Bone Mineral Density Loss in Postmenopausal Onset Rheumatoid Arthritis Is Not Greater Than Premenopausal Onset Disease

Background: postmenopausal onset rheumatoid arthritis (post-ra) is expected to have greater bone mineral density (bmd) loss than premenopauasal onset (pre-ra) due to estrogen deficiency and aging. this study aimed to compare the bmd status of the two ra groups with age-matched non-ra controls. methods: the patients with ra on follow-up examination were stratified according to age of onset. femoral neck and lumbar spine bmd (fn-bmd and ls-bmd) were assessed by dxa method. the patients of the two groups were compared with non-ra controls in regard to bmd gr/cm2 and the risk of osteoporosis (op). results: forty-eight post-ra and 94 pre-ra were compared with 31 and 57 age-matched controls. fn-bmd gr/cm2 and ls-bmd gr/cm2 in both groups of ra was significantly lower than the controls (p=0.001 for all). in post-ra, fn-bmdgr/cm2 was 16% lower than controls versus 21% in pre-ra, whereas, ls-bmd reductions were 5% and 12%, respectively (p=ns). fn-op was observed in 32(68%) and 9 (29%) post-ra and controls (p=0.001) versus 29 (30.8%) and 4 (7%) pre-ra and controls, respectively (p=0.001). corresponding percentages for ls-op in post-ra and controls were (37.5% vs 35.5%, p=0.52) and in pre-ra and controls were (21.3% vs 3.5%, p=0.002), respectively. risk of osteoporosis at either measurement sites of fn or ls in post-ra increased by the adjusted odds of 1.54(95% ci, 0.60-3.9, p=0.36) and in pre-ra by the adjusted odds of 5 (95% ci, 1.78-14.5, p=0.002), respectively. conclusion: these findings indicate that bmd loss in post-ra is not greater than pre-ra as expected. it is possible that estrogen deficiency by modulating immunologic reactions compensates the negative effects of estrogen deprivation on bone mass in post-ra patients.