Effects of Quinine on the Glycaemic Response to, and Gastric Emptying of, a Mixed-Nutrient Drink in Females and Males

Intraduodenal quinine, in the dose of 600 mg, stimulates glucagon-like peptide-1 (GLP-1), cholecystokinin and insulin; slows gastric emptying (GE); lowers post-meal glucose men. Oral sensitivity to bitter substances may be greater women than We, accordingly, evaluated dose-related effects quinine on GE, glycaemic responses to, a mixed-nutrient drink females, compared higher with those males. A total 13 female male healthy volunteers received quinine-hydrochloride (600 mg (‘QHCl-600’) or 300 (‘QHCl-300’, females only) control (‘C’), intraduodenally (10 mL bolus) 30 min before (500 kcal, 74 g carbohydrates). Plasma glucose, insulin, C-peptide, GLP-1, glucose-dependent insulinotropic polypeptide (GIP) were measured at baseline, for after alone, then 2 h post-drink. GE was by 13C-acetate breath-test. QHCl-600 alone stimulated C-peptide GLP-1 secretion C. Post-drink, reduced plasma increased C-peptide/glucose ratio oral disposition index, while GIP less, also slowed C males QHCl-300 (p < 0.05). concentrations ratio, Magnitudes lowering increase We conclude that modulates glucoregulatory functions, associated females. However, appears males, without apparent differential GI functions.