Oral carnitine supplementation reduces body weight and insulin resistance in women with polycystic ovary syndrome: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE Limited data are available for evaluating the effects of oral carnitine supplementation on weight loss and metabolic profiles of women with polycystic ovary syndrome (PCOS). This study was designed to determine the effects of oral carnitine supplementation on weight loss, and glycaemic and lipid profiles in women with PCOS. DESIGN, PATIENTS AND MEASUREMENTS In a prospective, randomized, double-blind, placebo-controlled trial, 60 overweight patients diagnosed with PCOS were randomized to receive either 250 mg carnitine supplements (n = 30) or placebo (n = 30) for 12 weeks. Fasting blood samples were obtained at the beginning and the end of the study to quantify parameters of glucose homoeostasis and lipid concentrations. RESULTS At the end of the 12 weeks, taking carnitine supplements resulted in a significant reduction in weight (-2·7 ± 1·5 vs +0·1 ± 1·8 kg, P < 0·001), BMI (-1·1 ± 0·6 vs +0·1 ± 0·7 kg/m(2) , P < 0·001), waist circumference (WC) (-2·0 ± 1·3 vs -0·3 ± 2·0 cm, P < 0·001) and hip circumference (HC) (-2·5 ± 1·5 vs -0·3 ± 1·8 cm, P < 0·001) compared with placebo. In addition, compared with placebo, carnitine administration in women with PCOS led to a significant reduction in fasting plasma glucose (-0·38 ± 0·36 vs +0·11 ± 0·97 mmol/l, P = 0·01), serum insulin levels (-14·39 ± 25·80 vs +3·01 ± 37·25 pmol/l, P = 0·04), homoeostasis model of assessment-insulin resistance (-0·61 ± 1·03 vs +0·11 ± 1·43, P = 0·04) and dehydroepiandrosterone sulphate (-3·64 ± 7·00 vs -0·59 ± 3·20 μmol/l, P = 0·03). CONCLUSIONS Overall, 12 weeks of carnitine administration in PCOS women resulted in reductions in weight, BMI, WC and HC, and beneficial effects on glycaemic control; however, it did not affect lipid profiles or free testosterone.