weight (and thus especially the fatty tissue) significantly. Lots of exercise in the fresh air reduces the resistance to insulin in people with diabetes over the adiponectin level. However, excessive levels of adiponectin in the blood may increase the risk of dementia in female patients. Excessive adiponectin release may also promote cirrhosis.