Serum amyloid A and risks of all-cause and cardiovascular mortality in chronic kidney disease: a systematic review and dose-response meta-analysis

BACKGROUNDS: The available literature on the correlation between serum amyloid A (SAA) and prognosis of chronic kidney disease (CKD) are limited, and the findings from existing studies are inconclusive. This meta-analysis aimed to evaluate the available evidence regarding the link between SAA and risks of all-cause and cardiovascular mortality in CKD patients. Additionally, we aimed to investigate the potential dose-response relationships, provided that adequate data is accessible. METHODS: Pubmed and Embase were searched for related literature (last update: 12 July 2023). The pooled effect estimates were calculated using random- or fixed-effects models depending on heterogeneity among studies. RESULTS: This meta-analysis incorporated 8 studies encompassing 2331 CKD patients. The findings revealed an 85% increase in all-cause mortality risk [hazard risk (HR) 1.85, 95% confidence interval (CI) 1.29–2.65] and a 39% increase in cardiovascular mortality risk (HR 1.07, 95% CI 1.07–1.80) when comparing the highest tertile of baseline SAA levels to the lowest tertile. Furthermore, a positive linear relationship between SAA and all-cause mortality risk was observed (P(non-linearity) = 0.959), with a 17.7% increase in risk for each 10 mg/L SAA increase (HR 1.177, 95% CI 1.055–1.313). Similarly, a linear relationship between SAA and cardiovascular mortality risk was identified (P(non-linearity) = 0.477) with a 19.3% increase in risk for each 10 mg/L SAA increase (HR 1.193, 95% CI 1.025–1.388). CONCLUSIONS: This meta-analysis provided evidence that SAA levels are positively and linearly associated with risks of all-cause and cardiovascular mortality among CKD patients.