FRIDAY, Oct. 21 (HealthDay News) -- Blacks have a higher rate of multiple, large-joint osteoarthritis and knee osteoarthritis than whites do, a new study finds.

Osteoarthritis is a painful chronic disease caused by a loss of cartilage in the joints.

Researchers assessed white and black men and women aged 45 and older who were participants in the Johnston County Osteoarthritis Project, and found that osteoarthritis affected 62 percent in the spine, 42 percent in the knee, 36 percent in the hip and 32 percent in the hands.

After adjusting for age, gender and body-mass index, the investigators noted that blacks were twice as likely as whites to have knee osteoarthritis and 77 percent more likely to have knee and spine osteoarthritis together, but were much less likely to have osteoarthritis in fingertip joints alone or with other hand joints.

Other than fingertip joints, rates of osteoarthritis in hand joints were similar for both blacks and whites, according to the report published online Oct. 20 in the journal Arthritis & Rheumatism.

"Racial differences in osteoarthritis phenotypes were more significant than gender disparity," Dr. Amanda Nelson, of the University of North Carolina at Chapel Hill Rheumatology/Thurston Arthritis Research Center, explained in a journal news release. "Our findings suggest a substantial health burden of large-joint osteoarthritis, particularly hip and spine, among African-Americans and further studies that address this concern are warranted."

Osteoarthritis typically affects multiple joints and is the most common type of arthritis. More than 27 million U.S. adults aged 25 and older have osteoarthritis, according to the U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases.

More information

The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases has more about osteoarthritis.