An L-shape between Dietary Phosphorus Intake and Cardiovascular Disease in non-dialysis Chronic Kidney Disease American Adults: National Health and Nutrition Examination Survey

Abstract

Objective: This study aims to investigate the threshold effects and the shape of the association between dietary phosphorus intake and the prevalence of cardiovascular disease (CVD) in non-dialysis chronic kidney disease (CKD) patients. Understanding this relationship is crucial for dietary recommendations and clinical management in this vulnerable population.

Background: Phosphorus intake is strictly regulated in dialysis patients due to its significant impact on health outcomes. However, the association between phosphorus intake and CVD in non-dialysis CKD patients remains poorly understood. This knowledge gap prompted our investigation into whether dietary phosphorus intake influences CVD prevalence in this specific patient group.

Methods: The US National Health and Nutrition Examination Survey data from 2001 to 2018 were analyzed for this cross-sectional study. The diagnosis of chronic kidney disease is eGFR less than 60 (mL/min/1.73m²) or urinary albumin/creatinine ratio (ACR) greater than or equal to 30mg/g. Dietary phosphorus intake was evaluated using the 24 h dietary recall system.

Results: A total of 7,890 chronic kidney disease participants were included, divided into three groups according to dietary phosphorus intake: T1 (<1000 mg/day), T2 (1000-1200 mg/day), and T3 (>1200 mg/day). Of whom 2,198 (24.74%) reported having cardiovascular disease. Compared to T2 (1000-1200 mg/day), the adjusted odds ratios for CVD in T1 and T3 were 1.33 (95% confidence interval [CI]: 1.07-1.64, p = 0.01) and 0.98 (95% CI: 0.77-1.23, p = 0.834), respectively. Sensitivity analysis also showed an association between dietary phosphorus intake and cardiovascular disease.

Conclusion: Our analysis revealed an L-shaped relationship between dietary phosphorus intake and cardiovascular disease, indicating a higher risk at lower levels of intake.