The effect of L-carnitine supplementation on insulin resistance, sex hormone-binding globulin and lipid profile in overweight/obese women with polycystic ovary syndrome: a randomized clinical trial

Eur J Nutr. 2022 Apr;61(3):1199-1207. doi: 10.1007/s00394-021-02659-0. Epub 2021 Nov 2.

Abstract

Purpose: Polycystic ovary syndrome (PCOS) is a common endocrine disorder among reproductive-age women. Insulin resistance and dyslipidemia are linked to PCOS. L-Carnitine supplementation as a management strategy for women with PCOS has been proposed. The effect of L-carnitine supplementation on insulin resistance, sex hormone-binding globulin (SHBG) and lipid profile in overweight/obese women with PCOS was investigated.

Methods: This randomized, double-blind, controlled clinical trial, was conducted on 62overweight/obese women with PCOS. Participants were randomly assigned into two groups to receive 1000 mg/day L-carnitine or placebo (1000 mg starch) for 12 weeks.

Results: L-Carnitine supplementation compared to the placebo showed a significant improvement in insulin [- 0.7 (- 7.3 to 4.0) vs. 0.7 (- 3.0 to 5.2); P = 0.001], homeostatic model assessment for insulin resistance [- 0.4 (- 1.7 to 1.1) vs. 0.0 (- 0.7 to 1.3); P = 0.002], quantitative insulin sensitivity check index (+ 0.01 ± 0.02 vs. - 0.01 ± 0.01; P = 0.02) and a non-significant change toward improvement in SHBG (+ 11.5 ± 40.2 vs. - 3.2 ± 40.2; P = 0.2). However, there was no significant differences between the two groups in serum levels of fasting plasma glucose, total cholesterol, triglyceride, low density lipoprotein-cholesterol and high density lipoprotein cholesterol (P > 0.05).

Conclusion: 12-week L-carnitine supplementation in overweight or obese women with PCOS ameliorate insulin resistance, but has no effect on SHBG and lipid profile. Studies with higher dosages and duration of L-carnitine intake are required. The trial was registered on 30 December 2019 at Iranian Registry of Clinical Trials IRCT20191016045131N1.

Trial registration: Registered on 30th December 2019 at Iranian Registry of Clinical Trials (IRCT20191016045131N1).

Keywords: Insulin resistance; L-Carnitine; Lipid profile; Polycystic ovary syndrome; Sex hormone-binding globulin.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Carnitine / therapeutic use*
  • Cholesterol, HDL
  • Dietary Supplements*
  • Double-Blind Method
  • Female
  • Humans
  • Insulin
  • Insulin Resistance*
  • Iran
  • Lipids / blood
  • Obesity / complications
  • Obesity / drug therapy
  • Overweight / complications
  • Overweight / drug therapy
  • Polycystic Ovary Syndrome* / complications
  • Polycystic Ovary Syndrome* / drug therapy
  • Sex Hormone-Binding Globulin / analysis

Substances

  • Cholesterol, HDL
  • Insulin
  • Lipids
  • Sex Hormone-Binding Globulin
  • Carnitine

Associated data

  • IRCT/IRCT20191016045131N1