AbstractsWomens Studies

Changes in bone mineral content in the lumbar spine and femoral neck in rheumatoid arthritis and juvenile idiopathic arthritis : -focusing on long-term disease duration, premenopausal women, young adults, disease activity, and use of osteoporosis drugs

by Harri Hämäläinen

Institution: University of Helsinki
Department: Institute of Clinical Medicine, rheumatology; The Rheumatism Foundation Hospital, Heinola, Finland; Social Insurance Institution Research Department, Turku, Finland; ORTON Orthopeadic Hospital and ORTON Foundation, Helsinki, Finland
Year: 2015
Keywords: lääketiede
Record ID: 1142215
Full text PDF: http://hdl.handle.net/10138/152760


ABSTRACT The purpose of this study was to explore bone mineral content (BMC) and bone mineral density (BMD) development and related factors in patients with rheumatoid arthritis (RA) between 15 and 20 years from disease onset (I), in premenopausal women with RA (II), and in young adults with juvenile idiopathic arthritis (JIA) (III), and to ascertain osteoporosis (OP) drug use in patients with early RA (IV). BMD of the lumbar spine and the femoral neck were measured by dual-energy X-ray absorptiometry in patients with RA in two longitudinal studies and in young adults with JIA in a cross-sectional study. In assessing BMD at 15 years from disease onset in an inception cohort of RF-positive RA patients, it was found that eighteen out of 59 (31%) patients had OP. However, the decreases in central bone mineral in this patient group were of low degree and after the subsequent five years no essential change in central BMD was found. None of the explanatory variables: sex, age, ESR, HAQ, Larsen score, and cumulative prednisolone dose between 15-20 years from disease onset, proved to be a significant predictor of BMD change at the lumbar spine and femoral neck from 15- to 20-year check-ups (I). In assessment of BMC and BMD development in premenopausal, regularly cycling RA patients with and without GCs and in controls, it was found that RA patients with GCs had lower BMD values than those without GCs at commencement of follow-up. Furthermore, the mean BMD decreased significantly in both lumbar spine (P 0.002) and femoral neck (P smaller than 0.001) only in the RA patients with GCs during the 2-year follow-up. However, there was no statistically significant difference between the three groups in change in BMC or projectional area in the lumbar spine or femoral neck. Comparing results on bone mineral density change between the three groups it is relevant to report changes both in bone mineral content and in projectional area to clarify the basics of the bone mineral density change. BMD is expressed as BMC per projectional area. Only weight was found to be a significant predictor of BMD change (II). Assessment of BMC and BMD development in young adults with JIA and controls assumed to have reached their peak bone mass, showed that three (2.6%) out of 116 patients with JIA had OP. The male and female JIA patients had lower weight- and height-adjusted BMD values in the femoral neck than the controls. Dividing the patients into two groups, those with active and those with inactive JIA, both groups had lower BMC values in the femoral neck than the controls (P smaller than 0.001). Comparing BMC values in the femoral neck in both men and women with JIA a difference was found only among men (P 0.006). Among men, use of GCs and weight were significantly associated with BMC in the femoral neck. Among women, use of GCs, weight and also height were associated statistically significantly with BMC in the femoral neck, and among women GC use and height were also associated with BMC in the lumbar spine (III). A total of 14 878…