Vasomotor symptoms in the menopause Santiago Palacios

Definitions A hot flush is a sensation of warmth that is generally most intense over the face, neck and chest, with objective signs of cutaneous vasodilatation and a drop in core temperature Sweating, palpitations, anxiety, irritability and panic may accompany the hot flush The frequency, duration and intensity vary It is not possible to predict whether a particular woman will have hot flushes

n = 12,357; SWAN = Study of Women’s Health Across the Nation SWAN study: reported prevalence of vasomotor symptoms in perimenopausal women Ages 40–55 years Women reporting hot flushes/night sweats (%) Race/ethnicity African American (n = 3650) Hispanic (n = 1712) White (n = 5746) Chinese (n = 542) ) Japanese (n = 707) Gold EB, et al. Am J Epidemiol 2000;152:463–73

Body temperatures during hot flushes Adapted from Molnar. J Appl Physiol 1975;38:499–503 Temperature (°C) Time (min) Flush Rectum Tympanum Toe Finger

Estrogen withdrawal does not explain the etiology of hot flushes There are no correlations between hot flush occurrence and plasma, urinary and vaginal levels of estrogens Nor are there differences in plasma levels between asymptomatic and symptomatic women Clonidine reduces hot flush frequency without changing circulating estrogen levels Estrogen withdrawal is necessary to explain the occurrence of hot flushes, but is not, by itself, sufficient to do so

Sweating threshold Shivering threshold ASYMPTOMATICSYMPTOMATIC Hot flush Sweating threshold Thermoneutral zone Shivering threshold TcTc Tc Tc Freedman RR. Semin Reprod Med 2005;23:117 Thermoneutral zone Small core body temperature (Tc) elevations acting within a reduced thermoneutral zone trigger hot flushes in symptomatic postmenopausal women

Hot flush: conclusions Hot flushes are most common menopausal symptom Major impact on quality of life Estrogen is best and most logical treatment Of currently available alternatives, SSRIs or gabapentin seem best