The most common time for hot flushes to occur is approximately 1 year after menopause, but the overall duration of hot flushes is unclear. Generally, it is stated that the duration of hot flushes for most women is approximately 6 months to 2 years but more information is needed about the duration of hot flushes to be able to advise on the clinical management of menopausal symptoms.
Dr Ellen Freeman and colleagues in Philadelphia have reported on a study looking at this important issue. The goal of the study was to estimate the duration of moderate to severe menopausal hot flushes and to identify potential risk factors for hot flush duration among women monitored for 13 years in the Penn Ovarian Aging Study. Interviews at 9 to 12 month intervals allowed assessment of hot flushes. Duration of moderate to severe hot flushes in 259 women, was the main study endpoint, and a secondary analysis was performed in 349 women who reported any hot flushes. The investigators looked at menopausal stage, age, race, reproductive hormone levels, body mass index (BMI), and current smoking as potential risk factors associated with hot flushes.
The median duration of moderate to severe hot flushes was 10.2 years. Duration was strongly associated with menopausal stage at onset, with the longest reported duration of more than 11.57 years for hot flushes applying to those first having hot flushes as they first entered into the menopause transition, 7.35 years for those beginning in the early transition stage, and 3.84 years for those beginning in the late transition to postmenopausal stages.
The most common ages at onset of moderate to severe hot flushes were 45 to 49 years, with median duration of 8.1 years. Compared with white women, African American women had a longer duration of hot flushes.
The authors concluded that the median duration of hot flushes considerably exceeded the timeframe that is generally accepted in clinical practice. The identified risk factors, particularly menopausal stage, race, and BMI, are important to consider in individualizing treatment and evaluating the risk-to-benefit ratio of hormones and other therapies.
Limitations of this study include possible overestimation of hot flush duration, possible causation of some hot flushes by conditions other than menopause, exclusion of women using hormone therapy, and lack of generalisability to other populations.
It was suggested that perhaps treatments for vasomotor symptoms should be targeted more commonly to younger, irregularly menstruating women, although at this stage, finding the best type of hormone therapy which provides good control of irregular bleeding and effective contraception, at times of fluctuating hormone production, can be difficult. The authors also concluded “Other treatments for hot flushes need to be evaluated, particularly for women who have not reached menopause. Race and body mass index also significantly influenced the duration of hot flushes and are important considerations in individualizing treatment, particularly when the predicted duration of hot flushes is substantially longer than the length of hormone therapy that is currently recommended.”
In conclusion, it seems that for some women, especially for those who experience hot flushes early on in the menopausal transition, hot flushes may continue for many years. While it is important that diet and lifestyle factors are examined, and especially attention is made to those with high BMI, treatment options such as HRT should be considered. Although many hold the view that HRT can only be taken for a short time, while it is still the most effective treatment currently available for controlling menopausal symptoms, it seems that for those with long duration of symptoms, its use may be needed for the same long duration and for these women, it is very likely that long-term use will continue to have more benefits than risks.
Reference: Duration of Menopausal Hot Flushes and Associated Risk Factors.
Freeman, Ellen W. PhD; Sammel, Mary D. ScD; Lin, Hui MS; Liu, Ziyue PhD; Gracia, Clarisa R. MD
Obstetrics & Gynecology: May 2011 – Volume 117 – Issue 5 – pp 1095-1104