Effect of L-Carnitine Supplementation on Metabolic Status in Obese Diabetic Women With Hypocaloric Diet

The effect of L-Carnitine supplementation on clinical symptoms, C-reactive protein and malondialdehyde in obese women with knee osteoarthritis: a double blind randomized controlled trial

BACKGROUNDS

L-carnitine decreases oxidation and inflammation by reducing the fatty acid in plasma and using oxygen in ATP synthesis. As such, knee osteoarthritis (KOA) can be improved by reducing apoptotic chondrocytes. This study was designed to compare the effect of L-carnitine supplementation and low-calorie diet on improving KOA among obese women. We further investigated the effect of L- carnitine on improvement of KOA in obese women on low calorie diet.

METHODS

To conduct the study, 76 obese women with KOA were randomly assigned into two low-calorie diet groups: the first received 1000 mg of LCG and the second took the placebo (PLG) (n = 38). Anthropometry indices, body composition, lipid profile, C-reactive Protein (CRP), Malondialdehyde (MDA), and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were assessed at the baseline condition and after 12 weeks.

RESULTS

The mean change of body mass index (BMI) (- 1.21 ± 0.84 vs. -0.79 ± 0.70; P = 0.02) and weight (- 2.76 ± 1.69 vs. -1.95 ± 1.73; P = 0.05) were significant in the LCG compared with the PLG. Likewise, LCG compared to the PLG showed insignificant improvement in waist circumference (WC) (- 5.65 ± 5.85 vs. -3.64 ± 3.37; P = 0.08). Total cholesterol (P = 0.02), MDA (P = 0.03), fat mass (P = 0.03) and visceral fat (P = 0.001) only showed decreased levels in LCG in comparison to the baseline condition. There was no significant difference between LCG and PLG, in the mean changes of hip circumference, visceral fat, free fat mass, fat mass, lipid profiles, CRP, MDA as well as stiffness, physical function, decrease of pain and total scores (P > 0.05).

CONCLUSION

The 12-week L-carnitine supplementation could improve BMI, but had no significant effect on other anthropometric and body composition measures as well as clinical symptoms, CRP, MDA, and lipid profile in women with KOA. Further trials with higher doses and longer durations are required. IRCT registration number: IRCT2017011932026N2. Registration date: 2017-04-27.

Effects of carnitine supplementation on liver aminotransferase enzymes: A systematic review and meta-analysis of randomized controlled clinical trials

BACKGROUND AND AIMS

This meta-analysis of the randomized controlled trials was performed to assess effects of carnitine supplementation on serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels.

METHODS

A comprehensive literature search of PubMed, Cochrane's library, Web of Science, Scopus, and Embase was performed up to May 2018. From a total of 2012 articles identified initially, only 17 articles were included in the final meta-analysis to evaluate the effects of carnitine supplementation on serum levels of ALT and AST enzymes.

RESULTS

Random effects model meta-analysis showed that carnitine supplementation led to reduction in serum ALT (weighted mean difference [WMD] - 10.25 IU/L; 95% CI = - 15.73, - 4.77; p < 0.001) and AST levels (WMD - 7.85 IU/L; 95% CI = - 11.85, - 3.86; p < 0.001). The results of subgroup analysis showed that carnitine could reduce serum AST levels at dosages equal to 2000 mg/day (p = 0.014) or more than 2000 mg/day (p < 0.001). However, carnitine supplementation at dosages of ≤ 1000 mg/day (p = 0.035) or equal to 2000 mg/day (p = 0.013) resulted in significant reduction in ALT level, while doses more than 2000 mg/day did not change ALT significantly. Carnitine exerts its reducing effect on serum ALT and AST levels only when these aminotransferases are raised or when the duration of supplementation lasts at least 3 months.

CONCLUSION

Results of the current meta-analysis showed that carnitine supplementation can decrease serum AST and ALT levels significantly, especially when supplementation lasts 3 months or more in patients with elevated serum aminotransferase levels.

Possible role of l-carnitine in improvement of metabolic and hepatic changes in hyperuricemic and hyperuricemic-Fructose-supplemented rats

Hyperuricemia was linked to diabetes mellitus, metabolic syndrome, and oxidative stress, and could be induced by higher fructose consumption through altering energy status in liver. l-Carnitine is an antioxidant, affecting mitochondria and cellular energetics; however, little is known about its effects in hyperuricemic states. This study investigated metabolic and hepatic effects of hyperuricemia and fructose feeding, and demonstrated the role of l-Carnitine in such states. Fifty adult male Wistar rats were randomly divided into control, untreated hyperuricemic, fructose-supplemented hyperuricemic, l-Carnitine-treated hyperuricemic, and l-Carnitine-treated fructose-supplemented hyperuricemic groups. The separated plasma was used for determination of the glycemic control, lipid profile, liver function tests, uric acid level, and oxidative stress markers. Atherogenic index, HOMA-IR, and body mass index (BMI) were calculated. Left liver lobe and left kidney specimen from all groups were used for histopathological studies. Hyperuricemic rats exhibited significantly hypoalbuminemia, dyslipidemia, insulin resistance, and oxidative stress compared to the controls. Fructose-supplemented hyperuricemic group showed obesity and more deleterious effects, as well as, steatosis, and renal tubular damage compared to the hyperuricemic rats. Concomitant l-Carnitine treatment with hyperuricemia improved such effects, despite causing adiposity. While combined l-Carnitine treatment and fructose supplementation in hyperuricemia limited the aggressive hyperuricemic picture of fructose supplementation. It is concluded that hyperuricemia has detrimental metabolic and hepatic effects. Artificial fructose supplementation worsened such effects, while l-Carnitine was efficient in ameliorating these hyperuricemia and/or excess fructose-induced hyperuricemia effects, through its anti-inflammatory, antisteatotic, and antioxidant properties.