THE EFFECT OF PROGESTINS ON BEHAVIORAL STRESS RESPONSES IN POSTMENOPAUSAL WOMEN

OBJECTIVE: We assessed the effects of progestin when added to estrogen on the adaptive patterns to provoked stress in postmenopausal women. METHODS: Fourteen postmenopausal women were randomized to receive eith er a transdermal estrogen patch (TE(2)) (n = 7) for and weeks or TE(2) with added medroxyprogesterone acetate (10 mg) (TE(2)/MPA) (n = 7) fo r the last 10 days of the 6-week regimen. Behavioral stress tests were administered to each group, with measurements of biophysical and neur oendocrine responses. In a crossover fashion, after each group receive d the first treatment and testing, treatment was continued for another and weeks with the alternate regimen, at which time another stress te st was administered. Responses to stress in the two treatment groups w ere compared to each other and to established placebo responses. RESUL TS: Biophysical responses in the TE(2) group were significantly blunte d compared to both TE(2)/MPA and placebo responses (P <.05). Without M PA treatment, there were significantly blunted speech (P <.05) and col d pressor (P <.01) blood pressure responses. With added progestin, the re war a greater systolic blood pressure response (P <.01) compared wi th estrogen alone. Both groups (TE(2) and TE(2)/MPA) had blunted and n onsignificant responses of ACTH and cartisol upon testing, whereas the placebo group showed a significant response (P <.01). Plasma norepine phrine responses, however, were significantly blunted after TE(2), com pared with the increased responses observed with both TE(2)/MPA and pl acebo (P <.01). CONCLUSION: Although estrogen significantly reduces be haviorally induced stress reactivity in postmenopausal women, certain doses of progestin administration may blunt this effect.