摘要Objective The benefits of caffeine to human health have been widely reported,but the association between caffeine intake and mortality among patients with chronic kidney disease(CKD)has been rarely reported in large epidemiologic studies.This study aimed to investigate the association between caffeine intake and mortality among CKD patients.Methods Our study was conducted among non-dialysis CKD patients in the 2003-2016 National Health and Nutrition Examination Survey(NHANES).Weighted COX regression analysis was used to explore the linear relationship between caffeine intake and mortality among CKD patients(including all-cause mortality,as well as mortality due to cardiovascular disease,cancer,cerebrovascular disease,nephropathy,and influenza or pneumonia).Restricted cubic spline analysis was performed to explore the nonlinear relationship.Finally,threshold effects were analyzed through fitting a two-piecewise linear regression model.Results In a fully adjusted model,no significant linear association was found between caffeine intake and mortality.How-ever,there was a U-shaped association between caffeine intake and all-cause mortality(inflection point:277 mg).Moreover,there was a J-shaped association between caffeine intake and cardiovascular mortality(inflection point:252 mg)and cancer mortality(inflection point:79 mg).Conclusion All-cause mortality was reduced in CKD patients when caffeine intake was less than 277 mg(about 1.85 cups of Americano).However,excessive caffeine intake was associated with increased all-cause mortality,cardiovascular mortality and cancer mortality in this population.