4-Pyridoxic Acid/Pyridoxine Ratio in Patients with Type 2 Diabetes is Related to Global Cardiovascular Risk Scores.

Rima Obeid,Juergen Geisel,Wilfred A Nix

doi:10.3390/diagnostics9010028

Rima Obeid, Juergen Geisel + Show 1 more

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https://doi.org/10.3390/diagnostics9010028

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Abstract

Background: Vascular diseases are multifactorial and several risk factors may have synergetic effect on the global vascular risk. Among patients with diabetes, we investigated whether vitamin B6 species differ according to global cardiovascular risk. Methods: The present observational study included 122 patients with type 2 diabetes (mean (SD) age = 69.9 (9.1) years; 50% men). Concentrations of vitamin B6 vitamers were measured. Classical blood biomarkers and risk factors were used to compute a multivariate risk score. Results: Plasma concentrations of 4-pyridoxic acid were higher in patients with high risk versus those with low risk scores (48.2 (63.7) vs. 31.9 (15.0) nmol/L; p = 0.031). Plasma pyridoxine was significantly lowered in patients at high risk (2.8 (28.4) vs. 38.1 (127.8) nmol/L; p = 0.003). PAr index (4-pyridoxic acid/pyridoxal + pyridoxal 5′-phosphate) (1.05 (0.07) vs. 0.84 (0.06); p = 0.017) and the ratio of 4-pyridoxic acid/pyridoxine (7.0 (4.8) vs. 3.9 (3.2); p < 0.001) were higher in patients at high risk. After adjustment for cystatin C and C-reactive protein, only pyridoxine and 4-pyridoxic acid/pyridoxine ratio remained significantly different according to vascular risk scores. 4-Pyridoxic acid/pyridoxine ratio was the best marker to discriminate between patients according to their risk scores—area under the curve (AUC) (95% confidence intervals (CI)) = 0.72 (0.62–0.81). 4-Pyridoxic acid/pyridoxine ratio was directly related to plasma levels of soluble vascular cell adhesion molecule 1. Conclusion: Vitamin B6 metabolism was shifted in patients with multiple vascular risk factors. The catabolism to 4-pyridoxic acid was enhanced, whereas the catabolism to pyridoxine was lowered. High 4-Pyridoxic acid/pyridoxine ratio is independently associated with global cardiovascular risk.

Highlights

Accelerated vitamin B6 catabolism is associated with poor clinical outcomes in epidemiological studies on vascular diseases or cancer [1,2]
After adjustment for cystatin C and C-reactive protein, only pyridoxine and 4-pyridoxic acid/pyridoxine ratio remained significantly different according to vascular risk scores. 4-Pyridoxic acid/pyridoxine ratio was the best marker to discriminate between patients according to their risk scores—area under the curve (AUC) (95% confidence intervals (CI)) =
The present study has shown enhanced vitamin B6 catabolism to 4-pyridoxic acid in plasma of patients with diabetes and high vascular risk scores compared to patients at low risk

Summary

Introduction

Accelerated vitamin B6 catabolism is associated with poor clinical outcomes in epidemiological studies on vascular diseases or cancer [1,2]. Plasma pyridoxal 50 -phosphate (PLP) (i.e., the active vitamin B6 form) shows a dose–response inverse association with chronic inflammation and the presence of vascular disease [3,4]. The relationship between plasma PLP levels and vascular disease could be partly due to inflammation [3]. The ratio of 4-pyridoxic acid/(pyridoxal + pyridoxal 50 -phosphate), called PAr index, is a marker of enhanced vitamin B6 catabolism especially during inflammation [6,7]. Results: Plasma concentrations of 4-pyridoxic acid were higher in patients with high risk versus those with low risk scores (48.2 (63.7) vs 31.9 (15.0)

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