Enteric cholinergic neuropathy in patients with diabetes: Non‐invasive assessment with positron emission tomography

Enteric cholinergic neuropathy in patients with diabetes: Non‐invasive assessment with positron emission tomography:
By applying the novel ¹¹C‐Donepezil PET/CT technique, we found that patients with type 1 diabetes and gastrointestinal symptoms had reduced cholinergic innervation of the gut and enlargement of the small intestinal wall. This non‐invasive method holds promise as a future technique for assessment of enteric neuropathy.

Abstract

Background

¹¹C‐Donepezil positron emission tomography (PET) allows non‐invasive assessment of cholinergic innervation of visceral organs. We aimed to compare cholinergic innervation in the gut in patients with diabetes mellitus (DM) and in healthy controls (HC).

Methods

¹¹C‐Donepezil PET and computed tomography (CT) were performed in 19 patients with type 1 DM and gastrointestinal symptoms and in 19 age‐ and sex‐matched HC in a cross‐sectional design.

Key Results

All patients had severe gastrointestinal symptoms when assessed by standard questionnaires. DM patients had significantly increased volume of the small intestinal wall (DM: median 557 cm³ [interquartile range [IQR] 446‐697] vs HC median: 448 cm³ [IQR; 341‐518; P < .01]), and the ¹¹C Donepezil PET uptake was reduced in patients (DM: median 7.08 standardized uptake value [SUV] [IQR; 5.94‐8.43] vs HC: median 9.18 SUV [IQR; 8.57‐10.11; P < .01]). A similar pattern was found in colon (DM: median volume 1064 cm³ [IQR; 882‐1312] vs HC: median 939 cm³ [IQR; 785‐1081; P = .13] and DM: median 1.22 SUV (IQR; 1.08‐1.36) vs HC: median 1.42 SUV (IQR; 1.32‐1.53; P = .03). Furthermore, patients had significantly reduced pancreatic volume (DM: median 53 cm³ [IQR; 41‐69] vs HC: median 98 cm³ [IQR;82‐110; P < .01]) and reduced PET uptake of the pancreas (DM: median 13.14 SUV [IQR;9.58‐15.82] vs HC: median 21.46 SUV [IQR;18.97‐24.06; P < .01]) as well as the adrenal gland (DM: median 7.62 SUV [IQR;7.61;15.82] vs HC: median 15.51 SUV [IQR;12.22;19.49; P = .03]).

Conclusion and Inferences

Assessed with ¹¹C‐Donepezil PET/CT, patients with DM and severe bowel symptoms have reduced cholinergic innervation of the gut indicative of parasympathetic denervation.