ASSOCIATION OF SERUM RETINOL CONCENTRATION WITH CARDIOVASCULAR DISEASES IN THE US NATIONAL HEALTH AND NUTRITION EXAMINATION SURVEY (NHANES) 2001-2006

Objective: The association between serum retinol concentration and cardiovascular disease is controversial. This study aimed to investigate the relationship between serum retinol concentration and cardiovascular diseases. Design and method: This cross-sectional study included 8240 non-pregnant participants aged over 20 in the National Health and Nutrition Examination Survey (NHANES) 2001-2006. Cardiovascular diseases were defined as a self-reported history of coronary heart diseases, heart attacks, angina pectoris, and stroke. Restricted cubic spline and logistic regression were employed to examine the association of serum retinol concentration with cardiovascular diseases with adjustments for potential confounders (i.e., demographics, socioeconomic status, body mass index, physical activity, alcohol, smoking, medical history, and use of vitamin A supplements). Results: 6.8% (95% CI, 6.0-7.6) of the participants had cardiovascular diseases. The mean (±standard error) serum retinol concentration was 2.06±0.13 μmol/L. Serum retinol concentration had a J-shaped relationship with cardiovascular diseases, with the lowest risk observed between 0.82 and 1.20 μmol/L. Stratified by gender, the serum retinol concentration with the lowest odds ratio was 0.99 μmol/L in men and 1.07 μmol/L in women. The lower and upper tail of serum retinol concentrations (< 0.82μmol/L or >1.20μmol/L) were associated with cardiovascular diseases [OR = 1.70, 95%CI (1.23-1.85), P<0.01] after adjusting for covariates. Conclusions: Serum retinol concentration has a J-shaped association with cardiovascular diseases. While serum retinol may be an independent predictor of cardiovascular diseases, further studies are needed to determine if this is a causal relationship.