Introduction

Leptin is known to regulate pathways of energy metabolism, reproduction, and control appetite. Whether plasma leptin levels reflect changes in metabolites of these pathways is unknown.

Objectives

We aimed to find whether there is an association between leptin levels and levels of metabolites of energy and hormone metabolism.

Methods

We performed an untargeted metabolomics analysis of plasma from 110 healthy adults (men: women = 1:1; aged 18–40 years), using liquid chromatography-tandem mass spectrometry. Blood samples were collected from all the study subjects in the fasting state. Clinical features and markers of obesity and Type 2 diabetes mellitus (T2DM) were assessed in all. The association between levels of metabolites and clinical and biochemical parameters was identified using the multivariable-adjusted linear regression model and PLS-DA analysis.

Results

The leptin level was found to have a significant association with a substantial number of metabolites in women and men. Leptin level was positively associated with glycocholic acid and arachidic acid, metabolites related to energy metabolisms, pregnanediol-3-glucuronide, a metabolite of progesterone metabolism, and quercetin 3′-sulfate, a diet-derived metabolite. Leptin level was negatively associated with ponasteroside A and barringtogenol C levels. Leptin level was positively correlated with adiponectin and negatively with total calorie intake and levels of triglyceride and very-low-density lipoprotein. Leptin levels were associated with lipid and sex hormone metabolism in women, while metabolites involved in amino acid metabolism were correlated to leptin in men.

Conclusion

Our study indicates that leptin level reflects metabolome alterations and hence could be a useful marker to detect early changes in energy and hormone metabolisms.

中文翻译：

---

血浆瘦素水平反映了年轻人的代谢组变化。

介绍

瘦素可调节能量代谢，繁殖和控制食欲的途径。血浆瘦素水平是否能反映这些途径代谢产物的变化尚不清楚。

目标

我们旨在发现瘦素水平与能量和激素代谢的代谢产物水平之间是否存在关联。

方法

我们使用液相色谱-串联质谱法对110名健康成年人（男性：女性= 1：1；年龄18至40岁）的血浆进行了非目标代谢组学分析。在禁食状态下从所有研究对象中采集血液样本。评估了肥胖症和2型糖尿病（T2DM）的临床特征和标志。使用多变量调整的线性回归模型和PLS-DA分析确定了代谢物水平与临床和生化指标之间的关联。

结果

发现瘦素水平与男女中大量代谢物有显着关联。瘦素水平与糖胆酸和花生四烯酸，与能量代谢有关的代谢产物，孕激素代谢的代谢物孕孕二醇-3-葡糖醛酸和饮食来源的代谢物槲皮素3'-硫酸正相关。瘦素水平与ponasteroside A和barringtogenol C水平呈负相关。瘦素水平与脂联素呈正相关，与总卡路里摄入量，甘油三酸酯和极低密度脂蛋白呈负相关。瘦素水平与女性脂质和性激素代谢相关，而参与氨基酸代谢的代谢产物与男性瘦素相关。

结论

我们的研究表明，瘦素水平反映了代谢组的变化，因此可能是检测能量和激素代谢早期变化的有用标记。