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The effects of intraduodenal nutrient infusion on serum CCK, LES pressure, and gastroesophageal reflux


Address for Correspondence
Brian E. Lacy, MD, PhD, Division of Gastroenterology & Hepatology, Dartmouth-Hitchcock Medical Center, Area 4C, 1 Medical Center Drive, Lebanon, NH 03756.
Tel: +1 603 650 5215; fax: +1 603 650 5225;


Background  Fats cause reflux symptoms in many patients and cholecystokinin (CCK) may play a role. This study was designed to evaluate the effects of intraduodenal nutrient infusion on serum CCK levels, lower esophageal sphincter (LES) pressure, and gastroesophageal reflux (GER).

Methods  Twenty-four asymptomatic volunteers were studied. A Dent sleeve catheter assessed LES function while an impedance-pH catheter measured reflux events. Participants were randomized to fat (F), carbohydrate (C) or protein (P) infusion. Serum CCK and LES pressures were measured at baseline and after nutrient infusion.

Key Results  Baseline LES pressures and CCK levels were similar in all three groups. A significant linear decrease was found in LES pressure during F, but not C or P, infusion (P = 0.004). A significant interaction effect was noted between the infusion groups and CCK levels (P = 0.002). A significant linear increase was noted in CCK levels during F but not during C or P infusion (P = 0.02). A significant inverse correlation was found between CCK levels and LES pressure (ρ = −0.43; P = 0.04). Esophageal acid exposure was significantly increased in the F infusion group (median; interquartile range: 1.10%; 0.25–4.7%) compared to both the C (0.03%; 0.00–0.39%) and P infusion (0.03%; 0.00–0.39%) groups (P = 0.04).

Conclusions & Inferences  Intraduodenal F infusion was associated with an increase in CCK levels, while P and C were not. LES pressure decreased significantly after fat infusion and reflux events were more frequent. Fat-induced CCK release is another mechanism that contributes to GER.