Francis A. Greenspan, MD
Chief, Thyroid Clinic, Member Division of Endocrinology and the Department of Endocrinology
University of California, San Francisco
Osteoporosis is a disease characterized by a reduction in the amount of bone in your skeleton as well as deterioration of bone structure. The result is an increase in your risk for fractures.
Osteoporosis affects 4 to 6 million post menopausal Caucasian women. Approximately half of all Caucasian women will experience an osteoporotic fracture during their lifetime. In the United States there are approximately 1.5 million osteoporotic fractures every year. Women tend to develop osteoporosis at a rate higher than men primarily because of accelerated bone loss that occurs after menopause. Men have a lower risk, but their lifetime risk for osteoporosis is still 25% for a 60 year old man.
Patients who have had either hyperthyroidism or thyroid cancer are at increased risk for osteoporosis. Those with a history of hyperthyroidism may have lost bone during their period of increased thyroid activity. Most patients with thyroid cancer are maintained in a mildly hyperthyroid state to try to decrease the likelihood of cancer recurrence by suppressing thyroid stimulating hormone (TSH) from your pituitary gland. This increases the risk of osteoporosis.
The diagnosis of osteoporosis is made by a bone density test, commonly measuring the bone density of your spine and or hip.
The first approach to treating osteoporosis is the reduction of factors that may increase your risk for the problem. This may include eliminating smoking and alcohol abuse, as well as, adding physical conditioning to reduce your risk of falling. Total calcium intake from diet and supplements should be 1200 to 1500 milligrams per day. A daily intake of 400 IU of vitamin D or up to 800 IUs in those over 65 will help maintain healthy bones.
Estrogen used to be given to women after menopause. Although this reduced of osteoporosis developing, it had the unfortunate side effect of increasing the risk for heart disease and breast cancer. Although very effective for short-term use, these medications are no longer recommended for long term treatment.
Calcitonin was one of the first medications shown to be a potent inhibitor of bone breakdown. It is given in a nasal spray and has few side effects. Unfortunately, careful studies have not shown significant in vertebral fractures in individuals taking Calcitonin compared to those who don’t.
Bi-phosphonates are a class compounds developed for industrial use to inhibit the growth of crystals. They were soon discovered to have a number of biological effects, including the ability to inhibit bone breakdown. Aledronate (Fosamax) was the first of this class of drugs available for the treatment of osteoporosis. Those who have been able to take aledronate have achieved significant increase in bone density (mean 7%-9% at the spine and 5%-8% at the hip) compared to placebo.
The bi-phosphonates must be taken on an empty stomach first thing in the morning with water only and cannot be followed by any food nor drink for at least 30 minutes. Unfortunately they may cause inflammation of the stomach (gastritis) and esophagus (esophagitis) in some patients. Medications to reduce these intestinal effects and control stomach acid will help. These drugs include Ranitidene, Pepcid, Protonics, Prilosec, and Nexium. It’s also possible to take the medicine only once a week, which appears to reduce the frequency and severity of intestinal problems.
Actonel is another bi-phosphonate that works in the same manner as aledronate, reducing the risk of fracture by increasing bone density. In one study Actonel reduced the risk of spine fractures by approximately 40% at 3 years. In another study there was a reduction in the incidence of hip fracture of approximately 40% by the third year of treatment.
Parathyroid hormone regulates calcium balance through a mechanism completely different from that of estrogen, Calcitonin, or bi-phosphonates. It not only increases bone mass but also seems to restore bone architecture. Unfortunately it has to be given by injection daily. It seems to be better than all other approaches to increasing bone density and reducing fracture risk. Studies in progress may show it to be a valuable addition to the treatment of osteoporosis either alone or in combination with drugs that prevent bone resorption, but long term data, including toxcity and not yet available.
In summary, your doctor has a variety of treatments available for osteoporosis. If that is your problem, you can expect your physician to either discuss these alternatives at the time your treatment is planned or to refer you to an endocrinologist who specializes in bone disease to guide you to the medication that is best for you.
Goiter refers to enlargement of your thyroid gland.