Effects of Aging on the Endocrine System

Effects of Aging on the Endocrine System

Age-related changes to the endocrine system include a gradual decrease in the secretion of some, but not all, endocrine glands. Some of the decreases in secretion may be due to the fact that older people commonly engage in less physical activity.

 GH secretion decreases as people age, but the decrease is great-est in those who do not exercise, and it may not occur at all in older people who exercise regularly. Decreasing GH levels may explain the gradual decrease in bone and muscle mass and the increase in adipose tissue seen in many elderly people. So far, administering GH to slow or prevent the consequences of aging has not been found to be effective, and unwanted side effects are possible.

 A decrease in melatonin secretion may influence age-related changes in sleep patterns, as well as the decreased secretion of some hormones, such as GH and testosterone.

 The secretion of thyroid hormones decreases slightly with age. Age-related damage to the thyroid gland by the immune sys-tem can occur. Approximately 10% of elderly women experience some reduction in thyroid hormone secretion; this tendency is less common in men.

 The kidneys of the elderly secrete less renin, reducing the abil-ity to respond to decreases in blood pressure.

 Reproductive hormone secretion gradually declines in elderly men, and women experience menopause .

 Secretion of thymosin from the thymus decreases with age. Fewer functional lymphocytes are produced, and the immune system becomes less effective in protecting the body against infec-tions and cancer.

 Parathyroid hormone secretion increases to maintain blood calcium levels if dietary Ca2+ and vitamin D levels decrease, as they often do in the elderly. Consequently, a substantial decrease in bone matrix may occur.

 In most people, the ability to regulate blood glucose does not decrease with age. However, there is an age-related tendency to develop type 2 diabetes mellitus for those who have a familial tendency, and it is correlated with age-related increases in body weight.