Pyridoxal-5′-phosphate deficiency is associated with hyperhomocysteinemia regardless of antioxidant, thiamine, riboflavin, cobalamine, and folate status in critically ill patients

Background & aims: Critically ill patients develop severe stress, inflammation and a clinical state that may raise the utilization and metabolic replacement of pyridoxal-5'-phosphate decreasing their body reserves. This study was designed to assess the nutritional pyridoxal-5'-phosphate status in critical care patients with systemic inflammatory response syndrome, comparing them with a group of healthy people, and studying it's association with factors involved in the pyridoxine and other B vitamins metabolism, as the total antioxidant capacity and Hcy as cardiovascular risk biomarker. Methods: Prospective, multicentre, comparative, observational and analytic study. One hundred and three critically ill patients from different hospitals, and eighty four healthy subjects from Granada, Spain, all with informed consent. Data from daily nutritional assessment, ICU severity scores, clinical and nutritional parameters, antioxidant status and homocysteine levels was taken at admission and at the seventh day of the ICU stay. Results: Thiamine, riboflavin, pyridoxine and folate status proved deficient in a large number of patients, being significantly lower in comparison with control group, and significantly decreased at 7th day of ICU stay. Higher homocysteine was observed in patients compared with control group (p < 0.05) where 31.5 and 26.8 percent of subjects presented hyperhomocysteinemia at initial and final of study, respectively. Antioxidant status was lower than control group in two periods analysed, and decreased at 7th day of ICU stay (p < 0.05) being associated with PLP deficiency. PLP deficiency was also correlated with hyperhomocysteinemia at two times measured (r. -0.73, p < 0.001; r. -0.69, p < 0.001, respectively), showing at day 7 an odds ratio of 6.62 in our multivariate model. Conclusion: Critically ill patients with SIRS show deficient B vitamin and low antioxidant statuses. Despite association found between PLP deficiency and low antioxidant status in critically ill patients, PLP deficiency was only associated with hyperhomocysteinemia regardless of antioxidant, riboflavin, cobalamine, and folate statuses in critically ill patients with SIRS at seventh day of ICU stay. PLP deficient patients presented about six times more risk of cardiovascular disease than non deficients. (C) 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.