Fat delays emptying but increases forward and backward antral flow as assessed by flow-sensitive magnetic resonance imaging

Authors


RobinSpiller Dr Department of Therapeutics, South Block, Floor C, University Hospital, Nottingham NG7 2UH, UK

Abstract

Flow has been assessed in the gastric antrum using a velocity-sensitive version of the high-speed magnetic resonance imaging technique, echo planar imaging (EPI). Eight healthy volunteers attended fasted on three separate days and consumed 800 mL of either a 5% glucose (0.2 kcal mL−1), 10% glucose (0.4 kcal mL−1) or an isotonic mixed nutrient meal, FresubinR (1 kcal mL−1, 27.2 g fat). Gastric volumes were obtained at 10-min intervals for 1 h. Flow measurements were performed on a single slice through the antropyloric region 5 and 35 min after meal ingestion. Gastric volumes at 45 min were inversely proportional to the calorie density of the meal with (mean ± SEM) 89 ± 10%* of the Fresubin, 64 ± 5%* of the 10% glucose and 41 ± 5% of the 5% glucose remaining (*P < 0.005 vs 5% glucose). Substantial forward and backward antral flow was observed after all three meals in the initial 5-min imaging period. At 35 min flow activity was significantly greater after both the high-calorie meals relative to the 5% meal (total number of flow events: Fresubin = 6.6 ± 1.7,† 10% glucose = 9.9 ± 2.2,‡ 5% glucose = 2.5 ± 0.9,† P < 0.03,‡ P < 0.007 vs 5% glucose, n = 8). Peak forward velocities for the initial phase of emptying tended to be greater for the rapidly emptying 5% meal (5.9 ± 0.8 cm−1) compared with the Fresubin (3.3 ± 0.6 cm−1, P < 0.069, n = 8) and the 10% glucose (2.9 ± 1.0 cm−1, P < 0.068, n = 8) meals. In spite of delayed gastric emptying, high-calorie meals were associated with substantial to and fro movements which may be important for meal tritruration and fat emulsification.

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