Fasting levels of glicentin are higher in Roux-en-Y gastric bypass patients exhibiting postprandial hypoglycemia during a meal test

Abstract

Background: Post-bypass postprandial hypoglycemia (PPH) is a frequent complication of Roux-en-Y Gastric Bypass (RYGB) but predictors remain poorly identified and are needed to assess individual risk. After RYGB, exaggerated secretion of glucagon-like peptide-1 (GLP-1) and insulin could lead to PPH, but other proglucagon-derived peptides, including glicentin and glucagon, could also contribute to this phenomenon.

Objectives: To identify biological hypoglycemia in relation to the secretion of proglucagon-derived peptides during a mixed-meal test (MMT) in RYGB patients.

Setting: University hospital.

Methods: Twenty RYGB patients reporting symptoms consistent with PPH were examined 36.9 ± 5.1 months after surgery. Plasma levels of glucose, c-peptide, glucagon, GLP-1 and glicentin were assessed before and during MMT. Patients with postprandial hypoglycemia ≤3 mM (54 mg/dL) during MMT were assigned to HYPO group and compared with patients not exhibiting hypoglycemia (NONHYPO group).

Results: Seven patients displayed hypoglycemia ≤3 mM (HYPO) during the MMT. Lower fasting glycemia (4.5 mM versus 5.3 mM, P<.05) and higher fasting glicentin (22.6 pM versus 14.0 pM, P<.05) were observed in HYPO versus NONHYPO patients. Fasting glicentin was inversely correlated with postprandial nadir glucose. Examining the receiver-operating characteristics curve analysis, a cutoff of 17.2 pM for fasting glicentin identified PPH with 85.7% sensitivity and 53.8% specificity. All patients exhibited a similar increase of postprandial GLP-1, glucagon, and glicentin secretions that correlated with each other.

Conclusions: These results suggest that fasting glicentin is a potential biomarker to examine in operated-obese patients at risk of developing PPH. Further studies are needed before proposing fasting glicentin as a predictive factor of PPH.

Keywords: Bariatric surgery; Glicentin; Glucagon; Glucagon-like peptide-1; Intestinal hormone; Mixed-meal test; Post-bypass postprandial hypoglycemia; Proglucagon-derived peptides.