Effects of short term metformin administration on androgens in normal men

To study the effect of metformin on androgens in normal men.

A total of 12 healthy males volunteered to participate in the study. A blood sample was obtained from each of them and analyzed for the following: Testosterone (total and free), sex hormone binding globulin dehydroepiandrosterone sulphate, 17-hydroxyprogesterone, luteinizing hormone, and follicle stimulating hormone. In addition, each participant was subjected to a glucose tolerance test and his insulin level was measured. Metformin 850 mg twice daily for 2-weeks was given to each subject after which the above tests were repeated. A paired t-test was used to assess the statistical significance of any observed differences before and after metformin.

After metformin administration, there was a significant reduction in serum level of total testosterone (p=0.0001), free testosterone (P=0.002), and 17 hydroxyprogesterone (p=0.0001). There was also a significant increase in serum level of sex hormone binding globulin (p=0.009) and dehydroepiandrosterone sulphate (P=0.0008). Serum levels of luteinizing hormone and follicle stimulating hormone showed no significant changes. Similarly, there were no changes in fasting plasma glucose, fasting serum insulin, weight, or blood pressure.

Metformin administration was associated with a reduction in total testosterone, free testosterone, and 17-hydroxyprogesterone and an increase in sex hormone binding globulin and dehydroepiandrosterone sulphate in normal males. The clinical significance of these findings needs further investigation.