BACKGROUND AND AIMS The relationship between serum amyloid A (SAA) and coronary heart disease (CHD) remains inconsistent, and the correlation of SAA levels and some factors have not been thoroughly evaluated in CHD. The present study assessed the associations of SAA levels and CHD, and the correlation of SAA levels and CRP, fibrinogen, interleukin-6 (IL-6), and HDL-C levels in CHD patient. METHODS We systematically searched databases of Cochrane Library, PubMed, Embase, and ScienceDirect from their inception to 2018. Pooled standardized mean difference (SMD), correlation coefficient (r), and 95% confidence intervals (CI) were computed using random-effect model. RESULT A total of 26 studies were identified for analysis, involving a total of 6466 CHD cases and 16,184 participants. Compared with the control group, the case group had markedly higher SAA levels (SMD = 0.38, 95% CI 0.21, 0.56). Subgroup analysis manifested that SAA level difference between case group and control group were associated with age, continent, and study type. Moreover, meta-regression model suggested that different continent, sex, and publication year can explain the origin of 52.05%, 50.17%, 28.07% heterogeneity, respectively. By stratified analyses, we further found that the concentration of SAA increased gradually with the aggravation of CHD. Additionally, the meta-analysis of correlation showed that SAA levels were positively related with CRP (r = 0.45, 95% CI 0.19, 0.71), fibrinogen (r = 0.41, 95% CI 0.35, 0.47), and IL-6 (r = 0.48, 95% CI 0.41, 0.54) levels, but negatively linked with HDL-C levels (r = - 0.28, 95% CI - 0.38, - 0.18) in CHD patients. CONCLUSION High levels of SAA are significantly associated with increased risk of CHD, especially for participants aged more than 55 years, subjects from Europe and Asia, or case-control study. Furthermore, we find that SAA concentrations increased with the severity of CHD. Importantly, our study suggests that high levels of SAA might play a role in CHD by increasing CRP, fibrinogen, IL-6 levels, or attenuating HDL-C levels.

中文翻译：

---

血清淀粉样蛋白A水平与冠心病之间的关联：对26项研究的系统评价和荟萃分析。

背景与目的血清淀粉样蛋白A（SAA）与冠心病（CHD）之间的关系仍然不一致，并且SAA水平与某些因素之间的相关性尚未在CHD中进行彻底评估。本研究评估了冠心病患者的SAA水平与CHD的相关性，以及SAA水平与CRP，纤维蛋白原，白介素6（IL-6）和HDL-C水平的相关性。方法我们从Cochrane图书馆，PubMed，Embase和ScienceDirect的数据库开始到2018年，系统地对其进行了搜索。使用随机效应模型计算了合并的标准均值差（SMD），相关系数（r）和95％置信区间（CI）。 。结果共鉴定出26项研究进行分析，涉及6466例冠心病病例和16,184名参与者。与对照组相比，该病例组的SAA水平明显较高（SMD = 0.38，95％CI 0.21，0.56）。亚组分析表明，病例组和对照组之间的SAA水平差异与年龄，大陆和研究类型有关。而且，元回归模型表明，不同大陆，性别和出版年份可以分别解释异质性的起源，分别为52.05％，50.17％和28.07％。通过分层分析，我们进一步发现SAA的浓度随着CHD的增加而逐渐增加。此外，相关性的荟萃分析表明，SAA水平与CRP（r = 0.45，95％CI 0.19，0.71），纤维蛋白原（r = 0.41，95％CI 0.35，0.47）和IL-6（r正相关= 0.48，95％CI 0.41，0.54）水平，但与CHD患者的HDL-C水平呈负相关（r =-0.28，95％CI-0.38，-0.18）。结论高水平的SAA与冠心病风险增加显着相关，特别是对于55岁以上的参与者，欧洲和亚洲的受试者或病例对照研究。此外，我们发现SAA浓度随冠心病的严重程度而增加。重要的是，我们的研究表明，高水平的SAA可能通过增加CRP，纤维蛋白原，IL-6水平或减弱HDL-C水平而在冠心病中发挥作用。