Low levels of plasma agmatine in the metabolic syndrome

Background: The biophysiology of the amino acid l-arginine has been a field of active research. Agmatine, which is a metabolite of l-arginine, is known to participate in many biophysical reactions, including those in the cardiovascular system. We sought to investigate plasma agmatine levels in human subjects as a potential biomarker for the metabolic syndrome. Methods: Agmatine concentration was measured in plasma from 322 elderly participants in the Ansan Geriatric study. The metabolic syndrome was defined according to an Asian modified version of criteria established in the Third Report of the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults. We observed that the metabolic syndrome was associated with low levels of plasma agmatine concentration. Results: The mean plasma agmatine level in the metabolic syndrome group was lower than that in the non-metabolic syndrome group (79.42 ng/mL vs. 82.44 ng/mL, P = 0.024). Agmatine remained significant within the regression model after adjustment for different covariates (adjusted odds ratio, 0.962; 95% confidence interval, 0.933-0.993). Conclusions: We concluded that plasma agmatine levels were lower in subjects with the metabolic syndrome than in those without the metabolic syndrome.