不同年龄反复呼吸道感染患儿维生素D含量变化与免疫功能的关系及其发病的高危因素研究OA

Objective To investigate changes in vitamin D level and their relationship with immune function in children of different ages with recurrent respiratory tract infections(RRTIs),and high-risk factors for the disease.Methods Clinical data of 115 children with RRTIs who admitted to our hospital from October 2020 to October 2025(case group)were retrospectively analyzed.They were divided into three age groups:0-3 years old group(33 cases),4-6 years old group(40 cases),and 7-14 years old group(42 cases).Additionally,115 healthy children matched for age and gender who received regular physical examination during the same period were selected as healthy control group.The serum levels of vitamin D and immune function indicators of the children in the case group and the healthy control group,and those in the three age groups were statistically analyzed.Multivariate Logistic analysis was used to analyze high-risk factors for occurrence of RRTIs.Spearman correlation analysis was used to analyze relationships between 25-hydroxy vitamin D[25-(OH)D]and immune indicators.Results The children in the case group had lower levels of 25-(OH)D,CD4+,CD4+/CD8+,immunoglobulin A(IgA),IgG and IgM compared to the healthy control group(t=12.232,8.380,14.123,32.171,10.138 and 43.239 respectively,all P<0,05),while they had higher level of CD8+(t=7.462,P<0.05).The proportions of children exposed to passive smoking,having history of allergies and poor dietary habits in the case group were higher than those in the healthy control group(χ2=8.469,18.991 and 5.708 respectively,all P<0.05).Multivariate Logistic regression analysis showed that 25-(OH)D(OR=0.593,95%CI:0.441-0.797),CD4+/CD8+(OR=0.602,95%CI:0.437-0.828),IgA(OR=0.564,95%CI:0.388-0.821),IgG(OR=0.610,95%CI:0.444-0.837)and IgM(OR=0.642,95%CI:0.483-0.853)were protective factors for occurrence of RRTIs in children(all P<0.05),while passive smoking(OR=2.192,95%CI:1.338-3.593),allergy history(OR=2.312,95%CI:1.333-4.010)and poor dietary habits(OR=2.217,95%CI:1.324-3.712)were risk factors for occurrence of RRTIs in children(all P<0.05).Within the case group,the levels of 25-(OH)D,CD4+,CD4+/CD8+,IgA,IgG and IgM of the children in the 0-3 years old group were the lowest among the three age groups(F=213.776,25.996,115.814,99.794,41.458 and 88.861 respectively,all P<0.05).25-(OH)D level was positively correlated with CD4+,CD4+/CD8+,IgA,IgG and IgM(r=0.484,0.593,0.451,0.588 and 0.519 respectively,all P<0.05),while it was negatively correlated with CD8+(r=-0.552,P<0.05).Conclusion Vitamin D deficiency,specific immune dysfunction,and environmental behavioral factors(passive smoking,poor dietary habits)are closely related to occurrence of RRTIs in children.Among Which,vitamin D level is correlated with immune function indicators,and vitamin D level and immune function indicators are both lower in younger children.This provides a basis for intervention of RRTIs through screening and correcting vitamin D deficiency and improving family environments.