Generalized Osteoporosis in Korean Rheumatoid Arthritis Patients

Joo, Yeong Shil; Lee, Shin Seok; Kim, Wan Uk; Min, Jun Ki; Park, Sung Hwan; Hong, Yeon Sik; Lee, Sang Heon; Cho, Chul Soo; Kim, Ho Youn

Abstract

OBJECTIVES
To assess the extent of generalized osteoporosis in Korean rheumatoid arthritis patients and evaluate the importance of disease activity, duration of disease, menopausal status, corticosteroid use and markers of bone metabolism.
METHODS
Bone mineral density was measured by dual energy x-ray absorptiometry (DEXA) at 3 locations in 134 rheumatoid arthritis patients, aged 21~80 (57 premenopausal and 66 postmenopausal patients). Markers of bone metabolism were measured and assessed in relation to the disease activity and corticosteroid use.
RESULTS
The mean age of the study population was 49 years and mean age of the menopause was 48.1+/-3.6 years. Decreased bone mineral density was observed at all 3 locations measured in the study population (Z-score -0.36, -0.14 and -0.66 for BMD of L-spine, femoral neck and femur Ward? triangle respectively). Fifty nine percent of the patients showed osteopenia (T-score <-1) and 13.4% showed T-score lower than -2.5. The best independent predictors of bone mass (stepweise multiple regression analysis) was body mass index, cortocosteroid use, and CRP in premenopausal patients and years post menopause, age, alkaline phosphatase and rheumatoid factor in postmenopausal patients. Urinary excretion of deoxypyridinoline was increased in both pre- and postmonopausal RA patients while serum osteocalcin level was normal in both groups. Deoxypyridinoline level was significantly correlated with CRP in premenopausal RA patients.
CONCLUSION
Generalized osteoporosis is also prevalent in Korean rheumatoid arthritis patients. Bone metabolism appears to be uncoupled. Deoxypyridinoline correlated best with CRP and thus can provide a rational approach for selecting and treating patients with RA to reduce the risk of osteoporotic fracture.