Age peculiarities of bone mineral density in young female with juvenile idiopathic arthritis

Povorozniuk V.V. ¹, Amosova K.M. ², Dzhus M.B. ²

• ¹ДУ «Інститут геронтології ім. Д.Ф. Чеботарьова НАМН України», Київ
• ²O.O. Bohomolets National Medical University, Kyiv

Summary. Objective: to study the bone mineral density (BMD) in young adult females with juvenile idiopathic arthritis (JIA) depending on the age. Materials and methods: 99 females aged 19–39 (40 patients with JIA and 59 practically healthy persons) were examined. All surveyed were divided into 2 groups by age: I group — 20–29 years old and II group — 30–39 years old. The age of disease onset, delay in diagnosis, disease duration, ILAR-variant of JIA, BMD, T-score and Z-score were estimated. Results: the BMD was significantly lower at the lumbar spine (p<0.001) and at the total body (p<0.01) in both groups, and at the femoral neck (p<0.001) in patients aged 20–29 years in comparison with healthy group. BMD in the ultradistal forearm was reduced in patients with JIA in comparison with healthy (p<0.01). Both lumbar spine T-score (p<0.001) and Z-score (p<0.001) were reduced in the I group, but in the II group only the Z-score (p<0.01) was reduced. Total body T-score and Z-score were reduced in female of both groups (group I: T-score p<0.01, Z-score p<0.001; group II: T-score p<0.05, Z-score p<0.0001). Patients of I and II groups had lower femoral neck T-score (respectively, p<0.001, p<0.05) but the Z-score was lower (p<0.001) only in group I. The ultradistal forearm T-score and Z-score decrease were revealed only in group II (p<0.01, p<0.01, respectively). Conclusions: The presence of JIA in childhood had negative effects on the formation of peak bone mass and BMD at young female. Reduction of BMD in the total body and in the ultradistal forearm testified the negative influence of JIA on bone tissue, and the increase of the disease duration lead to loss of BMD, especially in the ultradistal part of forearm in such patients. It is advisable to use not only the Z-score, but also the T-score for the diagnosis of osteoporosis in young female with JIA.