Hormone

Thyrotoxic Myopathy

Thyrotoxic myopathy (TM) is a neuromuscular disorder that may accompany hyperthyroidism (Graves’ disease, caused by overproduction of the thyroid hormone thyroxine).

While hyperthyroidism is more common in women, the development of TM is more common among men with hyperthyroidism.

Symptoms may include:

  • Muscle weakness
  • Wasting of the pelvic girdle
  • Wasting of the shoulder muscles
  • Fatigue
  • Heat intolerance

Muscle breakdown may occur in acute cases. Physical acts such as climbing stairs may be difficult. Patients may develop muscle damage to the eyes and eyelids, which may affect mobility of the eye muscles, and temporary, but severe, attacks of muscle weakness known as periodic paralysis.

Patients who are diagnosed with TM have a normal life expectancy and can ultimately lead healthy lives if proper treatment is administered. The effects of TM can be controlled and in most cases reversed, leaving no lasting effects. However, untreated TM can eventually cause severe respiratory distress or even arrest, possibly leading to death, yet this is very rarely seen.

Treatment is based on treatment for hyperthyroidism and may include:

  • Prescription of iodine and other drugs
  • Beta-blockers
  • Surgery

Myopathy may improve by restoring normal thyroid function. Complete or partial removal of the thyroid may be required in severe cases.

Typically, once the over production of thyroxine is corrected and thyroid function adequately reaches a stable level, patients begin to regain muscle strength within two to four months. Depending on the severity of the TM symptoms, it may take up to a year to completely reverse the damage done.

Prolactinoma

A prolactinoma is a benign (noncancerous) tumor of the pituitary gland that produces a hormone called prolactin. Prolactinomas are the most common type of pituitary tumor.

Prolactin stimulates the breast to produce milk during pregnancy. After giving birth, a mother’s prolactin levels fall unless she breastfeeds her infant. Each time the baby nurses, prolactin levels rise to maintain milk production.

Although small benign pituitary tumors are fairly common in the general population, symptomatic prolactinomas are uncommon. Prolactinomas occur more often in women than men and rarely occur in children.

The cause of pituitary tumors remains largely unknown. Most pituitary tumors are sporadic, meaning they are not genetically passed from parents to their children.

Symptoms of prolactinoma are caused by too much prolactin in the blood (hyperprolactinemia) or by pressure of the tumor on surrounding tissues. In women, high levels of prolactin in the blood often cause infertility and changes in menstruation. In some women, periods may stop. In others, periods may become irregular or menstrual flow may change. Women who are not pregnant or nursing may begin producing breast milk. Some women may experience a loss of interest in sex. Intercourse may become painful because of vaginal dryness.

In men, the most common symptom of prolactinoma is erectile dysfunction. Because men have no reliable indicator such as changes in menstruation to signal a problem, many men delay going to the doctor until they have headaches or eye problems caused by the enlarged pituitary pressing against nearby optic nerves. They may not recognize a gradual loss of sexual function or libido. Only after treatment do some men realize they had a problem with sexual function.

The goals of treatment are to:

  • Return prolactin secretion to normal
  • Reduce tumor size
  • Correct any visual abnormalities
  • Restore normal pituitary function

In the case of large tumors, only partial achievement of these goals may be possible.

Because dopamine is the chemical that normally inhibits prolactin secretion, doctors may treat prolactinoma with the dopamine agonists bromocriptine (Parlodel) or cabergoline (Dostinex). Agonists are drugs that act like a naturally occurring substance. These drugs shrink the tumor and return prolactin levels to normal in approximately 80 percent of patients.

Surgery to remove all or part of the tumor should only be considered if medical therapy cannot be tolerated or if it fails to reduce prolactin levels, restore normal reproduction and pituitary function, and reduce tumor size. If medical therapy is only partially successful, it should be continued, possibly combined with surgery or radiation.

Rarely, radiation therapy is used if medical therapy and surgery fail to reduce prolactin levels.

How does prolactinoma affect pregnancy?

If a woman has a small prolactinoma, she can usually conceive and have a normal pregnancy after effective medical therapy. If she had a successful pregnancy before, the chance of her having more successful pregnancies is high.

A woman with prolactinoma should discuss her plans to conceive with her physician so she can be carefully evaluated prior to becoming pregnant. This evaluation will include an MRI scan to assess the size of the tumor and an eye examination with measurement of visual fields.

As soon as a woman is pregnant, her doctor will usually advise her to stop taking the medications. Although the drugs are safe for the fetus in early pregnancy, their safety throughout an entire pregnancy has not been established. Many doctors prefer to use bromocriptine in patients who plan to become pregnant because it has a longer record of safety in early pregnancy than cabergoline.

The pituitary enlarges and prolactin production increases during pregnancy in women without pituitary disorders. Women with prolactin-secreting tumors may experience further pituitary enlargement and must be closely monitored during pregnancy. Less than 3 percent of pregnant women with small prolactinomas have symptoms of tumor growth such as headaches or vision problems. In women with large prolactinomas, the risk of symptomatic tumor growth is greater, and may be as high as 30 percent.

Most endocrinologists see patients every 2 months throughout the pregnancy. A woman should consult her endocrinologist promptly if she develops symptoms of tumor growth—particularly:

  • Headaches
  • Vision changes
  • Nausea
  • Vomiting
  • Excessive thirst or urination
  • Extreme lethargy

Treatment with medications may be reinitiated and additional treatment may be required if the woman develops symptoms during pregnancy.

Pituitary Tumors

Pituitary adenomas are tumors in the pituitary gland, located in the center of the head behind the eyes. The pituitary gland is less than a half inch in diameter and controls many of the body’s hormones — chemicals that regulate essential body processes.

There are several types of pituitary tumors. Some tumors may cause Cushing’s disease, in which too many hormones called glucocorticoids are released into the bloodstream. This causes fat to build up in the face, back and chest while the arms and legs become very thin. Other symptoms include too much sugar in the blood, weak muscles and bones, a flushed face and high blood pressure.

Other pituitary tumors can cause a condition called acromegaly, where the hands, feet and face are larger than normal. In very young people, the entire body may grow much larger than normal.

Almost all pituitary tumors are benign, rather than malignant or cancerous, and are relatively slow growing. They rarely spread to other areas of the body.

If a pituitary tumor exists, the pituitary gland may make an excessive amount of hormones. Tumors that make hormones are called functioning tumors and those that don’t make hormones are called nonfunctioning tumors.

Tumors that secrete hormones tend to be smaller than the pituitary gland when they’re diagnosed. In fact, most pituitary tumors are microadenomas that measure 3 to 9 millimeters in diameter. Less common tumors are macroadenomas that are 10 millimeters or larger in diameter.

Tumors that don’t secrete hormones, called endocrine-inactive adenomas, tend to be larger and may compress other tissue such as the optic nerves, causing vision loss.

Patients with pituitary tumors may experience one or more of the following symptoms:

  • Headache
  • Decreased mental function
  • Dizziness
  • Loss of peripheral vision or decreased acuity in one or both eyes
  • Nausea with or without vomiting
  • Double vision
  • Weight loss or gain
  • Loss of appetite
  • Joint pain
  • Fatigue or decreased energy
  • Increase in shoe or ring size
  • Development of high blood pressure or diabetes mellitus

One type of pituitary tumor can cause a woman’s breasts to produce milk even though she isn’t pregnant and can stop her periods. Women may experience irregular or lack of periods and infertility, while men may have erectile dysfunction, loss of body or facial hair, loss of sexual drive and infertility.

Treatment options depend on the type of tumor and on its size. Certain medications can decrease tumor size as well as alleviate symptoms. In cases where the tumor is large, treatment can be with radiation therapy or surgery. Surgery is a common treatment for pituitary tumors. Trans-sphenoidal adenectomy surgery can often remove the tumor without affecting other parts of the brain.

Osteoporosis

Osteoporosis means “porous bones.” If you have osteoporosis, your bones don’t look any different, but they lose substance as well as calcium and other minerals. As a result, your bones have less strength and are more likely to fracture, particularly if you fall. The most common osteoporosis fractures resulting from falls are in your wrist or hip.

You also are much more likely to have compression fractures in your vertebrae, the bones in your spine. A compression fracture is the result of the weakened bone cracking from the normal pressure of being upright. This often results in the curvature of the spine at the shoulders in older people sometimes called a “widow’s hump.”

Osteoporosis affects an estimated 10 million people and almost 34 million have low bone mass, putting them at increased risk for developing osteoporosis. The condition is typically considered a woman’s disease, but 2 million of those with the disease are men. In fact, about 30 percent of hip fractures occur in men, and one in eight men over 50 years of age will experience an osteoporotic fracture.

The appearance of the widow’s hump or a fractured wrist or hip from a fall may be the first actual symptoms of osteoporosis unless your doctor has been measuring your bone density. Men also should watch for a loss of height, change in posture or sudden back pain. There are a number of risk factors that increase a person’s likelihood of having osteoporosis.

Risk Factors for Women

  • European or American ethnic background
  • Personal history of fracture as an adult
  • Poor general health
  • Smoking tobacco
  • Lifelong low calcium intake
  • Alcoholism
  • Low body weight, less than 127 pounds
  • Estrogen deficiency
  • Early menopause, before age 45
  • Prior to menopause, having a time in your life when you went more than a year without a menstrual period
  • Surgical removal of the ovaries before age 45
  • Taking medical therapy that lowers estrogen levels, such as for breast cancer or endometriosis
  • Poor vision despite correction, like wearing glasses
  • Falling
  • Inadequate physical activity

Risk Factors for Men

  • Heredity
  • Race — White men appear to be at the greatest risk for developing osteoporosis, although the condition can affect people of all ethnic groups
  • Age — Bone loss increases with age
  • Smoking tobacco
  • Alcoholism
  • Lifelong low calcium intake
  • Undiagnosed low levels of testosterone
  • Falling
  • Inadequate physical activity
  • Chronic disease that alters hormone levels and affects the kidneys, lungs, stomach and intestines
  • Low body weight

In addition, having a history of one of the following diseases can increase both a woman and man’s risk of developing osteoporosis:

Taking one of the following medications can increase one’s risk as well:

  • Seizure medication
  • Immunosuppressive drugs
  • Steroids (prednisone, hydrocortisone, dexamethasone)
  • Heparin
  • Lithium
  • Excess Thyroxine, thyroid replacement

There are several medications used to treat osteoporosis, depending on gender. Antiresorptive medications work primarily by reducing bone resorption, while bone anabolic medications build bone rather than inhibit resorption.

Hyperparathyroidism

Hyperparathyroidism (HPT) is a hormonal disorder that occurs when one or more of your four parathyroid glands become enlarged and overactive, causing them to produce excessive amounts of parathyroid hormone (PTH).

About 28 out of 100,000 North Americans develop HPT each year. Twice as many women develop this disease and the incidence increases with age.

Your parathyroid glands are located behind the thyroid gland at the front of your neck. They produce PTH, the hormone that maintains the correct levels of calcium in your blood and bones, helps absorb calcium from food and prevents you from losing too much calcium in your urine.

If you have HPT, too much calcium leaves your bones and collects in your blood. This can result in excess bone loss or osteoporosis as well as other problems such as kidney stones and kidney malfunction.

In 85 percent of people with HPT, a benign tumor, called an adenoma, has formed on one of the parathyroid glands, causing it to become overactive. In most other cases, the excess hormone comes from two or more enlarged parathyroid glands, a condition called hyperplasia. Very rarely, hyperparathyroidism is caused by cancer of a parathyroid gland.

Often people with hyperparathyrodism do not experience any symptoms or attribute them to other causes. Skeletal weakening is one of the classic effects of hyperparathyroidism and may make people susceptible to broken bones. A high blood calcium level also can lead to kidney stones and kidney malfunction. Other common symptoms of hyperparathyroidism include:

  • Loss of appetite
  • Thirst
  • Frequent urination
  • Lethargy and fatigue
  • Muscle weakness
  • Joint pain
  • Constipation
  • Nausea and vomiting
  • Abdominal pain
  • Memory loss

Treatment for hyperparathyroidism is usually surgery to remove the parathyroid tumor (parathyroid adenoma) or parathyroid gland.

Graves Disease

Graves disease, also known as hyperthyroidism, is a condition that causes your thyroid gland to make too much thyroid hormone, or become over-active.

The thyroid gland is located in the neck and is shaped like a butterfly. There are several hormones made by the thyroid gland that are important for growth and development. These same hormones also help with your energy level and help the heart, liver, kidneys and skin work correctly. These important hormones are called thyroxin (T4) and triiodothyronine (T3).

The thyroid gland is told to make T4 and T3 by another hormone which is made in the brain. This hormone is called thyroid-stimulating hormone (TSH). When a child’s TSH is low, the body might be making special cells that act like TSH. These cells are called antibodies. In this case, the antibodies tell the thyroid gland to make more T3 and T4. When this happens a child has Graves disease or hyperthyroidism.

Graves disease is more common in teenage girls, but can be found in boys and girls of any age.

Graves disease is caused by the body’s immune system when it gets confused and begins to attack cells, tissues or organs that it is supposed to protect. When the immune system attacks the tissues in the thyroid gland, the gland releases too much T4 and T3 into the blood stream.

Signs and symptoms of graves disease/hyperthyroidism include:

  • Increased energy with periods of extreme tiredness
  • Trouble sleeping
  • Inability to tolerate heat
  • Trouble concentrating in school
  • Diarrhea
  • Fast, pounding heart beat

Hyperthyroidism, in many cases, can be easily treated by taking an anti-thyroid medication every day. This medication keeps your thyroid gland from making too much hormone. It is very important to make sure your child takes his/her medicine everyday at about the same time. At first, your child may need to take this medicine several times a day. The doctor will let you know when you can take the medicine less often. Never change the medicine dose on your own. There are several symptoms to watch for that can help your doctor treat your child with the correct dose of medication.

The dose may be too low if your child has any of the following symptoms:

  • Trouble sleeping
  • Shaking (tremors)
  • Loses weight
  • Irritability
  • Diarrhea
  • Excessive hunger
  • Abnormal menstrual cycles

The dose may be too high if your child has any of the following symptoms:

  • Sleeping too much
  • Constipation
  • Cold, dry skin
  • Gaining weight too quickly
  • Low energy/activity level
  • Abnormal menstrual cycles

The doctor will want to see you frequently during the first year to check on your child’s growth and development. Depending on your particular situation, your doctor may want to see your child as often as once a month. Blood tests during these visits will help your doctor make sure the medication dose is correct.

Once your child starts to take thyroid medication, he/she may have more energy and better concentration at school. When a child is on the correct dose of anti-thyroid medicine, he/she should not have any symptoms of hyperthyroidism.

Radiation therapy can be used to treat hyperthyroidism when medication does not work. With this therapy, a radioactive form of iodine is given to stop the thyroid gland from working. Another treatment occasionally used, is removal of part or all of the thyroid gland with surgery. If your child needs either radioactive iodine therapy or surgery, your doctor will further discuss the risks/benefits with you.

Empty Sella Syndrome

Empty Sella Syndrome (ESS) is a disorder that involves the sella turcica, a bony structure at the base of the brain that surrounds and protects the pituitary gland. ESS is a condition that is often discovered during tests for pituitary disorders, when radiological imaging of the pituitary gland reveals a sella turica that appears to be empty.

There are two types of ESS: primary and secondary.

Primary ESS happens when a small anatomical defect above the pituitary gland increases pressure in the sella turica and causes the gland to flatten out along the interior walls of the sella turica cavity.

Primary ESS is associated with obesity and high blood pressure in women. The disorder sometimes results in a build-up of fluid pressure inside the skull and the pituitary gland may be smaller than usual.

Secondary ESS is the result of the pituitary gland regressing within the cavity after an injury, surgery, or radiation therapy.

Individuals with secondary ESS due to destruction of the pituitary gland have symptoms that reflect the loss of pituitary functions, such as:

  • The ceasing of menstrual periods
  • Infertility
  • Fatigue
  • Intolerance to stress
  • Intolerance to infection

In children, ESS may be associated with:

  • Early onset of puberty
  • Growth hormone deficiency
  • Pituitary tumors
  • Pituitary gland dysfunction

MRI scans are useful in evaluating ESS and differentiating it from other disorders that produce an enlarged sella.

ESS is not a life-threatening illness. Unless the syndrome results in other medical problems, treatment for endocrine dysfunction associated with pituitary malfunction is symptomatic and supportive. In some cases, surgery may be needed.

Diabetic Neuropathy

Diabetic neuropathy is a peripheral nerve disorder caused by diabetes or poor blood sugar control.

The most common types of diabetic neuropathy result in problems with sensation in the feet. It can develop slowly after many years of diabetes or may occur early in the disease. The symptoms are numbness, pain, or tingling in the feet or lower legs. The pain can be intense and require treatment to relieve the discomfort. The loss of sensation in the feet may also increase the possibility that foot injuries will go unnoticed and develop into ulcers or lesions that become infected. In some cases, diabetic neuropathy can be associated with difficulty walking and some weakness in the foot muscles.

There are other types of diabetic-related neuropathies that affect specific parts of the body. For example, diabetic amyotrophy causes pain, weakness and wasting of the thigh muscles, or cranial nerve infarcts that may result in double vision, a drooping eyelid, or dizziness.

Diabetes can also affect the autonomic nerves that control blood pressure, the digestive tract, bladder function, and sexual organs. Problems with the autonomic nerves may cause:

  • Lightheadedness
  • Indigestion
  • Diarrhea or constipation
  • Difficulty with bladder control
  • Impotence

The prognosis for diabetic neuropathy depends largely on how well the underlying condition of diabetes is handled. Treating diabetes may halt progression and improve symptoms of the neuropathy, but recovery is slow. The painful sensations of diabetic neuropathy may become severe enough to cause depression in some patients.

The goal of treating diabetic neuropathy is to prevent further tissue damage and relieve discomfort. The first step is to bring blood sugar levels under control by diet and medication. Another important part of treatment involves taking special care of the feet by wearing proper fitting shoes and routinely checking the feet for cuts and infections. Analgesics, low doses of antidepressants, and some anticonvulsant medications may be prescribed for relief of pain, burning, or tingling. Some individuals find that walking regularly, taking warm baths, or using elastic stockings may help relieve leg pain.

Diabetes Mellitus

Diabetes melitus has become an epidemic in North America with about 1 million people over age 20 diagnosed with the condition each year. About 17 million people, or 6 percent of the population, have diabetes mellitus, a disease in which the body doesn’t produce or properly use insulin, a hormone produced in the pancreas that converts sugar into energy.

Diabetes, the sixth leading cause of death in North America, can cause serious health complications such as blindness, kidney failure, nerve damage and the need for lower-extremity amputations. In addition, diabetes is a major risk factor for cardiovascular disease, dramatically increasing the risk for heart disease and stroke.

There are three main types of diabetes, including:

  • Type 1 Diabetes — Aboout 5 percent to 10 percent of those with diabetes have type 1 diabetes. It’s considered an autoimmune disease, meaning that the body’s own immune system mistakenly attacks and destroys the insulin-producing cells in the pancreas. Patients with type 1 diabetes have very little or no insulin, and must take insulin everyday. Although the condition can appear at any age, typically type 1 diabetes is diagnosed in children and young adults, which is why it was previously called juvenile diabetes.
  • Type 2 Diabetes — Accounting for 90 percent to 95 percent of those with diabetes, type 2 diabetes is the most common form of the condition. Usually, it’s diagnosed in adults over age 40 and 80 percent of those with type 2 diabetes are overweight. Because of the increase in obesity, type 2 diabetes is being diagnosed at younger ages and now is frequently seen in children. Initially in type 2 diabetes, insulin is produced, but the insulin can’t function properly, leading to a condition called insulin resistance. Eventually, most people with type 2 diabetes suffer from insulin resistance and decreased insulin production.
  • Gestational Diabetes — Gestational diabetes develops during pregnancy. It occurs more often in African Americans, Native Americans, Latinos and people with a family history of diabetes. Typically, it disappears after delivery, although the condition is associated with an increased risk of developing diabetes later in life.

If you think that you have diabetes, visit your doctor immediately for a definite diagnosis. Common symptoms include the following:

  • Frequent urination
  • Excessive thirst
  • Sudden vision changes
  • Tingling or numbness in the hands or feet
  • Feeling very tired much of the time
  • Unexplained weight loss
  • Extreme hunger
  • Very dry skin
  • Sores that are slow to heal
  • More infections than usual

Some people may experience only a few symptoms that are listed above. About 50 percent of people with type 2 diabetes don’t experience any symptoms and don’t know they have the disease.

All forms of diabetes have been treatable, and type 2 diabetes may be controlled with medications. Both type 1 and 2 are chronic conditions that usually cannot be cured. Treatments include:

  • Medications
  • Pancreas transplants (Type 1 DM)
  • Gastric bypass surgery (Type 2 DM)
  • Blood pressure control
  • Smoking cessation
  • Maintaining a healthy body weight

Adequate treatment of diabetes is important to avoid complications.

Diabetes Insipidus

Diabetes insipidus (DI) is a rare disease that occurs when the body’s precise system of regulating the kidneys’ handling of fluids is disrupted, causing frequent urination.

The body has a complex system for balancing the volume and composition of body fluids. The kidneys remove extra body fluids from the bloodstream. These fluids are stored in the bladder as urine. If the fluid regulation system is working properly, the kidneys make less urine to conserve fluid when water intake is decreased or water is lost, for example, through sweating or diarrhea.

With DI, the large volume of urine is diluted, mostly water. To make up for lost water, a person with DI may feel the need to drink large amounts and is likely to urinate frequently, even at night, which can disrupt sleep and, on occasion, cause bedwetting. Because of the excretion of abnormally large volumes of dilute urine, people with DI may quickly become dehydrated if they do not drink enough water. Children with DI may be irritable or listless and may have fever, vomiting, or diarrhea.

Diabetes insipidus should not be confused with diabetes mellitus (DM), which results from insulin deficiency or resistance leading to high blood glucose, also called blood sugar. DI and DM are unrelated, although they can have similar signs and symptoms, like excessive thirst and excessive urination. DI is a different form of illness altogether.

Milder forms of DI can be managed by drinking enough water, usually between 2 and 2.5 liters a day. DI severe enough to endanger a person’s health is rare.

Central DI results from damage to the pituitary gland, which disrupts the normal storage and release of ADH – antidiuretic hormone that directs the kidneys to reabsorb water into the bloodstream and make less urine. Damage to the pituitary gland can be caused by different diseases as well as by head injuries, neurosurgery, or genetic disorders.

To treat the ADH deficiency that results from any kind of damage to the hypothalamus or pituitary, a synthetic hormone called desmopressin can be taken by an injection, a nasal spray, or a pill.

Nephrogenic DI results when the kidneys are unable to respond to ADH. The kidneys’ ability to respond to ADH can be impaired by drugs and by chronic disorders including polycystic kidney diseasesickle cell disease, kidney failure, partial blockage of the ureters, and inherited genetic disorders. Sometimes the cause of nephrogenic DI is never discovered.

A person with nephrogenic DI may be given hydrochlorothiazide (HCTZ) or indomethacin. HCTZ is sometimes combined with another drug called amiloride. The combination of HCTZ and amiloride is sold under the brand name Moduretic.

Dipsogenic DI is caused by a defect in or damage to the thirst mechanism, which is located in the hypothalamus. This defect results in an abnormal increase in thirst and fluid intake that suppresses ADH secretion and increases urine output.

Scientists have not yet found an effective treatment for dipsogenic DI.

Gestational DI occurs only during pregnancy and results when an enzyme made by the placenta destroys ADH in the mother.

Most cases of gestational DI can be treated with desmopressin. In rare cases, however, an abnormality in the thirst mechanism causes gestational DI, and desmopressin should not be used.