Department of Obstetrics and Gynecology Didactics, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Poland.
Department of Obstetrics and Gynecology, First Faculty of Medicine, Medical University of Warsaw, Warsaw, Poland.
PLoS One. 2019 Nov 7;14(11):e0224863. doi: 10.1371/journal.pone.0224863. eCollection 2019.
Studies have demonstrated leptin involvement in the physiology and pathophysiology of pregnancy and suggest that leptin may be a prognostic marker for some complications of pregnancy although the association remains unclear. To date no studies have reported leptin reference intervals established in normal pregnancy, which could be used for interpreting the differences in leptin levels found in normal and pathological pregnancies.
To determine leptin concentrations at delivery, in maternal serum in normal pregnancy and in cord blood and to establish reference intervals for leptin.
The study was performed in 194 pregnant women without any comorbid health conditions. Leptin concentrations in maternal serum and in cord blood were measured by ELISA and subsequently analyzed by gestational age (weeks), maternal Body Mass Index (BMI), mode of delivery and infant gender and birth weight. For comparative analyses of normally distributed variables, parametric tests such as the Student-t were used to test the assumption of homogeneity or non-homogeneity of variance and a One-Way ANOVA when more than two groups were compared. The Pearson correlation coefficient was calculated to assess the correlation between normally distributed variables (p<0.05). The reference intervals for leptin were obtained by referring to the central 95% of laboratory test values.
In normal pregnant women, the mean serum leptin concentration at delivery was 37.17 ± 28.07 ng/mL and the established reference interval was 33.19-41.14 ng/mL. The mean leptin concentration in cord blood was 14.78 ± 15.97 ng/mL and the established reference interval was 12.32-17.67 ng/mL. There was a statistically significant positive correlation between maternal serum and cord blood leptin concentrations (r = 0.37; p = 0.00). Mean leptin concentrations in cord blood increased with gestational age (p = 0.00). No statistically significant differences in maternal serum and cord blood leptin concentrations were found in regard to mode of delivery and neonatal gender. A statistically significant correlation was found between maternal serum leptin and third-trimester BMI (r = 0.22; p = 0.00), but there was no association between maternal BMI and cord blood leptin concentration. There was a statistically significant positive correlation between cord blood leptin concentration and birth weight (r = 0.23; p = 0.00).
Reference intervals for leptin in maternal serum and in cord blood established in normal pregnancy could be used in clinical practice for interpreting the differences in leptin concentrations found in normal pregnancy and in complications of pregnancy. The results indicate a strong association between maternal serum leptin levels and obesity and between cord blood leptin levels and birth weight.
研究表明瘦素参与妊娠的生理和病理生理学，并提示瘦素可能是某些妊娠并发症的预后标志物，尽管其相关性尚不清楚。迄今为止，尚无研究报告在正常妊娠中建立瘦素参考区间，该区间可用于解释正常和病理妊娠中瘦素水平的差异。
测定正常妊娠时产妇血清和脐血中的瘦素浓度，并建立瘦素参考区间。
本研究纳入了 194 名无任何合并健康状况的孕妇。通过 ELISA 法测定产妇血清和脐血中的瘦素浓度，随后按孕周、产妇体重指数（BMI）、分娩方式和婴儿性别及出生体重进行分析。对于正态分布变量的比较分析，采用参数检验，如学生 t 检验来检验方差同质性或异质性的假设，当比较两组以上时采用单因素方差分析。用 Pearson 相关系数评估正态分布变量之间的相关性（p<0.05）。瘦素参考区间是通过参考实验室检测值的中央 95%获得的。
在正常孕妇中，分娩时血清瘦素浓度的平均值为 37.17 ± 28.07 ng/mL，建立的参考区间为 33.19-41.14 ng/mL。脐血中瘦素的平均浓度为 14.78 ± 15.97 ng/mL，建立的参考区间为 12.32-17.67 ng/mL。产妇血清和脐血中瘦素浓度呈显著正相关（r = 0.37；p = 0.00）。随着胎龄的增加，脐血中瘦素浓度呈显著增加趋势（p = 0.00）。分娩方式和新生儿性别对产妇血清和脐血中瘦素浓度无显著影响。产妇血清瘦素与孕晚期 BMI 呈显著正相关（r = 0.22；p = 0.00），但产妇 BMI 与脐血瘦素浓度无关。脐血瘦素浓度与出生体重呈显著正相关（r = 0.23；p = 0.00）。
正常妊娠时产妇血清和脐血中瘦素的参考区间可用于临床实践，以解释正常妊娠和妊娠并发症中瘦素浓度的差异。结果表明，产妇血清瘦素水平与肥胖密切相关，脐血瘦素水平与出生体重密切相关。
