FEEDING AND THE DEVELOPMENT OF ENTEROINSULAR HORMONE SECRETION IN THE PRETERM INFANT: EFFECTS OF CONTINUOUS GASTRIC INFUSIONS OF HUMAN MILK COMPARED WITH INTERMITTENT BOLUSES

ABSTRACT. Preterm infants receive gastric milk feeds as continuous infusions or intermittent boluses. It is not known whether these feeding methods have different effects on the development of digestive metabolism. We have measured plasma levels of insulin, pancreatic polypeptide (PP), gastric inhibitory polypeptide (GIP), gastrin, motilin, enteroglucagon (EG) and neurotensin (NT) in 19 preterm infants (28-34 weeks gestation) tolerating full enteral feeding from birth. 7 infants received human milk by continuous infusion, 12 infants were bolus fed. Hormones were measured in cord blood and at 6 and 13 days of age; samples were drawn preprandially in bolus fed infants. Both groups showed similar significant increases in plasma motilin, PP, NT and EG levels. At 13 days infusion fed infants had higher insulin. GIP and gastrin levels. No difference in rate of weight gain was seen in the two groups of infants. We conclude that both methods of feeding induce progressive changes in circulating enteroinsular hormone levels. However, the endocrine milieu is different in the two groups, particularly since bolus-fed infants experience marked cyclical surges in hormones after boluses of milk by 13 days of age. These differences in hormone release may affect metabolic homeostasis.     

PLASMA SECRETIN IN NEONATES

Abstract. Lucas, A., Adrian, T. E., Bloom, S. R. and Aynsley-Green, A. (University Department of Paediatrics, John Radcliffe Hospital, Oxford and Hammersmith Hospital, London). Plasma secretin in neonates. Acta Paediatr Scand, 69: 205, 1980.—Plasma secretin has been measured in 96 normal 6-day-old term infants and in 158 healthy preterm infants whose mean post-partum ages were 2½, 6, 13 or 24-days. At birth, plasma secretin levels in both term and preterm infants were high compared with those seen in healthy fasting adults ( p > 0.001), but subsequently declined towards adult values. In contrast, preterm infants who had not been fed for the first 6 days of life, had presistently high basal plasma secretin values. In term infants at 6 days of age and in preterm infants up to 13 days, there was no se-cretin response to a feed. However, by 24 days, preterm infants showed a marked post-prandial secretin elevation ( p > 0.02). No correlations were found between plasma secretin concentrations and either blood glucose or plasma insulin concentrations following a feed. Significant adjustments in plasma secretin levels occur in the early weeks of life which may be influenced by enteral feeding.     

PLASMA PANCREATIC POLYPEPTIDE IN THE HUMAN NEONATE

Abstract. Lucas, A., Adrian, T. E., Bloom, S. R. and Aynsley-Green, A. (University Department of Paediatrics, John Radcliffe Hospital, Oxford and Hammersmith Hospital, London). Plasma pancreatic polypeptide in the human neonate. Acta Paediatr Scand, 69: 211, 1980.—Plasma pancreatic polypeptide (PP) concentrations have been studied in 197 healthy term and preterm infants. At birth plasma concentrations were lower than those found in the young fasting adult ( p > 0.01), but by the sixth postnatal day in both term and preterm infants basal concentrations had risen to adult levels. In preterm infants, who were studied at two further postnatal ages, 13 and 24 days, basal plasma PP concentrations peaked at 13 days with levels that were over twice those seen in fasting adults ( p > 0.005). However, the marked PP elevations following feeding that have been reported in adults, were not seen in any of the groups of neonates studied. PP physiology thus appears to differ in neonates and adults. These findings may be relevant to adaptation to postnatal life.     

THE EFFECT OF FEEDS OF DIFFERING COMPOSITION ON ENTERO-INSULAR HORMONE SECRETION IN THE FIRST HOURS OF LIFE IN HUMAN NEONATES

Abstract. Little is known on the enteral stimuli for gastro-intestinal hormone release in newborn infants. We have compared the effect of the first feed of human breast milk (5 ml/kg) or 10% dextrose (5 ml/kg) on blood glucose and plasma gastrin, enteroglucagon, Gastric Inhibitory polypeptide (GIP), pancreatic glucagon, and insulin in 21 full-term infants at 4–6 hours of age. The first feed of human milk caused a rise in blood glucose and plasma insulin, gastrin and enteroglucagon, but no change occurred in GIP or pancreatic glucagon. The 10% dextrose feed did not stimulate enteroglucagon release, although similar changes occurred in blood glucose and plasma insulin and gastrin. We conclude that the composition of the feed influences the pattern of gastro-intestinal hormone release during the first hours of life and that the entero-insular responses to feeding differ in the neonate and the adult.     

THE ROLE OF NUTRITIONAL STATUS, AIRWAY OBSTRUCTION, HYPOXIA, AND ABNORMALITIES IN SERUM LIPID COMPOSITION IN LIMITING EXERCISE TOLERANCE IN CHILDREN WITH CYSTIC FIBROSIS

Abstract. Coates, A. L., Boyce, P., Muller, D., Mearns, M. B. and Godfrey, S. (Department of Paediatrics, Hammersmith Hospital, Queen Elizabeth Hospital, and the Institute of Child Health, London, England). The role of nutritional status, airway obstruction, hypoxia, and abnormalities in serum lipid composition in limiting exercise tolerance in children with cystic fibrosis. Acta Paediatr Scand, 69:353, 1980.—Previous work has shown that impaired exercise tolerance in children with cystic fibrosis (C.F.) is related to the severity of airway obstruction without elucidating the possible roles of hypoxia or malnutrition. It has been suggested that poor nutrition leads to abnormalities in serum fatty acids composition, which may lead to tissue hypoxia. We investigated the roles of hypoxia, pulmonary mechanics, nutritional status, and serum fatty acid composition in limiting exercise tolerance in C.F. In 20 children with C.F., exercise tolerance, while breathing air and while breathing oxygen, was evaluated on a cycle ergometer and compared to pulmonary function tests, anthropometric data, serum lipid composition, and clinical condition. The mean percent work expected from height (W_max) was 75, and was unchanged by 0_z. W_max correlated significantly with the degree of respiratory impairment, the discrepancy between height and weight, and the clinical score but not serum fatty acid composition. Where measured, no child at any time had an elevated end tidal CO₂(P_etCO2). We conclude that nutritional status and airway obstruction are closely correlated with exercise tolerance in C.F. and that, unlike the case in adults with chronic obstructive pulmonary disease, exercise-limiting dyspnea occurs in the presence of a normal P_etCO2.     

THE CORD SERUM FREE AMINO ACID LEVELS IN APPROPRIATE AND SMALL FOR GESTATIONAL AGE NEWBORN INFANTS OF MOTHERS WITHOUT CLINICAL MALNUTRITION IN ABIDJAN

Abstract. Reinhardt, M. C. and Burkhalter, J. F. (Department of Immunology, Institute of Child Health, London, England and Laboratoire Central, Centre Hospitalier Universitaire Vandois, Lausanne, Switzerland). The cord serum free amino acid levels in appropriate and small for gestational age newborn infants of mothers without clinical malnutrition in Abidjan. Acta Paediatr Scand, 69: 201, 1980.—The cord serum amino acid levels were determined in nine small for gestational age and fourteen appropriate for gestational age newborn infants of Abidjan, Ivory Coast. Small for gestational age newborns had a significantly lower total amount of amino acids, but the characteristic deviation of the individual concentrations and the high glycine/valine ratio seen in experimental and clinical protein deficiency were not found.     

METABOLIC AND ENDOCRINE RESPONSES TO A MILK FEED IN SIX-DAY-OLD TERM INFANTS: DIFFERENCES BETWEEN BREAST AND COW'S MILK FORMULA FEEDING

ABSTRACT. Lucas, A., Boyes, S., Aynsley-Green, A. (Department of Paediatrics, John Radcliffe Hospital, Oxford) and Bloom, S. R. (Hammersmith Hospital, London, England). Metabolic and endocrine responses to a milk feed in six-day-old term infants: JMfferences between breast and cow's milk formula feeding. Acta Paediatr Scand, 70:195, 1981. – There is little information on the metabolic and endocrine responses to milk feeding in the neonatal period particularly in relation to the mode of nutrition and composition of the milk. Plasma concentrations of insulin, glucagon and gastric inhibitory polypeptide (GIP) together with blood levels of glucose, ketone bodies, pyruvate, lactate and glycerol were measured pre- and post-prandially in 79 healthy six-day-old term infants who had been either breast fed or fed on a modified cow's milk formula (Cow and Gate Premium) from birth. Formula fed infants had a greater insulin and GIP response to feeding and their basal and postprandial blood ketones were considerably lower than in breast fed infants. In addition a significantly greater post feed rise in both lactate and pyruvate concentrations was observed with formula feeding. These results may have significant implications regarding infant feeding and postnatal metabolism.     

EFFECT OF SOMATOSTATIN INFUSION ON INTERMEDIARY METABOLISM AND ENTERO-INSULAR HORMONE RELEASE IN INFANTS WITH HYPERINSULINAEMIC HYPOGLYCAEMIA

Abstract. Aynsley-Green, A., Barnes, N. D., Adrian, T. E., Kingston, J., Boyes, S., and Bloom, S. R. (University Department of Paediatrics, John Radcliffe Hospital, Oxford, Department of Paediatrics, New Addenbrookes Hospital, Cambridge, and Department of Medicine, Hammersmith Hospital, London, England). Effect of somatostatin infusion on intermediary metabolism and enteroinsular hormone release in infants with hyperinsulinaemic hypoglycaemia. Acta Paediatr Scand, 70: 889, 1981.-The hypoglycaemia of infantile hyper-insulinism is often exceedingly difficult to control. The use of somatostatin has been advocated recently in such infants because of its effect on inhibiting insulin release, but nothing is known of the wider effects of this potent hormone in the young child. Two infants presenting at 9 weeks and 5 days of age with severe hyperinsulinaemic hypoglycaemia were studied during an infusion of somatostatin. In both infants normoglycaemia was restored with suppression of insulin secretion. An increase in blood ketone bodies occurred, but no change was seen in blood pyruvate, lactate or alanine concentrations. The plasma concentrations of glucagon, Cortisol, growth hormone, motilin.-pancreatic polypeptide, gastric inhibitory polypeptide, neurotensin, gastrin and vasoactive intestinal peptide decreased markedly during the somatostatin infusion. No consistent change occurred in plasma enteroglucagon or secretin values. We conclude that somatostatin effectively suppresses abnormal insulin secretion in infants, but it has profound effects on the release of nine other hormones. Further studies are needed to define the consequences of suppressing the release of these hormones before somatostatin can be used routinely in the management of infantile hyperinsulinism.