The cessation of women’s monthly estrus cycle is often wrought with much anticipation, agitation, and even anxiety. Menopause is the absence of menstruation for a full year from the last menstrual period, a definition that has been consistent for decades. Physiologically, the transition takes years, during which time there is a diminution of ovarian function, its production of estrogen and progesterone and, ultimately, the end of ovulation.
In the United States, the average age of menopause is 51.3 years, and 11 million women reach natural menopause each year.1 More than 85% of these women experience symptoms associated with estrogen deficiency related to menopause. The most common symptoms are vasomotor symptoms and vaginal dryness. Vasomotor symptoms are usually described as night sweats, hot flashes, and flushes. Vulvovaginal atrophy, often called vaginal dryness, is related to decreased estrogen associated with menopause, and it’s the most common cause of dyspareunia in menopausal and postmenopausal women.
Risk Factors for Vasomotor Symptoms
- African American ethnicity
- Obesity (adipose tissue is thermogenic)
- Low socioeconomic status
In this 2-part series on menopause, vasomotor symptoms will be discussed here in part 1, and part 2, which will be featured in 2 weeks, will focus on vulvovaginal atrophy.
Vasomotor symptoms are the most commonly reported menopausal symptoms. These symptoms, often called hot flashes, are characterized by a sudden increase of blood flow, often to the face, neck, and chest, that causes the sensation of extreme heat and profuse sweating.1 When symptoms occur at night they are called “night sweats” and can cause significant sleep disturbances. Episodes of vasomotor symptoms can last 1 to 5 minutes and can be associated with perspiration, flushing, chills, anxiety, and even heart palpitations.
While vasomotor symptoms vary greatly in their intensity and frequency among menopausal women, these symptoms typically are most debilitating during the first one to two years of menopause. For some women, however, they may persist indefinitely.
There also may be ethnic and genetic predispositions for vasomotor symptoms, since up to 20% of women do not experience them. According to the results of the SWAN study (Study of Women’s Health Across the Nation), which assessed menopausal symptoms in 14,906 women with diverse ethnic backgrounds aged 40 to 55 years in the United States, African American women are most likely to report having vasomotor symptoms, and Asian women (Japanese and Chinese) are the least likely to report symptoms.2
Other risk factors for VMS include obesity (adipose tissue is thermogenic), smoking, depression/anxiety, and low socioeconomic status.
In addition, there is neurotransmitter involvement in the genesis of vasomotor symptoms, and therapies have been fashioned around this understanding. One example of this is the recent FDA approval of the SSRI paroxetine capsules (Brisdelle), indicated for moderate to severe vasomotor symptoms associated with menopause. This drug does come with a black box warning for suicidal thoughts and behaviors, as does other SSRI antidepressants.
As clinicians treating these women, we’ve heard the complaints. Our patients describe feeling either hot or cold. At night, they can’t sleep because they find themselves sweating and then taking the covers off, only to wake up cold and shivering. Understandably, they want our advice and ask what they can do to alleviate these symptoms.
The exact physiology of vasomotor symptoms continues to elude us, although there is good data to support that the “thermoregulatory zone” is narrowed for menopausal women. Because vasomotor symptoms parallel what physiological studies confirm—that the fluctuations in core body temperature are more pronounced in postmenopausal women—adding back estrogen does re-widen the thermoregulatory zone.
By far, systemic hormone replacement therapy (HRT) with estrogen alone or in combination with progestin is the most effective therapy for vasomotor symptoms. A meta-analysis of 24 randomized controlled trials (RCT) with 3,329 participants found a 75% reduction in weekly hot flashes frequency in users of oral estrogen or estrogen+progestin compared with placebo.3
1. ACOG practice bulletin no. 141: management of menopausal symptoms. Obstet Gynecol. 2014;123:202-216.
2. Thurston RC, Joffe H. Vasomotor symptoms and menopause: findings from the Study of Women’s Health Across the Nation. Obstet Gynecol Clin North Am. 2011;38:489-501.
3. MacLennan AH, Broadbent JL, Lester S, Moore V. Oral oestrogen and combined oestrogen/progestogen therapy versus placebo for hot flushes. Cochrane Database System Rev. 2004;4:CD002978. DOI: 10.1002/14651858.CD002978.pub2.
4. Rossouw JE, Anderson GL, Prentice RL, et al. Risks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women’s Health Initiative randomized controlled trial. Writing Group for the Women’s Health Initiative Investigators. JAMA. 2002;288:321-333.