Cystatin C and mortality risk in the general population: systematic review and dose response meta-analysis.

INTRODUCTION: Cystatin C has been identified as an independent predictor of all-cause and cardiovascular mortality in the general population. This meta-analysis to evaluate the association between serum cystatin C level and all-cause and cardiovascular mortality. We additionally conducted a dose-response analysis to examine a linear association between cystatin C and cardiovascular mortality. METHODS: PudMed and Embase databases were searched until January, 2021. All prospective cohort studies that reported a multivariate-adjusted risk estimated of all-cause and cardiovascular mortality for the highest compared with lowest cystatin C level were included. RESULTS: 13 prospective cohort studies, a total of 57,214 participants were included in this analysis. Meta-analysis indicated that the highest compared with lowest cystatin C level was associated with an increase of all-cause mortality (hazard ratio [HR]: 2.01; 95% confidence intervals [CI]: 1.60-2.53; I2=89%) and cardiovascular mortality (2.62 [1.96-3.51]; I2=52%). We found a significant log-linear dose-response association between cystatin C and cardiovascular mortality (p < 0.01). Every 0.1 mg/L increase in cystatin C level was associated with a 7.3% increased cardiovascular mortality. CONCLUSIONS: Elevated serum cystatin C is associated with an increased risk of all-cause and cardiovascular mortality in the general populations. Particularly, cystatin C level and cardiovascular mortality showed linear correlation.