AbstractCardiovascular disease (CVD) is a group of health conditions affecting the heart and vascular system with very high prevalence and mortality rates. The presence of CVD is characterised by high levels of inflammation which have previously been associated with increased plasma concentrations of N-acetyl neuraminic acid (Neu5Ac). While Neu5Ac has been studied in the context of CVD, Neu5,9Ac2 has not, despite being the second most abundant sialic acid in human plasma. A small-scale pilot study of thirty plasma samples from patients with diagnosed CVD, and thirty age and sex-matched healthy controls, was designed to gain insight into sialic acids as biomarkers for CVD and potential future areas of study. Each sample was assayed for Neu5Ac and Neu5,9Ac2 concentrations. Mean Neu5Ac and Neu5,9Ac2 concentrations were significantly elevated in patients with CVD compared to healthy controls (Neu5Ac: P < 0.001; Neu5,9Ac2: P < 0.04). Receiver operator curve (ROC) analysis indicated that both Neu5Ac and Neu5,9Ac2 have reasonable predictive power for the presence of CVD (Neu5Ac AUC: 0.86; Neu5,9Ac2 AUC: 0.71). However, while Neu5Ac had both good sensitivity (0.82) and specificity (0.81), Neu5,9Ac2 had equivalent specificity (0.81) but very poor sensitivity (0.44). A combination marker of Neu5Ac + Neu5,9Ac2 showed improvement over Neu5Ac alone in terms of predictive power (AUC: 0.93), sensitivity (0.87), and specificity (0.90). Comparison to a known inflammatory marker, high sensitivity c-reactive protein (hs-CRP: P-value: NS, ROC:0.50) was carried out, showing that both Neu5Ac and Neu5,9Ac2 outperformed this marker. Further to this, hs-CRP values were combined with the three different sialic acid markers to determine any effect on the AUC values. A slight improvement in AUC was noted for each of the combinations, with Neu5Ac + Neu5,9Ac2 + hs-CRP giving the best AUC of 0.97 overall. Thus, Neu5Ac would appear to offer good potential as a predictive marker for the presence of CVD, which the addition of Neu5,9Ac2 predictive power improves, with further improvement seen by the addition of hs-CRP.
摘要心血管疾病(CVD)是一组影响心脏和血管系统的健康问题,发病率和死亡率都非常高。心血管疾病的特征是高水平的炎症,而炎症与血浆中 N-乙酰神经氨酸(Neu5Ac)浓度的升高有关。尽管 Neu5Ac 是人体血浆中含量第二高的硅醛酸,但却没有针对心血管疾病研究过 Neu5,9Ac2。为了深入了解作为心血管疾病生物标记物的硅酸以及未来潜在的研究领域,我们设计了一项小规模试验研究,研究对象是 30 名确诊心血管疾病的患者以及 30 名年龄和性别匹配的健康对照者。每个样本都检测了 Neu5Ac 和 Neu5,9Ac2 的浓度。与健康对照组相比,心血管疾病患者的平均 Neu5Ac 和 Neu5,9Ac2 浓度明显升高(Neu5Ac:P < 0.001;Neu5,9Ac2:P < 0.04)。接收运算曲线(ROC)分析表明,Neu5Ac 和 Neu5,9Ac2 对心血管疾病都有合理的预测能力(Neu5Ac AUC:0.86;Neu5,9Ac2 AUC:0.71)。然而,Neu5Ac 的灵敏度(0.82)和特异性(0.81)都很好,而 Neu5,9Ac2 的特异性(0.81)相当,但灵敏度(0.44)很差。Neu5Ac + Neu5,9Ac2组合标记物的预测能力(AUC:0.93)、灵敏度(0.87)和特异性(0.90)均优于单独的Neu5Ac。与已知的炎症标记物高灵敏度 c 反应蛋白(hs-CRP:P 值:NS,ROC:0.50)进行比较后发现,Neu5Ac 和 Neu5,9Ac2 均优于该标记物。此外,还将 hs-CRP 值与三种不同的硅酸标记物相结合,以确定对 AUC 值的影响。每种组合的 AUC 值都略有提高,其中 Neu5Ac + Neu5,9Ac2 + hs-CRP 的 AUC 值最高,为 0.97。由此看来,Neu5Ac 作为心血管疾病的预测标志物具有很好的潜力,加入 Neu5,9Ac2 可提高预测能力,加入 hs-CRP 可进一步提高预测能力。