Background: Carnitine plays essential roles in energy production, oxidative stress and glucose metabolism. This study was planned to determine serum total L-carnitine levels in non-obese women with polycystic ovary syndrome (PCOS).
Methods: There were 27 non-obese women with PCOS and 30 healthy, age- and body mass index (BMI) matched controls were evaluated in this controlled clinical study. Serum lipid sub-fractions, fasting glucose, insulin and other hormones (gonadotrophins, androgens) and total L-carnitine levels were measured. Homeostasis model assessment (HOMA-IR) was used to estimate insulin resistance.
Results: The women with PCOS had significantly higher serum dehydroepiandrosterone sulfate, total testosterone, free androgen index (FAI), luteinizing hormone (LH), low-density lipoprotein (LDL) cholesterol, non-high density lipoprotein (HDL) cholesterol, fasting insulin levels and HOMA-IR measurement and LH/FSH ratios than healthy women. However, total L-carnitine and sex hormone-binding globulin (SHBG) levels were significantly lower in women with PCOS. L-Carnitine level was negatively correlated with FAI, but positively correlated with SHBG. Multiple regression analysis revealed that SHBG was a strong predictor of serum total L-carnitine level.
Conclusions: Decreased total L-carnitine levels may be associated with hyperandrogenism and/or insulin resistance in non-obese women with PCOS. Long-term studies are needed to evaluate carnitine metabolism in PCOS, especially with regard to the molecular basis.