Glucose Tolerance in the Neonatal Period and During the First Six Months of Life

Abstract

Glucose tolerance was studied in 142 healthy children divided into different age-groups. The results confirmed the presence of a low fasting blood sugar level in newborn children. It is probably due to a high uptake of glucose in insulin-independent tissues, above all the central nervous system. The glucose tolerance expressed as the disappearance rate of intravenously injected glucose (kG) was low during the first hours of life (kG = 0.78), increased a little during the following 24 hours (kG = 0.88), but remained low throughout the first eight days of life (kG = 1.21). In contrast, children aged 1-6 months had a significantly higher tolerance (kG = 2.09) even when compared with a group of 5 to 15-year-old children (kG = 1.65). Possible causes of the low tolerance in the neonatal period are discussed and include hyperadrenocorticism and hypoinsulinism in the physiological state of starvation of the newborn infant. In contrast, the high tolerance in the infant of 1 to 6 months is explained by an adaptation to a relative hyperinsulinism in the extreme anabolic phase of growth during infancy.