FNDC5 and Hyperglycemia: Studies have shown that circulating irisin concentrations are inversely associated with cardiovascular health risk factors such as hyperglycemia, triglycerides, visceral fat, and extracellular lipid deposition [47,48,49], but negatively correlated with risk factors of cardiovascular health such as hyperglycemia, triglycerides, visceral adiposity, and extramyocellular lipid deposition [47].