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Effects of l-carnitine supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials

Journal of Human Hypertension volume 33, pages 725–734 (2019)Cite this article

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Abstract

l-carnitine plays a fundamental biological role in the metabolism of lipids and may positively affect blood pressure by decreasing insulin resistance, although the latter remains less clear. We aimed to assess the effects of l-carnitine supplementation on systolic (SBP) and diastolic blood pressure (DBP). A search was conducted using databases of EMBASE, PubMed, Scopus, Cochrane Library, and ISI web of Science from inception to February 2019 without limitations in language. A meta-analysis was conducted on a total of ten eligible randomized controlled trials using a random-effects model to estimate the pooled effect sizes of l-carnitine supplementation on SBP and DBP levels. Results were expressed as weighted mean difference (WMD) and 95% confidence intervals (CI). l-carnitine supplementation decreased DBP (−1.162 mmHg, 95% CI: −2.020, −0.303, p = 0.008) without changing SBP levels (−0.085 mmHg, 95% CI: −1.455, 1.285, p = 0.903). Results of the subgroup analyses revealed l-carnitine supplementation decreased DBP levels in participants with overweight and obesity (−1.232 mmHg, 95% CI: −2.297, −0.167, p = 0.023) and with doses of <2 g/d (−1.639 mmHg, 95% CI: −3.038, −0.240, p = 0.022). No evidence of publication bias was observed about the effects of l-carnitine supplementation on SBP (p = 0.307) and DBP (p = 0.729), as evidenced by the results of the Egger’s test. In conclusion, l-carnitine supplementation decreased DBP without affecting SBP levels. Research is required to determine the molecular mechanism underlying the relationship between of l-carnitine on blood pressure.

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Authors and Affiliations

  1. Department of Community Nutrition, School of Nutritional Sciences and Dietetics, International Campus, Tehran University of Medical Sciences (TUMS), Tehran, Iran

    Moein Askarpour, Azadeh Dehghani Kari Bozorg, Omid Sadeghi & Ali Sheikhi

  2. Halal Research Center of IRI, FDA, Tehran, Iran

    Amir Hadi

  3. Department of Clinical Nutrition, School of Nutrition and Food Science, Isfahan University of Medical Sciences, Isfahan, Iran

    Amir Hadi

  4. Division of Nutritional Sciences, Human Metabolic Research Unit, Cornell University, Ithaca, NY, USA

    Maryam Kazemi

  5. Students’ Scientific Research Center (SSRC), Tehran University of Medical Sciences (TUMS), Tehran, Iran

    Ehsan Ghaedi

  6. Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran

    Ehsan Ghaedi

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  1. Moein Askarpour
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MA, AS, ADKB and AH screened and extracted articles. EG performed the statistical analyses. OS drafted the manuscript and interpreted the results with contributions from MA, AS, ADKB, and AH. MK edited the manuscript for native language. All authors reviewed and commented on the final draft and approved the final version.

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Correspondence to Ehsan Ghaedi.

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Askarpour, M., Hadi, A., Dehghani Kari Bozorg, A. et al. Effects of l-carnitine supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials. J Hum Hypertens 33, 725–734 (2019). https://doi.org/10.1038/s41371-019-0248-1

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