A possible association between the -2518 A>G MCP-1 polymorphism and insulin resistance in school children

ABSTRACT Objective Monocyte chemoattractant protein 1 (MCP-1) has been suggested to be involved in the pathophysiology of insulin resistance (IR); therefore, variants in the MCP-1 gene may contribute to the development of this disease. The aim of this study was to analyze the relationship of the -2518 A>G MCP-1 (rs1024611) gene polymorphism with insulin resistance in Mexican children. Subjects and methods A cross-sectional study was performed in 174 children, including 117 children without insulin resistance and 57 children with IR, with an age range of 6-11 years. Levels for serum insulin and high-sensitivity C-reactive protein were determined. The -2518 A>G MCP-1 polymorphism was identified by the polymerase chain reaction-restriction fragment length polymorphism method. Insulin resistance was defined as a HOMA-IR in the upper 75th percentile, which was ≥ 2.4 for all children. Results Genotype frequencies of the rs1024611 polymorphism for the insulin-sensitive group were 17% AA, 48% AG and 35% GG, and the frequency of G allele was 59%, whereas frequencies for the insulin-resistant group were 12% AA, 37% AG and 51% GG, and the frequency of G allele was 69%. The genotype and allele frequencies between groups did not show significant differences. However, the GG genotype was the most frequent in children with IR. The GG genotype was associated with insulin resistance (OR = 2.2, P = 0.03) in a genetic model. Conclusion The -2518 A>G MCP-1 gene polymorphism may be related to the development of insulin resistance in Mexican children.

ABSTRACT
目的 单核细胞趋化蛋白1（Monocyte chemoattractant protein 1, MCP-1）已被提示参与胰岛素抵抗（insulin resistance, IR）的病理生理过程，因此MCP-1基因的变异可能参与该疾病的发生发展。本研究旨在分析-2518 A>G MCP-1（rs1024611）基因多态性与墨西哥儿童胰岛素抵抗的关联。
研究对象与方法 本研究为横断面研究，共纳入174名6~11岁儿童，其中无胰岛素抵抗者117名，合并胰岛素抵抗者57名。检测受试者血清胰岛素及高敏C反应蛋白水平。采用聚合酶链反应-限制性片段长度多态性（polymerase chain reaction-restriction fragment length polymorphism, PCR-RFLP）方法鉴定-2518 A>G MCP-1基因多态性。胰岛素抵抗定义为稳态模型评估胰岛素抵抗指数（HOMA-IR）处于所有受试者的前75百分位数，即≥2.4。
结果 胰岛素敏感组rs1024611多态性的基因型频率分别为AA型17%、AG型48%、GG型35%，G等位基因频率为59%；胰岛素抵抗组的基因型频率分别为AA型12%、AG型37%、GG型51%，G等位基因频率为69%。两组间基因型及等位基因频率无显著统计学差异，但GG基因型在胰岛素抵抗儿童中最为常见。在遗传模型分析中，GG基因型与胰岛素抵抗存在显著关联（比值比OR=2.2，P=0.03）。
结论 -2518 A>G MCP-1基因多态性可能与墨西哥儿童胰岛素抵抗的发生发展相关。