IGF1 and diabetes mellitus: IGF1 is a potent growth factor which mediates the cellular effects of growth hormone, but it also regulates maintenance and dynamics of axon growth [7, 8], and therefore the neuronal up-regulation of IGFBP5 which appears as a protective mechanism to prevent cell growth under the metabolic conditions of diabetes also prevents the IGF-1 signaling from Schwann cells which is necessary for axon stability, axon dynamics and excitability of sensory neurons [51].