Hyperhomocysteinemia (high blood levels of homocysteine) increases the risk of blood vessel complications in people with diabetes. Supplementation with B vitamins (pyridoxine, folic acid, B12) reduces these levels.

Researchers in Canada report the results of the (Diabetic Intervention with Vitamins to Improve Nephropathy [DIVINe]) study, which was designed to determine whether B-vitamin therapy might slow progression of diabetic kidney disease and prevent vascular complications.

First, the details.

• 238 participants with type 1 or 2 diabetes and a diagnosis of diabetic nephropathy were randomly assigned to a treatment group for 36 months.
  • 1 tablet per day of B vitamins containing folic acid (2.5 mg), vitamin  B6 (25 mg), and vitamin B12 (1 mg)
  • Matching placebo
• Changes in glomerular filtration rate (kidney function) were recorded.
• The needs for dialysis and a composite outcome of heart attack, stroke, revascularization (surgery to improve blood flow), and death due to any cause were recorded.
• Blood levels of homocysteine were also measured.
• Neither the patients nor researchers knew the treatment given — double blind.

And, the results.

• Kidney function significantly decreased in the B-vitamin group vs placebo.
• There was no difference in the need for dialysis.
• The composite outcome occurred significantly more often in the B-vitamin group.
• Homocysteine blood levels decreased significantly in the B-vitamin group compared with an increase with placebo.

The bottom line?

The authors concluded, “Given the recent large-scale clinical trials showing no treatment benefit, and our trial demonstrating harm, it would be prudent to discourage the use of high-dose B vitamins as a homocysteine-lowering strategy outside the framework of properly conducted clinical research.”

Furthermore, the American Heart Association and the American Diabetes Association tell us that taking B vitamins to lower homocysteine is not recommended for otherwise healthy diabetics either.

5/5/10 21:34 JR