Submitted to: Gastroenterology
Publication Type: Abstract Only
Publication Acceptance Date: 4/20/2006
Publication Date: 5/23/2006
Citation: Shulman, R.J., Ramirez, A., Wong, W.W. 2006. Effects of osmolality, volume, and nutrient density on gastric emptying (GE) in preterm infants [abstract]. Gastroenterology. 130(4):A23. Interpretive Summary:
Technical Abstract: Impaired GE is an important component of feeding intolerance in preterm infants. However, the factors regulating GE are unclear. We sought to clarify the independent as well as the interactive effects of osmolality, volume, and nutrient density on GE. In Study I, 10 infants (birth gestational age: 29 +/- 1 wk; postnatal age: 28 +/- 15 d; mean +/- SD) received in random order one of four feedings (A,B,C,D; i.e., one per day) to test a single variable on GE. Infants received their usual feeding (human milk or preterm infant formula). Sorbitol was used to increase osmolarity because it does not add energy and has similar effects on GE as glucose (J. Physiol. 1960;154:254). In Study II, 7 infants (birth gestational age: 27 +/- 1 wk; postnatal age: 34 +/- 14 d) received in random order one of two feedings (D, E; i.e., one per day) to test the combined effects of altering osmolality and volume on GE. GE was determined by measuring 13C breath (over 4 h) after adding 10 L/kg 13C-octanoic acid (99% 13C) to the feedings to obtain the time it took to empty half of the stomach contents (T1/2). Cumulative percent dose recovered was similar among feedings for both studies (Study I: 50 +/- 20, 59 +/- 15, 45 +/- 9, 57 +/- 22, A,B,C,D, respectively; Study II: 37 +/- 5, 33 +/- 6, D,E, respectively). Study I: T1/2 was similar among feedings (90 +/- 24, 93 +/- 13, 85 +/- 22, 97 +/- 35; A,B,C,D, respectively). Study II: T1/2 was significantly faster with feeding E vs D (102 +/- 15 vs 125 +/- 35, respectively; P = 0.035). Using results from all infants (n=17) for feeding D (i.e., full strength human milk or formula), T1/2 was inversely related to gestational age at birth (P = 0.026, r2 = 0.24) but did not correlate with birthweight, postnatal age, study weight, or type of feeding (human milk vs formula). In contrast to adults, individual alterations in osmolality, volume, and nutrient density do not differ in their effects on GE in preterm infants. Simultaneously decreasing osmolality and increasing volume enhances GE by 25% and we speculate, may account, in part, for reduced feeding intolerance seen clinically with this regimen (Am. J. Dis. Child. 1988;142:730 and Indian Pediatr. 1990;27:829). Birth gestational age still exerts an influence on GE even at one month postnatal age.