Research Activities, August 2013
Serum and urine biomarkers point to possible gender, racial differences in mechanism of lumbar spine osteoarthritis
Joint metabolism biomarkers found in serum and urine suggest possible gender and racial differences in the mechanisms underlying lumbar spine osteoarthritis, suggests a new study. Community-based studies of intervertebral disk degeneration, a key sign of spinal osteoarthritis, occurs in 50–64 percent of individuals 65 years and older.
So far, there is no evidence leading to a predictive test. But there are associations between important biomarkers of bone degeneration and two radiographic indications of osteoarthritis of the lumbar spine, disc space narrowing (DSN) and osteophytes (OST)—also called bone spurs, according to the study.
The researchers examined 547 persons enrolled in the Johnston County Osteoarthritis Project. Measuring biomarkers related to the collagen proteins that act as reinforcing rods in bone (NTX-1, CTX-II, C2C, CP-II), the bone matrix that cements them together (cartilage oligomeric matrix protein, or COMP), and osteoarthritis-related inflammation (hyaluronic acid, or HA), the researchers found significant differences in mean biomarker levels for HA and C2C across the severity of DSN, and of CTX-II across the severity of both DSN and OST.
An association between HA and DSN occurs in women, but not in men. In whites, there was a modest 10 percent reduction in the association between NXT-I and OST, and no association in blacks. Persons with low back pain symptoms were almost twice as likely to have DSN, but no association was seen for persons without lower back symptoms.
Some of these associations suggest to the researchers that biological differences in the pathologic processes leading to DSN and OST may be gender- and race-specific. The study was funded in part by AHRQ (HS19479, Contract No. 290-10-00014).
More details are in "Association between serum and urine biomarkers and lumbar spine individual radiographic features: the Johnston County Osteoarthritis Project," by Adam P. Goode, P.T., D.P.T., Ph.D., Steve W. Marshall, Ph.D., Virginia Byers Kraus, M.D., Ph.D., and others in the November 2012 Osteoarthritis and Cartilage 20(11), pp. 1286-1293.