腹部肥胖之代謝症候群的B-維生素（維生素B-6、B-12及葉酸）與同半胱胺酸、發炎反應及脂質過氧化之相關性

Abstract

Metabolic syndrome, homocysteine, inflammatory response and abnormal lipid metabolism were considered to be the risk factors of cardiovascular disease. The relationships among B-vitamins (vitamin B-6, B-12 and folate), homocysteine, inflammatory responses and abnormal lipid metabolism have been widely discussed in cardiovascular disease, but not in metabolic syndrome. Studies have shown that central obesity is a major cause of inflammatory responses and abnormal lipid metabolism among metabolic syndrome indicators. This cross-sectional study was undertaken to study the relationships among B-vitamins, homocysteine, inflammatory responses and lipid peroxidation in metabolic syndrome with central obesity. The inclusion criteria of metabolic syndrome was based on Bureau of Health Promotion, Department of Health in Taiwan. Fifty-five subjects with metabolic syndrome were recruited from the Division of Metabolism, Chung Shan Medical University Hospital, Taichung. Subjects were further divided into either central obesity group (n = 42) and non-central obesity (n = 13) according to whether subjects having abdominal obesity (waist circumference ≧90 cm in men;≧ 80 cm in women). Subjects’ weight and height were measured, and body mass index was then calculated. Fasting blood sample was obtained to estimate hematological parameters, serum B-12 and folate, plasma B-6 (pyridoxal 5’-phosphate, PLP; 4-pyridoxic acid, 4-PA), urine 4-PA, homocysteine,inflammatory (high-sensitivity C-reactive protein, hs-CRP; interleukin-6,IL-6; fibrinogen) and lipid peroxidation indicators (thiobarbituric acid reactive substances, TBARs; oxidized low-density lipoprotein, ox-LDL).Results showed that plasma PLP concentration (78.4 ± 40.5 vs. 53.1 ±4 34.1 nmol/L, p=0.006) was significantly higher in the non-central obesity group than that in the central obesity group; whereas the levels of hs-CRP (0.1 ± 0.1 vs. 0.4 ± 0.4 mg/dL, p=0.007) and fibrinogen (287.2 ± 75.9 vs. 350.1 ± 72.5 mg/dL, p=0.011) were significantly lower in the non-central obesity group than those in the central obesity group. There were no significant differences in serum B-12 and folate, inflammatory and lipid peroxidition indicators between two groups. There was no correlation between plasma PLP and homocysteine, while vitamin B-12 and serum folate significantly and negatively correlated with homocysteine. Plasma PLP was negatively correlated with hs-CRP (r = -0.31, p = 0.045) in the central obesity group and with IL-6 (r = -0.57, p = 0.044) in the non-central obesity group. No significant correlation was found between vitamin B-12 or folate and inflammatory responses or lipid peroxidation indicators in either groups. Negative correlation still remained between plasma PLP and hs-CRP after subjects were pooled (r = -0.40, p = 0.003). Metabolic syndrome subjects with central obesity had significantly lower plasma PLP and higher inflammatory response indicators. In addition, plasma PLP had a significant correlation with inflammatory responses.