OSTEOPOROSIS

What Is Osteoporosis? The word osteoporosis means "porous bone." In this disease, bones gradually lose calcium and phosphorus, leaving them weak and vulnerable to fracture under minimal strain. Bone is a dynamic, living tissue; old bone is constantly being reabsorbed and replaced with new bone in a process called bone turnover or remodeling. Osteoporosis results from an imbalance in bone removal and replacement; many factors contribute to this disparity. Up to 50% of Caucasian women aged 50 or older will have an osteoporosis-related bone fracture. However, osteoporosis is not a disease of women alone; as many as one-third of men aged 75 or older are also afflicted.

What Causes Osteoporosis? Bone density is maintained under the influence of the body's internal environment as well as external factors. Dietary calcium intake must be sufficient, as must its absorption by the gastrointestinal tract. Vitamin D is required for the body's utilization of calcium; this vitamin can be obtained in the diet and is also produced by skin exposed to sunlight. Healthy kidneys and liver are required for normal vitamin D metabolism. Mineral deposition in bone is stimulated by the sex hormones estrogen and testosterone, calcitonin (a hormone produced by the thyroid gland), and weight-bearing exercises such as jogging, walking, and weight training. Osteoporosis, therefore, is caused by deficiencies of calcium or vitamin D, by malabsorption, by hormonal changes and by lack of physical activity. Deficiency of calcium is common among people with eating disorders (anorexia), lactose intolerance, and those who simply do not consume adequate dairy products or other calcium-rich foods. Absorption of calcium is compromised in people with gastrointestinal diseases like inflammatory bowel disease, in those who are deficient in vitamin D due to malnutrition or lack of sunlight, and in patients with kidney or liver disease. Hormonal changes are perhaps the most important regulator of bone strength; under the influence of estrogen and testosterone, healthy bone reaches a peak density between the ages of 20 and 30, after which a gradual decline begins. The risk of developing osteoporosis is related to the peak bone mineral density reached during young adulthood, and its subsequent rate of decline. In women, this rate of decline increases sharply after menopause when production of estrogen drops.

Am I At Risk? Individuals most likely to develop osteoporosis are post-menopausal, Caucasian women of slight build. Among ethnic groups, blacks are least likely to be afflicted, and Asians and Hispanics are at intermediate risk. The incidence of osteoporosis increases with age; it is rare in healthy pre-menopausal women, but is common in post-menopausal women and in men aged 75 or older. Cigarette smoking, excessive alcohol and caffeine ingestion, and sedentary lifestyle can all contribute to bone loss. Family history of osteoporosis is also a risk factor. Certain medications, including corticosteroids (prescribed most commonly for asthma, rheumatoid arthritis, and psoriasis), diuretics (usually to lower blood pressure), heparin (a blood thinner), and anti-seizure drugs have been linked to bone mineral loss.

What Are The Signs And Symptoms Of Osteoporosis? Osteoporosis is a silent disease; there are no symptoms of gradual bone mineral loss, which is a completely painless process. Therefore, the first sign of osteoporosis is often a fracture. Osteoporosis can render bones so weak that even minimal strain such as reaching for a high shelf or stooping to pick something up can cause a fracture. The areas of the skeleton most likely to be affected are the upper spine, the hips, and the wrists. After fractures have occurred, patients may notice a curvature or hump developing in the spine, and may find hemlines suddenly too long as numerous small fractures can lead to decreased height. Fractures occurring with only minor trauma may or may not be painful; the patient may be completely unaware of their incidence. The gold standard for diagnosis of osteoporosis is a bone density scan which allows direct measurement of the mineral content of the skeleton in the areas most likely to fracture. If you have had a fracture (e.g. of the wrist) and believe that you may have osteoporosis, talk to your physician about getting a bone density scan done.

What Is The Treatment Of Osteoporosis? Perhaps even more true in osteoporosis than in other diseases, the best treatment is prevention. Although some risk factors are not changeable, obtaining adequate calcium and vitamin D, participating in weight-bearing exercise regularly, not smoking, and consuming alcohol and caffeine only in moderation all help to preserve healthy bones. Maintaining good posture and avoiding falls are important in avoiding excess strain on the skeleton. In post-menopausal women, hormone replacement therapy or estrogen replacement therapy (HRT or ERT) is the most effective preventive measure and treatment for osteoporosis; it reduces the risk of osteoporosis-related fracture by as much as 50%. HRT is protective against unpleasant menopausal symptoms such as mood swings and hot flashes; however, not all women should take HRT, as some are at increased risk of endometrial (uterine) cancer, and its link to breast cancer is still in debate. A recent extensive analysis suggests that it may not protect against heart disease as previously believed. HRT should be carefully discussed with your family doctor before a decision is made to start it. An alternative to HRT is a class of drugs called bisphosphonates, including Fosamax (alendronate). Bisphosphonates act to maintain bone density by inhibiting breakdown of bone. They are not hormones, and have no effect on the cardiovascular or reproductive systems; they have proven to be both highly effective and well-tolerated, with few side effects (nausea being the most common). Men with osteoporosis can also benefit from taking them.

Should I Take Calcium Or Vitamin D Supplements? The recommended daily calcium intake for pre-menopausal women, post-menopausal women taking HRT, and men under 65 is 1000 milligrams (mg). This can be obtained in the diet by consuming approximately 3 servings of dairy products daily. For adolescents, post-menopausal women, and men over 65, the recommended daily intake is 1500 mg. If calcium is obtained through dairy foods, then vitamin D consumption will also be adequate; 400 I.U. (international units) are suggested daily. People who do not consume milk products and rarely go outdoors may require vitamin D supplementation. If you are unsure about your calcium and vitamin D consumption, consult your family doctor or a dietitian. Calcium supplements are available in several forms. Calcium citrate is more easily absorbed than calcium carbonate, but often contains less elemental calcium measure for measure; be sure to read labels carefully to monitor how much calcium is in each dose. Calcium-containing antacids are a good alternative. Whatever form of supplement you choose, each dose should be a maximum of 500 mg of elemental calcium, and is best taken at mealtime. Possible side effects include constipation and gas, which are minimized by drinking lots of water. Excess of calcium can lead to painful kidney stones, so do not exceed the daily recommended dose.