Abstract
BACKGROUND & AIMS: Hyperglycemia is implicated as a major risk factor for delayed gastric emptying in diabetes mellitus and vice versa. However, the extent to which hyperglycemia can affect gastric emptying and vice versa and the implications for clinical practice are unclear. We systematically reviewed the evidence for this bidirectional relationship and the effects of pharmacotherapy for diabetes on gastric emptying. METHODS: Full-length articles investigating the relationship between diabetes mellitus and gastroparesis were reviewed primarily to quantify the relationship between blood glucose concentrations and gastrointestinal sensorimotor functions, particularly gastric emptying, and gastrointestinal symptoms. The effects of drugs and hormones that affect glycemia on gastrointestinal sensorimotor functions were also evaluated. RESULTS: Acute severe hyperglycemia delayed gastric emptying relative to euglycemia in type 1 diabetes; the corresponding effects in type 2 diabetes are unknown. Limited evidence suggests that even mild hyperglycemia (8 mmol/L) can delay gastric emptying in type 1 diabetes. Long-term hyperglycemia is an independent risk factor for delayed gastric emptying in type 1 diabetes. There is little evidence that delayed gastric emptying causes hypoglycemia in diabetes and no evidence that improved control of glycemia improves gastric emptying or vice versa. Glucagon-like peptide-1 agonists but not dipeptidylpeptidase-4 inhibitors given acutely delay gastric emptying, but tachyphylaxis may occur. CONCLUSIONS: Although acute severe and chronic hyperglycemia can delay gastric emptying, there is limited evidence that delayed gastric emptying is an independent risk factor for impaired glycemic control or hypoglycemia in diabetes. The impact of improved glycemic control on gastric emptying and vice versa in diabetes is unknown.