| Summary: | 博士 === 中山醫學大學 === 營養學研究所 === 99 === The purposes of this study were to investigate traditional and non-traditional risk factors for cardiovascular disease (CVD) in relation to the endothelial function in patients with rheumatoid arthritis (RA); to determine which measure is a better predictive indicator for the risk of endothelial dysfunction in RA patients, and to study the effect of a high dose of vitamin B-6 on improving inflammatory and immune responses in RA patients. Forty-three RA patients (5 men, 38 women) participated in this study. Thirty-five patients were randomly allocated into either the control (5 mg/day folic acid only; n = 15) group or the vitamin B-6 (5 mg/day folic acid plus 100 mg/day vitamin B-6; n = 20) supplementation group for 12 weeks. Traditional (i.e., smoking, drinking, systolic and diastolic blood pressures and lipid profiles) and non-traditional risk factors [i.e., indicators of inflammatory and immune responses, plasma homocysteine and deficiency of B-vitamins (i.e., folate, vitamin B-6 and B-12)] for CVD were recorded or measured. The results showed systolic blood pressure (SBP) was significantly higher in RA patients with abnormal endothelial function. Among the risk factors being investigated, SBP was significantly associated with the degree of abnormal endothelial function (β = 20.7, P < 0.01) than RA patients with normal endothelial function after adjusting for potential confounders. SBP had the highest area under the receiver operating characteristic curve (AUC) (AUC = 0.80; 95% CI, 0.65-0.94) to predict the risk of endothelial dysfunction. Patients with vitamin B-6 deficiency [plasma pyridoxal 5’-phosphate (PLP) < 20 nmol/L] had significantly higher hs-CRP levels and immune parameters than did patients with adequate plasma PLP concentration. There was no significant association between plasma PLP levels and inflammatory parameters. The significant inverse correlation of plasma PLP with the numbers of white blood cell, neutrophils, total lymphocytes, T lymphocytes and T helper cells disappeared after serum albumin concentration was considered. Plasma IL-6 and TNF-α levels significantly decreased in patients receiving vitamin B-6 supplementation at week 12. In addition, the inverse association between plasma PLP and plasma IL-6 remained significant after adjusting for potential confounders (β = −0.01, P = 0.01). SBP could be a practical measure to screen the risk of endothelial dysfunction for patients with RA. Patients with RA should monitor their blood pressure in order to reduce the risk of CVD. RA patients with deficient plasma PLP concentration had more severe inflammatory and immune responses than did patients with adequate plasma PLP concentration. There is a lack of association of low plasma PLP concentration with inflammatory and immune parameters after serum albumin concentration was considered in patients with RA. Howener, a high dose vitamin B-6 supplementation may have suppressed pro-inflammatory cytokines in patients with RA.
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