Hot flushes, menstrual status, and hormone levels in a population-based sample of midlife women.

OBJECTIVE: To determine the frequency of hot flushes in a population sample of 453 pre-, peri-, and postmenopausal women (aged 48-59 years), and to investigate the relationship of hot-flush reporting with menstrual status, serum levels of estradiol (E2), inhibin, and FSH, history of premenstrual complaints, and physical and life-style factors. METHODS: We used a population-based sample. Interviews were conducted in the women's homes. RESULTS: Frequency of hot-flush reporting was associated with menstrual status (P < .001). Twenty-nine percent of women who had more than 3 and less than 12 months of amenorrhea, and 37% of postmenopausal women experienced hot flushes several times a day. In total, 13% of premenopausal women, 37% of perimenopausal women, 62% of postmenopausal women, and 15% of women on hormone therapy reported having had at least one hot flush in the previous 2 weeks. Follicle-stimulating hormone levels were higher in women who experienced hot flushes at least once a day or more (P < .001); E2 levels were higher in women experiencing one or no hot flushes per week (P < .001). The women in the perimenopausal group who experienced hot flushes had higher FSH levels (P = .008) and were more likely to have reported premenstrual complaints at the first interview 3 years earlier (P = .03). In the postmenopausal group, there was no significant difference with any of the variables studied between the women who were experiencing hot flushes and those who were not. CONCLUSION: Reporting of hot flushes is greatest 3 months or more after the final menstrual period. The frequency of hot flushes is associated with increasing FSH, decreasing E2, and a history of premenstrual complaints.