Clinical Analysis Of Serum Vitk₂ And Its Relationship With Bone Metabolic Markers OC And CTX In 1732 Children

ObjectiveVitamin K₂（Vit K₂）is a series of menthoquinone derivatives with strong antioxidant biological activity,which has biological effects such as promoting bone formation,inhibiting bone absorption,accelerating bone mineralization,regulating glucose and lipid metabolism,and protecting nerves.However,there are few relevant data on children.This study by detecting serum Vit K₂children and bone metabolic markers level,analyzed Vit K₂relevant clinical data and bone metabolic markers osteocalcin（OC）,a formerⅠtype collagen amino terminal propeptide（PINP）,collagen typeⅠcrosslinking carboxyl terminal peptide（CTX）,in order to prevent children vitamin K deficiency and improve the quality of children’s bone and bone strength,To provide scientific reference and advice for maintaining bone health.MethodsFirstly,1732 children who underwent routine physical examination in the Department of Child Health care and Youth Development Clinic from October,2020 to October,2021 were selected.The serum Vit K₂level was determined by HPLC-MS/MS method,and the nutritional status of Vit K₂in children of different genders and ages was preliminatively investigated.Secondly,in order to exclude the effect of vitamin D on bone metabolism,samples with 25（OH）D<50nmol/L were excluded,and those with insufficient blood collection and incomplete data were also excluded.Finally,309children were included in the study of Vit K₂and bone metabolism markers.Serum OC,PINP and CTX were detected by enzyme-linked immunoassay（ELISA）,and the clinical characteristics of Vit K₂deficient children and their relationship with the above bone metabolism markers were analyzed.Vit K₂deficiency was defined as<0.1ng/m L and 25（OH）D deficiency was defined as<50nmol/L.Results一.Analysis results of serum Vit K₂levels in 1732 children1.Among the 1732 subjects,the age was 7.32（3.81,10.69）years old,and the rate of serum Vit K₂deficiency was 69.63%.The percentages of unreliable sleep,overweight/obesity and growth pain（≥3 years old）were 33.78%,15.65%and 29.97%of the subjects.Compared with girls,the incidences of unsound sleep,overweight/obesity and growth pain（≥3 years old）were significantly higher in boys（P<0.05）.However,there was no significant difference in serum Vit K₂level and deficiency rate between boys and girls.2.According to the level of serum Vit K₂,the children were divided into normal group and deficiency group.Compared with the normal group,the incidences of anorexia,overweight/obesity and growth pain（≥3 years old）were higher in the Vit K₂deficiency group（P<0.05）.3.The median serum Vit K₂level（quartile interval）of 1732 cases was0.09（0.05,0.16）ng/m L.When there was no significant difference in sex,the serum Vit K₂level increased with age.Compared with other age groups,<1-year-old and 7-14-year-old were high risk groups for serum Vit K₂deficiency（54.31%55.59%）,and the difference was statistically significant（P<0.05）.二.Results of correlation analysis between serum Vit K₂and bone metabolism markers in 309 children1.309 subjects with 25（OH）D≥50nmol/L were divided into age groups.When there was no significant difference in sex,the level of serum CTX decreased with the increase of age,while the levels of serum OC and PINP increased with age.There were significant differences among different age groups（P<0.05）.The serum CTX level of<1-year-old children was significantly higher than that of other age groups（P<0.001）,and decreased with the increase of age,while the serum OC and PINP levels of<1-year-old children were significantly lower than that of other age groups（P=0.012;P<0.001）,and increased with the increase of age.2.Spearman correlation analysis showed that age was positively correlated with serum levels of Vit K₂,OC and PINP（r=0.136,P<0.05;r=0.433,r=0.415,P<0.01）.There was a significant negative correlation between age and serum CTX level（r=-0.488）,a significant positive correlation between serum Vit K₂and OC（r=0.347）,and a negative correlation between serum CTX and PINP（r=0.317）.The differences were statistically significant（P<0.01）.But there was no correlation between serum Vit K₂and serum CTX and PINP（P>0.05）.Conclusions1.Overweight/obese children,<1-year-old and 7-14-year-old are high-risk groups of serum Vit K₂deficiency.Attention should be paid to daily monitoring and timely supplementation of Vit K₂levels in overweight/obese children and children at this age.2.The main clinical manifestation of serum Vit K₂deficiency in children over 3years old is growth pain.Therefore,clinicians and parents of such children should pay attention to their serum Vit K₂nutritional status.3.Serum Vit K₂was significantly positively correlated with serum OC levels,suggesting that Vit K₂was involved in the process of bone formation and bone matrix mineralization,while serum Vit K₂was not correlated with CTX and PINP,which might be related to the small sample size in this study.