Background & aims

Several randomized clinical trials (RCTs) have investigated the effect of l -carnitine supplementation on lipid profile and glycaemic control in adults with cardiovascular risk factors; however, the results were conflicting. Therefore, a meta-analysis was performed to assess the eﬀect of l -carnitine on lipid profile and glycaemic control in adults with cardiovascular risk factors.

Methods

We searched PubMed, Scopus, Cochrane Databases, Google Scholar, ProQuest, Web of Science and Embase for randomized, placebo-controlled human trials that investigated the effect of l -carnitine supplementation on lipid profile and glycaemic control up to April 2017. From the eligible trials, 24 articles were selected for the meta-analysis. The meta-analysis was performed in a random-effects model. Heterogeneity was determined by I 2 statistics and Cochrane Q test.

Results

The result showed significant effect of l -carnitine on TC (WMD: −13.73 [95% CI: −22.28, −5.17] mg/dL; P < 0.001), LDL-C (WMD = − 7.70 [95% CI: − 11.80, −3.61]mg/dL; p < 0.001), HDL-C (WMD = 0.82 [95% CI: 0.44, 1.21] mg/dL; P > 0.001), Lp(a) (WMD = − 7.13 [95% CI: −9.82,− 4.43]mg/dL; P < 0.001), FPG (WMD = −6.25 [95% CI: −10.35, −2.16] mg/dL; P < 0.001), HbA1C (WMD (%) = − 0.35 [95% CI: −0.65,− 0.05]; p = 0.02) and HOMA-IR (WMD (%) = − 0.94 [95% CI: −1.89, −0.00]; P = 0.05). No effect of l -carnitine was detected in TG, Apo A-I and Apo B 100 on pooled effect size. Additionally, sensitivity analysis showed l -carnitine supplementation could improve glycaemic control, particularly along with hypocaloric diet.

Conclusion