Activities of Trypsin and Lipase in Duodenal Aspirates of Healthy Preterm Infants: Effects of Gestational and Postnatal Age

Abstract

Lipase and trypsin activities were estimated in preprandially aspirated duodenal juice of preterm infants with gestational ages between 29 and 32 weeks (group I, n = 33) or between 33 and 36 weeks (group II, n = 22) during the first 6 weeks of postnatal life. The results were compared with the enzyme activities measured in 2- to 6-year-old children. There were no significant differences of the mean lipase or trypsin activities between the two groups (lipase; group I 13.7 ± 7.9, group II 15.9 ± 9.8 U/ml; trypsin: group I.7.9 ± 4.7, group II 8.5 ± 5.1 U/ml). The activities of both enzymes increased significantly and similarly in both groups with postnatal age (lipase: group I r = 0.732, p < 0.01, group II r = 0.743, p < 0.01; trypsin: group I r = 0.705, p < 0.01, group II r = 0.669, p < 0.01). At the end of the study the lipase activities of both groups reached approximately 35% of the values found in the older children, whereas the trypsin activities reached the reference values within the 1st month of life. The results indicate an asynchronously age-related development of lipase and trypsin. The development of the lipase activity is delayed in comparison to the trypsin activity which should be considered in the nutritional management of preterm infants.

Docosahexaenoic and Arachidonic Acid Absorption in Preterm Infants Fed LCP-Free or LCP-Supplemented Formula in Comparison to Infants Fed Fortified Breast Milk

“…Intralu minal factors which play a role in the absorp tion of fat, particularly in preterm infants, include the availability of bile acids [25], the activity of lipolytic enzymes [9,26] and the intraluminal acid base status [27], In a pre viously reported study, the bile acid concen trations as well as the activity of pancreatic lipase were found to be similar in infants fed human milk or the same LCP-supplemented formula as used in the present study [28]. The fact that the total fat absorption was similar in all the groups indicates that the intraluminal conditions were comparable among the study groups.…”

“…Feeding formulas supplemented with fish oil results in an improvement of the n-3 LCP sta tus of blood lipids but could lead to a decrease in the n-6 LCP status [3,4]. Consequently, formulas enriched with n-3 and n-6 LCP in amounts typical for human milk lipids arc recommended for the nutrition of preterm infants [5], Particularly in preterm infants, there are observations that fat from formulas is less efficiently utilized than fat from human milk [6,7], This is mainly due to the low activity of pancreatic lipase as well as the low biliary con centrations of bile acids [8,9] in these infants. Compositional factors of human milk fat may also influence fat absorption [4], The fatty acid apparent absorption rates are lower for saturated than for unsaturated fatty acids, and they decrease with increasing chain length [10].…”

Infant digestion physiology and the relevance of in vitro biochemical models to test infant formula lipid digestion

“…While lipolytic activities in the intestinal lumen under fasted conditions in infants (65.9–144) and adults (100–400) are quite similar, upon ingestion of a meal, infant lipolytic activity can drop from 254 ± 17 down to 27–105 U/mL, while in adults it increases from ∼580 to 800–1150 U/mL . After birth, there is considerable development of pancreatic function with postnatal age .…”

“…Human milk contains considerable levels of amylase (0.08-3.53 IU/mL) [60,61], which some believe compensates for the underdeveloped pancreas; however, amylase is not able to digest human milk oligosaccharides nor lactose [61]. While lipolytic activities in the intestinal lumen under fasted conditions in infants (65.9-144) and adults (100-400) are quite similar, upon ingestion of a meal, infant lipolytic activity can drop from 254 ± 17 down to 27-105 U/mL, while in adults it increases from ß580 to 800-1150 U/mL [55,59,[62][63][64][65][66]. After birth, there is considerable development of pancreatic function with postnatal age [67].…”

Ursodeoxycholic Acid Treatment in Preterm Infants: A Pilot Study for the Prevention of Cholestasis Associated With Total Parenteral Nutrition

“…Bile acids are needed for emulsification of fat before and during lipolysis, and they act as activator for the bile acid-depending lipase in breast milk. Stable solubilization of fat during digestion by bile acids is one of the main prerequisites for sufficient fat absorption (1)(2)(3).…”