POS1152 BONE AND MUSCLE IMPAIRMENT AND HIGHER VISCERAL ADIPOSE TISSUE MASS IN WOMEN WITH LONG-TERM POLYARTICULAR JUVENIL IDIOPATHIC ARTHRITIS

Abstract

BackgroundSome studies suggest that patients with juvenile idiopathic arthritis (JIA) may have reduced bone parameters and muscle mass. Despite those considerations, there is no validated consensus about this topic in the literature as the population and the methods for bone and muscle evaluation are often heterogeneous and not standardized.ObjectivesTo assess bone parameters and body composition of women with long-term polyarticular JIA and compare them to healthy controls.MethodsTwenty-seven women with long-term polyarticular JIA were compared with twenty-seven healthy controls, matched by sex, age, and body mass index (BMI). Dual-energy X-ray absorptiometry (DXA) was performed to evaluate the lean mass, body fat percentage (% Fat), and visceral adipose tissue mass (VATm). High resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and tibia was performed to assess trabecular (Tb.) and cortical (Ct.) volumetric bone mineral density (v.BMD) and strength bone parameters (stiffness - S; estimated fail load - FL). Group means were compared using Student’s t-test.ResultsPolyarticular JIA patients have a lower trabecular and cortical volumetric bone density, a lower bone strength, and a lower lean mass compared to healthy controls. Moreover, long-term JIA patients have a higher visceral adipose tissue mass (Table 1).Table 1.Bone parameters using high resolution peripheral quantitative computed tomography (HR-pQCT) and body composition in long-term polyarticular patients and healthy controls.Polyarticular JIA n=27Healthy controls n=27p-valueAge, years31.8 ± 7.633 ± 8.20.597BMI, Kg/m224 ± 4.824.6 ± 4.70.931Disease duration, years22 ± 10-----Remission or low activity, n (%)16 (59)-----Use of prednisone, n (%)5 (18)-----Rheumatoid factor9 (33)0 (0)Lean mass, kg35.7 ± 4.739 ± 7.2<0.001%Fat, %39 ± 837 ± 70.364VATm, kg588 ± 538212 ± 2090.001HR-pQCT at the distal radiusTb.v.BMD, mg HA/cm3125 ± 32159 ± 38<0.001Ct.v.BMD, mg HA/cm3994 ± 461035 ± 43<0.001S, kN/mm64 ± 1178 ± 180.001FL, N3174 ± 8793710 ± 827<0.001HR-pQCT at the distal tibiaTb.vBMD, mg HA/cm3128 ± 48162 ± 320.003Ct.vBMD, mg HA/cm3990 ± 57993 ± 520.811S, kN/mm179 ± 39212 ± 40<0.001FL, N8519 ± 17739675 ± 25250.004Data expressed as mean ± standard deviation or frequency (percentage). Tb.vBMD – trabecular volumetric bone mineral density, Ct.vBMD – cortical volumetric bone mineral density; S - stiffness; FL - estimated fail loadConclusionPre-menopausal women with long-term polyarticular JIA have an impairment of bone mineral density at peripheral sites in addition to lower muscle mass and higher visceral adipose tissue. These findings may contribute to the increasing osteoporosis/fractures and cardiovascular risk in this population, suggesting that measures should be considered to prevent these damages.