The present invention provides methods, systems and apparatuses for effecting excitation or inhibition of small sensory nerve fibers, such as C-afferent fibers, by electrical stimulation of nerves innervating the pancreas. In an aspect the methods are directed to affecting insulin production (either enhancement or inhibition) and for the treatment of pre-diabetes and diabetes. This invention includes a closed or open loop feedback control system in which biomarker levels are monitored in order to direct electrical stimulation. An implantable or external neural stimulation device is also provided.
