Estrogen raises the sweating threshold in postmenopausal women with hot flashes.
OBJECTIVE
To determine if estrogen ameliorates hot flashes by raising the core body temperature sweating threshold, by reducing core body temperature fluctuations, and/or by reducing sympathetic activation (as measured by plasma 3-methoxy-4-hydroxyphenylglycol).


METHODS
Laboratory physiological study.


METHODS
University medical center.


METHODS
Twenty-four healthy postmenopausal women reporting frequent hot flashes.


METHODS
Participants were randomly assigned, in double-blind fashion, to receive 1 mg/d 17beta-estradiol orally or placebo for 90 days.


METHODS
Core body temperature, core body temperature fluctuations, mean skin temperature, sternal sweat rate, laboratory hot flash counts (sternal skin conductance), plasma 3-methoxy-4-hydroxyphenylglycol.


RESULTS
The E(2) group had significant increases in plasma E(2) (8 +/- 2 vs. 132 +/- 22 pg/mL) and core body temperature sweating threshold (37.98 +/- 0.09 vs. 38.14 +/- 0.09 degrees C) and decreases in plasma FSH (58.8 +/- 8.9 vs. 40.1 +/- 7.6 mIU/mL) and hot flashes (1.4 +/- 0.5 vs. 0.6 +/- 0.6). These changes did not occur in the placebo group. There were no significant changes in any other measure.


CONCLUSIONS
E(2) ameliorates hot flashes by raising the core body temperature sweating threshold, but does not affect core temperature fluctuations or plasma 3-methoxy-4-hydroxyphenylglycol.
Freedman
Robert R
RR
Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA. aa2613@wayne.edu
Blacker
Charla M
CM
D001831:Body Temperature / Q000187:drug effects / Q000502:physiology; D004311:Double-Blind Method; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D015914:Estrogen Replacement Therapy; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D019584:Hot Flashes / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D008734:Methoxyhydroxyphenylglycol / Q000097:blood; D008875:Middle Aged; D017698:Postmenopause; D013546:Sweating / Q000187:drug effects* / Q000502:physiology; D013686:Telemetry
D004958:Estradiol; D008734:Methoxyhydroxyphenylglycol; D005640:Follicle Stimulating Hormone