The relation of physiological changes to subjective symptoms in postmenopausal women with and without hot flushes

This study was designed to fully correlate the temporal relationship between augmented digital perfusion, (vasodilatation) and hot flushes, peripheral temperature, plasma luteinizing hormone, (LH) epinephrine and norepinephrine. Plasma samples were measured every 3 min for 2-4 h, in 5 symptomatic women before and after estrogen replacement and in 3 asymptomatic post-menopausal women. In all 5 symptomatic women the augmented digital perfusion occurred at a mean (+/- SEM) of 1.5 +/- 0.2 min before the initiation of the flush, at least 3 min before the initial rise in temperature and 9 min before the LH rise. There was a significant (P less than 0.05) rise in epinephrine but not norepinephrine at 3 and 6 min after the initiation of augmented digital perfusion. Although subjective improvement occurred in all 3 women receiving estrogen, all measured parameters disappeared in only 1 subject and the 2 others continued having augmented digital perfusion, flushes, and temperature vasomotor changes although the related LH increase was absent. Surprisingly, asymptomatic women who never received estrogens also demonstrated similar augmented digital perfusion and temperature changes, but failed to show the LH related rise, as observed in women with short-term estrogen treatment. In conclusion, these results demonstrate that augmented digital perfusion consistently precedes the hot flush, the rise in temperature and plasma LH in symptomatic post-menopausal women. The increase in epinephrine may be a homeostatic mechanism to compensate for the peripheral vasodilatation. The finding that augmented digital perfusion and temperature changes also occur in asymptomatic post-menopausal women indicates that objective changes are more specific and reliable indicators of vasomotor instability than the subjective sensation of hot flushes.