Association of vitamin B-6 status with inflammation, oxidative stress, and chronic inflammatory conditions: the Boston Puerto Rican Health Study1,2,3

Jian Shen, Chao-Qiang Lai, Josiemer Mattei, Jose M Ordovas and Katherine L Tucker

1 From the Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University Boston MA (JS C-QL JM JMOKLT)the Bouvé College of Health Sciences at Northeastern University Boston MA (KLT).

2 Supported by the National Institutes of Health, National Institute on Aging grant 01AG023394-02 and National Heart, Lung, and Blood Institute grant HL54776; and the US Department of Agriculture, Agricultural Research Service contracts 53-K06-5-10 and 58-1950-9-001.

3 Address correspondence to J Shen, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, Boston, MA 02111-1524. E-mail: jian.shen@tufts.edu.

Background: Low vitamin B-6 status has been linked to an increased risk of cardiovascular diseases. The cardioprotective effects of vitamin B-6 independent of homocysteine suggest that additional mechanisms may be involved.

Objective: Our objective was to examine the cross-sectional association of vitamin B-6 status with markers of inflammation and oxidative stress.

Design: We measured plasma pyridoxal-5′-phosphate (PLP), C-reactive protein (CRP), and an oxidative DNA damage marker, urinary 8-hydroxydeoxyguanosine (8-OHdG), in Puerto Rican adults who were living in Massachusetts (n = 1205, aged 45–75 y).

Results: There was a strong dose-response relation of plasma PLP concentration with plasma CRP. Increasing quartiles of PLP were significantly associated with lower CRP concentrations (geometric means: 4.7, 3.6, 3.1, and 2.5 mg/L; P for trend < 0.0001) and with lower urinary 8-OHdG concentrations (geometric means: 124, 124, 117, and 108 ng/mg creatinine; P for trend: 0.025) after multivariate adjustment. These negative associations persisted after plasma homocysteine was controlled for. Plasma PLP concentrations were significantly correlated with plasma fasting glucose (r = –0.1, P = 0.0006), glycated hemoglobin (r = –0.08, P = 0.006), and homeostasis model assessment of β cell function (r = 0.082, P = 0.005). Metabolic syndrome, obesity, and diabetes were also significantly associated with low plasma PLP concentrations (P = 0.011, 0.0007, and 0.004, respectively).

Conclusions: Low vitamin B-6 concentrations are associated with inflammation, higher oxidative stress, and metabolic conditions in older Puerto Rican adults. Our data suggest that vitamin B-6 may influence cardiovascular disease risk through mechanisms other than homocysteine and support the notion that nutritional status may influence the health disparities present in this population.

Source: American Journal Clinical Nutrition  www.ajcn.org/cgi/content/abstract/91/2/337