Abstract: Objective To examine the mediating effects of changes in adipocytokine levels on the association between body mass index (BMI) and blood pressure (BP) among obese children with hypertension. Methods A total of 120 obese children treated in the Second Affiliated Hospital of Xi′an Jiaotong University from June 2012 to August 2014 were enrolled in this study.And children with high blood pressure were intervened for six months on life style.Anthropometric data(including height, weight, waistline, BMI and BP), adiponectin,chemerin,leptin,Sfrp5,Wnt5a,hsCRP and TNF-α were assessed at baseline and after 6-month lifestyle intervention.Mediation analysis was conducted to examine whether the association between BP reduction and weight loss was mediated by changes in adipocytokines (ΔSfrp5, Δadiponectin, Δchemerin or ΔhsCRP) on the independent variable (ΔSBP or ΔDBP). Results Serum levels of Sfrp5 and adiponectin were significantly lower in obese children with hypertension, but serum levels of Wnt5a, hsCRP and chemerin were higher in obese children with hypertension(P＜0.05).There was no significant difference on the levels of TNF-α between obese children with hypertension and without hypertension(P＞0.05).The levels of adiponectin and Sfrp5 increased after intervention, while the levels of chemerin, leptin, Wnt5a,hsCRP decreased after intervention(P＜0.05).The changes in Sfrp5 and adiponectin showed a partial mediating effect on the relationship between weight loss and BP reduction after controlling for covariates, while the changes in chemerin and hsCRP had no mediating effect. Conclusion Sfrp5 and adiponectin have a certain mediating effect on the increase of blood pressure in obese children.

Key words: obesity, blood pressure, cytokines, body mass index, mediating effect analysis

摘要： 目的 探讨肥胖高血压患儿血中脂肪细胞因子水平变化在体重指数(BMI)与血压关联的中介效应,为控制肥胖儿童高血压的进展提供一定理论依据及临床指导。方法 以2012年6月—2014年8月就诊于西安交通大学第二附属医院小儿内分泌门诊的120例肥胖儿童为研究对象,根据血压测量结果对高血压组儿童进行为期6个月的生活方式干预,入院后及生活方式干预前后测量所有儿童及高血压组儿童身高、体重、腰围、BMI及血压,用酶联免疫法检测血中脂联素、趋化素、瘦素、分泌型卷曲相关蛋白5(Sfrp5)、Wnt家族分泌性相关蛋白a(Wnt5a)、超敏C反应蛋白(hsCRP)和肿瘤坏死因子α(TNF-α)浓度。以给予生活干预前后细胞因子的变化作为中介变量,BMI的变化为自变量(ΔBMI),舒张压及收缩压的降低为因变量(ΔSBP和ΔDBP)进行中介效应分析。结果 高血压组儿童与非高血压组比较,Sfrp5及脂联素显著降低,而趋化素、瘦素、Wnt5a、hsCRP显著升高,差异有统计学意义(P<0.05);TNF-α在两组间比较差异无统计学意义(P<0.05);生活方式干预后肥胖高血压组儿童血中脂联素及Sfrp5与干预前相比显著升高,而趋化素、瘦素、Wnt5a、hsCRP则显著降低(P<0.05)。肥胖高血压患儿在接受生活方式干预后BMI的变化(ΔBMI)与收缩压及舒张压的变化关联中,控制协变量后,ΔSfrp5及Δ脂联素具有部分中介效应,而Δ趋化素及ΔhsCRP在BMI的变化(ΔBMI)与收缩压及舒张压变化的关联中无中介效应。结论 Sfrp5和脂联素在肥胖儿童血压升高的过程中具有一定中介作用。

关键词: 肥胖, 血压, 细胞因子, 体重指数, 中介效应分析