Association of Leptin and Leptin receptor Gene Polymorphisms with Insulin Resistance in Pregnant Women: A Cross-Sectional Study

Introduction: The objective of the study was to find the association between leptin/LEPR gene polymorphism and insulin resistance, in order to find the extent of risk of leptin gene polymorphism in causing insulin resistance in pregnant women.
Methodology: Two hundred and eight pregnant women participated in this cross-sectional study of which 74 were insulin resistant cases and 134 were insulin sensitive controls. Genotyping of leptin and its receptor gene was carried out using the PCR-RFLP method. Serum levels of leptin, insulin, and C peptide were assayed using ELISA. Statistical analysis was carried out using SPSS 23.
Results: Insignificant association was observed between leptin receptor gene polymorphisms and insulin resistance (chi-square=0.1275 p=0.721) and leptin gene and insulin-resistant women ((chi-square 0.221, p = 0.638). There was no significant difference in the serum leptin levels between the cases and control (61.62±29.23 and 59.88±22.25). However, fasting blood sugar, insulin, C peptide, TG and VLDL levels were significantly higher in cases as compared to controls. Subjects with homozygous dominant, ‘GG’ of LEPR showed higher insulin resistance and hyperinsulinemia than other genotypes. However, subjects with homozygous dominant, ‘AA’ of leptin gene showed hyperglycemia as compared to other genotypes.
Conclusion: This study, therefore, concluded that no established association of gene polymorphism in detecting insulin resistance in pregnancy, hyperleptinemia in pregnancy is also not a finding in predicting insulin resistance. However, an increase in C peptide, insulin, glucose, and triglyceride levels in pregnant women can help detect insulin resistance at the earliest and prevent gestational diabetes.

研究背景与目的：本研究旨在探讨瘦素（leptin）/瘦素受体基因（LEPR）多态性与胰岛素抵抗（insulin resistance）的关联，明确孕妇群体中瘦素基因多态性引发胰岛素抵抗的风险程度。
研究方法：本横断面研究（cross-sectional study）共纳入208名孕妇，其中74例为胰岛素抵抗病例组，134例为胰岛素敏感对照组。采用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）法对瘦素及其受体基因进行基因分型。采用酶联免疫吸附测定（ELISA）法检测血清瘦素、胰岛素及C肽水平。统计分析采用SPSS 23软件完成。
研究结果：瘦素受体基因多态性与胰岛素抵抗无显著关联（卡方检验（chi-square）=0.1275，P=0.721）；瘦素基因多态性与胰岛素抵抗孕妇亦无显著关联（卡方值=0.221，P=0.638）。病例组与对照组的血清瘦素水平无显著差异（61.62±29.23与59.88±22.25）。但病例组的空腹血糖（fasting blood sugar）、胰岛素、C肽、甘油三酯（TG）及极低密度脂蛋白（VLDL）水平均显著高于对照组。携带瘦素受体基因纯合显性基因型“GG”的受试者，相较于其他基因型受试者，表现出更高的胰岛素抵抗与高胰岛素血症（hyperinsulinemia）。而携带瘦素基因纯合显性基因型“AA”的受试者，相较于其他基因型受试者，更易出现高血糖（hyperglycemia）症状。
研究结论：综上，本研究得出结论：在孕妇胰岛素抵抗的检测中，未发现基因多态性具有明确的关联价值；妊娠期高瘦素血症（hyperleptinemia）也无法用于预测胰岛素抵抗。但孕妇体内C肽、胰岛素、血糖及甘油三酯水平升高，可帮助尽早检出胰岛素抵抗，进而预防妊娠期糖尿病（gestational diabetes）。