Pyridoxine reduces cholesterol and low-density lipoprotein and increases antithrombin III activity in 80-year-old men with low plasma pyridoxal 5-phosphate

We have previously observed that pyridoxine treatment reduced plasma total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol concentrations and increased antithrombin III (AT III) activity in atherosclerotic patients with subnormal plasma pyridoxal 5-phosphate (PLP) levels. In order to confirm these results, we selected 17 males with low plasma PLP levels from a group of 122 80-year-old males in whom PLP has been determined. After supplementation with 120 mg of pyridoxine per day for 8 weeks their mean plasma TC and LDL cholesterol concentrations were decreased by 10% (p less than 0.01) and 17% (p less than 0.001), respectively. There was no effect on high-density lipoprotein cholesterol and triglycerides but plasma AT III activity was increased by 6% (p less than 0.05). The mechanism by which pyridoxine acts is unclear but it is hypothesized that pyridoxine-derived PLP may enhance the catabolism of LDL and the activity of AT III by inhibiting their glycosylation.