E18 What is the relationship between body mass index and juvenile idiopathic arthritis characteristics?

Abstract

Abstract Introduction Juvenile idiopathic arthritis (JIA) is a group of pediatric chronic inflammatory joint diseases. The various forms of JIA may be associated with delayed growth or local growth disturbances. Objectives We conducted this study to evaluate the relationship between the different clinical and biological characteristics of JIA and the anthropometric parameters of patients. Methods Retrospective study including adults with long-standing JIA according to International League of Associations of Rheumatology (ILAR) criteria over a period from 1994 to 2022. Clinical and biological parameters were collected. Body mass index (BMI) was interpreted according to World Health Organization cut-offs as follows: underweight <18.5, normal [18.5–24.9], overweight [25–29.9], and obese ≥30 kg/m2. Results Seventeen women and 12 men were included. The mean age was 35.69 ± 11.72 [18–61] years. The mean age of disease onset was 11.10 ± 4.25 [2–16] years. The average diagnostic delay was 52.96 ± 95.97 [0–336] months. The average disease duration was 24.48 ± 12.76 [1–47] years. The polyarticular form was the most frequent (55.2%). Rheumatoid factor, ACPA and antinuclear antibodies were present in 41.4%, 24.1% and 17.2% of cases respectively. At least one extra-articular manifestation was noted in 16 patients: ophthalmologic (n = 6), skin (n = 4), cardiac (n = 4), pulmonary (n = 3) and renal (n = 2) involvement. Osteoporosis was noted in 7 cases. Mean C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were 42.74 ± 63.37 [2–218] mg/l and 69.67 ± 36.23 [36–108] mm. An elevation of inflammation markers was noted in 19 cases. The mean haemoglobin value was 11.31 ± 2.10 [6.5–15] g/dl Anaemia was noted in 20 cases. The mean body mass index was 21.20 ± 4.88 [14.17–27.55] kg/m2, 36.4% of patients were underweight, 27.2% had a normal BMI, and 36.4 were overweight. No patient was obese. Growth delay was noted in 3 cases. Our statistical study found a correlation of BMI with ESR (r = 0.998; P < 0.001), rheumatoid factor positivity (r = -1.000; P < 0.001), and osteoporosis (r = 0.803; P = 0.030). No other correlation of BMI with clinical and biological characteristics of the study population was identified. Conclusion BMI should be well considered in the JIA evaluation and treatment. BMI correlated with ESR, rheumatoid factor positivity, and osteoporosis in our study.