The relationship between focal erosions and generalized osteoporosis in postmenopausal women with rheumatoid arthritis.
OBJECTIVE
Among rheumatoid arthritis (RA) patients who have had the disease for 10 years, more than half have focal erosions, and the risk of fracture is doubled. However, there is little information about the potential relationship between focal erosions and bone mineral density (BMD). The aim of this study was to determine whether lower BMD is associated with higher erosion scores among patients with RA.


METHODS
We enrolled 163 postmenopausal women with RA, none of whom were taking osteoporosis medications. Patients underwent dual x-ray absorptiometry at the hip and spine and hand radiography, and completed a questionnaire. The hand radiographs were scored using the Sharp method, and the relationship between BMD and erosions was measured using Spearman's correlation coefficients and adjusted linear regression models.


RESULTS
Patients had an average disease duration of 13.7 years, and almost all were taking a disease-modifying antirheumatic drug. Sixty-three percent were rheumatoid factor (RF) positive. The median modified Health Assessment Questionnaire score was 0.7, and the average Disease Activity Score in 28 joints was 3.8. The erosion score was significantly correlated with total hip BMD (r=-0.33, P<0.0001), but not with lumbar spine BMD (r=-0.09, P=0.27). Hip BMD was significantly lower in RF-positive patients versus RF-negative patients (P=0.02). In multivariable models that included age, body mass index, and cumulative oral glucocorticoid dose, neither total hip BMD nor lumbar spine BMD was significantly associated with focal erosions.


CONCLUSIONS
Our results suggest that hip BMD is associated with focal erosions among postmenopausal women with RA, but that this association disappears after multivariable adjustment. While BMD and erosions may be correlated with bone manifestations of RA, their relationship is complex and influenced by other disease-related factors.
Solomon
Daniel H
DH
Brigham and Women's Hospital, Division of Rheumatology, Boston, Massachusetts 02115, USA. dsolomon@partners.org
Finkelstein
Joel S
JS
Shadick
Nancy
N
LeBoff
Meryl S
MS
Winalski
Carl S
CS
Stedman
Margaret
M
Glass
Roberta
R
Brookhart
M Alan
MA
Weinblatt
Michael E
ME
Gravallese
Ellen M
EM
D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000188:drug therapy / Q000503:physiopathology*; D015519:Bone Density / Q000502:physiology; D001847:Bone Diseases / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology; D006225:Hand / Q000000981:diagnostic imaging; D006306:Health Surveys; D006621:Hip Joint / Q000000981:diagnostic imaging; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008875:Middle Aged; D015999:Multivariate Analysis; D015663:Osteoporosis, Postmenopausal / Q000150:complications* / Q000503:physiopathology*; D011859:Radiography; D012307:Risk Factors; D012720:Severity of Illness Index; D013131:Spine / Q000000981:diagnostic imaging; D016896:Treatment Outcome
D018501:Antirheumatic Agents