The development of bone mineral density and the occurrence of osteoporosis from 15 to 20 years of disease onset in patients with rheumatoid arthritis.

OBJECTIVE: To ascertain the occurrence of osteoporosis and the development of central bone mineral density (BMD) in long-term rheumatoid arthritis (RA) METHODS: BMD of the lumbar spine (L2-L4) and the femoral neck were measured by dual-energy X-ray absorptiometry in a cohort of 59 patients (49 women and 10 men) with rheumatoid factor-positive RA followed up for 20 years. BMD measurements were obtained at the 15- and 20-year follow-up visits. RESULTS: At the 15-year check-up the mean age was 61 (SD 13)for men and 54 (SD 11) years for women. Bone densitometry of these patients revealed decreased BMD at both lumbar spine and femoral neck, the mean T-scores being -1.1 [95%CI: -1.6 to -0.6] and -1.3 [95%CI: -1.6 to -1], respectively). Eighteen (31 %) patients thus had osteoporosis (BMD T -score < or = -2.5) and 32 (54%) patients were osteopenic (BMD T-score -1.0 to -2.5). However, when compared with reference values, the decreases in central bone mineral in this patient group were of low degree; the mean Z-score -0.2 [95%CI: -0.7 to 0.2] at the lumbar spine and -0.5 [95%CI: -0.8 to -0.3] at the femoral neck, respectively. After the subsequent five years the mean Z-score increased 0.45 [95%CI: 0.32 to 0.58] at the lumbar spine and the mean T-score decreased -0.20 [95%CI: -0.32 to -0.08] at the femoral neck. ESR, Larsen score, gender and cumulative dose of prednisolone during the 5 year follow-up and HAQ-index were used as explanatory parameters of BMD change between the 15- and 20-year follow-ups. None of these parameters explained the BMD change. CONCLUSION: We conclude that in long-term RA central bone densities seemed to be only moderately decreased after 15 years from eruption of RA. No essential change in central BMD was found after the consecutive 5 years.

Sustained maintenance of exercise induced muscle strength gains and normal bone mineral density in patients with early rheumatoid arthritis: a 5 year follow up.

OBJECTIVE: To investigate at 5 years whether an initial 2 year home based strength training period imposes sustained effects on muscle strength, bone mineral density (BMD), structural joint damage, and on disease activity in patients with early rheumatoid arthritis (RA). METHODS: Seventy patients were randomised either to perform home based strength training with loads of 50-70% of repetition maximum (EG) or range of motion exercises (CG). Both groups were encouraged to take part in aerobic activities 2-3 times a week. Maximal muscle strength of different muscle groups was measured by dynamometers, and BMD at the femoral neck and lumbar spine by dual x ray densitometry. Disease activity was assessed by the 28 joint disease activity score, and joint damage by x ray findings. RESULTS: 62 patients completed 2 years' training and 59 patients attended check up at 5 years. Mean (SD) maximum muscle strength indices increased from baseline to 2 years-in EG from 212 (78) kg by a mean (95% CI) of 68 (55 to 80) and in CG from 195 (72) kg by 35 (13 to 60) kg-and remained at that level for the next 3 years. Development of BMD in EG tended to be more favourable than that in CG. Muscle strength training was not detrimental to joint structures or disease activity. CONCLUSION: The patients' exercise induced muscle strength gains during a 2 year training period were maintained throughout a subsequent self monitored training period of 3 years. Despite substantial training effects in muscle strength, BMD values remained relatively constant. Radiographic damage remained low even at 5 years.

Atlantoaxial disorders in rheumatoid arthritis associate with the destruction of peripheral and shoulder joints, and decreased bone mineral density.

OBJECTIVE: To evaluate whether cervical spine changes are associated with the destruction of shoulder or peripheral joints and with bone mineral density (BMD) in patients with long-term RA. METHODS: An inception cohort of 67 patients with seropositive and erosive RA were followed up for 20 years. Cervical spine, shoulder, hand and foot radiographs, and the BMD of the lumbar spine and femoral neck were evaluated. RESULTS: A positive relationship was detected between the occurrence of atlantoaxial disorders and the destruction of both shoulder (p < 0.001) and peripheral (p = 0.001) joints. In addition, the severity of anterior atlantoaxial subluxation and atlantoaxial impaction positively correlated with the grade of destruction in the evaluated joints. Furthermore, patients with atlantoaxial disorders presented decreased BMD of the femoral neck (p = 0.019). The occurrences of subaxial subluxations (SAS) and subaxial disc space narrowings only associated with higher onset age of RA. CONCLUSIONS: Patients with severe RA and osteoporosis have an increased risk for atlantoaxial disorders. The co-existence of shoulder destruction and cervical spine disorders makes the differential diagnosis of shoulder and neck pain challenging.

Increased type I collagen degradation correlates with disease activity in reactive arthritis.

OBJECTIVE: The assay for the cross-linked carboxyterminal telopeptide of type I collagen (ICTP) has been shown to reflect increased type I collagen degradation in patients with rheumatoid arthritis. To look for increased collagen degradation in other inflammatory rheumatic diseases, we studied plasma ICTP in patients with reactive arthritis (ReA). METHODS: ICTP was determined by radioimmunoassay from 69 ReA patients. ICTP data on 56 patients aged > or = 20 years were compared with normal ICTP values available for that age group. RESULTS: The median (range) plasma ICTP concentration of the patients > or = 20 years of age was 3.9 (2.1-9.6) micrograms/l, and in 13 (23%) of them the value was elevated if compared with the normal upper reference limit (mean + 2SD), 5.2 micrograms/l, given by the manufacturer. The mean (SD) duration of joint symptoms was 76 (61) days in patients with ReA. Modest albeit statistically significant correlations were noted between the plasma ICTP and the erythrocyte sedimentation rate, C-reactive protein and the Lansbury articular index (Spearman's r 0.39, 0.37 and 0.29, respectively). The median values for all of the above mentioned parametres were at least twice as high in the group of patients with elevated ICTP compared with those in patients with normal values (p < 0.05). No statistically significant correlation was detected between the plasma ICTP and the duration of joint symptoms. CONCLUSION: Increased type I collagen degradation can take place in ReA, and this process seems to correlate with the extent and activity of the joint disease.

US assessment of hip joint synovitis in rheumatic diseases. A comparison with MR imaging.

PURPOSE: To assess the significance of ultrasonography (US) in detecting hip joint synovitis in patients with rheumatic diseases. MATERIAL AND METHODS: Forty patients with rheumatic disease and suspected hip joint synovitis underwent MRI and US of the hip joint. In addition to the throughout MRI evaluation, the anterior collum-capsule distance (CCD) was determined by both MRI and US. Thirteen healthy volunteers were examined with MRI to establish the criteria for normal findings in MRI when classifying hip joints to those with synovitis and those without. MRI was used as a gold standard. RESULTS: Synovitis was found using MRI in 31 hips of 22 patients (9 patients had bilateral synovitis). The intraclass correlation was 0.61 between MRI and US in measuring CCD. In classifying hip joint synovitis with US, the sensitivity of the method was 87% and specificity 42%, when the CCD criterion for synovitis was determined to be > or = 7 mm. If the cut-off point was raised to 9 mm, the sensitivity decreased to 61% while specificity increased to 94%. A difference in CCD of > or = 1 mm between the hips as an additional criterion for synovitis increased the number of false-positive findings. CONCLUSION: Measurement of CCD with US proved to be a rather inaccurate method to point out synovitis in rheumatic patients when using MRI as a reference. The main reason for this result was the thickened capsule, which US could not differentiate from a thickened synovium.

Uveitis as a marker of active arthritis in 372 patients with juvenile idiopathic seronegative oligoarthritis or polyarthritis.

OBJECTIVE: To compare the activity of arthritis in children with recently diagnosed seronegative oligoarthritis or polyarthritis with or without uveitis. METHODS: The study covered 372 JIA children with recently diagnosed seronegative oligoarthritis or polyarthritis. The mean prospective follow-up period was 4.5 years. Asymptomatic anterior uveitis was found in 96 cases. The activity of arthritis in all 372 patients was assessed clinically and by laboratory parameters. RESULTS: The erythrocyte sedimentation rate was significantly higher (p = 0.001) at the diagnosis of arthritis and at the end of the follow-up (p = 0.02) in the 96 JIA patients with uveitis than in the 276 JIA patients without uveitis. The hemoglobin value was significantly lower (p = 0.008) at the diagnosis of arthritis in patients with uveitis, but not at the end of the follow-up. The number of inflamed joints was significantly greater at the end of the follow-up in patients with persistent polyarthritis and uveitis (p = 0.01) compared to those polyarthritis patients without uveitis. Patients with uveitis were significantly more often treated with oral prednisolone (p < 0.001), glucocorticoid joint injections (p < 0.001), and with methotrexate (p = 0.003) compared to patients without uveitis. Clinical remission of arthritis was achieved significantly less frequently in patients with uveitis than in patients without uveitis (21% versus 42%, p<0.001). CONCLUSION: The inflammatory activity of arthritis seems to be increased in patients with seronegative oligo- or polyarthritis and uveitis compared to those without uveitis.

A randomized two-year study of the effects of dynamic strength training on muscle strength, disease activity, functional capacity, and bone mineral density in early rheumatoid arthritis.

OBJECTIVE: To evaluate the impact of a 2-year program of strength training on muscle strength, bone mineral density (BMD), physical function, joint damage, and disease activity in patients with recent-onset (<2 years) rheumatoid arthritis (RA). METHODS: In this prospective trial, 70 RA patients were randomly assigned to perform either strength training (all major muscle groups of the lower and upper extremities and trunk, with loads of 50-70% of repetition maximum) or range of motion exercises (without resistance) twice a week; all were encouraged to engage in recreational activities 2-3 times a week. All patients completed training diaries (evaluated bi-monthly) and were examined at 6-month intervals. All were treated with medications to achieve disease remission. Maximum strength of the knee extensors, trunk flexors and extensors, and grip strength was measured with dynamometers. BMD was measured at the femoral neck and lumbar spine by dual x-ray densitometry. Disease activity was determined by the Disease Activity Score, the extent of joint damage by the Larsen score, and functional capacity by the Health Assessment Questionnaire (HAQ); walking speed was also measured. RESULTS: Sixty-two patients (31 per group) completed the study. Strength training compliance averaged 1.4-1.5 times/week. The maximum strength of all muscle groups examined increased significantly (19-59%) in the strength-training group, with statistically significant improvements in clinical disease activity parameters, HAQ scores, and walking speed. While muscle strength, disease activity parameters, and physical function also improved significantly in the control group, the changes were not as great as those in the strength-training group. BMD in the femoral neck and spine increased by a mean +/- SD of 0.51 +/- 1.64% and by 1.17 +/- 5.34%, respectively, in the strength-training group, but decreased by 0.70 +/- 2.25% and 0.91 +/- 4.07% in the controls. Femoral neck BMD in the 17 patients with high initial disease activity (and subsequent use of oral glucocorticoids) remained constantly at a statistically significantly lower level than that in the other 45 patients. CONCLUSION: Regular dynamic strength training combined with endurance-type physical activities improves muscle strength and physical function, but not BMD, in patients with early RA, without detrimental effects on disease activity.

Uveitis as a cause of visual loss in arthritides and comparable conditions.

OBJECTIVE: To examine the role of inflammatory rheumatic diseases and comparable conditions in the etiology of severe uveitis leading to visual impairment and blindness. METHODS: A retrospective study based on the Finnish Register of Visual Impairment. At the end of 1996, the Finnish Register of Visual Impairment included 296 uveitis patients in whom uveitis was the main cause of visual impairment. The patient records were examined retrospectively to investigate the etiology of severe uveitis. Due to the incompleteness of data obtained of the patients blinded a long time ago, we included only 174 uveitis patients whose visual handicap (best corrected visual acuity in the better eye < 20/60 or severe visual field loss) was stated during 1980-1996. RESULTS: A total of 174 uveitis patients were found, 72 male and 102 female. A diagnosed or presumed inflammatory rheumatic disease or comparable condition was found in 38/174 (22%) patients: juvenile rheumatoid arthritis in 14 (8%), spondyloarthropathy (ankylosing spondylitis or reactive arthritis) in 10 (6%), sarcoidosis in 5 (3%), seronegative rheumatoid arthritis in 4 (2%); Behçet's disease was diagnosed in 2 (1%), 1 patient had polymyositis, 1 polyarteritis nodosa, and 1 juvenile systemic lupus erythematosus. In addition to the above, 10 (6%) patients had chronic back pain and 5 (3%) patients various noninflammatory joint problems. Diverse other ophthalmologic or systemic disease was detected in 38 (22%) cases. Trauma or surgery caused uveitis in 9 (5%) patients. For 74/174 (43%) uveitis patients no specific associating condition could be shown. Legal blindness was documented in 65/174 (37%) patients, including 8 totally blind persons. CONCLUSION: This study provides first data on the relative importance of inflammatory rheumatic diseases and comparable conditions in the etiology of severe uveitis leading to visual handicap and blindness.

Muscle strength characteristics and central bone mineral density in women with recent onset rheumatoid arthritis compared with healthy controls.

Muscle strength and bone mineral density (BMD) at the lumbar spine (BMDspine) and femoral neck (BMDfem) were determined in 20 healthy women and in 20 women with recent onset rheumatoid arthritis (RA). The mean duration of articular symptoms of the patients was eleven months and none of them had used glucocorticoids or disease modifying antirheumatic drugs. BMDs were measured by dual x-ray absorptiometry (DXA). Knee extension, trunk extension, and flexion as well as grip strength were measured with David 200 and Digitest dynamometers. BMDspine (1.17 g/cm2 and 1.20 g/cm2) and BMDfem (0.98 g/cm2 and 0.96 g/cm2) between the women with early RA and healthy women did not differ. However, knee extension strength was 46%, grip strength 31%, trunk extension strength 14% and overall muscle strength index 29% lower in RA women (p < 0.020-0.001) than in healthy subjects. Femoral neck BMD correlated statistically significantly with knee extension strength and muscle strength index in both groups and with trunk extension and flexion strength as well as rapid force development in RA women. The data indicates that the loss of muscle strength is clearly visible during the first months of disease but the significant bone loss at central bone regions develops later.

Dynamic strength training in patients with early rheumatoid arthritis increases muscle strength but not bone mineral density.

OBJECTIVE: To assess the effects of 12 months' dynamic strength training on muscle strength and bone mineral density (BMD) at the lumbar spine and femoral neck in patients with early rheumatoid arthritis (RA). METHODS: Thirty-two subjects in the training group (EG) and 33 in the control group (CG) completed the study. EG carried out strength training 2 times a week with moderate loads of 50-70% of repetition maximum. They were also encouraged to do recreational physical activities. CG performed recreational physical activities and range of motion exercises. Maximal strength of the knee extensors, trunk extensors and flexors, and grip strength were recorded with dynamometers. BMD was measured using dual x-ray absorptiometry. Modified Disease Activity Score, erythrocyte sedimentation rate, and pain were used for the estimation of disease activity, and Stanford Health Assessment Questionnaire to measure functional disability. RESULTS: The 12 month resistance training in EG led to statistically significant mean increases of 22-35% in all muscle groups examined. CG patients were also able to increase their strength to some degree (3-24%), but at the end of the study strengths in CG were significantly lower than in EG. By the end of the study lumbar spine BMD had changed by +0.19% (4.24) in EG and by -1.14% (4.36) in CG. The corresponding changes of femoral BMD were +1.10% (3.71) and -0.03% (3.58). The changes in BMD were minor and statistically not significant in both groups. However, femoral BMD was found to be decreased among those patients treated periodically with oral glucocorticoids (n = 15, 3 subjects from EG and 12 from CG) compared with changes in BMD among those not treated with systemic glucocorticoids (n = 50). CONCLUSION: Minimally supervised strength training resulted in significant improvements in muscle strength without detrimental effects on disease activity. The detected annual changes in central BMD were minor and statistically insignificant in both groups. Special attention should be focused on those patients with RA with high disease activity and concomitant glucocorticoid treatment.

Weight-bearing physical activity, calcium intake, systemic glucocorticoids, chronic inflammation, and body constitution as determinants of lumbar and femoral bone mineral in juvenile chronic arthritis.

The associations between the lumbar and femoral bone mineral and several body constitutional, lifestyle, and disease related variables were studied in 111 children with juvenile chronic arthritis (JCA) by factor and multiple linear regression analyses. In addition to the measurement of bone mineral density (BMD), bone width and bone mineral volumetric density (BMDvol) were determined by dual-x-ray absorptiometry (DXA). Factor analysis of 13 explanatory variables yielded six non-correlating factors, named as body size, physical activity, calcium intake, glucocorticoids, disease duration, and disease activity. These six factors were used as new variables to explain BMD, BMDvol, and bone width by multiple linear regression analyses. These showed body size, physical activity, and calcium intake as significant positive and disease activity and glucocorticoids as significant negative determinants of BMD in JCA. The analyses revealed also considerable differences in the relationships between factors and BM Dvol or bone width.

Development of bone mineral density at the lumbar spine and femoral neck in juvenile chronic arthritis--a prospective one year followup study.

OBJECTIVE: To determine the magnitude of lumbar and femoral bone mineral gain in patients with juvenile chronic arthritis (JCA) using dual X-ray absorptiometry. METHODS: Bone mineral density (BMD) was measured at entry and again after 12 months at the lumbar spine and femoral neck in healthy children (n = 65) and children with oligoarticular (n = 36) and polyarticular (n = 69) JCA. Five of the oligoarticular and 38 polyarticular patients were treated with systemic glucocorticoids. In addition to the changes in BMD, the annual changes in calculated bone mineral volumetric density (BMDvol) and bone size were determined simultaneously. RESULTS: In polyarticular JCA, the acquisition of BMD was decreased at the femoral neck (2.2 vs 4.8%; p < 0.05), but remained the same at the spine compared with healthy children; in oligoarticular JCA, the increase in BMD at the femoral neck was similar to that in controls, but significantly increased at the spine compared with the change in the control group (7.4 vs 4.9%; p < 0.05). The detected annual changes in BMD were associated with the changes in BMDvol. Bone mineral gain was significantly delayed at the lumbar spine in children treated with glucocorticoids. CONCLUSION: In children with JCA, the development of bone mineral is different at the lumbar spine and at the femoral neck, but it also depends on the subtype of JCA and on the use of systemic glucocorticoids.

Growth retardation and bone loss as determinants of axial osteopenia in juvenile chronic arthritis.

The aim of the study was to evaluate the significance of growth retardation and bone loss as determinants of axial osteopenia in children with juvenile oligo- and polyarthritis. Bone mineral density (BMD), bone size (width), and bone volumetric density (BMDvol) were determined by dual x-ray absorptiometry at the lumbar spine and femoral neck in children with juvenile oligoarthritis (n = 36), polyarthritis (n = 75), and a group of healthy children (n = 66). Comparison of measurements showed that children with juvenile polyarthritis had a significantly reduced BMDvol (p < 0.05) and bone size (p < 0.01) at the lumbar spine, resulting in a 10.5% decrease in BMD (p < 0.001). At the femoral neck, the 16% decrease in BMD (p < 0.001) was attributed only to a decrease in BMDvol (p < 0.001). In juvenile oligoarthritis, the development of osteopenia was nonsignificant except at the femur, where the 6.6% decrease of BMD was associated with significant decrease of BMDvol (p < 0.05). The bone loss associated with juvenile chronic arthritis appears to develop with concurrent growth retardation at the spine, but without detectable growth retardation at the femoral neck.

Is continuous intranasal salmon calcitonin effective in treating axial bone loss in patients with active rheumatoid arthritis receiving low dose glucocorticoid therapy?

OBJECTIVE: To investigate the efficacy of intranasal salmon calcitonin (sCT) in treating axial bone loss in patients with rheumatoid arthritis (RA) taking low dose glucocorticoids. METHODS: In this open, multicenter study 32 women with RA were treated one year with sCT 100 IU/day and calcium (Ca) 500 mg/day; 31 women were treated with Ca alone. Bone mineral density (BMD) was measured at the lumbar spine and proximal femur (femoral neck, Ward's triangle, trochanter) before sCT therapy and again after 6 and 12 months. RESULTS: Among valid completers treated with sCT and Ca (n = 26), the mean BMD increased at the lumbar spine (L1-L4), femoral neck, and Ward's triangle. In contrast, valid completers treated with Ca (n = 23) showed bone loss at the spine (L1-L4), femoral neck, Ward's triangle, and trochanter area. The differences of the changes in BMD were statistically significant between these groups at the femoral neck, Ward's triangle, and trochanter. There were no significant differences between groups in bone loss over 12 months at the lumbar spine (L1-L4), although analysis of the upper segment (L1-L2) suggested some possible benefit of sCT. CONCLUSION: Intranasal sCT (100 IU/day) appears to have beneficial effects on bone loss at the proximal femur in patients with active RA treated with low dose glucocorticoids for 12 months; longer studies are needed to exclude transient bone remodelling effects.

Comparison of different models for interpreting bone mineral density measurements using DXA and MRI technology.

Bone mineral density measurements using dual X-ray absorptiometry (DXA) are commonly expressed as areal density (g/cm2). However, areal BMD (BMDareal) is dependent on bone size and this can lead to erroneous interpretations of BMD values. We have previously presented a simple method for calculating apparent volumetric bone mineral density (BMDvol) using ancillary DXA-derived data. In the present study we tested the validity of our model using in vivo volumetric data obtained from magnetic resonance imaging (MRI) of lumbar vertebrae. BMDareal and BMDvol of L3 were measured from sixteen pairs of identical twins (24 men, 8 women), aged 25-69 years. The dimensions of the lumbar vertebra L3 were measured from MR images and BMD values were corrected for these dimensions. The DXA-derived apparent volumetric bone mineral density (BMDvol) correlated moderately with MRI-derived BMDs (r values from 0.665 to 0.822). In contrast to BMDareal, BMDvol and MRI-derived BMDs were not related to body size variables. All these volume-corrected BMDs diminished the erroneous effect of vertebral size on areal BMD. We conclude that the simple DXA-derived BMDvol can be used for normalization of bone mineral density values in subjects of different body sizes, and especially in growing children.

Increased type I collagen degradation in early rheumatoid arthritis.

OBJECTIVE: To evaluate the serum concentration of the mature, crosslinked carboxy terminal telopeptide of type I collagen (ICTP) in patients with early onset rheumatoid arthritis (RA) and to assess its correlation with clinically relevant features of the disease. METHODS: The serum ICTP concentration was measured in 99 adult patients with RA with a duration of disease less than one year. The main clinical outcome measures were joint count, modified Lansbury index, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), Larsen index and number of erosions in peripheral joints. RESULTS: There was a strong positive correlation (p < 0.001) between the serum ICTP concentration and the Lansbury joint index and a weaker but still significant correlation (p < 0.01) between the serum ICTP concentration and the number of eroded hand and foot joints. CONCLUSION: Serum ICTP may have value as a marker of tissue destruction in patients with early RA.

Height loss rate as a marker of osteoporosis in postmenopausal women with rheumatoid arthritis.

The relation between the loss of height and bone mineral density (BMD) at the lumbar spine and proximal femur was determined in 61 women aged 56-70 years suffering from rheumatoid arthritis. Statistically highly significant negative correlations were found between the loss of height and the spinal and femoral BMD. A loss of 4 cm or more in height over 10 years seems to be associated with a significant decrease of BMD, and it can be recommended as a clinical marker of osteoporosis.

Development of bone mass and bone density of the spine and femoral neck--a prospective study of 65 children and adolescents.

The bone mineral density (BMD, g/cm2) of the lumbar spine (L2-L4) and femoral neck was measured twice with a 1-year interval by dual energy X-ray absorptiometry (DEXA) in 65 healthy children and adolescents aged 7-20 years. In addition, the BMD values were corrected for the size of bones to obtain the bone volumetric density (BMDvol, g/cm3) using a method developed previously. The annual increases of BMD and BMDvol in both spine and femoral neck were most marked in females at the time of menarche (during the age of 11-13 years), and in males between the ages of 13 and 17 years. The males showed significantly higher values in their mean annual increment rates of femoral bone mineral content (BMC) and femoral neck width, whereas no differences in spinal parameters were found. The acquisition of bone mass and bone density stopped or markedly diminished before the age of 20 years, supporting the theory that the major portion of the peak bone mass is attained in late adolescence. We could not find any significant relationship between the increment rate of bone density, and physical activity or calcium intake. This study emphasizes the significant effect of puberty and genetic factors on the development of bone mass and density.

Estimation of central osteopenia in children with chronic polyarthritis treated with glucocorticoids.

STUDY OBJECTIVE: To investigate the degree and determinants of osteopenia in juvenile chronic polyarthritis. DESIGN: Retrospective case-control study of central bone mineral density. SETTING: Rheumatism Foundation Hospital and Kuopio University Hospital, Finland. SUBJECTS: A sample of 43 girls aged 7 to 19 with juvenile chronic polyarthritis treated with systemic glucocorticoids and a control sample of 44 healthy girls matched for age. MAIN OUTCOME MEASURES: Bone mineral density and bone size (width) measured by dual-energy x-ray absorptiometry and bone volumetric density calculated as an approximation of true bone density at both the lumbar spine and femoral neck. RESULTS: The girls with juvenile chronic arthritis had reduced bone mineral density, bone size, and bone volumetric density at both the lumbar spine and femoral neck (statistically significant findings, P = .022 for the bone size of the femoral neck and P < .001 for the other parameters). At the spine, the mean bone mineral density was 80%, the mean bone size 89%, and the mean bone volumetric density 89% of the values in the control group. At the femoral neck, the values were 78%, 93%, and 83%, respectively. The groups were matched for age, but the girls with arthritis were smaller and lighter. In the juvenile arthritis group, the femoral bone mineral density and bone volumetric density and the spinal bone width correlated negatively with the mean glucocorticoid dose. CONCLUSION: Axial bone mineral density is clearly reduced in severe juvenile polyarthritis and is mediated by both decreased bone volumetric density and diminished growth.