Digestive, Anorectal, and Urogenital Functions in Patients with Type 2 Diabetes Mellitus, Impaired Glucose Tolerance and Normal Glucose Tolerance: Association with Autonomic Neuropathy.

AIMS: Gastrointestinal disorders, including constipation and fecal incontinence, are common in type 2 diabetes mellitus (T2DM) and may derive from diabetic autonomic neuropathy, severe intestinal bacterial overgrowth, or a dysfunctional anorectal sphincter. The present study aims to characterize the correlation between these conditions. METHODS: Patients with T2DM, prediabetes, and normal glucose tolerance (NGT) were included. The anorectal function was assessed with high-resolution anorectal manometry. Patients were screened for autonomic neuropathy by measuring olfactory, sweat, and erectile dysfunction as well as heart rate variability. Constipation and fecal (in-)continence were evaluated using validated questionnaires. Breath tests were used to assess severe intestinal bacterial overgrowth. RESULTS: We included 59 participants (32 (54.2%) with T2DM, 9 (15.3%) with prediabetes, and 18 (30.5%) NGT). The presence of autonomic neuropathy, severe bacterial overgrowth, and symptoms of constipation and incontinence were comparable. HbA1c was correlated with an increased anorectal resting sphincter pressure (r=0.31, P=0.019) and constipation symptoms (r=0.30, P=0.031). In patients with a long-standing diagnosis of T2DM, significantly higher values for maximum anorectal resting pressure (Δ=+27.81±7.84 mmHg, P=0.0015) and baseline pressure (Δ=20.50±9.74 mmHg, P=0.046) were found compared with NGT, but not with prediabetes. CONCLUSIONS: Long-standing T2DM increases anorectal sphincter activity, and constipation symptoms are associated with higher HbA1c levels. The lack of an association of symptoms with autonomic neuropathy suggests glucotoxicity as the primary mechanism.

Upper gastrointestinal motility and symptoms in individuals with diabetes, prediabetes and normal glucose tolerance.

AIMS/HYPOTHESIS: Type 2 diabetes has been associated with upper gastrointestinal motility dysfunction, but the relationship with diabetes duration and glucose control is less well understood. Gastric emptying, oesophageal motility and gastrointestinal symptoms were examined in volunteers with diabetes, prediabetes (impaired fasting glucose [IFG] or impaired glucose tolerance [IGT]) and normal glucose tolerance (NGT). METHODS: The study included 41 patients with type 2 diabetes, 17 individuals with IFG/IGT and 31 individuals with NGT. A gastric emptying breath test and high-resolution oesophageal manometry were performed. Gastrointestinal symptoms were assessed using questionnaires. RESULTS: Gastric emptying was delayed in individuals with IFG/IGT (p < 0.05) but was normal in the diabetic group. Amongst the diabetic patients, gastric emptying rate was fastest in those with longer diabetes duration and the highest HbA1c levels (p < 0.001). Oesophageal motility variables were similar between the groups. However, the lower oesophagus resting pressure was reduced in patients with longer diabetes duration (p = 0.01). Abdominal pain/discomfort was more frequent amongst patients with diabetes (p = 0.04) but was unrelated to gastric emptying. Significant associations between various oesophageal motility variables and gastrointestinal symptoms were observed. CONCLUSIONS/INTERPRETATION: Gastric emptying and oesophageal motility are not generally altered in patients with type 2 diabetes. In more advanced disease stages, however, gastric emptying and oesophageal motility may be disturbed, probably as a consequence of autonomic neuropathy. Delayed gastric emptying in IFG/IGT individuals might be secondary to acute hyperglycaemia. Determination of gastric emptying and oesophageal manometry should be considered for the diagnostic workup of patients with diabetes and gastrointestinal symptoms.