The associations between cardiometabolic index and mortalities in chronic kidney disease

The incidence of chronic kidney disease (CKD) is on the rise, and the presence of cardiovascular diseases can affect the lifespan of patients with CKD. Among CKD patients, uremic toxins gradually accumulate, leading to chronic inflammation and further promoting the progression of CKD. This study aimed to investigate the relationship between cardiometabolic index (CMI) and all-cause and cardiovascular mortality in patients with CKD using data from the National Health and Nutrition Examination Survey and to analyze the potential mediating roles of inflammatory markers. Multivariate Cox regression models were used to assess the association between CMI and mortality, subgroup analyses were performed to test for heterogeneity, and mediation models were used to quantify the proportion of mediation by inflammatory markers. The statistical software was R 4.3.2, and the significance threshold was set at P < .05. Among 3815 CKD patients followed for a median of 99.89 months, 1391 all-cause and 516 cardiovascular deaths occurred. After multivariate adjustment, a higher CMI was associated with increased all-cause mortality (hazard ratio = 1.12, 95% confidence interval = 1.03-1.22), but not with cardiovascular mortality. CMI was positively correlated with leukocyte (β = 0.40) and neutrophil (β = 0.18) counts (all P < .001). Mediation analysis showed that leukocytes and neutrophils mediated 5.60% and 7.27% of the effect of CMI on all-cause mortality, respectively (P < .01). CMI may serve as a potential biomarker for prognostic assessment in patients with CKD and emphasize the key role of systemic inflammation in metabolic-renal interactions.