Adiponectin is a hormone that is excreted exclusively from adipose (fat) cell and helps regulate several metabolic processes including the oxidation of fatty acids and glucose regulation. Levels are inversely correlated to the amount of body fat. Adiponectin plays a role in suppressing the metabolic dysfunction that often leads to metabolic syndrome, Diabetes (type 2), non-alcoholic fatty liver disease (NAFLD), obesity, and atherosclerosis. To underscore its role in regulating metabolism, adiponectin in conjunction with leptin was able to completely reverse insulin resistance in mice.
Adiponectin levels are generally higher in females than in males. Weight (body fat) reduction greatly increases serum levels of adiponectin. Diabetics have lower levels of adiponectin than non-diabetics. Obesity and TNF-a both decrease adiponectin levels. Low levels of adiponectin is an independent risk factor for developing diabetes and metabolic syndrome.
Molecules of adiponectin tend to join together to form polymers of adiponectin. These larger molecules seem to be the most active in regards to appropriate maintenance of glucose but this form is also associated with an increased risk of cardiovascular disease (CVD). At least some of the weight reduction effects of adiponectin occur in the brain and seems to work synergistically with Leptin in this regard.
Adiponectin has the following effects:
- It causes a decrease in the production of glucose (gluconeogenesis)
- It increases the uptake of glucose
- It increases the metabolism of fatty acids in the mitochondria (beta-oxidation)
- It decreases triglycerides by increasing their clearance from the blood
- It protects blood vessels from endothelial dysfunction
- It increases insulin sensitivity
- It promotes weight loss
- It helps regulate energy metabolism
- It upregulates uncoupling proteins – these are proteins that increase metabolism by utilizing energy sources but convert them to heat as opposed to energy
Interestingly, levels of adiponectin were disproportionately elevated in the blood of patients who went on to develop Alzheimer’s Disease (AD) as noted in the Framingham Heart Study. This information suggests that elevated levels of adiponectin could cause Alzheimer’s Disease. However, while we don’t know the answer to this piece, there are other potential explanations such as adiponectin resistance. For example, elevated insulin levels do not cause diabetes but are the result of insulin resistance that accompanies diabetes. This could be the same explanation for the development of AD in the setting of increased adiponectin levels.
How do you increase adiponectin? Berberine, EPA, & DHA have all been shown to increase the genetic expression of adiponectin. Curcumin, Resveratrol, astaxanthin, exercise, and Vitamin D (possibly) have been shown to increase adiponectin. The best options for improving adiponectin are supplements as listed above as well as optimizing body composition, decreasing body fat, exercising, and eating right.