Laser doppler-recorded reactive hyperaemia in the forearm skin during the menstrual cycle.

OBJECTIVE: By means of laser Doppler flowmetry to describe the changes in resting microvascular perfusion and post-occlusive reactive hyperaemia in skin of the forearm and finger pulp throughout the menstrual cycle. DESIGN: Prospective descriptive study. SETTING: University Hospital of Tromso, Norway. SAMPLE: Fifteen nonsmoking healthy women were studied in the follicular (days 2 to 7) and the luteal (days 19 to 24) phase of the menstrual cycle. RESULTS: Resting perfusion in forearm and finger pulp as well as post-occlusive reactive hyperaemia in finger pulp were unchanged from the follicular to the luteal phase. The peak perfusion value of the reactive hyperaemic response after 1 min of arterial occlusion was significantly reduced from the follicular to the luteal phase (P<0.01) in forearm skin. The repayment for the blood flow debt, which is the hyperaemic response in percentage of the ischaemic build-up, was also reduced (P<0.01). After 3 min of arterial occlusion, significant reductions in peak post-occlusive flow (P<0.01), recovery time, which is the total duration of the hyperaemic response (P<0.01), and the repayment (P<0.01) were observed. A significant correlation was found between the ratio serum oestradiol/progesterone and repayment after 3 min of arterial occlusion in forearm skin (r=0.71,P<0.001). CONCLUSIONS: Vascular reactivity is altered during the menstrual cycle. In the luteal phase, significant reductions in peak perfusion, repayment and recovery time were seen. The mechanisms behind these findings are unclear, but probably involve changes in both serum oestradiol and progesterone levels.