Qian Liu, Renyang Liu, Jing Yang, Jie Li
Background The C‐reactive protein–albumin–lymphocyte (CALLY) index is a novel composite marker that reflects systemic inflammation, nutrition, and immune status. However, its association with mortality among individuals with diabetes or prediabetes remains uncertain. This study aimed to assess the relationship between the CALLY index and both all‐cause (ACM) and cardiovascular mortality (CVM) in U.S. adults with diabetes or prediabetes. Methods A total of 8463 adults with diabetes or prediabetes from the U.S. NHANES (2003–2010 and 2015–2018) were included in the analysis. Cox proportional hazards models were used to evaluate potential linear associations between the CALLY index and ACM and CVM. Kaplan–Meier survival curves and log‐rank tests were used to compare cumulative survival across groups. Restricted cubic spline (RCS) models were applied to examine potential nonlinear associations. Results During an average follow‐up of 7.83 years, 1391 participants died, 470 from cardiovascular causes. After adjusting for all confounders, the natural log‐transformed (ln) CALLY index was inversely associated with ACM (HR = 0.83, 95% CI: 0.79–0.88) and CVM (HR = 0.82, 95% CI: 0.74–0.92). Compared to participants in the lowest quartile of the ln CALLY index, those in the highest quartile had significantly lower risks of ACM (HR = 0.67, 95% CI: 0.55–0.81) and CVM (HR = 0.66, 95% CI: 0.45–0.98). Kaplan–Meier survival analysis showed significantly higher survival probabilities among individuals in higher ln CALLY index quartiles ( p < 0.001). RCS models further indicated a nonlinear relationship between the ln CALLY index and both ACM and CVM ( p < 0.0001 for nonlinearity). Conclusions A higher CALLY index is independently associated with lower risks of ACM and CVM among individuals with diabetes or prediabetes. These findings suggest that the CALLY index may serve as a valuable marker for monitoring mortality risk in these populations.