Testing For Joint Substance In Blood Might Improve Diagnosis Of Osteoarthritis

[Guest guest]

Testing For Joint Substance In Blood Might Improve Diagnosis Of

Osteoarthritis

CHAPEL HILL — Measuring a biological chemical called hyaluronan found

naturally in joints and the fluid that lubricates cartilage might

enable doctors to diagnose osteoarthritis of the knee and hip earlier

or more accurately, a new study concludes. Improving diagnosis of the

painful inflammatory disorder should become increasingly important as

baby boomer age, doctors say.

The research, conducted at the University of North Carolina at Chapel

Hill and in ston County, N.C., revealed that levels of the

chemical, also known as HA, in blood samples corresponded with how

advanced osteoarthritis was in a group of rural patients, both blacks

and whites.

" Our study shows statistically significant differences in average

levels of serum hyaluronan (HA) between individuals with osteoarthritis

of the knee as shown on X rays and those without knee or hip

osteoarthritis, " said study director Dr. Joanne M. Jordan. " Serum HA

levels not only were associated with the presence of osteoarthritis but

also showed a trend of increasing values as severity of the disease

increased. "

Jordan is associate professor of medicine and orthopaedics at the UNC

School of Medicine. Also associate director of the Thurston Arthritis

Research Center, she is principal investigator for the long-term

ston County Osteoarthritis Project. That investigation is the

largest of its kind ever done and involves more than 3,000 volunteers

whose health and experiences with arthritis doctors follow and analyze.

A report on the findings appears in the January issue of Arthritis &

Rheumatism, a journal published by the American College of

Rheumatology.

Besides Jordan, UNC schools of medicine and public health authors are

Dr. Alan L. Elliott, a rheumatology fellow; Dr. Jordan Renner,

professor of radiology and allied health sciences; and Anca D. Dragomir

and Gheorghe Luta, doctoral students in epidemiology and biostatistics,

respectively.

Dr. Virginia B. Kraus, associate professor of medicine, and

Stabler, both at Duke University, Dr. D. Helmick of the Centers

for Disease Control and Prevention and Dr. Marc C. Hochberg of the

University of land also participated in the study.

Hyaluronan is produced by cells of what is called the extracellular

matrix, Jordan said. It is thought to contribute to lubricating joints,

a process without which walking and running would be unbearably

painful. Earlier work suggested HA might serve as a sign, or biomarker,

of osteoarthritis.

" Our study is unique in that it consisted of a large, ethically

diverse, population-based sample of African Americans and Caucasians

and incorporates five definitions of osteoarthritis as shown on X

rays, " she said. " This was the first study of hyaluronan and

osteoarthritis to include African Americans and to consider how other

health problems commonly occurring with osteoarthritis might confound

the relationship between serum HA and osteoarthritis. "

The researchers studied 753 subjects, including 455 with osteoarthritis

in their knees. Volunteers ranged in age from about 51 to 72 and

averaged almost 62. About 39 percent suffered from high blood pressure,

the most common other illness. The least common was cancer.

Average serum HA levels correlated with age, Jordan said. Whites and

men showed higher levels than blacks and women, which could reflect

genetic or physiologic factors. Such sex and racial differences would

need to be taken into account when determining the usefulness of HA and

other potential biomarker testing.

Medical scientists have known for the past decade that levels of an

important protein known as COMP were higher in cartilage, ligaments,

tendons and joint lubricating fluid of whites with osteoarthritis than

in whites without the painful, degenerative illness, Jordan said.

In 2003, she and her UNC colleagues showed for the first time that the

same thing is true in blacks. They also found average levels of the

protein to be higher in blacks -- both patients and others -- than in

whites and higher among white men than among white women.

" These discoveries are likely to be important in the search for better

ways to predict who is at strong risk of developing osteoarthritis, who

has it already and whose illness is most likely to progress, " Jordan

said.

Osteoarthritis, the most common form of arthritis, afflicts almost a

million North Carolinians and more than 21 million people nationally,

including many adults over age 65, the physician said. Some estimates

suggest that as many as 70 million Americans will suffer from some form

of arthritis within the next 20 years as baby boomers age.

Support for the research came from the CDC, the National Institute of

Arthritis and Musculoskeletal and Skin Diseases and the Arthritis

Foundation.

http://www.sciencedaily.com/print.php?url=/releases/2005/02/

050225104213.htm

a

[Guest guest]

ston County, NC, is my home county. And yes, it is a rural area.

Sue

On Friday, March 4, 2005, at 10:34 PM, a wrote:

>

> The research, conducted at the University of North Carolina at Chapel

> Hill and in ston County, N.C., revealed that levels of the

> chemical, also known as HA, in blood samples corresponded with how

> advanced osteoarthritis was in a group of rural patients, both blacks

> and whites.

[Guest guest]

ston County, NC, is my home county. And yes, it is a rural area.

Sue

On Friday, March 4, 2005, at 10:34 PM, a wrote:

>

> The research, conducted at the University of North Carolina at Chapel

> Hill and in ston County, N.C., revealed that levels of the

> chemical, also known as HA, in blood samples corresponded with how

> advanced osteoarthritis was in a group of rural patients, both blacks

> and whites.