THE IMPORTANCE OF THE GEOGRAPHIC LATITUDE OF LIVING AND THE SEASON OF THE YEAR IN THE OBSERVATION OF CHILDREN WITH JUVENILE IDIOPATHIC ARTHRITIS

Shevchenko N.S.¹, Khajinova Yu.V.²

• ¹V.N. Karazin Kharkiv National University
• ²SU «Institute for Children and Adolescents Health Care at the National Academy of Medical Sciences of Ukraine», Kharkiv

Summary. Juvenile idiopathic arthritis (JIA) remains one of the pressing problems of modern rheumato­logy. Studies of the risk factors for the disease and its adverse trends are continuing, among which the role of Vitamin D is widely discussed. It is known that the main source of Vitamin D is endogenous synthesis induced by sunlight exposure, it’s intensity might be variable depending on season and geographic location. The purpose of this study was to study the status of Vitamin D in children with JIA depending on the geographical latitude and season of the year. The research data from different countries of the world were analyzed, among which 13 publications on the study of Vitamin D levels in children with JIA depending on geographical latitude were found. Determination of Vitamin D level in blood serum using chemiluminescence method was performed on 91 children with the JIA who have been treated at the Department of Cardiorheumatology. An analysis of literary sources revealed an insufficient level of Vitamin D and a lack of reliable dependence of its reduction on the latitude of the patients with JIA living. A study of Vitamin D levels in children with JIA confirmed the presence of deficiency in 85.44% patients (average 22.75±1.97 ng/ml), which did not reliably depend on the gender and age of patients. The level of Vitamin D in patients varied throughout the year from 19.52±1.61 ng/ml (May) to 29.62±2.48 ng/ml (September) (p<0.05), but the normal concentration was not reached. Conclusion: Children with JIA are characterized by a deficiency of Vitamin D in most patients regardless of geographical latitude and season. The research results prove the necessity of revising the regimens of the appointment of Vitamin D in this cate­gory of patients.