Can L-carnitine improve glycemic control? Original paper

    In this meta-analysis of randomized controlled trials, supplementation with L-carnitine improved measures of glycemic control in adults.

    This Study Summary was published on April 3, 2023.

    Quick Summary

    In this meta-analysis of randomized controlled trials, supplementation with L-carnitine improved measures of glycemic control in adults.

    What was studied?

    The effects of supplemental L-carnitine on glycemic markers, including serum insulin, fasting blood glucose, glycated hemoglobin (HbA1c), and the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR).

    Who was studied?

    2,900 adults (age range of 18–101).

    How was it studied?

    The researchers performed a systematic review and meta-analysis of 41 randomized controlled trials. The included studies used daily doses of 0.25–4 grams of L-carnitine, and the duration of supplementation was 2–52 weeks.

    The researchers also conducted subgroup analyses to investigate whether the study duration, intervention dose, BMI of the participants, the presence of diabetes, or baseline levels of fasting blood glucose influenced the outcomes.

    What were the results?

    Supplemental L-carnitine improved several markers of glycemic control, including fasting blood glucose (−3.22 mg/dL), HbA1c (−0.27%), and HOMA-IR (−0.73).

    Subgroup analysis revealed that these beneficial effects of L-carnitine were stronger if taken for longer durations (≥12 weeks) and in higher doses (≥2 grams) and in participants with obesity, diabetes, or elevated levels of fasting blood glucose (≥100 mg/dL) at baseline.

    Anything else I need to know?

    Most studies included in the meta-analysis were at moderate (11 studies) and high (22 studies) risk of bias, which reduces confidence in the results.

    This Study Summary was published on April 3, 2023.