Gao Xiang, Tian Yuan, Randell Edward, Zhou Haicheng, Sun Guang
College of Life Sciences, Qingdao University, Qingdao, China.
Faculty of Medicine, Memorial University, St. John's, NL, Canada.
Front Endocrinol (Lausanne). 2019 Mar 26;10:168. doi: 10.3389/fendo.2019.00168. eCollection 2019.
We aimed to study the relationships between serum Trimethylamine N-oxide (TMAO) and L-carnitine levels with metabolic syndrome profiles, including obesity, blood pressure, serum lipids, serum glucose and insulin resistance (IR)-related index in humans. Cross-sectional study was performed in 1,081 subjects from the CODING study in Newfoundland. Serum TMAO and L-carnitine levels were quantified by LC-MS/MS. Metabolic markers were measured in all subjects using fasting blood samples. Partial correlation and linear regression analysis were employed after systematically controlling the major confounding factors, such as age, gender, calorie intake and physical activity level. Serum L-carnitine level was positively correlated with serum triglyceride (TG), serum insulin, IR in males with normal fasting glucose ( < 0.05 for all) and positively correlated with only serum TG ( < 0.05) in those with hyperglycemia. In females, significant positive correlations were identified between serum L-carnitine level with obesity, serum total cholesterol, glucose, insulin, and IR in those with normal fasting glucose level ( < 0.05 for all), while none was found in those with hyperglycemia. Serum TMAO level was only identified to be positively correlated with serum insulin level and IR in hyperglycemic males ( < 0.05 for all). Serum L-carnitine level was significantly associated with an unfavorable metabolic syndrome (MS) profile mainly in subjects with normal serum glucose level, while serum TMAO level was associated with an unfavorable MS profile in subjects with hyperglycemia. The gender difference warrants further investigations.
我们旨在研究血清氧化三甲胺（TMAO）和左旋肉碱水平与代谢综合征特征之间的关系，这些特征包括人类的肥胖、血压、血脂、血糖和胰岛素抵抗（IR）相关指标。对来自纽芬兰CODING研究的1081名受试者进行了横断面研究。采用液相色谱-串联质谱法（LC-MS/MS）对血清TMAO和左旋肉碱水平进行定量。使用空腹血样对所有受试者的代谢标志物进行检测。在系统控制年龄、性别、热量摄入和身体活动水平等主要混杂因素后，采用偏相关和线性回归分析。血清左旋肉碱水平与空腹血糖正常男性的血清甘油三酯（TG）、血清胰岛素、IR呈正相关（均P<0.05），与高血糖患者的血清TG呈正相关（P<0.05）。在女性中，空腹血糖水平正常者的血清左旋肉碱水平与肥胖、血清总胆固醇、血糖、胰岛素和IR呈显著正相关（均P<0.05），而高血糖者未发现相关性。血清TMAO水平仅在高血糖男性中与血清胰岛素水平和IR呈正相关（均P<0.05）。血清左旋肉碱水平主要在血糖正常的受试者中与不良代谢综合征（MS）特征显著相关，而血清TMAO水平在高血糖受试者中与不良MS特征相关。性别差异值得进一步研究。
