Uric Acid Variability and All-Cause Mortality: A Prospective Cohort Study in Northern China

Objectives Uric acid(UA) is related with cardiovascular disease, but the association of UA variability with all-cause mortality is rarely known. This study aimed to investigate the relationship between UA variability and all-cause mortality in Kailuan cohort study in northern China. Design Cohort study. Setting Kailuan community hospitals in Tangshan, Hebei province, Northern China. Participants A total of 55717 participants from Kailuan Study were enrolled, and our study followed up biennially from 2006 to 2010. Measurements Clinical records of the participants enrolled were analyzed. UA variation independent of mean (UAVIM) values were calculated and all the participants were quartile grouped into four groups as: Q1(UAVIM<0.68), Q2(0.68 <= UAVIM<1.10), Q3(1.10 <= UAVIM<1.67) and Q4(UAVIM >= 1.67). The endpoint event was all-cause death. Cox regression model was performed to evaluate the hazard ratios(HRs) of all-cause mortality based on UAVIM groups. Results During a median follow-up of 6.83 years, 2926 deaths occurred. The accumulated mortality rates were 4.6%, 4.8%, 5.4% and 6.1% in group Q1, Q2, Q3 and Q4 respectively. When adjusted potential confounders, the highest risk for all-cause mortality was in group Q4 and the adjusted HRs and 95% confidence intervals(CIs) of group Q2-Q4 for all-cause death were 1.044(0.937, 1.164), 1.182(1.064, 1.314) and 1.353(1.220, 1.501) compared with group Q1, respectively. Further analysis showed that the risk for all-cause death increased as UAVIM value increased. Sensitive analysis still showed the similar results when excluding participants with hyperuricemia or severe chronic kidney diseases. Sub-group analysis by age, gender, BMI or hypertension history also indicated analogous results. Conclusion Elevated UAVIM was related with increased all-cause mortality and UAVIM was an independent risk factor for all-cause mortality in the community cohort study.

Automated summary

This study found a positive correlation between UA variability and all-cause mortality in a community cohort study in northern China. The risk of all-cause death increased as UAVIM value increased. Sensitivity analysis excluding participants with hyperuricemia or severe chronic kidney diseases still showed similar results.