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Biomedical subjects

Johannes B van Goudoever

Publications and source records attributed to Johannes B van Goudoever.

17 recordsLinked to original sources

Complementary feeding patterns in preterm and term infants.

Complementary feeding is essential for infants' nutritional status and development, marking the transition to solid foods when breast milk or formula alone is insufficient. Despite its importance, clear recommendations on which foods to introduce when initiating complementary feeding in preterm infants are lacking. By using data from our previously published randomized controlled trial on the timing of complementary feeding in preterm infants, the current study explores the complementary feeding patterns of preterm infants and compares them with those of term-born infants, providing insights into parental decision-making and potential long-term health impacts. Complementary feeding practices differed significantly between preterm (n&#x202f;=&#x202f;255) and term (n&#x202f;=&#x202f;159) infants, with preterm infants more often receiving vegetables as their first solid food (85.4% versus 68.8%, difference 17.6% with 95% CI 12-35%). The group with early introduction of vegetables had a lower BMI-for-age z-scores (&#x3b2; -0.28 [95% CI -0.55 - 0.02]) and weight-for-height z-scores (&#x3b2; -0.27 [95% CI -0.53 to -0.01]) at two years of age. Additionally, preterm infants showed a greater variety in the numbers of different fruits and vegetables consumed by six months (corrected) age than term-born counterparts (8.29 (SD 3.65) versus 6.26 (SD 3.47), p&#x202f;<&#x202f;0.001). These results indicate that complementary feeding patterns in preterm infants differ from term-born infants, with potential positive implications on growth. These data contribute to the development of accurate feeding protocols for preterm infants. Given that feeding practices are culturally influenced, further multinational research is essential to refine complementary feeding guidelines for preterm infants and support caregivers in informed decision-making.

Humans↗

Splanchnic metabolism of ingested amino acids in neonates.

PURPOSE OF REVIEW: Neonates typically show rapid growth. Nutrient absorption in the neonatal period is higher than during any other time in life so as to meet the requirements for this rapid growth. Generally, nutrients are administered enterally, and in the past the gut was considered to absorb and digest these nutrients without major metabolism. Recent animal and human work has, however, revealed that the intestine and other splanchnic tissues contribute significantly to whole-body metabolism, and have their own specific functions. This review focuses on these observations. RECENT FINDINGS: The splanchnic tissues take up greatly different proportions of each of the amino acids, ranging from 80-100% for threonine and several nonessential amino acids to 15-30% for lysine. The metabolic fates of the utilized substrates differ as well. Some are predominantly used for constitutive protein synthesis, others for energy generation or for formation of (glyco-)proteins that are secreted into the lumen. Glucose appears to be the major contributor to energy generation, but amino acids are important as well. SUMMARY: Both animal and human studies have shown that the intestine uses substantial amounts of dietary amino acids. This has several implications for the nutritional needs of infants to maintain growth, especially during times of inadequate enteral nutrition.

Amino Acids↗

Causes and consequences of inadequate substrate supply to pediatric ICU patients.

PURPOSE OF REVIEW: The prevalence of malnutrition among children admitted to a pediatric intensive care unit is still high. Assessment of nutrient supply is essential in the care of critically ill children because inadequate nutrition can increase morbidity and mortality. This review covers the causes and consequences of inadequate nutrient supply to critically ill children. RECENT FINDINGS: A major factor contributing to the cause of inadequate nutrient supply is the difficulty in estimating nutritional needs of the individual child. Reasonable values for energy expenditure can be derived from prediction formulae but measuring energy expenditure by indirect calorimetry is useful in selected cases. Furthermore, under-prescription and inadequate delivery of nutrients caused by fluid volume restriction, procedural interruptions or cessation because of gastrointestinal intolerance or mechanical problems cause additional nutritional deficits. As routine nutritional assessment is lacking in many pediatric intensive care units, the ability to monitor the adequacy of nutritional support is poor. SUMMARY: In the majority of children admitted to a pediatric intensive care unit, nutritional problems--both underfeeding and overfeeding--occur during admission due to poor estimation of nutritional needs, under-prescribing and problems in the delivery of the nutrients. Recommendations are made in order to prevent inadequate nutritional supply and its potentially harmful consequences in critically ill children.

Child↗

Does small intestinal atresia affect epithelial protein expression in human newborns?

OBJECTIVES: Bowel segments distal to a congenital intestinal obstruction have been suggested to be immature. In other words, luminal components such as amniotic fluid (before birth) and/or enteral nutrition (after birth) may be required to activate intestinal epithelial protein expression, thereby influencing epithelial differentiation. We investigated cell-type-specific protein expression proximal and distal to jejunal and ileal atresias in human newborns. PATIENTS AND METHODS: We immunohistochemically studied intestinal tissue specimens of 16 newborns who had undergone surgery for jejunal or ileal atresia. Sections were taken from both the proximal and distal sides of the atresias. RESULTS: For all patients, the enterocyte-specific markers lactase, sucrase-isomaltase, sodium glucose cotransporter 1, glucose transporters 2 and 5, intestinal fatty acid-binding protein and alkaline phosphatase were expressed at a mean 3 +/- 1 days after birth, both proximal and distal to jejunal and ileal atresias. Expression of goblet cell-specific markers mucin 2 and trefoil factor 3 and that of the Paneth cell marker lysozyme was maintained at either side of the atretic segment. CONCLUSIONS: With respect to the markers used, the human small intestinal epithelium is already differentiated shortly after birth. The absence of intestinal continuity in case of a jejunal or ileal atresia does not affect epithelial protein expression. This would seem to indicate that the developing small intestinal epithelium matures independently of luminal components.

Biomarkers↗

Intestinal amino acid metabolism in neonates.

The portal-drained viscera (stomach, intestine, pancreas and spleen) have a much higher rate of both energy expenditure and protein synthesis than can be estimated on the basis of their weight. A high utilization rate of dietary nutrients by the portal-drained viscera might result in a low systemic availability which determines whole-body growth. From studies in our multiple catheterized piglet model, we conclude that more than half of the dietary protein intake is utilized within the portal-drained viscera and that amino acids are a major fuel source for the visceral organs. Specific stable isotope studies reveal that there are large differences in the utilization rate amongst the different amino acids. The majority of the results obtained from the piglet studies can be extrapolated to the human (preterm) infant. First-pass, splanchnic uptake of lysine and threonine differ substantially, while non-essential amino acids are oxidized to a great extend in the human gut. Overall, these studies indicate that gut amino acid metabolism has a great impact on systemic availability and hence growth in the neonate.

Amino Acids↗

Effects of early amino acid administration on leucine and glucose kinetics in premature infants.

We previously showed that, in prematurely born infants, an anabolic state without metabolic acidosis can be achieved upon intravenous amino acid (AA) administration in the immediate postnatal phase, despite a low energy intake. We hypothesized that the anabolic state resulted from an increased protein synthesis and not a decreased proteolysis. Furthermore, we hypothesized that the energy needed for the higher protein synthesis rate would be derived from an increased glucose oxidation. To test our hypotheses, 32 ventilated premature infants (<1500 g) received intravenously either solely glucose or glucose and 2.4 g AA/kg/d immediately postnatally. On postnatal d 2, each group received primed continuous infusions of either [1-13C]leucine or [U-13C6]glucose. 13CO2 enrichments in expiratory air and plasma [1-13C]alpha-KICA (as an intracellular leucine precursor) and [U-13C6]glucose enrichments were measured by mass spectrometry techniques. The AA administration resulted in an increased incorporation of leucine into body protein and a higher leucine oxidation rate, whereas leucine release from proteolysis was not affected. Glucose oxidation rate did not increase upon AA administration. In conclusion, the anabolic state resulting from AA administration in the immediate postnatal period resulted from increased protein synthesis and not decreased proteolysis. The energy needed for the additional protein synthesis was not derived from an increased glucose oxidation.

Amino Acids↗

Hormone levels in children during the first week of ICU-admission: is there an effect of adequate feeding?

BACKGROUND & AIMS: To evaluate the course of hormonal parameters in relation to clinical parameters, illness severity and nutritional intake in children admitted to the pediatric ICU during the first week of admission. METHODS: Prospective, observational study. Levels of triiodothyronine (T3), reverse T3 (rT3), ratio T3/rT3 and insulin-like growth factor I (IGF-1) were evaluated in 84 critically ill children (50 term neonates and 34 children aged 32 d-15 yr) admitted to our multidisciplinary tertiary pediatric intensive care unit within 24 h after admission, on days 4 and 6 after admission. Changes in hormones levels over time were related to illness severity, C-reactive protein-levels and the adequacy of feeding. RESULTS: For both age groups IGF-1 levels remained low until day 4, but at day 6 IGF-1 levels were significantly higher than admission level. In 88% and 89% of the older children, T3 levels remained below normal at days 4 and 6, respectively. In both age groups, rT3 levels declined significantly over time, whereas the ratio T3/rT3 increased. The increases in IGF-1, T3 and ratio T3/rT3 and decrease in rT3 were significantly associated with decreases in CRP-levels. No significant relations were found between changes in IGF-1 and thyroid hormone levels during admission and the adequacy of energy and protein intake. CONCLUSIONS: During the first week of ICU-admission, abnormalities in levels of IGF-1, T3 and rT3 were frequently observed in critically ill children, especially in the children aged >1 month. The adequacy of feeding did not seem to affect the normalization of IGF-1 and thyroid hormone levels.

Adolescent↗

Use of [13C]bicarbonate for metabolic studies in preterm infants: intragastric versus intravenous administration.

The metabolic fate of substrates in humans can be examined by the use of stable isotopes, one of which, [13C]bicarbonate, may serve to estimate CO2 production rate. In view of minimizing the burden of metabolic studies for preterm infants, the authors determined whether intragastric and intravenous infusions of [13C]bicarbonate would achieve the same 13CO2 enrichment in expired air during steady state. A second aim of this study was to determine the minimum time required to reach steady state during intragastric infusion. Ten preterm infants received a primed continuous [13C]bicarbonate infusion intragastrically, followed by an intravenous infusion the next day. Breath samples were obtained every 30 min by the direct sampling method. 13CO2 isotopic enrichment, expressed as atom percent excess, was measured by isotopic ratio mass spectrometry. Two-tailed t tests were used to detect statistically significant differences between the infusion routes. The isotopic enrichment at plateau did not differ between intragastric and intravenous infusion. A steady state of 13CO2 enrichment was achieved after 60 min of intravenous infusion and after 120 min of intragastric infusion. In conclusion, intragastric infusion of [13C]bicarbonate may serve to estimate the whole-body CO2 production rate in preterm infants. To reach 13CO2 steady state, a minimum of 120 min of bicarbonate administration is required.

Bicarbonates↗

The role of initial monitoring of routine biochemical nutritional markers in critically ill children.

AIMS: The objectives of this study were to determine whether abnormal values of routine laboratory parameters at admission predict outcome and changes in anthropometric parameters in critically ill children during intensive care unit (ICU) stay and to discuss the clinical implications of abnormalities. STUDY DESIGN: This is a prospective descriptive study in a tertiary multidisciplinary pediatric ICU. Serum urea, albumin, triglycerides and magnesium were measured in samples obtained from 105 children (age, 7 days-16 years) within the first 24 h after their admission. The prevalences of abnormalities in these parameters as well as their possible association with outcome (length of stay, days on mechanical ventilation) and changes in nutritional status (changes in S.D. scores for weight, mid upper arm circumference and calf circumference) between admission and discharge were assessed. RESULTS: Prevalences of hypomagnesemia, hypertriglyceridemia, uremia and hypoalbuminemia were 20%, 25%, 30% and 52%, respectively, with no significant associations between the different disorders. Except for uremia, no significant association was found between abnormalities in biochemical parameters and changes in S.D. scores of anthropometric measurements. Children with uremia showed larger declines in S.D. scores for weight and arm circumference between admission and discharge than children without uremia did. Children with hypertriglyceridemia had longer ventilator dependence (P<.01) and length of stay (P<.001) than children with normal triglyceride levels upon admission had. CONCLUSIONS: Abnormalities in routine nutritional laboratory parameters were frequently noted in critically ill children at admission. Detection of abnormalities was not predictive of changes in anthropometric parameters during ICU admission but can be important in individualizing nutritional support.

Adolescent↗

Illness severity and parental permission for clinical research in a pediatric ICU population.

OBJECTIVE: Research in child subjects requires parental permission. We examined whether parental authorization of involvement in a clinical study is influenced by the child's severity of illness at the time of the consent decision. DESIGN AND SETTING: Observational study in a multidisciplinary tertiary pediatric and neonatal intensive care. PATIENTS AND PARTICIPANTS: Parents of 421 children (age range from preterm to 18 years) were asked to consent for participation in a study focusing on measuring their child's nutritional status within 24 h after admission to the ICU. Over 20% of the parents (n=88) refused consent, most of them because they expected the study to be too burdensome for their child. MEASUREMENTS AND RESULTS: Patient and disease characteristics were comparable in the children for whom consent had or had not been obtained. A higher illness severity score did not decrease the probability of obtaining informed consent, but parents of children with a history of disease were 3.2 times less likely to consent. CONCLUSIONS: Parents of children with higher illness severity scores are not more likely to decline permission to include their child in clinical observational research on the ICU. History of disease and subjectively perceived burden to the child are important factors that must be considered.

Adolescent↗

Amino acid administration to premature infants directly after birth.

OBJECTIVES: To test the hypothesis that the administration of 2.4 g amino acids (AA)/(kg.d) to very low birth weight infants is safe and results in a positive nitrogen balance. STUDY DESIGN: We conducted a randomized, clinical trial. Preterm infants with birth weights <1500 g received either glucose and 2.4 g AA/(kg.d) from birth onward (n=66) or solely glucose during the first day with a stepwise increase in AA intake to 2.4 g AA/(kg.d) on day 3 (n=69). Blood gas analysis was performed daily during the first 6 postnatal days; blood urea nitrogen levels were determined on days 2, 4, and 6; AA plasma concentrations and nitrogen balances were determined on days 2 and 4. Student t tests, Mann-Whitney tests, and chi2 tests were performed to compare groups. RESULTS: Infants supplemented with AA had no major adverse side effects. Their blood urea nitrogen levels were higher, nitrogen balance turned positive upon AA administration, and more AA concentrations were within reference ranges. CONCLUSIONS: High-dose AA administration to very low birth weight infants can be introduced safely from birth onward and results in an anabolic state.

Amino Acids↗

Adequate feeding and the usefulness of the respiratory quotient in critically ill children.

OBJECTIVE: We determined incidences of underfeeding and overfeeding in children who were admitted to a multidisciplinary tertiary pediatric intensive care and evaluated the usefulness of the respiratory quotient (RQ) obtained from indirect calorimetry to assess feeding adequacy. METHODS: Children 18 y and younger who fulfilled the criteria for indirect calorimetry entered our prospective, observational study and were studied until day 14. Actual energy intake was recorded, compared with required energy intake (measured energy expenditure plus 10%), and classified as underfeeding (<90% of required), adequate feeding (90% to 110% of required), or overfeeding (>110% of required). We also evaluated the adequacy of a measured RQ lower than 0.85 to identify underfeeding, and an RQ higher than 1.0 to identify overfeeding. RESULTS: Ninety-eight children underwent 195 calorimetric measurements. Underfeeding, adequate feeding, and overfeeding occurred on 21%, 10%, and 69% of days, respectively. An RQ lower than 0.85 to identify underfeeding showed low sensitivity (63%), high specificity (89%), and high negative predictive value (90%). An RQ higher than 1.0 to indicate overfeeding showed poor sensitivity (21%), but a high specificity (97%) and a high positive predictive value (93%). Food composition, notably high-carbohydrate intake, was responsible for an RQ exceeding 1.0 in the overfed group. CONCLUSION: Children admitted to the intensive care unit receive adequate feeding on only 10% of measurement days during the first 2 wk of admission. The usefulness of RQ to monitor feeding adequacy is limited to identifying (carbohydrate) overfeeding and excluding underfeeding.

Adolescent↗

Threonine utilization is high in the intestine of piglets.

The whole-body threonine requirement in parenterally fed piglets is substantially lower than that in enterally fed piglets, indicating that enteral nutrition induces intestinal processes in demand of threonine. We hypothesized that the percentage of threonine utilization for oxidation and intestinal protein synthesis by the portal-drained viscera (PDV) increases when dietary protein intake is reduced. Piglets (n = 18) received isocaloric normal or protein-restricted diets. After 7 h of enteral feeding, total threonine utilization, incorporation into intestinal tissue, and oxidation by the PDV, were determined with stable isotope methodology [U-(13)C threonine infusion]. Although the absolute amount of systemic and dietary threonine utilized by the PDV was reduced in protein-restricted piglets, the percentage of dietary threonine intake utilized by the PDV did not differ between groups (normal protein 91% vs. low protein 85%). The incorporation of dietary threonine into the proximal jejunum was significantly different compared with the other intestinal segments. Dietary, rather than systemic threonine was preferentially utilized for protein synthesis in the small intestinal mucosa in piglets that consumed the normal protein diet (P < 0.05). Threonine oxidation by the PDV was limited during normal protein feeding. In protein-restricted pigs, half of the total whole-body oxidation occurred in the PDV. We conclude that, in vivo, the PDV have a high obligatory visceral requirement for threonine. The high rate of intestinal threonine utilization is due mainly to incorporation into mucosal proteins.

Animals↗

The effect of cumulative energy and protein deficiency on anthropometric parameters in a pediatric ICU population.

BACKGROUND AND AIMS: Nutritional support is essential in the care of critically ill children since inadequate feeding increases morbidity and negatively affects growth. We aimed to compare cumulative energy and protein intakes with recommended dietary intakes (RDA) and examine relationships between accumulated balances and anthropometric parameters. METHODS: Prospective, observational study. Total daily energy and protein intakes were determined during a maximum of 14 days in 261 children admitted to our multidisciplinary tertiary pediatric ICU. Actual intakes were subtracted from RDA and cumulative balances were calculated. Relations between cumulative balances, various clinical factors and changes in anthropometry (weight, arm and calf circumference) were analyzed using regression analysis. RESULTS: At 14 days after admission children showed significant cumulative nutritional deficits compared to RDA. These deficits were on average 27, 20, 12 kcal/kg and 0.6, 0.3, and 0.2 g protein/kg per day for preterm neonates (n = 103), term neonates (n = 91) and older children (n = 67), respectively. Age at admission, length of ICU-stay and days on mechanical ventilation were negatively related to cumulative balances. Cumulative energy and protein deficits were associated with declines in SD-scores for weight and arm circumference. CONCLUSIONS: Children admitted to the ICU accumulate substantial energy and protein deficits when compared to RDA. These deficits are related to decreases in anthropometric parameters.

Adolescent↗

Splanchnic bed metabolism of glucose in preterm neonates.

BACKGROUND: Glucose is a major oxidative substrate for intestinal energy generation in neonatal animals; however, few data in preterm infants are available. Early administration of enteral nutrition, including glucose, may be an effective strategy to support intestinal adaptation to extrauterine life in preterm neonates. OBJECTIVE: The purpose of the present study was to quantify the first-pass uptake and oxidation of glucose by the splanchnic tissues (intestine and liver) in human neonates. DESIGN: Eight preterm infants [birth weight ( +/- SD): 1.19 +/- 0.22 kg, gestational age: 29 +/- 1 wk] were studied while they received 2 different enteral intakes (A: 40% enteral, 60% parenteral, total glucose intake = 7.5 +/- 0.5 mg. kg(-1). min(-1), and B: 100% enteral, total glucose intake = 7.8 +/- 0.4 mg. kg(-1). min(-1)). Splanchnic and whole-body glucose kinetics were measured by use of dual-tracer techniques. RESULTS: During both feeding periods, approximately one-third of dietary glucose intake was utilized during the first pass by the splanchnic tissues. More than three-quarters of this utilized glucose was oxidized in both periods (79 +/- 36% with A and 84 +/- 45% with B). Whole-body glucose oxidation was substantial under both circumstances: 72 +/- 5% and 77% +/- 6% of the glucose flux was oxidized during partial (A) and full (B) enteral feeding, respectively. CONCLUSIONS: Approximately one-third of dietary glucose is utilized during the first pass by the splanchnic tissues, irrespective of the dietary intake. Most of the utilized glucose is used for energy generation.

Adaptation, Physiological↗

Validation of the direct nasopharyngeal sampling method for collection of expired air in preterm neonates.

In clinical studies, the oxidation of 13C-labeled substrates to 13CO2 and the measurement of the appearance of excess 13CO2 in expiratory air has progressed to an increasingly common method as it is noninvasive and lacks the radiation exposure associated with the use of 14C. The collection of respiratory CO2 currently used occurs via trapping of CO2 in sodium hydroxide (trapping method), sometimes in conjunction with indirect calorimetry. The aim of the present study was to determine the accuracy of our direct nasopharyngeal sampling method for the collection of breath samples in preterm infants compared with the currently used trapping method. We present a method that simplifies the collection of breath samples in preterm infants. Seven preterm infants with a gestational age of 26-29 wk were studied on different postnatal days (range, 8-52 d) while receiving full enteral feeding. A primed constant 3-h intragastric infusion of [13C]bicarbonate was given, and breath samples were collected by means of direct nasopharyngeal sampling and by a sodium hydroxide trap simultaneously. Breath CO2 isotopic enrichments rose rapidly to reach a plateau by 120 min with <5% variation of plateau in both methods. 13CO2 breath isotopic enrichments obtained by the direct nasopharyngeal sampling method correlated highly (r2 = 0.933; p < 0.0001) with the trapping method. The Bland-Altman analysis showed no significant variability between the two methods and demonstrated that the 95% confidence interval is within +/- 4.68 delta per thousand. These findings validate the simple method of direct nasopharyngeal sampling of expired air in neonates.

Bicarbonates↗

Feeding an elemental diet vs a milk-based formula does not decrease intestinal mucosal growth in infant pigs.

BACKGROUND: We previously showed that the level of enteral nutrient intake determines the rate of intestinal growth in piglets. Our objective was to determine whether providing enteral nutrition in the form of elemental nutrients (glucose, amino acids, lipid [ED]) rather than cow's milk formula (lactose, protein, lipid [FORM]) reduces small intestinal growth and lactase activity. METHODS: Three-week-old piglets were fed either ED (n = 7) intragastrically or FORM (n = 6) orally for 6 days. RESULTS: Intestinal protein and DNA masses, villus height, and crypt depth were not different in ED and FORM pigs. Crypt cell proliferation, measured by in vivo bromodeoxyuridine labeling, was significantly (p < .05) higher (+37%) in ED than in FORM pigs. Rates of mucosal protein synthesis (%/d), measured by in vivo 2H-leucine incorporation, were higher (p < .05) in ED than FORM (147 vs 89) pigs. Circulating concentrations (pmol/L) of the intestinotrophic peptide, glucagon-like peptide-2 (GLP-2), were also higher (p < .05) in ED than in FORM (148 vs 87) pigs. The mean lactase-specific activity (micromol/min/g) in proximal and distal segments was higher (p < .05) in FORM than in ED (124 vs 58) pigs. CONCLUSIONS: We conclude that intestinal mucosal growth and villus morphology are similar in pigs fed ED and FORM, despite higher cell proliferation and protein synthesis rates and lower lactase activity with ED. This implies that elemental diets may be as trophic as polymeric formulas to simultaneously provide nutrition and a stimulus for intestinal growth during bowel rest.

Animals↗