A current concept for the development of diabetic long-term complicati
ons is the involvement of oxidative stress, as, e.g., lipid peroxidati
on, in the diabetic state. Data published recently show also oxidative
damage to DNA, which might be one factor for accelerated aging and di
abetic microangiopathy. In our study we tested the hypothesis that L-a
rginine can reduce lipid peroxidation in patients with diabetes. We pe
rformed a blind placebo controlled study with crossing over two treatm
ent periods for 3 months. Thirty patients with diabetes mellitus were
randomly assigned to treatment group A (first treatment then placebo)
and B (first placebo then treatment). Treatment consisted of two daily
dosages of 1 g L-arginine free base. Lipid peroxidation as reflected
by malondialdehyde was evaluated in urine using a standard HPLC assay.
After 3 months of treatment there was a significant reduction in malo
ndialdehyde levels in group A (p < .0032), whereas there was no differ
ence compared to the baseline values after three months of placebo tre
atment in group B (p < .97). After crossing over, there was a signific
ant reduction in malondialdehyde levels in group B (p < .0002). Group
A showed a significant increase in malondialdehyde levels (p < .0063)
returning to baseline values. L-Arginine treatment was able to reduce
the lipid peroxidation product malondialdehyde. This provides evidence
that treatment with L-arginine may counteract lipid peroxidation and
thus reduce microangiopathic long-term complications in diabetes melli
tus. Copyright (C) 1996 Elsevier Science Inc.