Acetyl-L-carnitine arginate
January 20 2016

At this time, as of 2015, I am not sure what additional benefits acetyl l-carnitine arginate offers over plain ALC. There is very little human research on this supplement.

Benefit
Q. I'm passing on to you information about this product that was posted at Life Extension: "Acetyl-L-carnitine arginate dihydrochloride has several valuable properties. The attachment of an arginine molecule gives this compound a number of additional benefits for the aging brain. Acetyl-L-carnitine arginate appears to mimic the effects of a protein called nerve growth factor that supports the survival of neurons in areas of the brain associated with emotion, such as the hippocampus, and in the forebrain, which is associated with cognition, emotion, and important body functions."
    A. I have seen few human studies with this form, and hence any statements such as the one above are speculative and premature. I am not aware of studies comparing the two forms and hence there is no evidence that we know of that one form is superior to the other.

Diabetes and diabetics
Effect of oral acetyl L-carnitine arginate on resting and postprandial blood biomarkers in pre-diabetics.
Nutrition Metabolism. 2009. Cardiorespiratory / Metabolic Laboratory, The University of Memphis, Memphis, Tennessee.
We sought to determine the effects of acetyl L-carnitine arginate (ALCA) on resting and postprandial biomarkers of glucose and lipid metabolism, as well as oxidative stress. Twenty-nine pre-diabetic men and women were randomly assigned to either 3 g.day-1 of ALCA or placebo  in a double-blind design, to consume for eight weeks. After each fasting sample was obtained, subjects consumed a high fat, high carbohydrate meal and additional blood samples were taken at 1, 2, 4, and 6 hours post meal. Samples were analyzed for a variety of metabolic variables (e.g., glucose, HbA1c, lipid panel, C-reactive protein, nitrate/nitrite, and several markers of oxidative stress). ALCA, but not placebo, resulted in an increase in nitrate / nitrite from pre to post intervention, with post intervention values greater compared to placebo. ALCA resulted in slight improvements in glucose, HbA1c, and HOMA-IR. Supplementation with acetyl L-carnitine arginate results in an increase in resting nitrate/nitrite in pre-diabetics, without any statistically significant change in other metabolic or oxidative stress variables measured at rest or post meal.