Diabetic gastroparesis: what we have learned and had to unlearn in the past 5 years

Diabetic gastroparesis is a disorder that occurs in both type 1 and type 2 diabetes. It is associated with considerable morbidity among these patients and with the resultant economic burden on the health system. It is primarily a disease seen in middle-aged women, although the increased predisposition in women still remains unexplained. Patients often present with nausea, vomiting, bloating, early satiety and abdominal pain. The pathogenesis of this complex disorder is still not well understood but involves abnormalities in multiple interacting cell types including the extrinsic nervous system, enteric nervous system, interstitial cells of Cajal (ICCs), smooth muscles and immune cells. The primary diagnostic test remains gastric scintigraphy, although other modalities such as breath test, capsule, ultrasound, MRI and single photon emission CT imaging show promise as alternative diagnostic modalities. The mainstay of treatment for diabetic gastroparesis has been antiemetics, prokinetics, nutritional support and pain control. In recent years, gastric stimulation has been used in refractory cases with nausea and vomiting. As we better understand the pathophysiology, newer treatment modalities are emerging with the aim of correcting the underlying defect. In this review, what has been learned about diabetic gastroparesis in the past 5 years is highlighted. The epidemiology, pathogenesis, diagnosis and treatment of diabetic gastroparesis are reviewed, focusing on the areas that are still controversial and those that require more studies. There is also a focus on advances in our understanding of the cellular changes that underlie development of diabetic gastroparesis, highlighting new opportunities for targeted treatment.