Oestrogens are necessary for the development of female secondary sexual characteristics; they also stimulate myometrial hypertrophy with endometrial hyperplasia. In terms of oestrogenic activity natural oestrogens (estradiol (oestradiol), estrone (oestrone), and estriol (oestriol)) have a more appropriate profile for hormone replacement therapy (HRT) than synthetic oestrogens (ethinylestradiol (ethinyloestradiol) and mestranol). Tibolone has oestrogenic, progestogenic and weak androgenic activity.
The adrenal cortex normally secretes hydrocortisone (cortisol) which has glucocorticoid activity and weak mineralocorticoid activity. It also secretes the mineralocorticoid aldosterone. In deficiency states, physiological replacement is best achieved with a combination of hydrocortisone and the mineralocorticoid fludrocortisone; hydrocortisone alone does not usually provide sufficient mineralocorticoid activity for complete replacement.
Thyroid hormones are used in hypothyroidism (myxoedema), and also in diffuse non-toxic goitre, Hashimoto's thyroiditis (lymphadenoid goitre), and thyroid carcinoma. Neonatal hypothyroidism requires prompt treatment for normal development. Levothyroxine sodium (thyroxine sodium) is the treatment of choice for maintenance therapy. In infants and children with congenital hypothyroidism and juvenile myxoedema, the dose of levothyroxine should be titrated according to clinical response, growth assessment, and measurements of plasma thyroxine and thyroid-stimulating hormone.
Diabetes mellitus occurs because of a lack of insulin or resistance to its action. It is diagnosed by measuring fasting or random blood-glucose concentration (and occasionally by glucose tolerance test). Although there are many subtypes, the two principal classes of diabetes are type 1 diabetes and type 2 diabetes. Type 1 diabetes, also referred to as insulin-dependent diabetes mellitus (IDDM), occurs as a result of a deficiency of insulin following autoimmune destruction of pancreatic beta cells. Patients with type 1 diabetes require administration of insulin. Type 2 diabetes, also referred to as non-insulin-dependent diabetes (NIDDM), is due either to reduced secretion of insulin or to peripheral resistance to the action of insulin. Although patients may be controlled on diet alone, many also require oral antidiabetic drugs or insulin (or both) to maintain satisfactory control.