Vitamin B6 catabolism and psoriasis risk: a cross-sectional study.

BACKGROUND

Psoriasis is a common autoimmune inflammatory disease. Vitamin B6 is crucial for the body's inflammatory response, yet the relationship between 4-pyridoxic acid (4-PA), pyridoxal 5'-phosphate (PLP) and vitamin B6 turnover (4-PA/PLP) in psoriasis remains unexplored.

OBJECTIVES

To investigate the relationship of 4-PA, PLP and vitamin B6 catabolism with the risk of psoriasis.

METHODS

This cross-sectional study analysed records for 7540 participants from the US National Health and Nutrition Examination Survey. Vitamin B6 catabolism was assessed via the serum 4-PA to PLP ratio (4-PA/PLP). The primary outcome was psoriasis, evaluated using weighted univariate and multivariate logistic regression to determine odds ratios (OR) and 95% confidence intervals (CI). Subgroup analyses were performed by age, gender, body mass index (BMI), hypertension, dyslipidaemia and cardiovascular disease.

RESULTS

Of the participants, 208 had psoriasis. After adjusting for confounders, 4-PA levels in the 'cutoff above' group were positively associated with psoriasis (OR 1.51, 95% CI 1.03-2.20). Additionally, 4-PA/PLP correlated with an increased psoriasis risk (OR 1.82, 95% CI 1.02-3.26). However, PLP levels did not show a significant association. The positive link between 4-PA/PLP and psoriasis was consistent in individuals with BMI ≥ 25 kg m-² and hypertension, and in those without dyslipidaemia.

CONCLUSIONS

The results revealed a significant association between 4-PA and 4-PA/PLP levels in the presence of psoriasis. However, further extensive prospective studies are necessary to establish causality.