Cutaneous microvascular effects of mid-term hormone replacement therapy in healthy postmenopausal women: a...

To study the mid-term effects of Hormone Replacement Therapy (HRT) on cutaneous microcirculatory blood flow and reactivity in healthy postmenopausal women.

In a double-blind placebo controlled randomized study, 16 healthy postmenopausal women received either placebo or HRT (micronized estradiol: 1 mg/day, day 1-28, promegestrone: 0.25 mg/day, day 14-28). This regimen was completed 6 times. Cutaneous microcirculatory blood flow was recorded by laser-Doppler velocimetry on the foot dorsum, in the supine and then dependent positions, and after post-ischemic hyperemia.

At day 0, the two groups were similar and none of the following data differed significantly between treated and placebo group: (supine flux: 11.8 +/- 1.8 u vs. 13.2 +/- 3.9, venoarteriolar reflex: 5.6 +/- 1.3 vs. 6 +/- 3.3, and post-ischemic hyperemia: 35.2 +/- 3.9 vs.48.3+/-11). At the end of the study (day 26-28 of 6th cycle), the supine flux was 9.8 +/- 2.1 in the HRT group vs.12.9 +/- 6 in the placebo group (NS), the venoarteriolar reflex, 1.2 +/- 2 vs. 7+/-1.7 (p=0.04), and post ischemic hyperemia, 31.8 +/- 5.4 vs. 39.5 +/- 4.6 (NS). Intragroup values did not change significantly for any of the microcirculatory parameters measured, which remained stable throughout the 6 months of the study. Intergroup values for these parameters did not change either, except for the venoarteriolar reflex, which was lower at the end of the study in the HRT (EP period, cycle 6 day 26-28) than placebo group (p=0.04).

HRT does not impair the resting supine cutaneous microcirculation blood flow or post-ischemic hyperemia.