Exploring the renal-cardiovascular axis regulation mechanism and nursing considerations for cardiovascular disease and chronic kidney disease comorbidities based on the 2013–2014 NHANES database

Cardiovascular disease (CVD) and chronic kidney disease (CKD) often co-occur. The incidence of cardiovascular events in CKD patients is much higher than that in general population, and CVD, in turn, accelerates renal function deterioration, forming a vicious cycle. With the kidneys regulating cardiovascular function through water and salt balance, blood pressure, and other factors, cardiovascular system abnormalities also have a reciprocal effect on the kidneys. However, the regulation mechanism of renal-cardiovascular axis in comorbid conditions has not yet been fully elucidated. The data were derived from National Health and Nutrition Examination Survey database, with a total of 1235 participants selected from 2013 to 2014 dataset. The data included demographic characteristics (age, gender, race), socioeconomic characteristics (education level, income-to-poverty ratio), and lifestyle characteristics. Spearman correlation analysis, logistic regression analysis, and subgroup analysis were employed to investigate associations between various factors and renal aspects of CVD and CKD comorbidity. Receiver operating characteristic curves were used to assess performance of CKD-CVD comorbidity risk prediction. Key influencing factors were identified through feature importance analysis; box plots were used to reflect age and income-to-poverty ratio under different CKD-CVD states. Scatter plots were also utilized to illustrate impact of age and income ratio in CKD-CVD risk assessment. Patients with CKD-CVD comorbidity were characterized by older age, male predominance, lower socioeconomic status, insufficient pharmacological intervention, and reduced physical activity. Age, low income, and low physical activity emerged as potential risk factors, while use of antihypertensive medications may serve as a disease marker. Logistic regression and subgroup analyses revealed significant associations between age, income-to-poverty ratio, use of antihyperglycemic/antihypertensive medications, and physical activity intensity with comorbidity. High-intensity physical activity and female gender exhibited strong protective effects. The income-to-poverty ratio was identified as a key factor influencing the process of adjusting for confounding factors in statistical analysis, with age and use of antihyperglycemic medications also being important. Patients with CKD-CVD comorbidity are older age, higher proportion of men, low income, and insufficient physical activity. Increasing age, low income, and lack of exercise are associated with higher risk, while high-intensity physical activity and female sex are associated with protective effects.