Osteocalcin as a marker of Vitamin K2 in children with chronic kidney diseases

Background We aimed to investigate the relationship between vitamin K2 status, as measured by uOC, and bone health assessed through a bone turnover marker (bone alkaline phosphatase- BAP) in children with CKD taking in consideration the impact of eGFR. Methods We enrolled 75 patients classified into 3 groups: group A; CKD without KRT, group B; CKD on regular HD and group C; renal transplant recipients. Another 25 healthy individuals were involved as a control group. Under carboxylated osteocalcin (uOC) (as a sensitive indicator of vitamin K2 level) and BAP were measured in all patients. 24-hour dietary recall was used to assess vitamin k2, calcium, and phosphorus intake. Vitamin and mineral intake was calculated as a percent of target requirements of age and sex-matched healthy children. Results uOC was found significantly higher in the patient groups in comparison to the control group ( p  < 0.001). The highest level of uOC was detected in the HD group. In all groups, robust negative correlations were observed between uOC and vitamin K intake (%) levels. There was a statistically significant difference in uOC ( p  < 0.001) between those with history of bone fractures (No.= 7) compared to those without fractures (No.= 93). By logistic regression analysis, patients with a history of fractures were more likely to have a higher uOC (p = 0.012). Conclusion elevated uOC levels were observed in children with CKD and demonstrated a correlation with eGFR. Additionally, they exhibited a notable association with heightened bone turnover status, as indicated by BAP levels.