Dietary folate and vitamin B6 are independent predictors of peripheral arterial occlusive disease

Background: It has been suggested that hyperhomocysteinemia (HHcy) is an independent risk factor for peripheral arterial occlusive disease (PAOD). However, the relationship between dietary folate and vitamin B6, cofactors in the metabolism of homocysteine (Hcy), and PAOD is unclear. Aims. To study the relationship between dietary folate and B6 and PAOD. Methods: Case-control population based study of 392 men older than 50 years living in Huntingdon, United Kingdom. PAOD, defined as an ankle-brachial pressure index (ASPI) < 0.9, was present in 86 (22%) of subjects. Folate, vitamin 136, and vitamin B12 intakes were calculated by means of the EPIC (European Prospective Investigation into Cancer) food frequency questionnaire. Results. Daily folate intake was significantly lower in case subjects (mean, 288; 95% confidence interval [CI], 266-309 mug) than in control subjects (324; 95% CI, 313-335 mug). Daily vitamin B6 intake was also lower in case subjects (2.05; 95% CI, 1.92-2.19 mg versus 2.26; 95% CI, 2.19-2.33 mg). Daily folate and vitamin B6 intakes were independent predictors of PAOD after adjusting for age, blood pressure, cholesterol levels, diabetes, and smoking status in a logistic regression model. This model suggests that increasing daily folate intake by 1 standard deviation decreased the risk of PAOD by 46%. A similar increase in daily vitamin B6 intake decreased the risk of PAOD by 29%. Conclusion: In men older than 50 years, dietary folate and B6 intakes are independent predictors of PAOD. Longitudinal studies are required to determine whether dietary modification can reduce the incidence of PAOD in the population.