Metabolic and hormonal responses in the regulation of blood glucose levels in infants delivered by elective caesarean section

Background The postnatal failures of expression of the hepatic glucose-6-phosphatase system suggest there are developmental deficiencies in the mechanism to ‘switch-on’ this key enzyme of gluconeogenesis at the time of birth in both preterm and term infants. The evidence for hormonal regulation of this critical enzyme system in animal studies, in adult humans, and studies of cell lines make the possible failure of hormonal control around the time of birth an important hypothesis to test, but before this can be done, further studies of perinatal metabolism and its hormonal control need to be undertaken. Objective To describe the hormonal and metabolic profiles of ‘unstressed’ term infants delivered by elective caesarean section. Methods One hundred and fifty three women who had an elective caesarean section for a singleton pregnancy at term in Ninewells Hospital and Medical School, Dundee were recruited between July 2004 and April 2006. Maternal venous blood was taken for glucose and lactate estimations. Umbilical venous cord blood was obtained for the measurement of glucose, lactate, 3-hydroxybutyrate, free fatty acids, amino acids (alanine, arginine, citruline, cystine, GABA, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine ornithine, phenyalanine, serine,taurine, threonine, tyrosine and valine), insulin, glucagon, human growth hormone, cortisol, catechols (EPI, NE, DA, DOPA, DHPG, DOPAC) and their sulfated conjugates (EPI sulfate, NE sulfate, DA sulfate, DOPA sulfate, DHPG sulfate, DOPAC sulfate), and blood gas and acid-base profiles. Results The mean maternal glucose and lactate levels were 4.28 mmol/l and 1.8 mmol/l respectively. Three infants were hypoglycaemic with umbilical blood glucose levels of less than 2.6 mmol/l. The mean infant glucose and lactate levels were as expected for full term infants at 3.3 mmol/l and 2.2 mmol/l respectively. High mean levels of insulin and catechols were noted at birth. There was a significant positive association between umbilical venous cord glucose levels and maternal venous glucose levels (p=<0.001) but no association of umbilical venous cord glucose levels with amino acids, insulin, glucagon, human growth hormone, cortisol and catechols. Conclusions This extensive data set of levels of metabolites and hormones in infants at birth acts as a reference source and will be valuable for evaluating any effects of antenatal or intrapartum factors on the hormonal and metabolic profiles of infants at birth as well as to investigate the mechanisms to ‘switch-on’ the key enzyme glucose-6-phosphatase. Objective: To describe the hormonal and metabolic profiles of ‘unstressed’ term infants delivered by elective caesarean section. Methods: One hundred and fifty three women who had an elective caesarean section for a singleton pregnancy at term in Ninewells Hospital and Medical School, Dundee were recruited between July 2004 and April 2006. Maternal venous blood was taken for glucose and lactate estimations. Umbilical venous cord blood was obtained for the measurement of glucose, lactate, 3-hydroxybutyrate, free fatty acids, amino acids (alanine, arginine, citruline, cystine, GABA, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine ornithine, phenyalanine, serine, taurine, threonine, tyrosine and valine), insulin, glucagon, human growth hormone, cortisol, catechols (EPI, NE, DA, DOPA, DHPG, DOPAC) and their sulfated conjugates (EPI sulfate, NE sulfate, DA sulfate, DOPA sulfate, DHPG sulfate, DOPAC sulfate), and blood gas and acid-base profiles. Results: The mean maternal glucose and lactate levels were 4.28 mmol/l and 1.8 mmol/l respectively. Three infants were hypoglycaemic with umbilical blood glucose levels of less than 2.6 mmol/l. The mean infant glucose and lactate levels were as expected for full term infants at 3.3 mmol/l and 2.2 mmol/l respectively. High mean levels of insulin and catechols were noted at birth. There was a significant positive association between umbilical venous cord glucose levels and maternal venous glucose levels (p=<0.001) but no association of umbilical venous cord glucose levels with amino acids, insulin, glucagon, human growth hormone, cortisol and catechols.

Name dc:type.qualificationname

Doctor of Medicine

Level dc:type.qualificationlevel

Doctoral Thesis

Grantor dc:publisher.institution

University of Dundee

Year dc:date.issued

2009

Author dc:creator

• Koh, Daisy Ko Ming

• Blood glucose regulation
• Infant
• Elective caesarian section

Language dc:language

eng

Identifier

oai:discovery.dundee.ac.uk:studenttheses/98fce172-7f81-493e-b8e3-2ed82563bd5a

OAI identifier oai:identifier

oai:discovery.dundee.ac.uk:studenttheses/98fce172-7f81-493e-b8e3-2ed82563bd5a