Osteporosis: What is it and why is it important to me?
By Alan Morgan
Osteoporosis is a disease of the bone that is characterized by progressive loss in bone density and change in microarchitecture causing bones to become brittle and weakened, susceptible to fracture. Our bone mass typically peaks at around age 35 and then slowly begins to decline over time. An estimated 10 million Americans have osteoporosis and another 34 million have low bone density (osteopenia), placing them at risk for developing the disease. More than 1.3 million fractures related to osteoporosis occur in the US annually, with 50% of these being fractures of the vertebrae, 25% hip fractures, and 25% distal radius (Colles’) fractures. Women are at risk for osteoporotic fractures when their bone mineral density starts to decline after menopause due to decreasing estrogen levels. Osteoporosis can develop in men as well, especially in men who have hypogonadism, a low testosterone level. Other risk factors include low calcium intake, low body weight, cigarette smoking, hyperparathyroidism, and physical inactivity. Current or prior use of certain medications can also increase your risk for osteoporosis including corticosteroids, chemotherapy, anticonvulsants, and others.
Screening – Who should be tested?
Current guidelines recommend routine screening of all women over age 65. Screening of men and women should begin at an earlier age if there are other risk factors for osteoporosis as listed above. Prior fractures or diminished bone density on previous x-rays should prompt a workup for osteoporosis. We screen for osteoporosis by measuring the bone mineral density, most commonly with a dual-energy x-ray absorptiometry (DEXA) scan. This measures how much bone mass is present and the value is compared against average peak density of a 35 year old of your race and sex. Osteopenia is defined as bone mineral density that is 1 to 2.5 standard deviations below the mean, and osteoporosis is greater than 2.5 standard deviations below the mean peak bone density. The risk for fracture increases as the density (and degree of osteoporosis) worsens.
Treatment – What are the options?
Adequate calcium intake is the first step in treatment, with a dosage of 1200 mg for premenopausal women and men, and 1500 mg in postmenopausal women. Vitamin D supplements are also important, at a dose of 800 IU per day. These can be with the calcium or separately. Weight bearing exercises, at least 30 minutes three times a week or more will also slow the loss of bone density. The first line of drug treatment options typically are the bisphosphonate class of drugs. These drugs include risedronate, alendronate, and ibandronate (Actonel, Fosamax, and Boniva). They work on the osteoclast cells in bone and inhibit bone resorption. Other drugs include SERMs (Selective Estrogen Receptor Modulators) including raloxifene (Evista) and calcitonin - primarily given as a nasal spray (Miacalcin). These also work by inhibiting osteoclast activity and reducing bone turnover, but perhaps not quite as effectively as the bisphosphonate class of drugs.
Complications – what are the side effects of the medications?
The bisphosphonates like any other medications can have side effects that you should be aware of and look for while you are taking the medication. The medication must be taken first thing in the morning on an empty stomach with a full 8 oz glass of water and you must avoid lying down or taking other medication for 30 minutes afterwards. One of the more common side effects that we watch out for is stomach and esophagus irritation. Bone, joint, and muscle pains can occur as well as a more serious complication known as osteonecrosis of the jaw (death of the bone in the jaw), but this is an extremely rare complication. This primarily occurs in cancer patients who receive intravenous forms of the medications. Please contact your doctor if you have any bone pain or stomach irritation while taking these medications.
Where can I go for more information?
Please visit the National Osteoporosis Foundation online at www.nof.org or the National Library of Medicine at www.nlm.nih.gov/medlineplus/osteoporosis.html for more information.
Opinions in the magazine are those of the authors and do not necessarily represent management views.