This meta- analysis concludes that l-arginine supplementation can significantly reduce blood TAG levels ; however , there is insufficient evidence to support its hypocholesterolaemic effects .
A number of clinical trials have examined the effect of l-arginine on lipid profile in recent years ; however , the results remain equivocal .
Therefore , the present study aims to summarise and quantitatively examine the available evidence on the effectiveness l-arginine supplementation on lipid parameters using a systematic review and meta-analytic approach .
Endocrine and lipid effects of oral L-arginine treatment in healthy postmenopausal women.
As a substrate for nitric oxide synthesis , L-arginine may give the same protection as estrogen , but its other biologic effects may adversely affect atherogenesis . Therefore , possible endocrine and lipid effects of L-arginine were investigated in a double-blind , placebo-controlled , single crossover study . After r and omization , oral L-arginine ( 9 g ) or placebo was given daily for 1 month , with crossover to the alternate therapy after a 1-month washout period , to 10 postmenopausal women receiving no estrogen .  Compared with placebo , L-arginine increased growth hormone ( 1.5+/-1.8 mg/L vs. 0.6+/-0.6 mg/L , P = .04 ) but had no effect on insulin and catecholamines . Total cholesterol , triglyceride , apolipoprotein E , and low- , very-low- , and high-density lipoprotein cholesterol levels were also unaffected . Lipoprotein(a ) measured by an immunoturbidimetric method was increased by L-arginine in 9 of 10 women relative to placebo ( 0.46+/-0.35 g/L vs. 0.38+/-0.30 g/L , P = .053 ) , and the changes in lipoprotein(a ) levels significantly correlated with the relative increase in growth hormone ( r = 0.85 , P = .03 ) . However , lipoprotein(a ) measured by an enzyme-linked immunosorbent assay failed to demonstrate significant changes . Lack of an increase by  L-arginine in lipoprotein(a ) with a verifiable apolipoprotein(a ) isoform-independent method , despite an increase in growth hormone , questions the validity of previous observations for growth hormone-induced increases in lipoprotein(a ) . The observed lack of effect on major endocrine hormones and lipid profile support the safety of oral L-arginine administration
This meta- analysis concludes that l-arginine supplementation can significantly reduce blood TAG levels ; however , there is insufficient evidence to support its hypocholesterolaemic effects .
A number of clinical trials have examined the effect of l-arginine on lipid profile in recent years ; however , the results remain equivocal .
Therefore , the present study aims to summarise and quantitatively examine the available evidence on the effectiveness l-arginine supplementation on lipid parameters using a systematic review and meta-analytic approach .