Glucose Disappearance Rate, Insulin Response and Growth Hormone Response in the Small for Gestational Age and Premature Infant of Very Low Birth Weight

Abstract

The purpose of the present investigation was to study the disappearance rate of intravenously administered glucose, plasma insulin, plasma growth hormone (GH) and their responses to an intravenous glucose load in 29 infants who were small for gestational age (SGA). The findings were compared to those in 19 premature babies of similar birth weight who were appropriate for gestational age (AGA); in all the weights were below 2,000 g. The babies were divided in two groups according to their age when tested, at < 24 and 25–48 h. SGA infants cleared glucose more rapidly than AGA infants (p < 0.01) whose clearance rates were similar to those previously reported in normal full-size and full-term newborns. Arterial insulin values before glucose loading were similar in all groups. The insulin response to glucose was poor in both SGA and AGA infants, but there was no significant difference between these two groups of infants. The response in the two groups at 24 and 25–48 h was similar. In 8 SGA babies insulin response was studied shortly after glucose injection to determine β-cell release, but there was no significant difference of insulin level before and after glucose administration. In 5 AGA and 8 SGA babies insulin response was studied simultaneously in portal vein and aorta. In AGA babies the insulin response was completely different in the two vessels with a high response in the vein; on the contrary, in SGA infants response was variable. Growth hormone levels were high before test in SGA and AGA; after a glucose load the plasma GH levels increase, but the response was identical in SGA and AGA.

Uterine Artery Ligation in the Maternal Rat Alters Fetal Tissue Glucose Utilization

“…However, because of their methodol ogy, they could not quantitate fetal tissue G U. Our results are also supported by reports of increased glucose disappearance rates in hypoglycemic IUGR hum an newborns (15,16). This observation has been considered to be the result of "growth-sparing" of metabolically active organs, e.g.…”

“…Ho wever, sm all-for-gestati on al-age human infants may ha ve increa sed metabolic rat es (13,14) and rapid clearance ofi.v. adm inistered glucose (15,16), which could also contribute to the development of hypoglycemia.…”

Experimental Intrauterine Growth Retardation in the Rat Causes a Reduction of Pancreatic B-Cell Mass, Which Persists into Adulthood

“…A glucose challenge in utero provokes only a small insulin secretory response [20] and this inability persist neonatally [21,22] . In the few cases which have been investigated morphologically there is evidence of a reduced pancreatic B-cell mass [23] .…”

Effects of Oral Glucose and Protein Load on Plasma Glucagon and Insulin Concentrations in Small for Gestational Age Infants

“…Sampling simultaneously from the portal vein and aorta pcrmits study of the concentration of insulin and glucagon resulting from secretion by the pancreas. We have previously reported the difference in insulin concentration between these vessels in small prcmature as well as in SGA infants after an intravenous load of glucose (19). We report a significant difference in the insulin response between aorta and portal vein; insulin levels are higher in the portal vein.…”

“…18, 25). We have shown previously that plasma insulin levels during hypoglycemia are identical or slightly higher in SGA infants as compared with fasting normal infants (19).…”