Adiponectin

What is adiponectin?

Adiponectin is a hormone and an adipokine protein that affects several metabolic processes. It’s mainly known for its roles in insulin sensitivity and blocking inflammation. Your adipose tissue (body fat) is mainly responsible for producing adiponectin. But other tissues in your body make it, as well.

Scientists discovered adiponectin in the 1990s, so they’re still learning about it. It may have more functions that they haven’t found yet.

What is the function of adiponectin?

Adiponectin plays an important role in several metabolic and cellular functions. Its two main functions deal with insulin sensitization and anti-inflammatory effects.

Adiponectin and insulin sensitivity

Insulin sensitivity refers to your body’s ability to use insulin effectively. The more insulin sensitivity you have, the more easily your body can use it and keep your blood glucose (sugar) levels in a healthy range.

Some of the ways adiponectin plays a role in insulin sensitivity include:

• Impacting insulin sensitivity in your skeletal muscle and liver
• Increasing insulin release from your pancreas
• Preventing glycogen production in your liver
• Promoting the breakdown of fatty acids to make energy

Adiponectin and inflammation

Inflammation happens when your immune system sends out cells to fight bacteria or heal an injury. Sometimes, inflammation is necessary. But chronic (long-term) inflammation can be harmful to your health.

Adiponectin decreases inflammation in:

• Macrophages (a type of white blood cell that surrounds and kills bacteria and viruses)
• Endothelial tissue (cells that make up a thin membrane that lines the inside of your heart and blood vessels)
• Muscle cells
• Epithelial cells (cells that form the covering on all internal and external surfaces of your body)

Adiponectin’s anti-inflammatory properties result in the protection of your:

• Vascular system
• Heart
• Lungs
• Colon

Where is adiponectin produced?

Energy-storing cells in your white adipose tissue, called adipocytes, primarily produce and release adiponectin. White adipose tissue is the main type of fat in your body. It’s located:

• Beneath your skin (subcutaneous fat)
• Around internal organs (visceral fat)
• In your bones (marrow fat)

Other types of cells can make adiponectin, including:

• Skeletal muscle cells
• Heart muscle cells
• Endothelial cells

How are adiponectin levels controlled?

Adiponectin is a relatively new discovery, so scientists are still studying it. So far, they’ve found several hormones help control adiponectin levels.

Insulin seems to play a role in the creation of adiponectin, though not all scientists agree on exactly how.

The hormones insulin-like growth factor (IGF-1) and growth hormone (GH) regulate adiponectin release in adipose tissue. Leptin (another adipokine) may also play a role in adiponectin regulation.

What test checks adiponectin levels?

A blood test can check your adiponectin level.

Healthcare providers might recommend an adiponectin blood test to help diagnose conditions like Type 2 diabetes and metabolic syndrome. But there are other, more common tests to diagnose these conditions.

What are normal adiponectin levels?

Normal adiponectin levels vary based on your sex organs and body mass index (BMI).

In general, normal adiponectin ranges for males include:

• BMI less than 25: 5 to 37 micrograms per milliliter (ug/mL)
• BMI of 25 to 30: 5 to 28 ug/mL
• BMI over 30: 2 to 20 ug/mL

In general, normal adiponectin ranges for females include:

• BMI less than 25: 5 to 37 ug/mL
• BMI of 25-30: 4 to 20 ug/mL
• BMI over 30: 4 to 22 ug/mL

Normal value ranges for adiponectin levels may vary slightly among different laboratories. Be sure to look at the range of normal values listed on your lab report. Ask your healthcare provider if you have questions about your results.

What conditions are associated with abnormal adiponectin levels?

Several health conditions are associated with abnormal adiponectin levels, including:

• Obesity and underweight
• Insulin resistance
• Atherosclerosis
• Lipodystrophy

Most of these conditions are associated with low adiponectin levels.

Adiponectin and obesity

People with obesity have decreased levels of adiponectin. On the other hand, adiponectin levels are high in people who have severe underweight. Conditions like anorexia nervosa or malnutrition can cause severe underweight.

In general, the more body fat someone has, the lower their adiponectin levels are, and vice versa. Weight loss in people with obesity results in increased adiponectin levels.

Adiponectin and insulin resistance

Since adiponectin aids in insulin sensitivity, people who experience insulin resistance typically have low adiponectin levels. Insulin resistance happens when cells in your body don’t respond to insulin as they should. It results in excess insulin release (hyperinsulinemia).

Insulin resistance can result in prediabetes, Type 2 diabetes and gestational diabetes. Insulin resistance is often associated with obesity. But people can have insulin resistance without having obesity. And people who have insulin resistance without obesity usually have low adiponectin levels, as well. This suggests that there may be a genetic factor involved with insulin resistance and adiponectin.

Adiponectin and atherosclerosis

Atherosclerosis is a condition that happens when plaque builds up on the inside walls of your arteries.

Adiponectin has anti-inflammatory effects that help protect your heart and blood vessels. So, low levels of adiponectin can contribute to atherosclerosis and other cardiovascular issues, like heart attacks.

Adiponectin and lipodystrophy

Lipodystrophy is a group of rare syndromes that cause you to have a lack of body fat in some parts of your body while having excess amounts in other areas.

A person can be born with lipodystrophy or develop it later in life. Congenital (from birth) and HIV-related lipodystrophies are associated with low levels of adiponectin. This is likely because adiponectin plays a role in how your body stores fat.

Is there treatment for abnormal adiponectin levels?

A natural treatment to improve adiponectin levels is consistent exercise and healthy weight loss. Always talk to your healthcare provider before making drastic changes to your eating patterns or exercise routine.

Diabetes medications like metformin and thiazolidinediones result in an increase in adiponectin levels.

Scientists are currently working on developing medications that can mimic the effects of adiponectin to treat chronic inflammatory conditions.

What’s the difference between adiponectin and leptin?

Leptin and adiponectin are both hormones, or adipokines, that your adipose tissue makes and releases. Leptin enhances metabolism and reduces appetite.

Like adiponectin, abnormal levels of leptin are associated with obesity — but in different ways. A higher body fat mass results in elevated leptin levels. A higher body fat mass results in lower adiponectin levels.