Neuroendocrine Research Studies in Anorexia Nervosa

What People with Anorexia Nervosa Need
to Know about Osteoporosis
(Osteoporosis and Related Bone Diseases-National Resource Center)

What is Anorexia Nervosa?

Anorexia nervosa is an eating disorder characterized by an irrational fear of weight gain. People with anorexia nervosa believe that they are overweight even when they are extremely thin. According to the National Institute of Mental Health, an estimated 0.5 to 3.7 percent of females suffer from anorexia nervosa. While the majority of victims are female, the National Association of Anorexia Nervosa and Associated Disorders has noted that male cases are being reported with increasing frequency.

Individuals with anorexia become obsessed with food and severely restrict their dietary intake. The disease is associated with several health problems and, in rare cases, even death. The disorder usually begins around the time of puberty. Girls with anorexia typically experience a delayed onset of their first menstrual period, while periods in those who have already reached puberty are often infrequent or absent.

What is Osteoporosis?

Osteoporosis is a condition in which the bones become less dense and more likely to fracture. Fractures from osteoporosis can result in significant pain and disability. It is a major health threat for an estimated 44 million Americans, 68% of whom are women.

Risk factors for developing osteoporosis include: thinness or small frame; family history of the disease; being postmenopausal or having had early menopause; abnormal absence of menstrual periods; prolonged use of certain medications, such as glucocorticoids; low calcium intake; physical inactivity; smoking; and excessive alcohol intake.

Osteoporosis is a silent disease that can often be prevented. However, if undetected, it can progress for many years without symptoms until a fracture occurs. It has been called "a pediatric disease with geriatric consequences," because building healthy bones in one's youth is important to help prevent osteoporosis and fractures later in life.

The Anorexia Nervosa-Osteoporosis Link

Anorexia nervosa has significant physical consequences. Affected individuals can experience nutritional and hormonal problems that negatively impact bone density. Low body weight causes the body to stop producing estrogen, resulting in a condition known as amenorrhea, or absent menstrual periods. Low estrogen levels contribute to significant losses in bone density. Severe anorexia has resulted in osteoporosis in patients as early as their 20s.

In addition, glucocorticoid levels tend to be higher in anorexic individuals. Sufferers tend to produce excessive amounts of the adrenal hormone cortisol, which is known to trigger bone loss. Other factors such as a decrease in the production of growth hormone and other growth factors, low body weight (apart from estrogen loss), calcium deficiency and malnutrition contribute to bone loss in girls and women with the disorder. Weight loss, restricted dietary input and testosterone deficiency may be responsible for the low bone density found in males with the disorder.

Studies suggest that osteopenia (low bone mass) is common in anorexic individuals and that it occurs early in the course of the disease. Up to two-thirds of teens with the disorder have bone density values significantly below the norm. Anorexic girls are less likely to reach their peak bone density and, therefore, are at increased risk for osteoporosis and fracture throughout life.

Osteoporosis Management Strategies

Up to half of peak bone density is achieved in adolescence. Anorexia typically originates in mid to late adolescence, a critical period for bone development. The longer the duration of the disorder the greater the bone loss and the less likely it is that bone mineral density will ever return to normal.

The primary goal of medical therapy for anorexic individuals is weight gain and (in females) the return of normal menstrual periods. However, attention to other aspects of bone health is also important.

Nutrition and Exercise. A well-balanced diet rich in calcium and vitamin D is important for healthy bones. Good sources of calcium include low-fat dairy products, dark green, leafy vegetables, and calcium fortified foods and beverages. Also, supplements can help ensure that the calcium requirement is met each day.

Vitamin D plays an important role in calcium absorption and bone health. It is synthesized in the skin through exposure to sunlight. Individuals may require vitamin D supplements in order to ensure an adequate daily intake.

Like muscle, bone is living tissue that responds to exercise by becoming stronger. The best exercise for bones is weight-bearing exercise that forces you to work against gravity. Some examples include walking, stair-climbing and dancing.

Regular exercises such as walking can help prevent bone loss and provide many other health benefits. However, the potential benefits of exercise need to be weighed against the risk of fractures, delayed weight gain and exercise- induced amenorrhea in anorexics and those recovering from the disorder.

Healthy Lifestyle. Smoking is bad for bones, as well as the heart and lungs. In addition, smokers may absorb less calcium from their diets. Alcohol can also negatively affect bone health. Those who drink heavily are more prone to bone loss and fracture, both because of poor nutrition as well as increased risk of falling.

Bone Density Test. Specialized tests known as bone mineral density (BMD) tests measure bone density in various sites of the body. These tests can detect osteoporosis before a fracture occurs and predict one's chances of fracturing in the future.

Medication . There is no cure for osteoporosis. However, there are medications available for the prevention and treatment of the disease in postmenopausal women, men, and women and men taking glucocorticoid medication. Some studies suggest that there may be a role for estrogen preparations among girls and young women with anorexia. However, experts agree that estrogen should not be a substitute for nutritional support.

Revision Date: 10/2002