Normal Growth with Subnormal Growth-Hormone Levels

Abstract

Nine patients had normal or superior rates of statural growth after the removal of tumors impinging upon the pituitary gland and hypothalamus (craniopharyngioma in eight and third-ventricle cyst in one). After operation hyperphagia and obesity, as well as deficiencies of vasopressin, thyroxine and cortisol, were observed. Four patients over 15 years of age remained sexually immature, with no measurable gonadotropin excretion. Immunoassay of plasma showed barely detectable growth hormone during fasting and after Stimulation by hypoglycemia in nine of the patients and after exercise in six. The patients were free of hypoglycemic symptoms, and fasting blood sugar levels were normal; the serum immunoreactive insulin levels were in the low-normal range, except in the presence of obesity. The endocrine data indicate that in these unusual patients, normal or accelerated growth can occur when growth-hormone secretion is so low as to be only barely detectable by presently available technics.