Resistin, a product of RSTN gene, is an adipose tissue hormone, involved in the regulation of insulin activity. In this study we investigated whether resistin concentrations fluctuate during the menstrual cycle and if resistin concentrations are correlated with estradiol, luteinizing hormone (LH), follicular stimulating hormone (FSH) and progesterone concentrations.

Ten ovulatory cycles of endocrinologically normal volunteers, with normal body mass index, were analyzed. Blood samples were taken on alternate days throughout the menstrual cycle for measurement of serum resistin, estradiol, LH, FSH and progesterone concentrations.

Mean serum concentrations of resistin varied between 4.07 and 4.932ng/ml. They were not significantly correlated with estradiol, LH and FSH. Resistin concentrations were significantly correlated with progesterone, four days (R=0.833; p=0.0053) and six days (R=0.929; p=0.0009) after LH surge, when peak progesterone levels were achieved.

Conclusively, resistin serum levels show little fluctuation during the menstrual cycle. The correlation between resistin and peak progesterone serum concentrations needs further investigation.