Association of Retinal Nerve Fiber Layer Thinning With Elevated High Density Lipoprotein Cholesterol in UK Biobank.

Purpose: The purpose of this study was to investigate the association between retinal nerve fiber layer (RNFL) thickness and high-density lipoprotein cholesterol (HDL-C) in a healthy population. Methods: This cross-sectional study included 31,738 UK Biobank participants with high quality optical coherence tomography (OCT) images, excluding those with neurological or ocular diseases. The locally estimated scatterplot smoothing (LOESS) curve and multivariable piecewise linear regression models were applied to assess the association between HDL-C and RNFL thickness, and HDL-C subclasses were further analyzed using nuclear magnetic resonance (NMR) spectroscopy. Results: Multivariate piecewise linear regression revealed that high HDL-C levels (>1.7 mmol/L in women or > 1.5 mmol/L in men) were associated with thinner RNFL thickness (women: β = -0.13, 95% confidence interval [CI] = -0.23 to -0.02, P = 0.017; male: β = -0.23, 95% CI = -0.37 to -0.10, P = 0.001). Conversely, a significant positive association between HDL-C and RNFL thickness was observed when HDL-C was between 1.4 and 1.7 mmol/L for female participants (β = 0.13, 95% CI = 0.02 to 0.24, P = 0.025). NMR analysis showed that these associations are potentially driven by distinct HDL-C subclasses. Conclusions: This study revealed an association between HDL-C levels and retinal markers of neurodegenerative diseases, suggesting that elevated HDL-C may serve as a new risk factor for neurodegenerative conditions. These findings may contribute to the implementation of preventive interventions and improved patient outcomes.