Background and Goals. Low serum levels of osteocalcin (OC), hemoglobin, and osteoporosis are linked to polyarthritic and systemic juvenile idiopathic arthritis (PJIA, SJIA), as well as type 1 diabetes mellitus (T1DM) and polyarthritic and systemic juvenile idiopathic arthritis (PJIA, SJIA). We looked into the relationship between serum OC levels and JIA, as well as how T1DM affected this relationship in participants. Our objective is to learn more about the underlying illness characteristics of chronic rheumatic diseases, which are most frequently seen in children, and to update existing knowledge and propose new therapeutic approaches