Meta-Analysis Of Zinc Deficiency Status And Its Influence Factors Among Children In China’s Mainland In The Past 15years

BACKGROUND: In recent years,zinc deficiency in children has attracted global attention.There are some differences in zinc deficiency in different countries and regions.However,there are few multi-center and large-sample studies on zinc deficiency in children in China’s mainland.OBJECTIVE: To analyze zinc levels and zinc deficiency in children in China’s mainland.METHODS: Pub Med,Embase,Cochrane Library,Web of Science,China Biomedical Literature Database,CNKI,Wanfang Data Knowledge Service Platform,Weipu Chinese Journal Database and other databases were searched from the establishment of the database to February 8,2021.Two researchers independently extracted age,gender,trace whole blood zinc level,zinc deficiency incidence and further data from the included literature,and evaluated the quality of the literature.STATA 14.0 software was used for Meta-Analysis.RESULTS: A total of 55 articles were included in this study,including 292,877 healthy children and adolescents.Overall blood zinc level was 72.44±16.53μmol/L.Meta-analysis results showed that the overall zinc deficiency rate was 27.0%(95%CI22.8%-31.3%).From which a total of 137641 children from coastal areas were incorporated into 18 articles.The blood zinc level was 70.21±15.98μmol/L,and the zinc deficiency rate was 21.7%(95%CI 16.2%-27.1%).The other 37 articles included155,236 children from inland area of China showed that the blood zinc level was75.01±20.83μmol/L,and the zinc deficiency rate was 29.6%(95%CI 24.9%-34.4%).Among them,21 articles reported the comparison of the whole blood zinc levels of81391 children with different genders,including 44,625 boys and 36,766 girls.Meta-analysis results showed that there was no statistically significant difference in zinc levels between male and female groups [SMD=-0.003,95%CI(-0.031,0.025),P=0.838].Another 21 articles reported a total of 83952 children with diverse genders,including47,162 boys and 36,790 girls.Meta-analysis showed that the zinc deficiency rate in the male group was greater than in the female group,and the difference was statistically significant [OR=1.052,95%CI(1.019,1.087),P=0.002].There are 38 articles including a total of 213347 cases of children reported the comparison of whole blood zinc levels between different age groups and the rate of zinc deficiency.Meta-analysis results show that the baby whole blood zinc levels were lower than children group [SMD = 0.692,95% CI(0.798,0.586),P = 0.000),the preschool group [SMD = 1.186,95% CI(1.312,1.061),P = 0.000),school-age children and adolescents [SMD = 1.533,95% CI(1.763,1.302),P = 0.000];The whole blood zinc level of the infant group was lower than that of the preschool group [SMD=-0.454,95%CI(-0.519,-0.389),P=0.000] and the school-age group [SMD=-0.749,95%CI(-0.998,-0.500),P=0.000],respectively.The preschool group was less than the school-age children and adolescents’ group[SMD=-0.324,95%CI(-0.475,-0.172).P=0.000],and the differences were statistically significant.The zinc deficiency rate in infant group was higher than that in infant group[OR=1.38,95%CI(1.16,1.64),P=0.000],preschool group [OR=1.475,95%CI(1.163,1.870),P=0.001],and school-age group [OR=1.746,95%CI(1.257,2.425),P=0.001],with statistical significance.There was no significant difference in zinc deficiency rate between the preschool group and the preschool group [OR=1.059,95%CI(0.918,1.222),P=0.429],the preschool group and the school-age group [OR=1.136,95%CI(0.848,1.523),P=0.394],and the preschool group and the school-age group [OR=0.986,95%CI(0.754,1.291),P=0.919].Four articles were reported the comparison of the factors of dietary providers with different education levels influence the rate of zinc deficiency,a total of 7406 cases of children with well-educated group 4112 cases,and a group of 3294 cases with poor-educated were included,Meta-analysis results showed that there was no statistically significant difference in zinc deficiency rate between the groups of well-educated and the poor-educated dietary provider.(OR = 1.095,95% CI(0.867,1.383),P = 0.446).Another 5 articles reported the comparison of a total of10,497 children with zinc deficiency rate in urban and rural areas,including 6875 children in the urban group and 3622 children in the rural group.Meta-analysis results showed that there was no statistical significance in zinc deficiency rate between urban group and rural group [OR=1.152,95%CI(0.810,1.637),P=0.432].CONCLUSIONS: At present,zinc deficiency in children and adolescents in China’s mainland is still serious,especially in infants,and zinc levels in all ages increase with age.There was no significant difference in zinc levels among children of different genders,and zinc deficiency rate in male children was more serious than that of female children.Factors such as different educational level of food providers and different areas from urban and rural were not the major influencing factors of zinc deficiency.