Metabolic and hormonal responses to glucose and glucagon in patients with infantile malnutrition

Abstract

The interrelations of plasma levels of glucose, free fatty acids (FFA), α-amino nitrogen (α-aaN), insulin, and growth hormone (GH) were studied in 26 malnourished infants shortly after admission to the hospital and again several weeks later when they had recovered. In the sick children (SC) fasting levels of FFA and GH were high, and insulin and α-aaN were low; with recovery FFA, α-aaN and insulin levels became normal, and GH levels fell. No change occurred in glucose levels. Ten infants were given glucose (0.5 g/kg body weight) intravenously on the 1st or 2nd day after admission and again 6-12 weeks later. Glucose tolerance was impaired in the sick group and, although improved, was not normal when the children had recovered from the nutritional insult. Insulin secretion was stimulated by glucose in those that had recovered (RC), but not in the SC. No significant change occurred in either FFA or α-aaN levels in these groups. Nine infants received glucagon (0.1 mg/kg body weight) intravenously on the 2nd to 6th day after admission and again 6-12 weeks later. Glucagon caused a rise in glucose levels that were greater in RC than in SC but did not cause a significant change in insulin levels in either group. Free fatty acid levels were higher in SC throughout the test, but in both groups FFA levels responded similarly to glucagon administration, falling 10 and 60 min after the injection. Changes in GH levels in plasma after glucose or glucagon administration were compared with the changes caused by five venepunctures in RC. Venepunctures and glucose caused similar rises in GH levels, but glucagon caused a greater rise than either. It was concluded that the stress of repeated venepunctures caused a rise in GH levels in plasma in all three tests, but that, independent of this, glucagon stimulated GH secretion. Speculation Insulin secretion is impaired in infantile malnutrition and does not improve at the same rate as clinical recovery occurs, suggesting that normal β cell function is not essential for rapid growth. The role of growth hormone in malnutrition is not clear, but it appears to be involved more in the metabolic adaptation to malnutrition than in the control of growth. © 1971 International Pediatric Research Foundation, Inc.