Developmental disorders of glucose metabolism in infants.
BACKGROUND
Developmental failures to adequately control postnatal blood glucose levels are common in the transition from fetal to infant life and can persist for many months. The standard method of functionally measuring hepatic glucose production and/or disordered glucose production is the response to a glucagon tolerance test.


METHODS
We adapted the standard glucagon tolerance test used for children and adults for use in preterm infants. 79 consecutive preterm infants gestational age range 25-36 weeks (mean 32.2 weeks), mean birth weight 1.66 kg admitted to the Neonatal Intensive Care Unit, Ninewells Hospital, Dundee and who survived to discharge home were recruited into the study. At the time of discharge home the characteristics of the group were as follows: adjusted mean gestational age 36.7 weeks, mean discharge weight 2.23 kg.


RESULTS
In this study of preterm infants the maximal increase in plasma glucose following administration of a glucagon tolerance test is 1.39 +/- 07 mmol/L, n = 78 (range 0-3.98 mmol/L).


CONCLUSIONS
An increase in plasma glucose of less than 4 mmol/L is considered abnormal in adults following administration of a fasting glucagon tolerance test. The responses of preterm infants and adults to glucagon are clearly different. The attenuated response to glucagon in the preterm infants is consistent with the low levels of hepatic glucose-6-phosphatase activity in premature infants as glucose-6-phosphatase is the terminal step of the two main pathways of liver glucose production.
Hume
R
R
Department of Child Health, Obstetrics and Gynaecology, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK. r.hume@dundee.ac.uk
McGeechan
A
A
Burchell
A
A
D001786:Blood Glucose / Q000378:metabolism*; D005934:Glucagon / Q000378:metabolism; D005951:Glucose Tolerance Test; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D007363:Intensive Care Units, Neonatal; D015997:Neonatal Screening; D012016:Reference Values; D006113:United Kingdom
D001786:Blood Glucose; D005934:Glucagon