Division of Pediatric Medicine and the Pediatric Outcomes Research Team (PORT), Hospital for Sick Children, Toronto, Ontario, Canada.
Division of Pediatric Medicine and the Pediatric Outcomes Research Team (PORT), Hospital for Sick Children, Toronto, Ontario, Canada; Sick Kids Research Institute, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Department of Pediatrics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
J Pediatr. 2019 Apr;207:198-204.e1. doi: 10.1016/j.jpeds.2018.11.035. Epub 2019 Jan 7.
To examine the association between body mass index (BMI) and iron deficiency in early childhood, while considering the influence of low-grade systemic inflammation.
Healthy children ages 1-3 years were included in a cross-sectional analysis. Age- and sex-standardized World Health Organization BMI z score (zBMI) was calculated using height/length and weight measurements; iron status was assessed by serum ferritin; inflammation was assessed by C-reactive protein (CRP). Children with CRP ≥10 mg/L were excluded because this may indicate acute systemic inflammation. Adjusted multivariable regression analyses were used to investigate the association between zBMI and both serum ferritin (µg/L), and iron deficiency (serum ferritin <12 µg/L). We performed prespecified subgroup analyses according to CRP level (normal [≤1.0 mg/L] and low-grade inflammation [>1.0 mg/L to <10.0 mg/L]).
Of 1607 children included, 20% were categorized as with zBMI >1, 13% had iron deficiency, and 18% had low-grade inflammation. Higher zBMI was associated with lower serum ferritin (-1.51 µg/L, 95% CI -2.23, -0.76, P < .0001) and increased odds of iron deficiency (OR 1.28, 95% CI 1.10, 1.50, P = .002). Though there was no interaction between zBMI and CRP for the adjusted linear regression model (P = .79) or logistic regression model (P = .43), children with low-grade inflammation had a higher serum ferritin (P < .0001).
Higher zBMI is associated with increased risk for iron deficiency in children between 1 and 3 years, and should be considered as a risk factor in targeted screening. Further research is needed to better understand the relationship between serum ferritin and CRP for children in all weight categories.
ClinicalTrials.gov: NCT01869530.
探讨儿童早期体重指数（BMI）与缺铁之间的关系，同时考虑低水平全身炎症的影响。
本研究采用横断面分析，纳入了 1-3 岁的健康儿童。采用身高/长度和体重测量计算年龄和性别标准化的世界卫生组织 BMI z 评分（zBMI）；血清铁蛋白评估铁状态；C 反应蛋白（CRP）评估炎症。排除 CRP≥10mg/L 的儿童，因为这可能表明存在急性全身炎症。采用调整后的多变量回归分析来研究 zBMI 与血清铁蛋白（µg/L）和缺铁（血清铁蛋白<12µg/L）之间的关系。我们根据 CRP 水平（正常[≤1.0mg/L]和低度炎症[>1.0mg/L 至<10.0mg/L]）进行了预设的亚组分析。
在 1607 名儿童中，20%的儿童 BMIz>1，13%的儿童缺铁，18%的儿童低度炎症。较高的 zBMI 与较低的血清铁蛋白相关（-1.51µg/L，95%CI-2.23，-0.76，P<0.0001）和缺铁的几率增加（OR 1.28，95%CI 1.10，1.50，P=0.002）。尽管在调整后的线性回归模型（P=0.79）或逻辑回归模型（P=0.43）中，zBMI 与 CRP 之间没有交互作用，但低度炎症儿童的血清铁蛋白更高（P<0.0001）。
在 1 至 3 岁儿童中，较高的 zBMI 与缺铁风险增加相关，应作为有针对性筛查的一个危险因素。需要进一步研究以更好地了解所有体重类别儿童的血清铁蛋白和 CRP 之间的关系。
ClinicalTrials.gov：NCT01869530。
