The associations of calf circumference and cardiovascular and all-cause mortality among population with chronic kidney disease stages 3–5

Previous studies have described the association between calf circumference (CC) and chronic kidney disease (CKD). We aim to evaluate the associations between CC and cardiovascular and all-cause mortality in patients with CKD stages 3-5. Data on CKD were sourced from the National Health and Nutritional Examination Survey (NHANES) 1999-2004. The population was stratified into three groups based on their CC tertile. Kaplan-Meier method with log-rank tests for significance was used for survival analysis. Weighted Cox proportional hazards regression models were employed to estimate the hazard ratios (HRs) for cardiovascular and all-cause mortality. The potential nonlinear relationship between CC and mortality was assessed using restricted cubic spline (RCS) models. Subgroup and sensitivity analyses were conducted to strengthen the results. A total of 1166 patients were eventually included in this study. After a mean follow-up of 127.78 months, a total of 922 all-cause deaths were recorded, with 515 of them attributed to cardiovascular diseases. The Kaplan-Meier curve indicated a significant difference in overall survival between the three groups (log-rank test, P 38.5 group, participants in the CC < 35.0 group had HR of 2.05 (1.44, 2.93) for all-cause mortality and 1.58 (0.75, 3.33) for cardiovascular mortality, respectively. We observed a significant nonlinear relationship between CC and cardiovascular and all-cause mortality (P-nonlinear < 0.05). Subgroup analysis further validated our results and demonstrated that the impact of CC on prognosis varies according to distinct characteristics. Sensitivity analyses yielded similar results for both all-cause and cardiovascular mortality. A reduced CC is correlated with a poorer prognosis in CKD stages 3-5 patients, suggesting its potential utility as an innovative prognostic marker.