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

Investigating the role of dietary vitamin B6 intake in the risk and prognosis of diabetic retinopathy (DR) could facilitate the management of DR. 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. 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. 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, p = 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, p = 0.041) or cardiovascular disease-related death (hazard ratio = 0.76, 95% confidence level: 0.58–0.98, p = 0.037). 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.</p

Matrix metalloproteinse 9 (MMP-9) expression profiles in each group.

<p>red, MMP9–positive; blue, DAPI-positive cells. (magnification:x20; scale bars: 50μm).</p

Electron microscopic findings of the lacrimal gland acinus.

<p>A, Secretory vesicle (SV) accumulation in the normal group(N), Scale bars = 1um. Atrophic SVs in the scopolamine-treated group (SCOP).Excessive accumulation of SVs in the 1-week in the E group (E1).Excessive accumulation of SVs in the 2-week group (E2). Excessive accumulation of SVs in the 4-week group (E4).Excessive accumulation of SVs in the 6-week group (E6). B: SV diameter. Total number of vesicles examined/group: 159/N group，254/SCOP group, 249/E1 group, 341/E2 group, 302/E4 group and 485/E6 group (Mann-Whitney U test). C: Percent SV area per acinus. Total number of acini examined/group: 148/N group ，177/SCOP group, 223/E1 group, 270/E2 group, 339/E4 group and 549/E6 group (Mann-Whitney U test) # P<0.001 versus the SCOP group, ** p<0.001 versus the normal group(N).~ P<0.001 versus the the E2 group. Original magnification: X10000. Hollow arrow, Ductal lumen; Arrows, Nuclei; Triangle, SV.</p

Lacrimal Gland Histology by H&E Staining.

<p>H&E staining of lacrimal gland from normal controls (N), the scopolamine-treated group(SCOP) and after desiccating stress in ICES for 1 week, 2week, 4 week and 6week (E1,E2,E4,E6). Arrows indicate ductal lumens. Circle indicates one acinus. Scale bars = 50μ m.</p

ICES Induced Corneal Epithelial Destruction.

<p>Corneal epithelial damage assessment by standard corneal fluorescein staining scores in ICES groups (E), the scopolamine-treated group (SCOP) and normal control group (N). *P < 0.05 versus the normal group (N).</p

Primers used for quantitative RT-PCR.

<p>Primers used for quantitative RT-PCR.</p

Inflammatory cells infiltration of the Lacrimal Gland.

<p>A-E, immunostained for CD4(A), CD8(B), CD103(C), CD11b(D), CD45(E) in the lacrimal glands sections. F, Cell counts in mouse lacrimal glands stained by immunohistochemistry for CD4, CD8, CD103, CD11b, CD45 sections in the normal group (N), the scopolamine-treated group (SCOP), and after desiccating stress in ICES for 1 week, 2 week, 4 week and 6 week (E1,E2,E4,E6). # P < 0.01 versus the scopolamine-treated group (SCOP), * P<0.05 versus the normal group(N) (Mann-Whitney U test). Original magnification:x20；scale bars = 50 μm. Experiments were repeated three times with two mice per group per experiment.</p

ICES Stimulates Inflammatory Cytokine Production in the Conjunctiva and Lacrimal Gland.

<p>A, Real-time PCR for the mRNA expression of IL-17, IL-23, IL-6, IL-1β, TNF-α, IFN-γ, TGF-β2 in the conjunctiva of normal group(Horizontal line), the scopolamine-treated group (SCOP), and after desiccating stress in ICES for 1 week,2week,4 week and 6week (E1,E2,E4,E6). B, mRNA transcript levels of IL-17,IL-23,IL-6,IL-1β, TNF-α, IFN-γ,TGF-β2 in the lacrimal gland. *P < 0.05 versus the normal group (N), #P < 0.05, versus the scopolamine-treated group (SCOP).</p