Adiponectin

What is adiponectin?

Adiponectin is a hormone-like protein, also called an adipokine, that is produced primarily by the body's fat cells (adipocytes). The hormone plays an important role in regulating the body's metabolism, insulin sensitivity, inflammation and energy metabolism. Unlike many other substances produced in adipose tissue, adiponectin is generally protective for the body and is associated with good metabolic health.

Adiponectin circulates in the blood in various forms and affects several organs, especially the liver, skeletal muscle, blood vessels and adipose tissue. Among other things, the hormone helps the body use glucose efficiently, increases fat burning and reduces low-grade inflammation.

The marker has become particularly interesting in modern metabolic research because low levels are often seen in conditions such as insulin resistance, type 2-diabetes , obesity and cardiovascular disease.

The function of adiponectin in the body

Adiponectin is an adipokine, which means a hormone-like signaling protein that is produced and released from the body's adipose tissue. The hormone has a central role in regulating the body's energy metabolism, insulin sensitivity, fat metabolism and inflammatory processes.

Unlike many other inflammatory substances secreted from adipose tissue, adiponectin mainly has protective and anti-inflammatory effects. High levels are generally associated with good metabolic health and improved insulin sensitivity, while low levels are often seen in insulin resistance, abdominal obesity and metabolic disease.

Adiponectin exerts its effects by binding to the receptors AdipoR1 and AdipoR2, which are found in, among other things, the liver, skeletal muscle, heart and blood vessels. When these receptors are activated, several metabolic signaling pathways are stimulated that improve the body's ability to use glucose and fatty acids as an energy source.

The hormone contributes to, among other things:

• increasing the sensitivity of cells to insulin
• increasing glucose uptake in skeletal muscle
• stimulating the oxidation and combustion of fatty acids
• reducing fat storage in the liver
• countering chronic low-grade inflammation
• protecting the endothelium of blood vessels against damage
• inhibiting the development of atherosclerosis
• contributing to normal energy metabolism and metabolic balance

Adiponectin is now considered an important biomarker for the metabolic function of adipose tissue. Although the hormone is produced by fat cells, lower levels are often seen in overweight and obese individuals, especially those with increased visceral fat and insulin resistance.

Low levels of adiponectin have been linked in studies to an increased risk of type 2 diabetes, metabolic syndrome, fatty liver, cardiovascular disease, and other conditions characterized by metabolic dysfunction and chronic inflammation.

Why is adiponectin analyzed?

Adiponectin blood test is primarily used in research and specialized metabolic or endocrinological care to assess the body's metabolic health and the function of adipose tissue.

The analysis may be relevant in the following conditions;

• suspected insulin resistance
• investigation of metabolic syndrome
• type 2 diabetes
• overweight and obesity
• fatty liver (NAFLD)
• cardiovascular disease
• PCOS (polycystic ovary syndrome)
• chronic low-grade inflammation
• evaluation of metabolic treatment or lifestyle changes.

Since adiponectin reflects the body's insulin sensitivity and metabolic balance, the marker can sometimes provide additional information beyond traditional samples such as glucose , HbA1c , insulin and blood lipids.

Low levels of adiponectin

Low levels of adiponectin are strongly linked to several common metabolic diseases and are often considered a sign of impaired function in adipose tissue.

Low adiponectin is often seen in:

• insulin resistance
• type 2 diabetes
• abdominal obesity
• metabolic syndrome
• high triglycerides
• low HDL cholesterol
• high blood pressure
• fatty liver
• cardiovascular disease.

Several studies show that low levels of adiponectin can occur several years before the development of type 2 diabetes , which makes the marker interesting as an early indicator of metabolic impact.

Adiponectin and insulin resistance

Adiponectin is closely linked to the body's insulin sensitivity. When levels drop, the cells' ability to respond to insulin deteriorates, which can lead to elevated blood sugar levels and increased stress. on the pancreas.

People with insulin resistance therefore often have low levels of adiponectin at the same time as insulin and glucose levels rise. This is commonly seen in abdominal obesity and metabolic syndrome.

The marker is therefore sometimes used together with:

• Glucose
• HbA1c
• Insulin
• HOMA-IR
• lipid status
• leptin

Adiponectin and cardiovascular disease

Adiponectin has anti-inflammatory and vascular protective properties. The hormone helps reduce inflammation in the vascular wall and counteracts the development of atherosclerosis, which means narrowing and plaque formation in the blood vessels.

Low levels have been associated with:

• atherosclerosis
• coronary artery disease
• hypertension
• heart attack
• increased cardiovascular risk

However, there is a phenomenon sometimes called the adiponectin paradox, where very high levels in older people or in advanced heart failure can paradoxically be associated with a worse prognosis. This is thought to be due to complex changes in metabolism and inflammation in chronic disease.

Adiponectin and fatty liver

Low levels of adiponectin are often seen in non-alcoholic fatty liver disease (NAFLD). The hormone normally helps reduce fat storage in the liver and improve the liver's insulin sensitivity.

When the concentration of Adiponectin is low, the risk of:

• fat storage in the liver
• inflammation of liver tissue
• impaired glucose metabolism
• development of metabolic liver disease.

Adiponectin and PCOS

Women with PCOS often have lower levels of adiponectin, especially if they are also insulin resistant or overweight. Low levels can contribute to hormonal imbalance, impaired ovulation and increased metabolic risk.

However, analysis of adiponectin is not routinely used in PCOS but is mainly used in research or more advanced metabolic investigations.

How is adiponectin analyzed?

Adiponectin is analyzed via a blood test. The analysis is usually performed on serum or plasma and usually does not require any special preparation, although fasting samples are sometimes recommended for metabolic investigations. There are still no fully standardized international reference ranges because levels are affected by several factors such as:

• gender
• age
• body composition
• insulin sensitivity
• degree of inflammation
• analysis method.

Women generally have higher levels of adiponectin than men.

Adiponectin in healthcare

Despite the fact that adiponectin is a biologically very interesting marker, it is still used relatively limitedly in routine healthcare. At present, the analysis is mainly used in research and specialized metabolic medicine. Reasons why the sample is not yet used routinely include:

• lack of standardized reference intervals
• variation between different analysis methods
• limited consensus on clinical use
• that other established markers are still used first-hand.

However, interest in adiponectin is increasing in precision medicine and preventive metabolic health because the marker can provide information about early metabolic impact before clear changes are visible in, for example, blood sugar or HbA1c.

Adiponectin and Metabolic Health

Adiponectin is now considered one of the most important biomarkers of metabolic health and adipose tissue function. High levels are generally associated with good insulin sensitivity, low inflammation, and a lower risk of metabolic diseases. Lifestyle factors that are often associated with improved adiponectin levels include:

• weight loss
• regular physical activity
• improved insulin sensitivity
• reduced abdominal obesity
• anti-inflammatory diet.

Adiponektin är därför inte bara en biomarkör utan även en viktig regulator av kroppens metabola balans och långsiktiga hälsa. Notera! Analys av adiponektin kan endast genomföras på Karolinska universitetslaboratoriet samt SYNLABS närlabb i Stockholm