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 .
L-arginine but not D-arginine stimulates insulin-mediated glucose uptake.
Our study aims at investigating a possible role for L-arginine and D-arginine in insulin-mediated glucose uptake .  Twelve lean healthy subjects volunteered for the study and were su bmi tted to three euglycemic-hyperinsulinemic glucose clamps to investigate the effect of L-arginine ( 0.5 g/min in the last 60 minutes of the clamp ) , D-arginine ( 0.5 g/min in the last 60 minutes of the clamp ) , and saline 0.9 % NaCl on insulin-mediated glucose uptake . All tests were made in r and om order . In study 1 , L-arginine versus saline infusion was associated with a significant increase in blood flow ( 131 % + /- 7 % v 87 % + /- 5 % , P < .001 ) and whole-body glucose disposal ( [ WBGD ] 61.4 + /- 4.4 v 41.3 + /- 3.5 mumol/kg fat-free mss [FFM].min , P < .001 ) . Analysis of substrate oxidation demonstrated that both oxidative and nonoxidative glucose metabolism was improved by L-arginine delivery . After adjustment for the change in blood flow , WBGD was still greater after L-arginine than after saline infusion . Along with L-arginine infusion and independently of the change in blood flow , the percent change in WBGD correlated with the percent change in plasma cGMP ( r = .55 , P < .05 ) . D-Arginine infusion did not affect insulin-mediated glucose uptake . In particular , WBGD ( 42.1 + /- 3.4 v 41.3 + /- 3.5 mumol/kg FFM.min , P = NS ) was similar in both experimental conditions . Basal levels ( 2.8 + /- 0.2 v 2.7 + /- 0.3 nmol/L , P = NS ) and the insulin-mediated increase ( 43 % + /- 5 % v 39 % + /- 4 % , P = NS ) in plasma cGMP were also superimposable along with insulin plus D-arginine and insulin alone , respectively . Finally , blood flow ( 224 + /- 29 v 230 + /- 35 mL/min , P = NS ) was not different at baseline and was similarly stimulated ( 84 % + /- 4 % v 87 % + /- 5 % , P = NS ) by insulin infusion . In conclusion , L-arginine but not D-arginine stimulates insulin-mediated glucose uptake . Nitric oxide ( NO ) , the metabolic mediator for L-arginine , potentiates insulin-mediated glucose uptake through the increase in blood flow . Nevertheless , an independent effect of intracellular cGMP on WBGD can not be ruled out
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 .