Association of vitamin B6 intake with the risk and prognosis of diabetic retinopathy: a NHANES-based study.

Clinical Relevance: Investigating the role of dietary vitamin B6 intake in the risk and prognosis of diabetic retinopathy (DR) could facilitate the management of DR.

Background: This study aimed to assess the association between dietary vitamin B6 intake and the risk of DR and further explore the association between vitamin B6 intake and mortality in patients with DR.

Methods: This retrospective cohort study gained data from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 and 2007-2008. The intake of dietary vitamin B6 was assessed by two 24-h dietary recall interviews. Mortality information in the National Death Index was recorded from the date of survey participation through 31 December 2019. Multivariate regression analyses were employed to assess the association between vitamin B6 intake and the risk of DR, and the association between vitamin B6 intake and the risk of mortality in patients with DR.

Results: A total of 5559 subjects were included, of which 693 (12.47%) had DR. Among these patients with DR, 429 (61.90%) were survivors. Multivariate analyses showed that the intake of vitamin B6 was negatively associated with the risk of DR (odds ratio = 0.81, 95% confidence level: 0.69-0.95,  = 0.012), and patients with DR with an increased intake of vitamin B6 had a significantly decreased risk of all-cause death (hazard ratio = 0.81, 95% confidence level: 0.66-0.99,  = 0.041) or cardiovascular disease-related death (hazard ratio = 0.76, 95% confidence level: 0.58-0.98,  = 0.037).

Conclusion: The intake of vitamin B6 was negatively associated with the risk of DR, and in patients with DR, a higher intake of vitamin B6 was associated with a lower risk of all-cause death and cardiovascular disease-related death, indicating the possible protective role of increased vitamin B6 intake.