Effect of estrogen replacement therapy with or without concomitant nonsteroidal anti-inflammatory drugs on pulsatility and resistance index of uterine arteries in healthy postmenopausal women.

Objective: This study assesses the existence of a prostaglandin-mediated effect of estrogen on uterine arteries.

Methods: The pulsatility index (PI) and the resistance index (RI) of 10 postmenopausal women aged 50 to 65 who had not been on estrogen replacement therapy (ERT) for the 6 weeks preceding the study were measured at baseline level (T1), after randomization for either placebo or nonsteroidal anti-inflammatory drug (NSAID) (600 mg of Sulindac for one day) (T2), after 1 week of washout and cross-over (T3). They were then supplemented with ERT (transdermal system 50 micrograms/d, twice a week, Systen) for a period of 3 months. PI and RI of uterine arteries were assessed again while using ERT (T4), after either placebo or NSAID for one day (T5) and after 1 week of placebo-NSAID cross-over (T6). Assays of total cholesterol as well as the HDL, HDL2, LDL, triglycerides, endothelin-1, lipoprotein (a), estradiol and FSH were also obtained at baseline before receiving ERT and after 3 months of ERT.

Results: A small but significant increase of the PI was observed after NSAID intake as compared to the baseline measurement (P < .05), but no difference was observed for the RI. After estrogen treatment for 12 weeks, no difference was found between baseline measurements and the placebo intake or the NSAID intake.

Conclusion: These results do not confirm a modulation by prostaglandin of the estrogen cardioprotective effect, although it is possible that the study lacks power.