National Institute of Arthritis and Musculoskeletal and Skin Diseases
What Research Is Being Done on Osteoarthritis? continued...
Research has shown that losing extra weight can help people who
already have osteoarthritis. Moreover, overweight or obese people who do not
have osteoarthritis may reduce their risk of developing the disease by losing
weight. A NIAMS-funded study is investigating the use of regular aerobic
exercise in people with osteoarthritis of the knee to determine if standard
guidelines for cardiovascular fitness may be useful for the treatment of early
osteoarthritis as well.
Researchers are studying the effectiveness of a variety of
different types of treatment. These include:
Drugs to prevent joint damage: No
treatment actually prevents osteoarthritis or reverses or blocks the disease
process once it begins. Present treatments just relieve the symptoms.
Researchers are looking for drugs that would prevent, slow
down, or reverse joint damage. Drugs under study include:
- doxycycline, an antibiotic drug that may stop certain enzymes known to
damage cartilage. A recent clinical trial found that doxycycline had a
modest effect on slowing the rate at which the joint space narrows in the knee.
The trial also found that people who were taking doxycycline experienced joint
pain less often than those who were not.
- the bisphosphonate drug risedronate: In a recent British study of
several hundred people with mildto-moderate osteoarthritis of the knee, those
treated with risedronate showed a clear trend toward reduced symptoms and
improved joint structure.
More studies are needed for both drugs.
Estrogen: In studies of older women,
scientists found a lower risk of osteoarthritis in those who had used oral
estrogens for hormone replacement therapy. The researchers suspect that having
low levels of estrogen could increase the risk of developing
However, the 15-year, NIH-funded Women’s Health Initiative
found that taking estrogen plus progestin increased the risk of heart attack,
stroke, blood clots, and breast cancer, while taking estrogen alone increased
the risk of stroke and blot clots. The Food and Drug Administration recommends
that hormone therapy be used at the lowest doses for the shortest duration
needed to achieve treatment goals. Hormone therapy should always be used under
a doctor’s care.
Several other research projects are underway. The goal of one
is to determine if estrogen protects cartilage. Other projects are examining
the effects on joint cartilage of a selective estrogen receptor molecule (SERM)
called raloxifene, which is often used in place of estrogen to treat and
Complementary and alternative
- acupuncture: One of the most popular alternative pain-relief
methods is acupuncture, an ancient Chinese practice in which fine needles are
inserted at specific points in the body. According to research funded by the
National Center for Complementary and Alternative Medicine, acupuncture may
help reduce pain and improve function for individuals with knee osteoarthritis
when used as an adjunct to medication.
One study underway compares the benefits of acupuncture with physical therapy
to the benefits of physical therapy alone. The hope is that acupuncture will
help relieve pain that makes exercise difficult and, therefore, will improve
the effectiveness of traditional exercise physical therapy.
- glucosamine and chondroitin sulfate: In recent years, the
nutritional supplement pair glucosamine and chondroitin has shown some
potential for reducing the pain of osteoarthritis, though no conclusive proof
has emerged to date. Both of these nutrients are found in small quantities in
food and are components of normal cartilage.
The recently concluded Glucosamine/Chondroitin Arthritis Intervention Trial
(GAIT), which was cosponsored by the National Center for Complementary and
Alternative Medicine and the National Institute of Arthritis and
Musculoskeletal and Skin Diseases, assessed the effectiveness and safety of
these supplements, when taken together or separately.
The trial found that the combination of glucosamine and chondroitin sulfate did
not provide significant relief from osteoarthritis pain among all participants.
However, a smaller subgroup of study participants with moderate-to-severe pain
showed significant relief with the combined supplements.
The 4-year trial was conducted at 16 sites across the United States. The
results were published in the Feb. 23, 2006 edition of the New England
Journal of Medicine.
- other complementary and alternative therapies: Other research
suggests that certain hyaluronic acid preparations; substances called
anthraquinones; gelatin-related substances; and electrical stimulation may have
a beneficial effect on cartilage growth and repair. Although these agents have
shown varying degrees of promise in basic and clinical studies, additional
trials are needed.
- vitamins D, C, E, and beta carotene: The progression of
osteoarthritis may be slower in people who take higher levels of vitamin D, C,
E, or beta carotene. NIAMS is sponsoring a clinical trial on use of Vitamin D
to treat osteoarthritis. More studies are needed to confirm these
- green tea: Many studies have shown that green tea possesses
anti-inflammatory properties. One recent study showed that mice predisposed to
a condition similar to human osteoarthritis had mild arthritis and little
evidence of cartilage damage and bone erosion when green tea polyphenols were
added to their drinking water. Another study showed that when added to human
cartilage cell cultures, the active ingredients in green tea inhibited
chemicals and enzymes that lead to cartilage damage and breakdown. Further
studies are looking at the effects of green tea compounds on human
- prolotherapy: This is a popular, growing, and unregulated therapy
for chronic musculoskeletal pain in which an irritant solution is injected into
painful ligaments and adjacent joint spaces. However, no rigorous,
scientifically valid clinical trials have proven the therapy’s action or
usefulness. A clinical trial sponsored by the National Center for Complementary
and Alternative Medicine is studying prolotherapy’s effectiveness for the pain
of knee osteoarthritis. It is also using animals to assess the healing response