Endocrine Function in the Elderly

Many différent changes in endocrine function with âge hâve been described. To give just some of many possible examples, there are increases in the levels of growth hormone in women, rises in thyroid stimulating hormone, modest decreases in triiodothyronine, and increased sensitivity of response to antidiuretic hormone (1). Levels of norepinephrine rise (2) and there are altered circadian patterns for cortisol, norepinephrine, and growth hormone (3). There are falls in renin and aldosterone levels (4) and a rise in parathyroid hormone levels, although this seems to be entirely due to decreased rénal excrétion (5). Pancreatic polypeptide and gastrin show rises with âge, although other gut hormones do not appear to change (6). However, thèse and many other described changes are generally small and of doubtful importance in a practical sensé. They are certainly dwarfed by the important and major changes in sex hormones and gonadotropins, and this chapter will therefore concentrate on this area. Changes in sex hormones and trophic hormones occur in both sexes with aging. Obviously the changes are far more dramatic in women in relation to the abrupt cessation of estrogen sécrétion by the ovary at the time of ménopause. However, although there is no abrupt change in testicular function with âge, there is a graduai diminution of Leydig cell function so that testosterone levels fall progressively. Gonadotropins rise in both sexes in response to thèse falls in sex hormone production.