Nonlinear Association Between Serum Lutein and Zeaxanthin Levels and Low Back Pain in US Adults: Results from the National Health and Nutrition Examination Survey.

Background: Oxidative stress plays a critical role in the pathogenesis of low back pain. Higher serum levels of lutein and zeaxanthin are associated with reduced susceptibility to this disease due to their potent antioxidant properties.

Objectives: Our study aimed to assess the correlation between serum lutein and zeaxanthin levels and low back pain.

Study design: This is a cross-sectional study based on publicly available data from the National Health and Nutrition Examination Survey.

Setting: The National Health and Nutrition Examination Survey employs a complex, multistage probability sampling design in order to select a nationally representative sample.

Methods: In our study, information was gathered from individuals who were 20 years old or older who took part in the National Health and Nutrition Examination Survey from 2001 through 2004. Detailed information was collected on low back pain, serum lutein and zeaxanthin levels, and various other crucial factors. Multivariable logistic regression and restricted cubic spline regression analyses were performed in order to investigate the relationship between serum lutein and zeaxanthin levels and the occurrence of low back pain.

Results: In our study 7,026 participants were included, of whom 38.21% (2,685 of 7,026) had low back pain. There was a nonlinear relationship (P < 0.001) between serum lutein and zeaxanthin levels and low back pain, depicted as a U-shaped curve in the restricted cubic spline. The occurrence rate for individuals with serum lutein and zeaxanthin levels below 25.3 nmol/dL was 0.975 (95% CI, 0.960-0.990; P < 0.001). In comparison, the occurrence rate for individuals with serum lutein and zeaxanthin levels exceeding 25.3 nmol/dL was 1.006 (95% CI, 1.000-1.013; P = 0.043).

Limitations: This is a cross-sectional study; therefore causality cannot be established.

Conclusion: A nonlinear association between serum lutein and zeaxanthin levels and the risk of low back pain was observed in US adults. The ideal serum lutein and zeaxanthin level that corresponds to the lowest risk of low back pain is approximately 25.3 nmol/dL.