J Rheum Dis 2018; 25(4): 248-254  
Prevalence of Lower Bone Mineral Density and Its Associated Factors in Korean Children and Adolescents with Juvenile Idiopathic Arthritis
JinShik Shin, Min Jae Kang, Kwang Nam Kim
Department of Pediatrics, Hallym University Sacred Heart Hospital, Anyang, Korea
Correspondence to: Kwang Nam Kim http://orcid.org/0000-0003-4024-5128
Department of Pediatrics, Hallym University Sacred Heart Hospital, 22 Gwanpyeong-ro 170beon-gil, Dongan-gu, Anyang 14068, Korea. E-mail:kwangnamkim@naver.com
Received: April 24, 2018; Revised: June 26, 2018; Accepted: June 28, 2018; Published online: October 1, 2018.
© Korean College of Rheumatology. All rights reserved.

This is a open Access article, which permits unrestricted non-commerical use, distribution, and reproduction in any medium, provided the original work is properly cited.
Objective. This study examined the prevalence of low-bone mineral density (BMD) and its associated factors in Korean children and adolescents with juvenile idiopathic arthritis (JIA). Methods. Thirty-nine patients with JIA were included in this cross-sectional study. The patients were examined for their bone age (BA) and bone mineral density (BMD). The BMD was measured using dual-energy X-ray absorptiometry on the lumbar spine. Each BMD value was converted to a Z-score by comparing the reference values of the healthy control group in terms of the age and sex of each patient, which was measured using the same device. A Z-score of less than -2.0 was defined as a low BMD. Laboratory tests were performed to detect the serum calcium, phosphorus, alkaline phosphatase, and 25-hydroxyvitamin D levels. Results. The mean age at the time of the examination was 12.2±3.6 years, and the study comprised a total of 39 patients (16 males, 23 females). Patients with systemic JIA had a lower BMD, which was calculated based on the CA, BA, and HA, than those with non-systemic JIA (P=0.020, P=0.049, and P=0.024, respectively); the corticosteroid user group also showed a lower BMD, which had been calculated based on the CA, BA, and HA, than the corticosteroid non-user group (p=0.002, p=0.022, and p=0.188, respectively). Conclusion. This study suggests that JIA patients have a lower BMD than control subjects. Therefore, treatment, and education are warranted while treating patients with JIA, particularly those requiring oral corticosteroids or those with systemic JIA and appropriate laboratory tests.
Keywords: Juvenile idiopathic arthritis, Bone mineral density

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