Somatotrophic, thyrotrophic and adrenocorticotrophic functions of the anterior pituitary in obesity

Abstract

The basal plasma level of GH, TSH and ACTH and the reserve capacities of the adenohypophysis in the secretion of these hormones was investigated radioimmunologically in 80 patients with excessive weight (from 15.3% to 180.0%) and a group of healthy subjects. It is shown that obesity is accompanied by diverse changes of the anterior pituitary GH, TSH and ACTH functions, which may be explained by their varied participation in the fatty metabolism. The pituitary somatotrophic function is weakened in obese subjects and its disorders advance with increase of the grade of obesity. Reduced pituitary thyrotrophic function in obesity causes weakening of thyroid function; disorders of the thyroid regulation occur at the hypothalamic level. The increased blood plasma concentration of ACTH in obese subjects has a compensatory character. The reserve capacities of the adrenocorticotrophic function of the pituitary are diminished in obestiy. Disturbances of the anterior pituitary GH, TSH and ACTH functions show a single-direction character both in alimentary-constitutional and in hypothalamic obesity.