Differences in plasma levels of long chain and very long chain ceramides between African Americans and whites: An observational study

BackgroundPopulation-wide reductions in cardiovascular disease (CVD) have not been equally shared in the African American community due to a higher burden of CVD risk factors such as metabolic disorders and obesity. Differential concentrations of sphingolipids such as ceramide, sphingosine, and sphingosine 1-phosphate (S1P) has been associated with the development of CVD, metabolic disorders (MetD), and obesity. Whether African Americans have disparate expression levels of sphingolipids that explain higher burdens of CVD remains unknown.MethodsA cross sectional analysis of plasma concentrations of ceramides, sphingosine, and S1P were measured from 8 whites and 7 African Americans without metabolic disorders and 7 whites and 8 African Americans with metabolic disorders using high performance liquid chromatography/tandem mass spectrometry methodology (HPLC/MS-MS). Subjects were stratified by both race and metabolic status. Subjects with one or more of the following physician confirmed diagnosis: diabetes, hypertension, hypercholesterolemia, or dyslipidemia were classified as having metabolic disease (MetD). Data was analyzed using a Two-Way ANOVA and Tukey’s post hoc test.ResultsTotal ceramide levels were increased in African Americans compared to African Americans with MetD. Ceramide C16 levels were higher in whites with MetD compared to African Americans with MetD (pConclusionsPlasma ceramide concentration patterns are distinct in African Americans with MetD. Further research with larger samples sizes are needed to confirm these findings and to understand whether racial disparities in sphingolipid concentrations have potential therapeutic implications for CVD-related health outcomes.

研究背景：全人群心血管疾病（CVD）发病率的下降并未在非裔美国人群体中得到同等程度的惠及，这是由于该群体所承担的心血管疾病危险因素（如代谢紊乱与肥胖）负担更重。神经酰胺、鞘氨醇及1-磷酸鞘氨醇（S1P）等鞘脂类物质的浓度差异，已被证实与心血管疾病、代谢紊乱（MetD）及肥胖的发生发展相关。目前尚不明确非裔美国人是否存在鞘脂表达水平的异常，而这或许可以解释其更高的心血管疾病负担。
研究方法：本研究采用高效液相色谱-串联质谱法（HPLC/MS-MS），对4组受试者的血浆神经酰胺、鞘氨醇及1-磷酸鞘氨醇浓度进行检测。受试者分组为：无代谢紊乱的白人8名、非裔美国人7名，以及合并代谢紊乱的白人7名、非裔美国人8名。所有受试者按种族与代谢状态进行分层。经医师确诊存在以下1项及以上病症者被归类为代谢疾病（MetD）患者：糖尿病、高血压、高胆固醇血症或血脂异常。数据采用双因素方差分析（Two-Way ANOVA）与Tukey事后检验进行统计学分析。
研究结果：与合并代谢紊乱的非裔美国人相比，整体非裔美国人的总神经酰胺水平升高。合并代谢紊乱的白人的神经酰胺C16水平高于合并代谢紊乱的非裔美国人（p
研究结论：合并代谢紊乱的非裔美国人的血浆神经酰胺浓度模式具有特异性。未来需开展更大样本量的研究以验证本研究结果，并明确鞘脂浓度的种族差异是否对心血管疾病相关健康结局具有潜在的临床治疗指导意义。