|Adipokine||Association with obesity and/or T2D in humans||Adipokine effect on insulin signalling in animal models||Adipokine effect on insulin signalling in human skeletal muscle|
|In Vivo||In Vitro|
|Leptin||Increased [25, 26, 127].||
Overexpression of leptin in a skinny mouse model increased insulin sensitivity .|
Administration of leptin (12–15 days) reversed insulin resistance in obese wistar rats .
Leptin reversed high fat diet induced skeletal muscle insulin resistance in rats, indirectly via reducing intramuscular triglycerides not though direct modulation of insulin signalling .
|Recombinant leptin reduces IRS-1 phosphorylation and glucose uptake in L6 myotubes .||Increased phosphorylation of AKT in commercially available primary human myotubes .|
Recombinant leptin increased glucose uptake in C2C12 myotubes .|
Acute (10mins-1 h) stimulation of L6 Myotubes directly increased glucose uptake via a PI3K-dependent pathway. Leptin pre-treatment (10 min) of L6 myotubes inhibits insulin stimulated glucose uptake .
24 h Pre-treatment of L6 myotubes had no effect on glucose uptake but did inhibit adiponectin stimulated glucose uptake .
|Adiponectin||Decreased [31, 32].||Adiponectin knockout mice demonstrate an obese and insulin resistant phenotype [37, 39].||Promotes glucose uptake in both C2C12 and L6 Myotubes [35, 36].||Induces fat oxidation through activation of AMPK in myotubes from lean subjects. Mechanism impaired in myotubes from T2D patients .|
|Systemic administration and overexpression of adiponectin drives increased insulin sensitivity in insulin resistant mice [38, 40].||Recombinant adiponectin increased glucose uptake via AMPK mediated reorganisation of the actin cytoskeleton and GLUT4 translocation via an independent mechanism .|
|Resistin||Increased [45, 46].||Administration of resistin (6 days) to wild type mice induces a state of insulin resistance .||Recombinant resistin Impaired insulin signalling and glucose uptake in both C2C12 and L6 myotubes [48, 49].||Unknown|
|Targeted reduction of resistin in insulin resistant mice via antisense oligodeoxynucleotide restored hepatic but not skeletal muscle insulin sensitivity .|
|Visfatin||Increased [134,135,136].||Visfatin overexpression in rats increased whole body insulin sensitivity and adipose tissue and liver IRS-1 phosphorylation in response to insulin .||Stimulated glucose uptake and increased GLUT4 membrane translocation and mRNA and protein expression in C2C12 myotubes via AMPK p38 MAPK signalling .||Unknown|
|Increased glucose uptake in rat EDL muscle .|