Analysis of gonadotropin pulsatility in hirsute women with normal menstrual cycles and in women with polycystic ovary syndrome.

Objective: To study the relation between plasma gonadotropin pulsatility, androgen levels, and estrogen levels in patients with polycystic ovary syndrome (PCOS), in hirsute women with normal menstrual cycles, and in healthy women.

Design: Prospective study.

Setting: University medical center-based cellular and molecular endocrinology laboratory.

Patient(s): Eight healthy women (group 1), 9 hirsute women with normal menstrual cycles (group 2), and 19 women with PCOS (group 3).

Intervention(s): Plasma concentrations of LH and FSH were measured by RIA every 15 minutes for 12 hours.

Main Outcome Measure(s): Rhythmic parameters of 12-hour LH and FSH secretion.

Result(s): Rhythmic parameters of 12-hour LH secretion were significantly higher in patients with PCOS (group 3) than in controls (group 1) or in hirsute women with normal menstrual cycles (group 2). The frequency of LH pulses was statistically higher in patients with PCOS (group 3) than in controls (group 1). Statistically significant correlations were found when the frequency of LH pulses was plotted against basal LH concentrations and rhythmic parameters of 12-hour LH secretion.

Conclusion(s): Luteinizing hormone pulse amplitude was higher in patients with PCOS than in hirsute women with normal menstrual cycles or in healthy women. The LH pulse frequency was increased only in patients with PCOS compared with healthy women and not in hirsute women with normal menstrual cycles.