The Latest Research on two widespread age-related bone diseases -- osteoporosis and osteoarthritis -- focused on challenging established drug regimens, developing new drugs and confirming the importance of diet and exercise.

Osteoporosis: Last summer's dramatic halt, for safety reasons, of the Women's Health Initiative's study of hormone replacement therapy in post-menopausal women cast a pall on some of the more encouraging initial data: Taking estrogen and progestin was shown to reduce the rate of hip and spine fractures by one-third and of osteoporosis-related fractures at other sites by nearly one-fourth. Many experts concluded that for most women, such benefits were not worth the increased risk of breast cancer and heart disease tied to HRT, given safer alternatives. A study in the Archives of Internal Medicine found that bone loss resumes but does not accelerate after stopping HRT.

On the dietary front, a study in the Journal of Clinical Nutrition found that a protein-rich diet, when combined with adequate calcium and vitamin D, increased bone mass in men and women over 65. But a study in the Journal of the American Medical Association (JAMA) suggested a high intake of vitamin A may promote hip fractures in post-menopausal women.

Another JAMA study found walking reduced the risk of fractures in post-menopaual women. A study in the journal Bone found similar benefits from back-strengthening exercise.

The Food and Drug Administration approved the first drug that stimulates bone growth. Teriparatide, marketed by Eli Lilly under the brand name Forteo, contains human parathyroid hormone, the body's primary regulator of calcium and phosphate metabolism in bones. The injectable drug, recommended only for those at high risk for fracture, has been linked to an increased cancer risk in animal, but not human, studies.

Osteoarthritis: Treatment remained focused on pain relief. But the news here was disturbing. A study in the Archives of Internal Medicine found that women who regularly use over-the-counter pain relievers like acetaminophen (found in Tylenol) and nonsteroidal anti-inflammatory drugs such as ibuprofen (found in Advil and Motrin) increased their risk of developing high blood pressure. And a study in the New England Journal of Medicine found that Celebrex (along with Vioxx, a top-selling prescription painkiller) didn't protect the stomach from bleeding ulcers much better than OTC competitors.

A study in The New England Journal of Medicine found that arthroscopic knee surgery, a common procedure to clear out the debris and repair cartilage in the knee joint, did little to relieve osteoarthritis pain.

The National Institutes of Health launched a study to compare the effectiveness of the popular supplement pills containing glucosamine and chondroitin to that of Celebrex. A study in the Archives of Internal Medicine found that long-term glucosamine treatment may slow the progression of osteoarthritis of the knee.

Recommendations Bisphosponates such as Fosamax continue to be the drugs of choice to treat osteoporosis. The National Osteoporosis Foundation (NOF) advises all Americans to get 1,000 to 1,200 milligrams per day of calcium and 400 to 800 IUs per day of vitamin D. It also recommends weight-bearing exercise such as walking or strength training and a bone mineral density test for all women 65 or older and for post-menopausal women under 65 who have other risk factors. The DXA, an X-ray that measures density of the spine, hip or entire body, is the best measure.

The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) recommends that people with osteoarthritis maintain a healthy body weight, do muscle strengthening and weight resistance exercise and control pain as needed with medication.

The Next Thing The search is on for an easier-to-use delivery method -- such as inhalers, patches or pills -- for bone-builder Forteo. Felicia Cosman, clinical director for NOF, says researchers also hope to develop more precise measures of bone quality to identify people at high risk of fracture. Research continues on the effects of estrogen-only therapy on bone density.

In the field of osteoarthritis, researchers remain hopeful about stem cell transplantation and tissue engineering, where cartilage is removed from the body, new cells are cloned or grown and then injected into the patient's joints to replace lost cartilage. Research is also underway to identify biomarkers for the disease.

Worry Index According to NIAMS and NOF, 10 million Americans have osteoporosis and another 18 million to 34 million have low bone mass that leaves them at risk for the disease. Americans spend $14 billion annually for direct medical costs for osteoporosis and $1.5 million for associated fractures, according to the NOF.

According to NIAMS, at least 20 million Americans have osteoarthritis. The disease mostly affects people who are over 65, overweight or obese and inactive. Women with the disease outnumber men.

Hype-O-Scope Despite a lack of credible evidence showing their effectiveness, creams and rubs containing glucosamine and chondroitin continue to be promoted heavily for relief of arthritis pain.

For More Information Arthritis Foundation: www.arthritis.org

National Institute of Arthritis and Musculoskeletal and Skin Diseases: www.niams.nih.gov

National Osteoporosis Foundation: www.nof.org

Women's Health Initiative: www.nhlbi.nih.gov/whi

-- Diane Knich

Osteoarthritis sufferers seek pain relief free of side effects.