Kanaka-Gantenbein Christina, Margeli Alexandra, Pervanidou Panagiota, Sakka Sophia, Mastorakos George, Chrousos George P, Papassotiriou Ioannis
First Department of Pediatrics, Division of Endocrinology, Metabolism and Diabetes, Athens University Medical School, Athens, Greece.
Clin Chem. 2008 Jul;54(7):1176-82. doi: 10.1373/clinchem.2007.099002. Epub 2008 May 16.
although there is much evidence regarding the physiologic and pathogenic roles of the newly described adipokines retinol-binding protein 4 (RBP4) and lipocalin-2 as potential promoters of insulin resistance in obese adults, relatively little information exists regarding their roles in obese children.
we investigated the circulating concentrations of RBP4 and lipocalin-2 in 80 obese girls (ages 9- 15 years) and their relationships with high-sensitivity C-reactive protein (hs-CRP) and the adipokines leptin and adiponectin. We divided participants by their body mass index standard deviation scores (BMI SDSs) into 4 groups of 20 girls each: overweight [mean BMI SDS (SD), 1.8 (0.4)], obese [2.2 (0.4)], morbidly obese [3.6 (0.4)], and lean controls [-0.11 (0.4)]. We measured plasma-soluble RBP4, the RBP4-binding protein transthyretin, lipocalin-2, hs-CRP, leptin, and adiponectin and calculated the homeostatic assessment model (HOMA) index from fasting glucose and insulin concentrations.
unexpectedly, plasma RBP4 and lipocalin-2 concentrations were correlated negatively with BMI SDS values (P = 0.005, and P < 0.03, respectively). These results were different from those of adults and were not correlated with the HOMA index. In contrast, hs-CRP and leptin concentrations were positively correlated with BMI SDS values (P < 0.0001, and P < 0.00001, respectively), as expected, whereas the adiponectin concentration was negatively correlated (P = 0.008).
although the correlations of leptin, adiponectin, and hs-CRP concentrations with BMI in children are similar to those of adults, the correlations of RBP4 and lipocalin-2 with BMI in children are the inverse of those observed in adults. Thus, although systemic inflammation and mild insulin resistance are present in childhood obesity, RBP4 and lipocalin-2 concentrations are not increased in children as they are in obese adults with long-standing severe insulin resistance and type 2 diabetes.
尽管有大量证据表明新发现的脂肪因子视黄醇结合蛋白4（RBP4）和lipocalin-2在肥胖成年人中作为胰岛素抵抗潜在促进因子的生理和致病作用，但关于它们在肥胖儿童中的作用的信息相对较少。
我们调查了80名肥胖女孩（9至15岁）循环中RBP4和lipocalin-2的浓度，以及它们与高敏C反应蛋白（hs-CRP）、脂肪因子瘦素和脂联素的关系。我们根据她们的体重指数标准差评分（BMI SDS）将参与者分为4组，每组20名女孩：超重[平均BMI SDS（标准差），1.8（0.4）]、肥胖[2.2（0.4）]、病态肥胖[3.6（0.4）]和瘦对照组[-0.11（0.4）]。我们测量了血浆可溶性RBP4、RBP4结合蛋白转甲状腺素蛋白、lipocalin-2、hs-CRP、瘦素和脂联素，并根据空腹血糖和胰岛素浓度计算稳态模型评估（HOMA）指数。
出乎意料的是，血浆RBP4和lipocalin-2浓度与BMI SDS值呈负相关（分别为P = 0.005和P < 0.03）。这些结果与成年人的不同，且与HOMA指数无关。相反，正如预期的那样，hs-CRP和瘦素浓度与BMI SDS值呈正相关（分别为P < 0.0001和P < 0.00001），而脂联素浓度呈负相关（P = 0.008）。
尽管儿童中瘦素、脂联素和hs-CRP浓度与BMI的相关性与成年人相似，但儿童中RBP4和lipocalin-2与BMI的相关性与成年人中观察到的情况相反。因此，尽管儿童肥胖中存在全身炎症和轻度胰岛素抵抗，但儿童中RBP4和lipocalin-2的浓度并不像患有长期严重胰岛素抵抗和2型糖尿病的肥胖成年人那样升高。
