Abstract
We investigated the associations of plasma cystatin C with all-cause and cause-specific mortality risk and identified potential modifying factors affecting these associations in middle-aged and elderly people (≥ 50 years). This community-based prospective cohort study included 13,913 individuals aged ≥ 50 years from the Health and Retirement Study. Cox proportional hazard models were used to estimate the associations between cystatin C concentrations and the risk of all-cause and cardiovascular and cancer mortality after adjustment for sociodemographic characteristics, lifestyle factors, self-reported medical history, and other potential confounding factors. During a total of 71,988 person-years of follow-up (median: 5.8 years; interquartile range 3.3-7.6 years), 1893 all-cause deaths were documented, including 714 cardiovascular-related and 406 cancer-related deaths. The comparisons of the groups with the highest (quartile 4) and lowest (quartile 1) cystatin C concentrations revealed that the adjusted hazard ratios and 95% confidence intervals were 1.92 (1.62-2.28) for all-cause mortality, 1.98 (1.48-2.65) for cardiovascular mortality, and 1.62 (1.13-2.32) for cancer mortality. The associations of cystatin C concentrations with all-cause, cardiovascular and cancer mortality did not differ substantially when participants were stratified by sex, age, BMI, current smoking status, current alcohol consumption, and regular exercise (all P for interactions > 0.05). Our study indicates that an elevated plasma cystatin C concentration is associated with an increased risk of all-cause, cardiovascular and cancer mortality both men and women among the middle-aged and elderly individuals.