TY - JOUR
T1 - Oral L-arginine improves hemodynamic response to stress and reduces plasma homocysteine in hypercholesterolemic men
AU - West, Sheila G.
AU - Likos-Krick, Andrea
AU - Brown, Peter
AU - Mariotti, François
PY - 2005/2
Y1 - 2005/2
N2 - When administered intravenously, L-arginine substantially reduces blood pressure (BP) and peripheral vascular resistance in healthy adults and in patients with vascular disease. Oral L-arginine has been shown to improve endothelial function; however, it is not clear whether oral administration has significant effects on systemic hemodynamics. In a randomized, placebo-controlled, crossover study we tested whether oral L-arginine (12 g/d for 3 wk) affected hemodynamics, glucose, insulin, or C-reactive protein in 16 middle-age men with hypercholesterolemia. After each treatment, hemodynamic variables were measured at rest and during 2 standardized Stressor tasks (a simulated public-speaking task and the cold pressor). Regardless of treatment, the stressor tasks increased BP and heart rate (P ≤ 0.02). Relative to placebo, L-arginine changed cardiac output (-0.4 L/m), diastolic BP (-1.9 mm Hg), pre-ejection period (+3.4 ms), and plasma homocysteine (-2.0 umol/L) (P ≤ 0.03). The change in plasma L-arginine was inversely correlated with the change in plasma homocysteine (r = -0.57, P = 0.03). Contrary to the results of previous studies of L-arginine administered intravenously, oral administration did not affect total peripheral resistance or plasma insulin. Oral L-arginine also did not affect plasma glucose, C-reactive protein, or lipids. This pattern of findings is consistent with the hypothesis that oral L-arginine reduces BP. This study is the first to describe a hemodynamic mechanism for the hypotensive effect of oral L-arginine and the first to show substantial reductions in homocysteine with oral administration.
AB - When administered intravenously, L-arginine substantially reduces blood pressure (BP) and peripheral vascular resistance in healthy adults and in patients with vascular disease. Oral L-arginine has been shown to improve endothelial function; however, it is not clear whether oral administration has significant effects on systemic hemodynamics. In a randomized, placebo-controlled, crossover study we tested whether oral L-arginine (12 g/d for 3 wk) affected hemodynamics, glucose, insulin, or C-reactive protein in 16 middle-age men with hypercholesterolemia. After each treatment, hemodynamic variables were measured at rest and during 2 standardized Stressor tasks (a simulated public-speaking task and the cold pressor). Regardless of treatment, the stressor tasks increased BP and heart rate (P ≤ 0.02). Relative to placebo, L-arginine changed cardiac output (-0.4 L/m), diastolic BP (-1.9 mm Hg), pre-ejection period (+3.4 ms), and plasma homocysteine (-2.0 umol/L) (P ≤ 0.03). The change in plasma L-arginine was inversely correlated with the change in plasma homocysteine (r = -0.57, P = 0.03). Contrary to the results of previous studies of L-arginine administered intravenously, oral administration did not affect total peripheral resistance or plasma insulin. Oral L-arginine also did not affect plasma glucose, C-reactive protein, or lipids. This pattern of findings is consistent with the hypothesis that oral L-arginine reduces BP. This study is the first to describe a hemodynamic mechanism for the hypotensive effect of oral L-arginine and the first to show substantial reductions in homocysteine with oral administration.
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U2 - 10.1093/jn/135.2.212
DO - 10.1093/jn/135.2.212
M3 - Article
C2 - 15671215
AN - SCOPUS:13244299029
SN - 0022-3166
VL - 135
SP - 212
EP - 217
JO - Journal of Nutrition
JF - Journal of Nutrition
IS - 2
ER -