Hot flushes during the menopause transition: a longitudinal study in Australian-born women

In Brief Objective: To investigate factors associated with the presence, severity, and frequency of hot flushes. Design: A 9-year prospective study of 438 Australian-born women, aged 45 to 55 years and menstruating at baseline. Annual fasting blood collection, physical measurements, and interviews including questions about bothersome hot flushes in previous 2 weeks were performed. A “hot flush index” score was calculated from the product of the severity and frequency data. Data were analyzed using random-effects time-series regression models. Results: A total of 381 women supplied complete data over the follow-up years. A total of 350 women experienced the menopause transition, of whom 60 (17%) never reported bothersome hot flushes. At baseline, women who reported hot flushes were significantly more likely to have higher negative moods, not be in full- or part-time paid work, smoke, and not report exercising every day. Over the 9-year period of the study, variables significantly associated with reporting bothersome hot flushes were relatively young age (P < 0.001), low exercise levels (P < 0.05), low estradiol levels (P < 0.001), high follicle-stimulating hormone (FSH) levels (P < 0.001), smoking (P < 0.01), being in the late menopause transition (P < 0.001), or being postmenopausal (P < 0.001). In women reporting hot flushes, the hot flush index score increased as their FSH levels increased (P < 0.01), as they entered the late stage of the menopause transition (P < 0.001), and as they became postmenopausal (P < 0.05), and decreased with as their age (P < 0.001) and exercise level (P < 0.05) increased. Between-women analyses found that the hot flush index score was greater in women with higher average FSH levels over time (P < 0.05). Conclusion: Menopause status, FSH and estradiol levels, age, exercise level, and smoking status all contributed to the experience of bothersome hot flushes. A longitudinal study of a population-based cohort of Australian-born women found that menopause status, levels of follicle-stimulating hormone (FSH) and estradiol, age, exercise level, and smoking status all contributed to experiencing bothersome hot flushes. In women reporting hot flushes, the frequency and severity of these flushes significantly increased as their FSH increased and as they entered the late stage of the menopause transition, and decreased as their age and exercise level increased.