POS1315 PREVALENCE OF SARCOPENIA IN YOUNG ADULTS WITH JUVENILE IDIOPATHIC ARTHRITIS

Abstract

BackgroundIn the 2019 sarcopenia consensus update (EWGSOP2 [1]) experts emphasize low muscle strength as a key characteristic of sarcopenia, adding low muscle mass to confirm the diagnosis of sarcopenia. Thus, the presence of the first criterion indicates probable sarcopenia, the presence of the first and second criteria confirms the diagnosis of sarcopenia, and the presence of all three criteria indicates severe sarcopenia. There are no available data about severe sarcopenia in young adults with juvenile idiopathic arthritis (JIA).ObjectivesThis study aims to assess the prevalence of severe sarcopenia in young patients with JIA.MethodsTo confirm the diagnosis of severe sarcopenia we used dual X-ray absorptiometry (DXA) to assess low muscle mass (cut off points for ASM/height2 <7 kg/m2 for men and <5,67 kg/m2 for women); dynamometry - to determine the low muscle strength (grip strength <27 kg for men, <16 kg for women); gait speed and short physical performance battery (SPPB) to assess physical function (cut off points <8 m/sec and score ≤8, respectively). Patients were divided into two groups according to the presence or absence of all three criteria for severe sarcopenia.ResultsWe studied 40 young adults with JIA, including 23 female patients and 17 male patients. The mean age of the patients was 24,4±5 years; the mean age at the onset of the disease was 10,1±4,4 years. Patients were divided into 2 groups according to all three criteria for severe sarcopenia. The first group (I group) included 25 patients with reduced muscle mass, strength, and physical function, and the second group (II group) included 15 patients without criteria of severe sarcopenia. In the I and the II groups mean ASM/height2 was 5,1±0,8 kg/m2 vs 7,7±1,01 kg/m2; p=0,01; handgrip strength 14,8 ±4,8 kg vs 27,1±8,3 kg; p=0,01; gait speed 0,6±0,1 m/sec vs 1,4±0,6 m/sec; p=0,01; SPPB score 6,5±1,5 vs 10,9±1,3; p=0,01. The research found out: the height and weight of patients in the group with severe sarcopenia were lower than in the group without severe sarcopenia (height 1,67±0,07 m vs 1,75±0,08 m; p=0,01; weight 56,1±9,2 kg, 72,0±12,8 kg; p=0,01, respectively). The age of patients was not significantly different between the two groups, but the duration of the disease was longer in the I group 16,4±8,2 vs 9,2±5,3; p=0,01. The data of DXA differed between groups: the patients of I group had statistically reduced total BMD 1,07±0,1 g/cm2 vs 1,15±0,14 g/cm2; ultra-distal radius BMD 0,35±0,1 g/cm2 vs 0,51±0,12 g/cm2; femoral neck BMD 0,85±0,1 g/cm2 vs 1,04±0,2 g/cm2; p=0,01, respectively. Comparing the two groups, we found important differences: the level of ESR was higher in the I group 25,05±18,3 vs 11,5±10,02; p=0,01; the index of disease activity either (DAS28 4,0±1,5 vs 2,7±1,2; JADAS27 15,8±9,2 vs 8,3±4,8; p=0,01, respectively). Articular and extraarticular damage index were higher in I group: JADI-A 5,08±7,3 vs 0,5±0,7; p =0,01; JADI-E 1,7±1,8 vs 0,3±0,6, p=0,02.ConclusionThe study confirms the presence of severe sarcopenia despite the young age of patients with JIA. Severe sarcopenia occurs in patients with a higher level of inflammatory activity, articular and extraarticular damage, reduced bone mineral density, and longer duration of the disease. Further study of the factors influencing the development of sarcopenia in this category of young patients is required.