Study On Serum Inhibin And Sexual Hormone Concentrations During Perimenopausal Period

Objective: To investigate the changes of serum inhibin(INH) and sexualhormone concentrations during perimenopausal period and relationship betweenchanges of other reproductive hormone levels.such as FSH,LH,and E₂.Methods: Serum INH and FSH,LH,E₂ concentrations were measured by RIAon the 3rd day of menstrual cycle in 10 healthy reproductive women,any timeof 20 postmenopausal women. So did the serum INH and FSH,LH,E₂determinations on the 3rd day of menstrual cycle in 60 perimenopausal women.According to change in menstrual cycle pattern, perimenopausal stage wereclassified 3 controls: A premenopausal stage, B early perimenopausal stage, andC late perimenopausal stage .In addition, to investigate the relationship betweenchanges of INH and FSH,LH,E₂.Results: The hormone concentration in perimenopausal control, INH wasnegatively correlated with FSH during follicular phase,r =—0.702, p<0.01,positive correlativity existed between INH and E₂, r =0.875, p<0.01. Earlyperimenopausal subjects had significantly lower levels of INH, statisticallynon-significant rise in FSH and no significant change in E₂. in lateperimenopausal subjects, INH fells to 0.21ng/L. FSH had risen significantly to30.16U/L. E₂ also fell significantly to 40.19pg/ml ,in the postmenopausalsubjects there were no further significant changes in FSH, but E₂ fell further to32.71 pg/ml .Conclustion: The major significant endocrine event in women in the earlyperi-menopausal phase of the menopausal transition is a substantial fall in thecirculating levels of INH with no significant change in E₂ or FSH. INH is asignificant factor in the endocrinology of the menopausal transition.