Validation of [F-18]fluorodeoxyglucose and positron emission tomography (PET) for the measurement of intestinal metabolism in pigs, and evidence of intestinal insulin resistance in patients with morbid obesity - UTU Research Portal

A1 Refereed original research article in a scientific journal

Validation of [F-18]fluorodeoxyglucose and positron emission tomography (PET) for the measurement of intestinal metabolism in pigs, and evidence of intestinal insulin resistance in patients with morbid obesity

Authors: Honka H, Makinen J, Hannukainen JC, Tarkia M, Oikonen V, Teras M, Fagerholm V, Ishizu T, Saraste A, Stark C, Vahasilta T, Salminen P, Kirjavainen A, Soinio M, Gastaldelli A, Knuuti J, Iozzo P, Nuutila P

Publisher: SPRINGER

Publication year: 2013

Journal: Diabetologia

Journal name in source: DIABETOLOGIA

Journal acronym: DIABETOLOGIA

Number in series: 4

Volume: 56

Issue: 4

First page : 893

Last page: 900

Number of pages: 8

ISSN: 0012-186X

DOI: https://doi.org/10.1007/s00125-012-2825-5

Abstract

Aims/hypothesisThe role of the intestine in the pathogenesis of metabolic diseases is gaining much attention. We therefore sought to validate, using an animal model, the use of positron emission tomography (PET) in the estimation of intestinal glucose uptake (GU), and thereafter to test whether intestinal insulin-stimulated GU is altered in morbidly obese compared with healthy human participants.
MethodsIn the validation study, pigs were imaged using [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) and the image-derived data were compared with corresponding ex vivo measurements in tissue samples and with arterial–venous differences in glucose and [18F]FDG) levels. In the clinical study, GU was measured in different regions of the intestine in lean (n = 8) and morbidly obese (n = 8) humans at baseline and during euglycaemic hyperinsulinaemia.

ResultsPET- and ex vivo-derived intestinal values were strongly correlated and most of the fluorine-18-derived radioactivity was accumulated in the mucosal layer of the gut wall. In the gut wall of pigs, insulin promoted GU as determined by PET, the arterial–venous balance or autoradiography. In lean human participants, insulin increased GU from the circulation in the duodenum (from 1.3 ± 0.6 to 3.1 ± 1.1 μmol [100 g]⁻¹ min⁻¹, p < 0.05) and in the jejunum (from 1.1 ± 0.7 to 3.0 ± 1.5 μmol [100 g]⁻¹ min⁻¹, p < 0.05). Obese participants failed to show any increase in insulin-stimulated GU compared with fasting values (NS).

Conclusions/interpretationIntestinal GU can be quantified in vivo by [18F]FDG) PET. Intestinal insulin resistance occurs in obesity before the deterioration of systemic glucose tolerance.