Serum Levels of Inhibin B,Follistatin and Activin A in Women:Relationship to Testosterone

Objective To explore the relationship between serum inhibin B,follistatin,activin A concentrations and testosterone in women. Methods Serum levels of testosterone (T),inhibin B,follistatin,activin A and other sex hormone:estradial (E_2),follicle-stimulating hormone (FSH),luteinizing hormone (LH),prolactin (PRL) on cycle day 3 were determined by a solid quantitative sandwich enzyme immunoassay technique (Sandwich ELISA) in 27 women without endocrine disease,and relationship between inhibin B,follistatin,activin A,body-mass-index (BMI),age and other sex hormone were analyzed. Results Nonparametric correlations analysis demonstrated that T serum levels were negatively correlated with age (r=0.577,P0.05),and FS (r=0.572,P0.05),were positively correlated with inhibin B (r=0.663,P0.05),has no correlations with activin A (r=0.293,P0.05),but were positively correlated with the ratio of activin A/follistatin (r=0.629,P0.05).T serum levels has no significant associations with BMI and other sex hormone. Conclusion Inhibin-follistatin-activin system may be partly responsible for the secretion of T in women in a special way.