L-carnitine is only a supplementary drug treatment, not a substitute for drug treatment (as a health food, it will be over-advertised). The bioavailability of oral L-carnitine is low, and intravenous administration will increase metabolic excretion. For example, 90% of L-carnitine injected intravenously 2g is excreted in urine within 12-24 hours, and only a small part can enter the skeletal muscles. .
Type 2 diabetes
◆ Meta analysis shows that L-carnitine supplementation can improve insulin resistance compared with placebo.
◆ However, the Meta analysis of four other randomized placebo-controlled trials showed that acetyl-L-carnitine (ALCAR) could not improve fasting blood glucose and glycosylated hemoglobin concentration in patients with type 2 diabetes.
◆ Meta analysis of 16 trials showed that ALCAR can reduce fasting blood glucose and glycosylated hemoglobin concentration, but not insulin resistance.
◆ In a double-blind randomized placebo-controlled trial, daily supplementation of ALCAR had no effect on blood pressure, blood lipids, kidney function, and diabetes indicators.
◆ Meta-analysis of randomized controlled trials showed that the use of L-carnitine in patients with myocardial infarction can reduce the risk of all-cause mortality and ventricular arrhythmia, but has no effect on the risk of subsequent myocardial infarction or heart failure.
◆ A Meta analysis of 17 randomized placebo-controlled trials of 1 625 patients with heart failure found that oral L-carnitine (1.5-6g/d, 7d-3 years) can significantly improve many indicators of heart function, but it is Because the mortality rate has no effect.
End-stage renal disease
◆ Hemodialysis patients with end-stage renal disease lack L-carnitine, leading to muscle weakness, fatigue, and anemia. A meta-analysis of 31 randomized controlled trials of 1 734 patients with end-stage renal disease found that oral or intravenous supplementation of L-carnitine can reduce C-reactive protein.
◆ The National Kidney Foundation does not recommend the routine use of L-carnitine for patients undergoing dialysis, but those who experience specific symptoms such as persistent muscle cramps or hypotension during dialysis, severe fatigue, skeletal muscle weakness or myopathy, cardiomyopathy, and anemia can Consider using.
◆ FDA approved the use of L-carnitine (10-20 mg/kg body weight, slow bolus) to treat patients with end-stage renal disease on hemodialysis who suffer from L-carnitine deficiency.
◆ Meta-analysis of 12 randomized controlled trials showed that 9 of them showed that compared with placebo, ALCAR can reduce depression symptoms (3g/d, 8 weeks); 3 studies compared ALCAR with antidepressants and found that Both are equally effective in treating depression symptoms.
◆ ALCAR has doubts about its effectiveness in the prevention and treatment of peripheral neuropathy caused by chemotherapy, and the test results are conflicting, and further study is needed.
◆Large trials have found that compared with placebo, ALCAR has little or no effect on cognitive decline caused by Alzheimer's disease, but there is another summary analysis showing that it has improved overall metrics.
◆ Limited evidence shows that compared with placebo, ALCAR can reduce the blood ammonia concentration in patients with hepatic encephalopathy.
◆ Meta-analysis showed that L-carnitine or ALCAR had no effect on cancer-related fatigue levels.
◆ Whether L-carnitine and ALCAR can play a role in the treatment of male infertility still needs evidence from large-scale clinical trials.
◆ Fitness enthusiasts prefer L-carnitine supplements based on some small, low-quality studies. However, in high-quality research, it has not been seen to improve aerobic or anaerobic exercise performance.