Associations between a healthy lifestyle score and retinal neurovascular health.

Aims: To investigate the associations between a healthy lifestyle score and retinal neurovascular health, and explore whether lower inflammation levels mediate these associations.

Methods: This study is based on the UK Biobank. The healthy lifestyle score ranged from 0 to 6 and comprised physical activity, diet, sleep duration, smoking status, alcohol consumption and bodyweight. Outcomes included retinal diseases (age-related macular degeneration (AMD) and retinal vascular occlusion (RVO)) from hospital admission records (378 648 participants), retinal vascular metrics from retinal photography (32 226 participants) and retinal neural metrics from optical coherence tomography (42 557 participants). An INFLA-score was used to characterise inflammation levels.

Results: Participants with better healthy life score (scored from 5 to 6) were associated with a 29% lower risk of AMD, 25% lower risk of RVO, 2% increase in artery-to-vein ratio (AVR), 0.22 µm increase in central retinal artery equivalent, 0.36 µm decrease in central retinal vein equivalent (CRVE), 0.004 increase in fractal dimension, 0.38 µm increase in retinal nerve fibre layer, 0.69 µm increase in ganglion cell-inner plexiform layer (GCIPL) and 0.35 µm increase in photoreceptor segment (PS) compared with those with worst lifestyle score (scored from 0 to 1) (all p_trend<0.01). In addition, INFLA-score partially mediated the associations between healthy lifestyle score and increased risk of AMD (mediated proportion (MP): 14.8%), higher AVR (MP: 12.76%), narrower CRVE (MP: 24.49%), thicker GCIPL (MP: 4.97%) and thicker PS (MP: 26.86%).

Conclusion: Great adherence to a healthier lifestyle was associated with better retinal health in a dose-response manner. Lower inflammation partially mediated the association between a healthy lifestyle score and retinal health.