L-carnitine ameliorated fasting-induced fatigue, hunger, and metabolic abnormalities in patients with metabolic syndrome: a randomized controlled study

Abstract

BackgroundThe present study aimed to determine that whether L-carnitine infusion could ameliorate fasting-induced adverse effects and improve outcomes.MethodIn this 7-day, randomized, single-blind, placebo-controlled, pilot study, 15 metabolic syndrome (MetS) patients (11/4 F/M; age 46.9 ± 9.14 years; body mass index [BMI] 28.2 ± 1.8 kg/m2) were in the L-carnitine group (LC) and 15 (10/5 F/M; age 46.8 ± 10.9 years; BMI 27.1 ± 2.3 kg/m2) were in the control group (CT). All participants underwent a 5-day modified fasting therapy introduced with 2-day moderate calorie restriction. Patients in the LC group received 4 g/day of intravenous L-carnitine, while patients in the CT group were injected with saline. Blood pressure (BP), anthropometric characteristics, markers of liver function, metabolic indices (plasma glucose, lipid profiles, uric acid, free fatty acid and insulin) and hypersensitivity C-reactive protein were measured. Perceived hunger was recorded daily by self-rating visual analogue scales. Fatigue was evaluated by Wessely and Powell scores.ResultsIn contrast to the CT group, total cholesterol, alanine aminotransferase, systolic and diastolic BP did not change significantly in the LC group after prolonged fasting. There were significant differences in weight loss (LC −4.6 ± 0.9 vs. CT −3.2 ± 1.1 kg, P = 0.03), and waist circumference (LC −5.0 ± 2.2 vs. CT −1.7 ± 1.16 cm, P < 0.001), waist hip ratio (LC −0.023 ± 0.017 vs. CT 0.012 ± 0.01, P < 0.001), insulin concentration (LC −9.9 ± 3.58 vs. CT −6.32 ± 3.44 µU/mL, P = 0.046), and γ-glutamyltransferase concentration (LC −7.07 ± 6.82 vs. CT −2.07 ± 4.18, P = 0.024). Perceived hunger scores were significantly increased (P < 0.05) in the CT group during starvation, which was alleviated with L-carnitine administration in the LC group. Physical fatigue (LC −3.2 ± 3.17 vs. CT 1.8 ± 2.04, P < 0.001) and fatigue severity (LC −11.6 ± 8.38 vs. CT 8.18 ± 7.32, P < 0.001) were significantly reduced in the LC group but were aggravated in the CT group.ConclusionIntravenous L-carnitine can ameliorate fasting-induced hunger, fatigue, cholesterol abnormalities and hepatic metabolic changes and facilitate fasting-induced weight loss in MetS patients.Trial registrationChiCTR-TNRC-12002835.

Hepatic proteomic analysis revealed altered metabolic pathways in insulin resistant Akt1 +/− /Akt2 −/− mice

“…Consistent with this, a previous study has shown decreased fatty acid accumulation in the livers of diabetic mice upon carnitine supplementation [51]. This proposed mechanism of carnitine facilitated fatty acid oxidation has led to multiple clinical trials with mixed results on metabolic parameters including blood glucose and lipid levels [52-54]. …”

L‐carnitine prevents metabolic steatohepatitis in obese diabetic KK‐Ay mice

“…a), which is consistent with previous reports using mouse models fed HFD and irregular diets . The reduction of body weight by L‐carnitine has also been reported in obese patients with metabolic syndrome and polycystic ovary syndrome . Moreover, L‐carnitine improved hyperlipidemia, hyperglycemia, and hyperinsulinemia (Figs.…”

Expression of Concern: Oral carnitine supplementation reduces body weight and insulin resistance in women with polycystic ovary syndrome: a randomized, double‐blind, placebo‐controlled trial

“…In addition, in a study by Ismail et al ., combined l ‐carnitine and clomiphene citrate significantly improved both ovulation and cumulative pregnancy rates in patients with clomiphene‐resistant PCOS. Taking intravenous l ‐carnitine (4 g/day) among patients with MetS for 7 days resulted in weight loss, improved fasting‐induced hunger and cholesterol abnormalities . Carnitine supplementation in human studies and animal models has indicted an improvement in parameters of glucose homoeostasis, particularly during an insulin‐resistant state .…”

“…Taking intravenous L-carnitine (4 g/day) among patients with MetS for 7 days resulted in weight loss, improved fasting-induced hunger and cholesterol abnormalities. 12 Carnitine supplementation in human studies and animal models has indicted an improvement in parameters of glucose homoeostasis, particularly during an insulin-resistant state. 13,14 However, carnitine administration did not affect weight loss outcomes in valproate-treated bipolar patients consuming an energy-restricted and low-fat diet.…”