From Medscape Medical News CME
Night Sweats in Postmenopausal Women Linked to Reduced 20-Year Mortality Rate CME/CE
News Author: Laurie Barclay, MD
CME Author: Désirée Lie, MD, MSEd
September 16, 2009 — Night sweats in relatively healthy postmenopausal women are linked to a reduced risk for death during the following 20 years, independent of use of hormone therapy, according to the results of a prospective, population-based cohort study reported in the September issue of Menopause.
"Night sweats, reported by approximately half of postmenopausal women, are thought to reflect more severe hot flashes, although there is some evidence that they have a different etiology and may have more severe consequences related to impaired sleep," write Johan Svartberg, MD, PhD, from the Department of Medicine, University Hospital of North Norway in Tromsø, Norway, and colleagues. "The purpose of this study was to examine the associations of vasomotor symptoms with risk of all cause, cardiovascular disease (CVD), and coronary heart disease (CHD) mortality in community-dwelling older women, with a mean age of 69 years."
The study cohort consisted of 867 postmenopausal women who gave lifestyle and menopause-related history at the 1984 to 1987 visit of the Rancho Bernardo Study and who responded to a questionnaire, mailed in 1989, on menopause and vasomotor symptoms. Follow-up for survival continued through July 2004 in 98% of the cohort. Average duration of follow-up was 11.5 years.
Hot flashes were reported by 73% of women, and 39% of these also reported night sweats. Of 405 deaths during follow-up, 194 were attributed to CVD and 71 to CHD. There was no apparent association between hot flashes alone and all-cause mortality. However, women who had night sweats as well as hot flashes had an almost 30% lower all-cause mortality risk vs women who did not have night sweats (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.55 - 0.94). This association was independent of body mass index (BMI), past or current use of estrogen or progestin, physical exercise, and smoking status.
After adjustment for past or current use of estrogen or progestin, there was a similar lower risk for CVD and CHD mortality in women with night sweats (HR, 0.62; 95% CI, 0.42 - 0.92 and HR, 0.51; 95% CI, 0.26 - 0.99, respectively). Although these associations were independent of hormone use, adjustment for BMI, physical exercise, and smoking abolished their significance.
"Reported night sweats at menopause are associated with reduced risk of death over the following 20 years, independent of multiple risk factors including past or current use of postmenopausal estrogen therapy," the study authors write. "A similar association was observed for CVD mortality that was not independent of heart disease risk factors. Although these results are intriguing, they need to be confirmed in other large population-based studies."
Limitations of this study include history of vasomotor symptoms obtained many years after menopause for some women; possible recall bias; and inability to evaluate the effect of more recent, frequent symptoms or duration of symptoms. Because women in the study cohort are white and upper middle class, the results may not be generalizable to other populations.
The study authors have disclosed no relevant financial relationships.
Menopause. 2009;16:888-891. Abstract
Hot flashes are reported by most perimenopausal and postmenopausal women, and night sweats are reported by half of them and may be associated with impaired sleep. Recent studies have suggested an adverse association between hot flashes and CVD mortality, suggesting that vasomotor symptoms may be a marker for a more hypoestrogenic state.
This is a prospective cohort study of postmenopausal women within a cohort from Rancho Bernardo in Southern California who responded to questionnaires and who were followed up for vital status.
Included were 867 postmenopausal white women from the Rancho Bernardo cohort who attended a follow-up clinic from 1984 to 1987.
The original Rancho Bernardo cohort consisted of 82% of all white women residing in a middle- to upper-middle class community who were enrolled in a study of heart disease risk factors in 1972 to 1974.
They responded to a 1989 mailed questionnaire and were followed up to 2004, with vital status known for 98%.
During the 1984 to 1987 clinic visits, a standard interview asked about medical history and reproductive and menopausal status including hysterectomy, oophorectomy, and use of hormone replacement therapy.
At that visit, blood pressure, lipid panel, and BMI were measured.
Women who self-admitted to being menopausal were asked if they had hot flashes or night sweats.
Follow-up time was calculated from the baseline 1989 mailed questionnaire to the date of death or to the end of the study period.
Vital status was determined by death certificates and the underlying cause certified by International Classification of Diseases, Ninth Revision, criteria.
Data were stratified by vasomotor symptoms (no symptoms, hot flashes only, or hot flashes with night sweats) and by a median age of 75 years.
Mean age was 69 years, BMI was 24 kg/m2, 80% exercised 3 or more times weekly, and mean age at menopause was 46 years.
Of 867 women, 73% reported hot flashes and 39% also reported night sweats.
Those with hot flashes were more likely to have smoked and to be using or have used estrogen or progestin therapy vs those without vasomotor symptoms.
Women who reported night sweats were younger and exercised more than women without vasomotor symptoms.
During follow-up, there were 405 deaths, of which 194 were from CVD and 71 from CHD.
All-cause mortality rate was 54.2, CVD mortality rate was 19.5, and CHD mortality rate was 7.1 per 1000 person-years.
Hot flashes alone were not associated with increased all-cause, CVD, or CHD mortality.
The presence of night sweats in addition to hot flashes was associated with a 30% reduction in all-cause mortality rate (HR, 0.72) independent of BMI, use of estrogen or progestin, exercise, and smoking.
The HR for CVD and CHD mortality in women with hot flashes and night sweats was 0.62 after adjustment for estrogen and progestin use.
However, the association was no longer significant after adjustment for BMI, exercise, and smoking.
The authors concluded that contrary to other studies, hot flashes were not associated with increased CVD or CHD mortality rates in postmenopausal women but that the presence of night sweats was associated with lower mortality rates.
Hot flashes in postmenopausal women are not associated with increased overall, CVD, or CHD mortality rates.
The presence of night sweats with hot flashes in postmenopausal women is associated with a reduced risk for all-cause mortality and CVD and CHD mortality, independent of hormone use.
1: Menopause. 2009 Sep-Oct;16(5):888-91.
Vasomotor symptoms and mortality: the Rancho Bernardo Study.
Svartberg J, von Mühlen D, Kritz-Silverstein D, Barrett-Connor E.
Department of Medicine, University Hospital of North Norway, Tromsø, Norway. firstname.lastname@example.org
OBJECTIVE: The purpose of this study was to examine the associations of vasomotor symptoms with risk of all-cause, cardiovascular disease (CVD), and coronary heart disease (CHD) mortality in community-dwelling older women, with a mean age of 69 years. METHODS: This prospective population-based study included 867 postmenopausal women who provided lifestyle and menopause-related history at the 1984 to 1987 visit of the Rancho Bernardo Study and answered a 1989 mailed questionnaire on menopause and vasomotor symptoms. Ninety-eight percent were followed for vital status through July 2004. RESULTS: Overall, 73% reported hot flashes, of whom 39% also reported night sweats. During the 11.5-year average follow-up, there were 405 deaths, of which 194 were attributed to CVD and 71 to CHD. Hot flashes alone were not associated with all-cause mortality, but women who, in addition to hot flashes, also had night sweats had an almost 30% (hazard ratio [HR], 0.72; 95% CI, 0.55-0.94) lower all-cause mortality risk compared with women without this symptom, independent of body mass index, past or current use of estrogen or progestin, physical exercise, and smoking habit. There was a similar lower risk of CVD and CHD mortality in women with night sweats when adjusted for past or current use of estrogen or progestin (HR, 0.62; 95% CI, 0.42-0.92 and HR, 0.51; 95% CI, 0.26-0.99, respectively). These associations were independent of hormone use but were no longer significant after adjusting for body mass index, physical exercise, and smoking. CONCLUSIONS: Reported night sweats at menopause are associated with reduced risk of death over the following 20 years, independent of multiple risk factors including past or current use of postmenopausal estrogen therapy.
PMID: 19421076 [PubMed - in process]