PROGESTERONE METABOLITE ALLOPREGNANOLONE IN WOMEN WITH PREMENSTRUAL-SYNDROME

Objective: To evaluate the anxiolytic 3 alpha-5 alpha-reduced progeste rone metabolite allopregnanolone in the luteal phase of the menstrual cycle in women with premenstrual syndrome (PMS) and controls. Methods: Thirty-five women with prospectively documented PMS and 36 controls w ere evaluated. Serum progesterone and allopregnanolone levels were mea sured on days 19 and 26 of the cycle as determined by urinary LH detec tion kits. Analysis of variance and Student t tests were used to analy ze the data. Results: Allopregnanolone levels were significantly lower on day 26 in the PMS group than in controls (3.6 +/- 0.8 versus 7.5 /- 1.3 ng/mL; P < .04). Significant differences in the ratio of the me tabolite to progesterone also were noted, with a smaller ratio in the PMS subjects (0.9 +/- 0.3 versus 3.2 +/- 1.3 ng/mL; P < .05). There we re no significant differences between the PMS and control groups with respect to serum progesterone levels. Conclusion: Subjects with PMS ma nifested lower levels of the anxiolytic metabolite allopregnanolone in the luteal phase when compared with controls. Diminished concentratio ns of allopregnanolone in women with PMS may lead to an inability to e nhance gamma aminobutyric acid-mediated inhibition during states of al tered central nervous system excitability, such as ovulation or physio logic or psychological stress. The lowered metabolite levels could con tribute to the genesis of various mood symptoms of the disorder, such as anxiety, tension, and depression. (C) 1997 by The American College of Obstetricians and Gynecologists.