Objective: Cardiovascular diseases (CVDs) has been identified as a primary cause of mortality on a global scale. The present study was conducted with the objective of investigating the association between serum vitamin E levels and the risk of developing CVDs, with the aim of identifying potential risk thresholds.
Methods: Using National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2002, we included 3,516 adult participants. Serum vitamin E concentrations were measured by high-performance liquid chromatography, and CVDs status was assessed through medical questionnaires and interviews. Multivariable logistic regression and segmented linear models analyzed the association between serum vitamin E and CVDs risk.
Results: A J-shaped relationship between serum vitamin E and CVDs risk was observed. Segmented linear regression revealed a nonlinear association between vitamin E concentration and CVDs incidence. At low concentrations (below 85.24 µg/dL), although the OR suggested a potential protective trend (OR: 0.968, 95% CI: 0.926-1.011), this association did not reach statistical significance (P = 0.1422), indicating no conclusive evidence of risk reduction. Beyond this threshold, CVDs risk significantly increased (OR: 1.056, 95% CI: 1.003-1.112, P = 0.0377). Notably, the high-concentration group demonstrated a substantially elevated CVDs risk, with a 4.18-fold increase (OR: 4.18, 95% CI: 2.84-6.16, P < 0.0001).
Conclusion: Maintaining serum vitamin E levels within an optimal range is crucial for reducing CVDs risk. The study reveals the complex nonlinear relationship between vitamin E concentration and disease risk, providing important insights for clinical practice and public health strategies.
Keywords: Cardiovascular diseases; Cross-sectional study; NHANES; Nonlinear relationship; Threshold effect; Vitamin E.
© 2025. The Author(s).