Lipovitasi-L carnitina

Am J Cardiol.2008 Nov 15;102(10):1413-7. Epub 2008 Sep 11.

Effects of carnitine supplementation on flow-mediated dilation and vascular inflammatory responses to a high-fat meal in healthy young adults.

Volek JS, Judelson DA, Silvestre R, Yamamoto LM, Spiering BA, Hatfield DL, Vingren JL, Quann EE, Anderson JM, Maresh CM, Kraemer WJ.

Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, CT, USA.

Because carnitine has been shown to decrease oxidative stress and improve endothelial cell functioning, we examined the effects of carnitine supplementation on postprandial flow-mediated dilation (FMD) and circulating biomarkers of inflammation and oxidative stress after a high-fat meal. A randomized, double-blind, placebo-controlled, crossover study design was used. Thirty men and women (age 30 +/- 8 year, body mass 72.9 +/- 17.1 kg, body fat 13.0 +/- 6.4%) participated in 2 vascular testing days, each preceded by 3 weeks of supplementation with either 2 g/day of L-Carnitine (L-Carnitine L-Tartrate) or placebo with a 3- to 5-week washout period between trials. Brachial artery FMD in response to 5 minutes of upper arm occlusion and circulating markers of oxidative stress and inflammation were measured in the fasting state and after a standardized high-fat meal. After 3 weeks of supplementation, peak FMD in the fasting state was similar between the carnitine and placebo trials, averaging 6.6%. Peak FMD during the postprandial period decreased to 5.8% at 1.5 hours during placebo and increased to 7.7% during the carnitine trial (n = 30: p = 0.043 for supplement by time interaction effect). This improvement in postprandial vascular function was most dramatic in subjects who showed a decrease in peak FMD in response to the meal (n = 15: p = 0.003 for supplement by time interaction effect). There was a significant increase in postprandial lipemia and plasma interleukin-6 but no effect of supplementation. There were no significant postprandial changes or supplement effects for plasma tumor necrosis factor-alpha and malondialdehyde. In conclusion, consistent with other work showing a beneficial effect of carnitine on vascular function, these findings indicate that carnitine supplementation in healthy individuals improves postprandial FMD after a high-fat meal.

Role of acetyl-L-carnitine in the treatment of diabetic peripheral neuropathy.

Evans JD, Jacobs TF, Evans EW.

Department of Clinical and Administrative Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, LA, USA.

OBJECTIVE: To examine the role of acetyl-L-carnitine (ALC) in the treatment of diabetic peripheral neuropathy (DPN). DATA SOURCES: A MEDLINE search (1966-April 2008) of the English-language literature was performed using the search terms carnitine, diabetes, nerve, and neuropathy. Studies identified were then cross-referenced for their citations. STUDY SELECTION AND DATA EXTRACTION: The search was limited to clinical trials, meta-analyses, and reviews addressing the use of ALC for the treatment of DPN. Studies that included other disease states that could cause peripheral neuropathy were excluded. Two large clinical studies that used ALC for the treatment of DPN were identified. No case studies were identified. DATA SYNTHESIS: The results from 2 published clinical trials involving 1679 subjects were included. Subjects who received at least 2 g daily of ALC showed decreases in pain scores. One study showed improvements in electrophysiologic factors such as nerve conduction velocities, while the other did not. Patients who had neuropathic pain reported reductions in pain using a visual analog scale. Nerve regeneration was documented in one trial. The supplement was well tolerated. A proprietary form of ALC was used in both studies. CONCLUSIONS: Data on treatment of DPN with ALC support its use. It should be recommended to patients early in the disease process to provide maximal benefit. Further studies should be conducted to determine the effectiveness of ALC in the treatment and prevention of the worsening symptoms of DPN.

Curr Sports Med Rep. 2008 Jul-Aug;7(4):218-23.

L-carnitine supplementation: influence upon physiological function.

Kraemer WJ, Volek JS, Dunn-Lewis C.

Human Performance Laboratory, Department of Kinesiology, University of Connecticut, Storrs, Connecticut 06269-1110, USA.

Carnitine (L-3-hydroxytrimethylamminobutanoate) is a naturally occurring compound that can be synthesized in mammals from the essential amino acids lysine and methionine or ingested through diet. Primary sources of dietary carnitine are red meat and dairy products; however, commercially produced supplements also are available and have been shown to be safe in humans. Carnitine is stored primarily in skeletal muscle, with lower concentrations in plasma. Biologically, carnitine is essential for the transport of long-chain (carbon chain length = 10) fatty acids across the outer- and inner-mitochondrial membranes (carnitine palmitoyltransferanse I and II, respectively). Conflicting results characterized the early research focused on L-carnitine supplementation's ability to enhance endurance performance, and studies showed no changes occurred in muscle carnitine levels. Nevertheless, promising findings for its use have been observed for various pathologies, including cardiovascular diseases, which show it might mitigate some negative effects and enhance physical function. Recent studies have focused upon a different paradigm for L-carnitine in regulating hypoxic stress and enhancing recovery from exercise.