Glucose Homeostasis – IGF1 and IGF2 Insulin-like growth factors IGFl and IGF2 are both able to produce hypoglycaemia when administered from an exogenous source, but only IGF2 is implicated in the pathogenesis of spontaneous hypoglycaemia. Like insulin and proinsulin, the IGFs suppress fatty acid release from adipocytes, and depress ketone production in the liver. They can therefore lower both plasma ketone levels and plasma glucose levels.