Androgen levels in adult females: changes with age, menopause, and oophorectomy.

CONTEXT

Changes in androgen levels across the adult female life span and the effects of natural menopause and oophorectomy have not been clearly established.

OBJECTIVE

The objective of this study was to document the effects of age on androgen levels in healthy women and to explore the effects of natural and surgical menopause.

DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional study was conducted of 1423 non-healthcare-seeking women, aged 18-75 yr, randomly recruited from the community over 15 months.

MAIN OUTCOME MEASURES

Serum levels by age of total testosterone (T), calculated free T, dehydroepiandrosterone sulfate, and androstenedione in a reference group of women free of confounding factors. Women in the reference group had no usage of exogenous steroid therapy; no history of tubal ligation, hysterectomy, or bilateral oophorectomy; and no hyperprolactinemia or polycystic ovarian syndrome. The effects of natural and surgical menopause on sex steroid levels were also examined.

RESULTS

In the reference population (n = 595), total T, calculated free T, dehydroepiandrosterone sulfate, and androstenedione declined steeply with age (P < 0.001), with the decline of each being greater in the earlier than the later decades. Examination of serum androgen levels by year in women aged 45-54 yr showed no independent effect of menopausal status on androgen levels. In women aged 55 yr or older, those who reported bilateral oophorectomy and were not on exogenous steroids had significantly lower total T and free T levels than women 55 yr or older in the reference group.

CONCLUSIONS

We report that serum androgen levels decline steeply in the early reproductive years and do not vary because a consequence of natural menopause and that the postmenopausal ovary appears to be an ongoing site of testosterone production. These significant variations in androgens with age must be taken into account when normal ranges are reported and in studies of the role of androgens in women.