Improvement in walking distance and quality of life in peripheral arterial disease by a nutritional product designed to enhance nitric oxide activity

Background: We investigated the clinical effects of a nutiritonal bar enriched with L-arginine and a combination of other nutrients known to enhance the synthesis or activity of endothelium-derived nitric oxide in individuals with claudication from atherosclerotic peripheral arterial disease (PAD). Methods: Using a double-blind placebo-controlled design, 41 individuals with symptomatic PAD were randomized to consume either 1 active bar and 1 placebo; (A1), 2 active bars; (A2), or 2 placebo bars/day (P) for 2 weeks. Each active bar contains 4g of L-arginine as well as antioxidant vitamins, niacin and isoflavenoids. Pain-free (PFWD) and total walking distances (TWD) were determined by treadmill-testing before and after intervention utilizing the Gardner Protocol. Quality of life was measured using the SF-36 Questionnaire. Results: Before treatment there were no differences in demographics, walking distances and SF-36 scores between the three groups. After treatment PFWD increased 66% in A2 (p < 0.05 vs. P), 21% in A1 and 18% in P (NS). TWD increased 20% in A2 (p < 0.05 vs. pre-treatment). A1; 15% and P; 4%, (NS vs. pre-treatment). The general and social/emotional health composite scores of the SF-36 also improved from 55 ± 6 to 65 ± 6 and 60 ± 5 to 66 ± 5 respectively (p<0.05 vs. pre-treatment). This effect was not seen in P. Laboratory values were unaffected. The bars were well tolerated and no significant adverse side-effects were reported. Conclusion: This form of dietary management improves physical functioning and quality of life in patients with PAD. P A1 A2 p value N 14 13 12 Δ PFWD (m) 19 ± 38 14 ± 67 100 ± 156* 0.05 Δ TWD (m) 7 ± 38 28 ± 77 69 ± 108* NS * p < 0.05 vs. pre-treatment by paired t-testing.