Serum 25-Hydroxyvitamin D Level Might Be a Useful Indicator of Disease Severity in Obese Children With Atopic Dermatitis:A Case-Control Study

Objective:To assess the relationship between the severity of atopic dermatitis(AD)in children of varying weight categories and their serum 25-hydroxyvitamin D[25(OH)D]levels.Methods:The study population comprised 899 patients with AD and 854 age-and sex-matched controls.The Mann-Whitney U test and Kruskal-Wallis H tests were used to assess differences between groups,and Spearman correlation analysis was used to test correlation.Results:The 25(OH)D level in the AD group was M(Q_(25),Q_(75)),24.0(19.7,28.4)ng/mL,which was significantly lower than the control group(26.4[23.6,29.9]ng/mL;Z=-3.34,P=0.001).25(OH)D levels in children with AD were negatively correlated with body mass index(r=-0.30,P<0.001),Severity scoring of Atopic Dermatitis(SCORAD;r=-0.14,P<0.001),total immunoglobulin E(r=-0.13,P<0.001),and eosinophil(r=-0.08,P=0.017).There were statistically significant differences in 25(OH)D(H=18.46,P<0.001),total immunoglobulin E(H=9.13,P=0.010),eosinophil(H=67.17,P<0.001),and SCORAD(H=10.49,P=0.005)among groups with different body mass index classification.The 25(OH)D levels were 22.3(17.5,27.1)ng/mL in the overweight AD group and 22.3(17.6,25.7)ng/mL in the obese AD group,which were significantly lower than those in the normal-weight AD group(24.7[20.4,25.5]ng/mL;P=0.003,P=0.004).25(OH)D levels were negatively correlated with SCORAD in obese AD patients(r=-0.25,P=0.010).Conclusion:Vitamin D insufficient or deficient is obvious in children AD patients.The 25(OH)D levels in the overweight/obese AD group are significantly lower than those in the normal-weight AD group.Vitamin D level is negatively correlated with SCORAD in obese children with AD.