瘦素和脂联素在儿童肥胖相关性高血压发病中的作用

Roles of serum leptin and adiponectin on the development of obesity-related hypertension in children and adolescents:the BCAMS study

目的探讨瘦素和脂联素在儿童肥胖相关性高血压发病中的作用。方法基于北京市儿童青少年代谢综合征研究项目的现况调查结果,非随机选择3502名6~18岁学龄儿童(其中男1784名,女1718名)为研究对象,按照超重(包括肥胖)和高血压状态将研究对象分为4组,正常体重正常血压组(对照组,1497名)、正常体重高血压组(HBP组,125名)、超重但血压正常组(OB组,1349名)和超重合并高血压组(OB+HBP组,531名)。通过比较4组人群血清瘦素和脂联素水平,以及瘦素和脂联素与血压之间的相关回归分析,探讨其与肥胖和血压之间的关系。结果超重肥胖人群BMI、血压、胰岛素和瘦素水平显著升高,脂联素水平降低。HBP组与对照组BMI、瘦素、脂联素水平差异无统计学意义。OB组和OB+HBP组与对照组比较,BMI、SBP、DBP、胰岛素和瘦素水平升高,脂联素水平降低,与HBP组比较仍可见BMI、胰岛素和瘦素水平升高,脂联素水平降低。与OB组比较,OB+HBP组BMI和胰岛素水平及男性的瘦素水平明显升高。血压与年龄、BMI、胰岛素、瘦素均呈显著正相关(r=0.260~0.643,P<0.01),与脂联素呈显著负相关(r=-0.171^-0.332,P<0.01)。但在调整胰岛素或BMI后,瘦素、脂联素与血压的相关性减弱或消失。结论超重人群血压、胰岛素及瘦素水平均高于对照人群,脂联素水平低于对照人群。瘦素、脂联素可能通过肥胖或胰岛素抵抗与血压相关。

Objective To explore the effects of serum leptin and adiponectin concentrations on the pathogenesis of obesity-related hypertension for children and adolescents.Methods A total of 3 502 schoolchildren （1 784 boys and 1 718 girls） aged 6-18 years were recruited from the BCAMS study, which was a cross-sectional representative population-based survey on metabolic syndrome for children and adolescents in Beijing. In this study, participants were categorized into four groups （Control group, HBP group, OB group and OB＋HBP group） according to the sex-, age-specific body mass index （BMI） cutoffs recommended by the Working Group on Obesity in China, and systolic blood pressure （SBP） and/or diastolic blood pressure （DBP） equal to or greater than the 95th percentile for age and gender of schoolchildren in Beijing in 2004. Blood samples were obtained after a 12-hour fast, and the levels of plasma insulin, serum leptin and adiponectin were measured by sensitive, specific double-antibody sandwich enzyme-linked immunosorbent assays （ELISA）. Variables including insulin, leptin and adiponectin were skewed distribution and natural logarithmical transformations were performed. Analysis of variance, Spearman correlation, and multivariate regression analysis were conducted.Results Higher BMI, SBP and DBP, lower insulin, leptin and adiponectin levels were found in boys than in girls. There were no differences in BMI, serum leptin and adiponectin levels between the control group and the HBP group. Higher BMI, plasma insulin and serum leptin, and lower adiponectin levels were found in the OB group and OB＋HBP group than those in the control group or HBP group. BMI, plasma insulin levels of the participants in the OB＋HBP group, but only boys′ serum leptin levels were higher than those in the OB group. Both SBP and DBP had positively correlated with leptin （r=0.260-0.643, P〈0.01）and negatively correlated with adiponectin （r=-0.171-0.332, P〈0.01） for both genders. After adjusting for insulin or BMI, above correlations became weak or disappeared. The odds ratios （OR） and 95% confidence interval （95%CI） for the prediction of hypertension were elevated in children in the upper quartile of leptin level 2.75（2.28-3.32） compared with that in the lower quartile. The figures were 1.59（1.31-1.92） in the lower quartile of adiponectin level compared with in the upper quartile. When BMI was included in the models, all ORs for the prediction of hypertension were not significant for both hyperleptinaemia and hypoadiponectinaemia.Conclusions Levels of blood pressure, plasma insulin, serum leptin were higher and serum adiponectin was lower in overweight children than in control group. Leptin and adiponectin may be related to blood pressure through obesity or insulin resistance.