Are gastrointestinal symptoms related to diabetes mellitus and glycemic control?

Many patients with diabetes mellitus suffer from upper and lower GI symptoms. The reported prevalence of these symptoms varies among different ethnic groups/populations. The natural history of GI symptoms as well as their pathogenesis in patients with diabetes remains poorly understood, although it is known that gastric emptying is influenced by hyperglycemia, euglycemia, and hypoglycemia. Poor glycemic control over a long period of time can lead to neuropathy and damage the vagus nerve, resulting in diabetic gastroparesis whose signs and symptoms vary in the individual patient. Gastroparesis can further worsen glycemic control by adversely altering the pharmacokinetics of orally administered hypoglycemic agents as well as by altering the delivery of diet-derived calories to intestines from which absorption, subsequently, determines incipient blood glucose, and thus effectiveness of various injectable antidiabetics including various insulins and related insulin analogs. As GI symptoms may overlap with other disorders, including functional dyspepsia, irritable bowel syndrome, and depression, it is important to have such patients/patients with diabetes undergo standardized testing for measuring gastric emptying. Certain medications including metformin, amylin analogues (i.e. pramlintide), glucagon-like peptide 1 analogs (i.e. exenatide, liraglutide), anticholinergic agents, antidepressants, calcium-channel blockers, and others may contribute to GI symptoms observed in patients with diabetes. Given the global diabetes pandemic, it is of utmost importance to not only diagnose and treat present patients with diabetes mellitus and its comorbidities, but also to help prevent the development of further disease burden by educating children and adolescents about healthy lifestyle modifications (avoidance of overeating, portion control, healthy food choices, increased physical and reduced sedentary activity), as changing behavior in adulthood has proven to be notoriously difficult.