Background & objectives: PCOS is one of the most prevalent endocrinology disorders and 5-15% of women in fertility age suffer from this disease. The leptin a 167 amin oacid peptide is secreted from adipose tissue in a pulsatile fashion. This hormone is essential in regulation of normal body weight and like the klotho hormone that is expressed most prominently in the distal convoluted tubules of kidneys and the choroid plexus of brain, has a role in pathogenesis of reproductive disorders. The secreted klotho has been identified as an anti-aging and anticancer hormone. Metformin is an anti-hyperglycemic drug with anorexic properties that could influence the function of ovaries.

Methods: In this case-control study, 45 patients with PCOS who referred to the infertility center of Jahad-e-Daneshgahi in the city of Ardabil from March 2013 through March 2014, were selected in accordance with the NIH criteria. Moreover, 45 healthy women were also selected as the control group. BMIs were calculated by division of weight by square of height and insulin resistance index was calculated by HOMA-IR model. Leptin and klotho serum levels were measured using ELISA kit. In the case group the measurements were repeated after a one-month course of therapy with metformin. Data analysis performed by SPSS software using dependent and independent t-tests.

Results: PCOS patients showed significant improvements after receiving metformin for one month.
Patients’ weights showed some decline. Fasting plasma glucose levels and insulin resistance decreased significantly (p<0.01). Hormonal assays indicated significant decrease in leptin and insulin levels and rise in Klotho levels. BMIs did not change meaningfully. Measurements of leptin and klotho levels showed a decrease in mean leptin levels from 34.74 to 28.41 ng/l and the level of klotho increased from 4.01 to 5.43 ng/l.

Conclusion: This study showed that metformin treatment can cause a rise in klotho and a decrease in leptin levels without considerable effects on the weights of women with PCOS. Probably, leptin exerts its physiological effects in low concentrations while klotho in contrast acts physiologically in higher concentrations.