Hormonal/Endocrine Disorders

What do the terms "endocrine" and "hormone" mean?

The endocrine glands of the body include the pituitary, thyroid, parathyroid, adrenal, pineal and thymus glands. The pancreas, ovaries and testes also act as endocrine glands. The endocrine system is a controlling system of the body. It controls cell activities by releasing chemical messengers called hormones into the bloodstream.

What are estrogen and testosterone?

Estrogens are female sex hormones produced mainly by the ovaries. Estrogens control the normal functioning of the female reproductive system including the appearance of female sex characteristics in girls at puberty and the regulation of menstrual function. Estrogens are also necessary for the growth (in girls and young women) and the maintenance (in adulthood) of normal healthy bone.

Testosterone is the male sex hormone produced mostly by the testes. In males, testosterone is responsible for normal development of sex organs, normal puberty, and fertility. Normal testosterone levels are also necessary for the growth and maintenance of muscle and bone mass in males.

What is the role of hormonal balance in the promotion of healthy bones in youth?

Peak bone mass, defined as the maximum bone density an individual will ever have, is reached between 16 and 25 years of age. Hormonal balance is one of the factors necessary to reach peak bone mass. Low levels of estrogen in females or low levels of testosterone in males during youth and young adulthood are associated with lower peak bone mass.

What is the role of hormonal balance in the promotion of healthy bones in adulthood?

In adulthood, after peak bone mass is reached, estrogen deficiency in women can increase the rate of bone breakdown and cause bone loss. In men, any condition or disease causing low levels of estrogen or testosterone may also result in bone loss.

The following conditions associated with endocrine/hormonal disorders (listed alphabetically) may increase the risk for osteoporosis:

Amennorhea
Cushing's Disease
Diabetes Mellitus
Eating Disorders
Hyperparathyroidism
Hyperprolactinemia
Kleinefelter Syndrome
Thyroid Disease
Turner Syndrome

AMENNORHEA

What is amennorhea?
Amenorrhea is the absence of menstrual cycles. The only healthy and expected reason to stop having menstrual periods during the premenopausal years is pregnancy. However, there are a number of disorders that can also cause amennorhea in premenopausal women. One disorder is referred to as the athletic female triad. It is a syndrome consisting of disordered eating, excessive exercise and amenorrhea that results in bone loss. Bone density is lower in athletes with amennorhea in comparison to athletes with regular menstrual cycles. Some other causes of amennorhea include the use of certain medications (some psychiatric medications and certain narcotics), thyroid disease, hyperprolactinemia, Cushing's disease, pituitary or hypothalamic disorders, polycystic ovarian syndrome, and uterine adhesions (perhaps due to an infection or recent surgery).

How does amennorhea affect bone health?
Amennorhea that is not related to pregnancy can often lead to lower bone density, particularly if it is related to lower estrogen levels. In all cases, it is important to consult with a doctor or healthcare provider to determine the cause for amennorhea. . Early detection and treatment of disorders that can cause amennorhea may help reduce the risk for osteoporosis.

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CUSHING'S DISEASE

What is Cushing's disease?
In Cushing's disease, the body produces an excess of cortisol, a steroid hormone. Cushing's disease is caused by the presence of a non-cancerous (benign) tumor on the pituitary gland.

How does Cushing's syndrome affect bone health?
This overproduction of cortisol can produce the same problems for bones as that caused by the use of steroid medications. See: http://www.niddk.nih.gov/health/endo/pubs/cushings/cushings.htm

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DIABETES MELLITUS

What is diabetes mellitus?
Diabetes Mellitus is a condition characterized by high blood glucose levels resulting from the body's inability to use blood glucose for energy. In Type 1 diabetes, the pancreas no longer makes insulin and therefore blood glucose cannot enter the cells to be used for energy. In Type 2 diabetes, either the pancreas does not make enough insulin or the body is not able to use insulin correctly.

How does Type 1 diabetes affect bone health?
Type I diabetes appears to be a significant risk factor for osteoporosis. In Type 1 diabetics, the cells that form bone do not seem to work as well as those in the general population, perhaps due to the absence of the bone forming effects of insulin. This may be one of the reasons why low bone mass occurs. Further research is needed to better understand the complex relationship between Type 1 diabetes and osteoporosis. Type 1 diabetes often has a young age of onset (before peak bone mass is reached) so low bone mass would seem to be a likely complication for individuals with Type 1 diabetes. There is evidence that low bone mineral density is associated with the following characteristics: diagnosis of Type 1 diabetes at a young age (before puberty), poor blood glucose control, high insulin requirements, and microvascular complications (such as neuropathy and retinopathy). Adult women with Type 1 diabetes have been shown to have a lower bone mass, increased fracture risk, higher rates of hip fracture (12 times more likely to report hip fractures than non-diabetics), and delayed fracture healing compared to women without diabetes. Delayed fracture healing may result from vascular complications that are common in diabetes

How does Type 2 diabetes affect bone health?
Patients with Type 2 diabetes usually have normal or even increased bone mass compared with nondiabetics. The higher body weight typical of individuals with Type 2 diabetes may account for the normal or increased bone mass. However, evidence suggests that despite normal bone mass, Type 2 diabetics have a two times higher risk for fracture than non-diabetics. Much of the increased risk for fracture is due to a higher risk for falls. To begin with, many women with Type 2 diabetes are overweight and inactive. These two factors tend to lessen coordination and balance making it more likely for a person to fall. People with Type 2 diabetes often have complications such as impaired vision, peripheral nerve damage, or foot problems, all of which can contribute to a fall. Finally, some people with Type 2 diabetes (especially if their blood glucose is poorly controlled) find that they frequently have to get out of bed during the night to use the bathroom. Walking around in the dark in a sleepy state, especially without proper lighting, can greatly increase the risk of falls.

How can people with Type 1 and Type 2 diabetes protect their bones?

There are many actions that individuals with diabetes can take to help protect their bones.

• It has been observed that bone loss is greater in patients with poorly controlled diabetes than in those whose diabetes is in tight control. Therefore, keeping blood glucose levels close to normal is the first line of defense against osteoporosis, falls, and fractures.
• It is important for all individuals with diabetes to achieve and maintain a stable, ideal body weight.
• Individuals with diabetes are advised to get adequate amounts of vitamin D  and calcium.
• Physical activity is another important defense. It reduces bone loss, improves muscle strength and balance, and helps prevent falls.
• Other important strategies for strong bones include avoidance of smoking and limited consumption of alcoholic beverages.
• All individuals with diabetes should have routine visual assessment.
• It is of utmost importance to implement strategies for fall prevention. For example, some well-placed nightlights can greatly help reduce the risk for falls during the night. If a patient is at increased risk for falling, it is important to speak to your healthcare provider about getting a referral to a physical therapist for a comprehensive falls evaluation and gait-training program.

When should individuals with diabetes speak to their doctor or healthcare provider about getting a bone mineral density test?

Postmenopausal patients and men with Type 1 diabetes should  get a bone mineral density (BMD). and should be alert for diabetes complications. Any individual with Type 2 diabetes who has had a fracture with minimal trauma should speak to his/her healthcare provider about getting a bone mineral density (BMD) test.

When should individuals with diabetes speak to their doctor or healthcare providerl about osteoporosis medications?

Individuals with a history of fracture, osteoporosis. or very low bone mass should speak with their doctor or healthcare provider about the FDA approved medications. for osteoporosis.

http://www.diabetes.org/
http://www.powerofprevention.net/pop.html

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EATING DISORDERS

What are eating disorders?
Eating Disorders are serious disturbances in eating behavior, such as extreme and unhealthy reduction of food intake or severe overeating, as well as feeling of distress or extreme concern about body shape or weight. Some examples of eating disorders include anorexia nervosa, bulimia, and binge eating disorder.

How do eating disorders affect bone health?
One type of eating disorder, anorexia nervosa, is clearly associated with an increased risk for osteoporosis for the following reasons:

• Low estrogen levels in women resulting in irregular or absent menstrual periods and low testosterone and estrogren levels in men
• Poor nutrition including low calcium and vitamin D intakes
• Excess production of cortisol, a powerful steroid hormone released by the body during stress that appears to accelerate bone loss

If anorexia nervosa occurs during youth and young adulthood, peak bone mass can be substantially lower than expected. Early diagnosis and treatment of eating disorders by a healthcare provider is urgent to help prevent osteoporosis and other complications of anorexia nervosa.

If an eating disorder is treated, can bone health improve?
The outcome of intervention is in part determined by age of the patient at the time of diagnosis and treatment. In youth and young adults who have not yet achieved peak bone mass (under age 25), there is usually some improvement in bone density that occurs when normal weight and normal menstrual functions in females are restored. In adult patients with a history of anorexia nervosa, deficits in bone density often remain following treatment.

National Association of Anorexia Nervosa
and Associated Disorders
P.O. Box 7
Highland Park, IL 60035
Phone: (847) 831-3438
Web site: http://www.anad.org

National Eating Disorders Association
603 Stewart Street, Suite 803
Seattle, WA 98101
Phone: (206) 382-3587
Web site: http://www.nationaleatingdisorders.org

National Institute of Mental Health (NIMH)
Office of Communications and Public Liaison
http://www.nimh.nih.gov/publicat/eatingdisorder.cfm

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HYPERPARATHYROIDISM

What are the parathyroid glands and what do they do?
The parathyroid glands are four small endocrine glands (the size of peas) that are located at the base of the neck next to the thyroid gland. Although they are neighbors and both part of the endocrine system, the thyroid and parathyroid glands are otherwise not related. The parathyroid glands produce parathyroid hormone that is largely responsible for maintaining normal levels of calcium in the blood.

What is primary hyperparathyroidism?
Hyperparathyroidism is overactivity of one or more of the parathyroid glands. In hyperparathyroidism, too much parathyroid hormone is produced. In primary hyperparathyroidism, excessive levels may be the result of a tumor (that is usually benign). A minor surgical procedure to remove the benign tumor is often required.

How does hyperparathyroidism affect bone health?
Hyperparathyroidism can result in the excessive loss of bone and elevated levels of calcium in the blood. The disease of primary hyperparathyroidism may lead to a lower bone mass at some skeletal sites while bone mass at other skeletal sites will be preserved. A recent study found that there was an increased risk for fractures at the spine, forearm and lower extremities in patients with primary hyperparathyroidism. The increased fracture risk is evident as long as 10 years before surgery to remove the parathyroid gland. Within one year after surgery, there is no excess fracture risk. This means that after removal of the parathyroid gland, fracture risk stabilizes and there is no additional fracture risk associated with the disease.

http://www.niddk.nih.gov/health/endo/pubs/hyper/hyper.htm

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HYPERPROLACTINEMIA

What is hyperprolactinemia?
Hyperprolactinemia is a condition characterized by an overproduction of prolactin, the hormone responsible for milk production in a woman's breasts. Often women with hyperprolactinemia experience a milky discharge from their breasts and amennorhea, the stopping of their menstrual periods.

How does hyperprolactinemia affect bone health?
Increased prolactin levels will lead to decreased bone density when compared with healthy individuals of the same age. The longer someone has hyperprolactinemia, the lower the bone mass will become. The more abnormal menstrual function is, the lower the bone density. It is important to consult a healthcare provider  to diagnose and treat hyperprolactinemia. Treatment with certain medications typically results in the return of normal ovarian function and lowers the risk for osteoporosis.

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KLINEFELTER SYNDROME

What is Klinefelter syndrome?
Kleinfelter syndrome is the most common sex chromosome variation in males. It is estimated to occur in 1 out of 500 men. The disease is caused by an extra X, or female, sex chromosome. The extra X chromosome interferes with the development of male characteristics. Men with Klinefelter syndrome often have low testosterone levels. Characteristics of Klinefelter syndrome vary from person to person but may include small testes, lack of sperm production, little or no body hair, enlarged breasts, infertility, and low bone mass or osteoporosis, among others.

How does Klinefelter syndrome increase the risk for osteoporosis?
The low testosterone levels associated with Klinefelter syndrome increase the risk for developing osteoporosis. The lower the testosterone level in these patients, the lower the bone density.

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THYROID DISEASE

What is thyroid hormone?
Thyroid hormone is a hormone secreted into the bloodstream by the thyroid gland located in the front of the neck. The purpose of thyroid hormone is to regulate the body's overall metabolism. It can affect heart rate, body weight, energy level, muscle strength, skin condition, mental state, intestinal function, menstrual regularity and bone health. If your thyroid gland is not working properly, neither will you.

How does thyroid disease affect bone health?
Too much thyroid hormone increases bone loss and increases the risk for osteoporosis. There are different conditions that result in excess thyroid hormone:

• Hyperthyroidism- Bone loss is seen in patients with a naturally occurring excess of thyroid hormone, a condition called overactive thyroid disease, hyperthyroidism or Graves disease.
• Hypothyroidism treated with excess thyroid medication- Hypothyroidism is a condition in which there is too little natural thyroid hormone. People with hypothyroidism commonly take thyroid medication to replace what their own glands are not making. Loss of bone occurs in patients with hypothyroidism who take more than the needed amount of thyroid replacement medication. In contrast, the correct amount of thyroid medication will not produce any adverse effects on bone.
• High doses of thyroid medication-. Some patients are treated with high doses of thyroid medication to stop the growth of small benign tumors called nodules. It is important to have nodules checked and the dose of medication reassessed by a doctor every six months. In rare cases of thyroid cancer, large doses of thyroid medication may also be necessary to prevent stimulation of the thyroid tissue. High doses of thyroid medication increase the risk for bone loss and osteoporosis.

How can people with thyroid disease protect their bones?

• Assess your risk for osteoporosis: The skeletal effects of thyroid disease vary based on gender, menopausal status and other risk factors for osteoporosis. By using the appropriate NYSOPEP risk assessment tool, you can find out more about your personal risk factors for osteoporosis.
• Get a BMD (bone mineral density) test when appropriate: Women who have conditions associated with excess thyroid hormone should get a bone density test as early as possible after menopause. It is important for men with thyroid disease to consult with their healthcare provider to find out the appropriate time for a BMD test.
• Ask your healthcare provider about a routine TSH blood test- Anyone on thyroid medication should be sure to see their healthcare provider regularly and get a blood test (called a TSH level) every 6 to 12 months, or as prescribed. This is necessary to make sure that the dose of thyroid medication is correct. It is important to take thyroid medication as instructed by your treating healthcare provider and not to stop taking it even if you feel better without talking to your healthcare provider first.
• Take action to modify the risks for osteoporosis- It is also important to speak to your healthcare provider about the effects of thyroid medication on bone and about the strategies to optimize bone health during treatment for thyroid disease.

American Association of Clinical Endocrinologists: http://www.aace.com
http://www.powerofprevention.com

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TURNER SYNDROME

What is Turner syndrome?
Turner syndrome is a chromosomal condition that only affects girls and women. It occurs when one of the two X chromosomes normally found in females is missing or incomplete. Almost all people with Turner syndrome have short stature and loss of ovarian function resulting in low estrogen levels. No real causes have been found for this condition. It appears to randomly occur and affects 1 out of 2500 females live births worldwide.

How does Turner syndrome affect bone health?
There is a high incidence of osteoporosis in women with Turner syndrome. The main cause of osteoporosis appears to be low levels of estrogen but there may also be defects in bone structure and strength. Children with Turner syndrome do not tend to have the increases in bone mass normally seen at puberty. Adults with Turner syndrome tend to have bone mass 19-27% less than people of the same age.

http://www.turner-syndrome-us.org/resource/faq.html
http://turners.nichd.nih.gov

Prevention of osteoporosis requires recognition of populations that are at risk plus screening programs targeting these populations. In all cases of osteoporosis resulting from a hormonal or endocrine disorder, it is essential that the medical condition be treated. In addition, use of the appropriate NYSOPEP risk assessment tool will help assess modifiable risk factors (that can be changed) to optimize healthy bones. All patients with low-trauma fractures should speak to their healthcare provider about getting a BMD test and about the FDA-approved medications for osteoporosis. Ideally, bone healthy behaviors should be started early in life while peak bone mass is still forming and continue throughout adulthood. However, it's never too late to start taking care of your bones.

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