The pituitary gland is a small gland attached to the base of the brain. Hypopituitarism refers to loss of pituitary gland hormone production.
What is hypopituitarism?
The pituitary gland produces a variety of different hormones:
- Adrenocorticotropic hormone (ACTH): controls production of the adrenal gland hormones cortisol and dehydroepiandrosterone
- Thyroid-stimulating hormone (TSH): controls thyroid hormone production from the thyroid gland.
- Luteinizing hormone (LH) and follicle-stimulating hormone
(FSH): LH and FSH together control fertility in both sexes and the secretion of sex hormones (estrogen and progesterone from the ovaries in women and testosterone from the testes in men).
- Growth hormone (GH): required for growth in childhood and has effects on the entire body throughout life.
- Oxytocin: required during labor and delivery
and for lactation and breast feeding.
What causes hypopituitarism?
There are numerous causes of hypopituitarism . The most
common cause of hypopituitarism is a pituitary tumor (also known as a pituitary adenoma). Pituitary adenomas are almost invariably benign (not cancerous). However, the pituitary adenoma itself may put pressure on the remaining normal part of the pituitary gland and limit or even destroy its
ability to produce hormones appropriately.
What are the symptoms and signs of hypopituitarism?
- ACTH deficiency causing cortisol deficiency: Symptoms include weakness, fatigue, weight loss, abdominal pain, low blood pressure
and low serum sodium levels. During a period of severe stress such as infection or surgery, cortisol deficiency may potentially result in coma and death. ACTH also stimulates DHEA secretion from the adrenal cortex.
- TSH deficiency causing thyroid hormone deficiency: Symptoms include fatigue, weakness, difficulty losing weight, generalized
body puffiness, feeling cold, constipation, difficulty with memory and an inability to concentrate. Skin may become dry and the
complexion pale. In addition, anemia, high cholesterol levels and liver problems may also occur. Patients with severe or long-term
deficiency can appear lethargic. Rarely, severe thyroid hormone deficiency can cause coma, low body temperature, and even death.
- LH and FSH deficiency in Women: LH and FSH deficiency may cause loss of menstrual cycles, infertility, decrease in sex drive and
vaginal dryness and osteoporosis, which can result in a tendency to develop bone fractures.
- GH deficiency: In children, GH deficiency causes slowing or lack of growth and an increase in body fat. In adults, GH deficiency
may cause a decrease in energy and physical activity, change in body composition (increased fat, decreased muscle mass), a
tendency toward increased cardiovascular risk factors/diseases and decreased quality of life (including an increased sense of social isolation).
- PRL deficiency: In the case of PRL deficiency, the mother might not be able to breast feed following delivery.
How is hypopituitarism diagnosed?
Hormone deficiency is diagnosed based on the patient’s symptoms and the results of blood and sometimes urine tests. When a pituitary adenoma or other tumor is detected near the pituitary, or when a person is exposed to some other potential cause of hypopituitarismF, the patients should be evaluated for hypopituitarism.
How is hypopituitarism treated?
Hormone deficiency is treated by replacing the deficient hormones.
The goals of treatment are to improve symptoms and to replace the deficient hormone or hormones at a level that is as close to physiologically correct (“mother nature”) as possible. However, one rule of hormone replacement is that no one dose will suit every patient. Thus, when hormone replacement therapy is prescribed, the patient will need to be seen regularly after starting treatment to assess the effect. It often takes
time and repeated dose changes to find the optimal dose for each patient.
Typically, once the optimal dose is determined, the dose remains adequate for long-term treatment unless other medications are added or the patient’s condition changes in a way that alters the blood levels (e.g., introduction
of GH therapy may require an increase in cortisol replacement, whereas pregnancy may require an increase in the dose of thyroid hormone).
What are the benefits of hormone treatment(s)?
The goal of hormone replacement therapy is to enable the patient to live a normal life, feel well and not have the consequences of hormone deficiency. With proper hormone replacement, this goal can be achieved.
Estrogen replacement is advised for premenopausal women with estrogen
deficiency who are at risk of developing osteoporosis and who, according to recent studies, may also have increased cardiovascular risk factors.