Table 3.

Pathophysiologic mechanisms of diabetic gastroparesis

Etiology	Mechanism
Extrinsic denervation of stomach	Delayed gastric emptying
Loss of nitric oxide synthase in enteric nerves	Impaired inhibitory input (1) Decreased gastric accommodation, and possible accelerated gastric emptying of liquids (2) Uncoordinated antral contractility resulting in delay in gastric emptying of solids (3) Pylorospasm, which in the presence of antral hypomotility, may impair gastric emptying
Altered function of immune cells such as type 2 macrophages	Loss of cytoprotective factors resulting in damage to ICC (cajalopathy) and smooth muscle
Loss of ICC (cajalopathy)	Decreased smooth muscle contractility and arrhythmias
Smooth muscle atrophy	↓ IGF-1 with resultant loss of ICC

ICC Interstitial cells of Cajal, IGF-1 insulin-like growth factor 1