In fact, FFA is one of the key factors that influence insulin activity, and elevated FFA levels are predictive of the progression from impaired glucose tolerance to clinical diabetes.33 Insulin is a potent inhibitor of lipolysis and suppresses the release of FFAs from the adipocyte by inhibiting hormone-sensitive lipase.34 High levels of circulating FFAs, which can be found in obese individuals, are thought to cause IR in the fibers of skeletal muscles. This evidence concerns the gene INS and diabetes mellitus.