Background: Elevated plasminogen activator inhibitor type 1 (PAI 1) plays an important role in the pathogenesis of excess blood coagulability in obese patients. L-arginine supplementation has shown to be associated with enhanced cardiovascular and metabolic health. The aim of the study was to assess the effect of L-arginine supplementation on PAI 1 concentration and to evaluate the relation to changes in nitric oxide (NO) plasma level, insulin sensitivity (M value), and total antioxidant status (TAS) in obese patients.
Material/subjects and methods: A randomized, double-blind, placebo-controlled study was conducted from March 2010 to June 2011. Eightyeight obese patients were randomly assigned to receive either 9 g of L-arginine or placebo daily for 6 months. At baseline and after 6 months, selected anthropometrical measurements and blood biochemical analyses were performed, and PAI 1, NO, TAS levels were assessed. Insulin sensitivity was evaluated using the hyperinsulinemic euglycemic clamp technique.
Results: We found that 6-month L-arginine supplementation resulted in significant decrease of PAI 1. Significant increase of NO, TAS, and insulin sensitivity level were noticed. In a group of patients treated with L-arginine, negative correlation between a change of insulin sensitivity value and a change of PAI 1 concentration was found.
Conclusions: The present findings demonstrate favorable influence of L-arginine supplementation on PAI 1 concentration in obese patients. Beneficial influence is related to insulin sensitivity improvement. The potential therapeutic role of L-arginine administration in patients with obesity needs further investigation.