Adiponectin

Serum or plasma

0.3 mL

0.1 mL (Note:This volume does not allow for repeat testing.)

Red-top tube, gel-barrier tube, or lavender-top (EDTA) tube

This test is used to measure the level of adiponectin in serum or plasma.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Enzyme-linked immunosorbent assay (ELISA)

See table.

Adiponectin is the most abundant peptide hormone secreted by adipocytes.^1-3 Other cell types such as skeletal and cardiac myocytes and endothelial cells can produce lesser amounts of this protein. Adiponectin has a short half-life of 45-75 minutes despite its minimal degradation during circulation. Its clearance is predominantly by the liver but can also bind pancreatic beta cells and certain heart and kidney cell types.¹ Adiponectin participates in glucose regulation but also exerts anti-inflammatory, anti-atherogenic and cardioprotective effects as well as effects on lipid metabolism and fatty acid oxidation.^1,4 Adiponectin directly acts on the liver, skeletal muscle, and vasculature through insulin sensitization and anti-inflammatory/anti-atherogenic effects.¹ Adiponectin increases insulin secretion from the pancreas and mediates insulin sensitivity in skeletal muscle.^1,3,5 Adiponectin enhances basal glucose and insulin-stimulated glucose uptake in adipose tissues.^1,3,4 Adiponectin increases insulin sensitivity and down-regulates gluconeogenesis in the liver while activating fatty acid oxidation.^1,3 Studies have shown that adiponectin decreases inflammation in macrophages, endothelial tissue, muscle, and epithelial cells.³ There is evidence that adiponectin prevents the production of reactive oxidative species and promotes down-regulation of inflammation.³ Moreover, it has been shown to inhibit CRP secretion and suppression of pathways involving NF-kB signaling and TNF-Alpha.³

Obese patients tend to have decreased serum levels of adiponectin. Various cross-sectional studies have established an inverse relationship between adiponectin serum levels and BMI and fat mass.^6-8 Adiponectin levels are increased in extremely lean patients suffering from conditions such as anorexia nervosa.⁷ Weight loss through means such as diet and exercise and bariatric surgery have resulted in increased plasma levels of adiponectin in patients.⁷ Diminished serum adiponectin levels is a feature in pathologies such as gestational diabetes.^7,9 Strong genetic associations between adiponectin levels and insulin resistance have also been established⁵ and low levels of it predict future onset of insulin resistance.^7,10 Adiponectin levels demonstrate an inverse correlation with adiposity and proinflammatory cytokines in patients suffering from metabolic syndrome.^11-14 Low levels of adiponectin predict a higher incidence of adverse cardiovascular events such as myocardial infarctions and atherosclerosis.^14,15

Recently, adiponectin has shown to exhibit activity in functions of cell proliferation, where it has been shown to counter cell growth and induce apoptosis.¹⁴ It is also noteworthy, however, that several recent studies have also demonstrated adiponectin to have anti apoptotic and proliferative roles.¹⁴ Accumulating evidence suggest that adiponectin is implicated in the pathogenesis of several malignancies.^13,16,17 Several observational studies showed that low adiponectin levels are associated with higher risk for breast, cervical, endometrial, ovarian and prostate cancer.^13,16,17 A relationship between adiponectin and the aggressiveness of some of these tumors has also been reported.^13,16-18