Diabetic neuropathy is one of the major debilitating complications of diabetes. It affects autonomic, motor, and sensory nerve fibers, often beginning in the very thin fibers with progression to thicker fibers. Findings suggest that diabetic autonomic neuropathy (DAN) due to small fiber damage occurs during the first years of diabetes diagnosis in both type 1 diabetes and type 2 diabetes. Distal symmetrical peripheral neuropathy (DSPN) is characterized by damage to both small and large fibers.1

Underlying mechanisms of diabetes-induced GI symptoms are multifactorial and poorly understood. However, evidence suggests involvement of alterations throughout the neurogenic pathway including the central nervous system, vagal nerves, and enteric nervous system.2

GI autonomic neuropathy (GAN) in people with diabetes presents a wide spectrum of symptoms including regurgitation, nausea, vomiting, abdominal pain, bloating, early satiety, diarrhea, and constipation. None of the symptoms are specific for the condition and show high variability in severity and significant day-to-day fluctuation. Objective methods for evaluating enteric dysmotility are multiple and include high-resolution esophageal manometry, gastric emptying time assessments by scintigraphy or breath test and enteric transit time recordings by Wireless Motility Capsule (WMC). Subjective and objective enteric findings correlate poorly, partly due to this diversity in subjective findings and objective assessment tools.3

Up to 40 % of people with diabetes report GI symptoms.4 Prevalence of both upper and lower GI symptoms is higher in people with diabetes compared to the background population,4 which indicates the requirement of a pan-enteric assessment of symptoms when evaluating the severity of the GI burden in people with diabetes.

Associations of GI symptoms to autonomic and distal symmetrical neuropathy, comprising both small and large fiber involvement in type 1 diabetes and type 2 diabetes using multiple modalities have to our knowledge not yet been explored.

The aim of this cross-sectional study was to explore whether a high overall GI symptom burden in type 1 diabetes and type 2 diabetes was associated with presence of the neuropathies mentioned above. We hypothesize that a high GI symptom burden assessed by the CWSS is associated with presence of both autonomic and peripheral neuropathy.