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Results for “Hot Flashes”

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PubMed1994

The thermoregulatory effects of menopausal hot flashes on sleep.

Menopausal hot flashes are thought to be a disorder of thermoregulation initiated centrally within the medial preoptic area of the hypothalamus. These heat-loss mechanisms appear to be activated in the presence of normal core body temperature. Previous studies have demonstrated that thermal stimuli have the potential to alter sleep stages. We performed 24-hour ambulatory recordings of hot flashes and all-night sleep parameters on 12 postmenopausal women with hot flashes and seven postmenopausal women without flashes to determine whether the presence of hot flashes prior to sleep or during sleep itself would result in alterations in sleep pattern. The results show that hot flashes are associated with increased Stage 4 sleep and a shortened first rapid eye movement period. Hot flashes occurring in the 2 hours prior to sleep onset were positively correlated with the amount of slow-wave sleep. The central thermoregulatory mechanism underlying hot flashes may affect hypnogenic pathways inducing sleep and heat loss in the absence of a thermal load.

Body Temperature Regulation↗

PubMed1991

Menopausal hot flashes: Randomness or rhythmicity.

Menopausal hot flashes are episodes of flushing, increased heart rate, skin blood flow and skin temperature, and a sensation of heat. The thermoregulatory and cardiovascular concomitants of hot flashes are associated with peaks in the levels of various hormones and neurotransmitters in the peripheral circulation. Although hot flashes affect about 75% of women, and are the primary reason that women at menopause seek medical attention, the mechanism of hot flashes is still not understood. Hot flashes vary in frequency and intensity both within and between individuals, and have been thought of as occurring randomly. Yet, some women report that their hot flashes are worse at a particular time of day or year. Initial examination of subjects' recordings of their hot flashes showed diurnal patterns of hot flash occurrence. There also seems to be a diurnal rhythm of hot flash intensity. Continuous physiological monitoring of hot flashes is facilitating the analysis of these patterns, which is revealing circadian and ultradian periodicities. The occurrence of hot flashes can be modulated by external and internal factors, including ambient temperature and fever. Rhythms of thermoregulatory and endocrine functions also may influence hot flash patterns. Examination of the interrelationships between the various systems of the body involved in hot flashes, and a multidisciplinary approach to the analysis of hot flash patterns, will aid our understanding of this complex phenomenon.

Journal Article↗

PubMedDate not supplied

Emotional antecedents of hot flashes during daily life.

OBJECTIVE: Hot flashes are among the most frequently reported menopausal symptoms. However, little is known about factors associated with their occurrence. Moreover, despite the wide use of self-report hot flash measures, little is known about their concordance with physiological flashes. This study evaluated emotional and behavioral antecedents of subjectively and objectively measured hot flashes during daily life. It also examined individual differences predicting concordance between objective and subjective hot flashes. METHODS: Forty-two perimenopausal or postmenopausal women (mean age = 50.5 +/- 4.8 years) reporting daily hot flashes completed 2 days of ambulatory sternal skin conductance monitoring, behavioral diaries 3 times an hour, and psychometric questionnaires. Hot flashes meeting objective physiological criteria and subjectively reported flashes not meeting physiological criteria were assessed. Likelihood of hot flashes following emotions and activities were examined in a case-crossover analysis. RESULTS: Relative to nonflash control times, objective hot flashes were more likely after increased happiness, relaxation, and feelings of control, and less likely after increased frustration, sadness, and stress. Conversely, subjective hot flashes not meeting physiological criteria were more likely after increased frustration and decreased feelings of control. Questionnaires revealed increased negative mood and negative attitudes were associated with fewer objective flashes and higher false-positive reporting rates. CONCLUSION: Increased positive and decreased negative emotions were associated with objective hot flashes, whereas increased negative and decreased positive emotions were associated with subjective flashes not meeting physiological criteria. The anecdotal association between negative emotions and hot flashes may be the result of self-reported flashes lacking physiological corroboration.

Activities of Daily Living↗

PubMed2006

Phase III double-blind, randomized, placebo-controlled crossover trial of black cohosh in the management of hot flashes: NCCTG Trial N01CC1.

PURPOSE: Hot flashes can cause significant morbidity in postmenopausal women undergoing or finished with breast cancer treatment. Black cohosh has been used to treat hot flashes, but definitive clinical data about efficacy have been equivocal. METHODS: A double-blind, randomized, cross-over clinical trial with two 4-week periods, was used to study the efficacy of black cohosh (1 capsule, Cimicifuga racemosa 20 mg BID) for the treatment of hot flashes in women. Participants kept a daily hot flash diary during a baseline week and then during two 4-week crossover treatment periods. Hot flash scores were measured by assigning points (1 to 4 for mild to very severe) to each hot flash based on severity and then adding the points for a given time period. RESULTS: Between October 31, 2003, to March 4, 2004, 132 patients were randomly assigned. Toxicity was minimal and not different by treatment group. Patients receiving black cohosh reported a mean decrease in hot flash score of 20% (comparing the fourth treatment week to the baseline week) compared with a 27% decrease for patients on placebo (P = .53). Mean hot flash frequency was reduced 17% on black cohosh and 26% on placebo (P = .36). Patient treatment preferences were measured after completion of both treatment periods by ascertaining which treatment period, if any, the patient preferred. Thirty-four percent of patients preferred the black cohosh treatment, 38% preferred the placebo, and 28% did not prefer either treatment. CONCLUSION: This trial failed to provide any evidence that black cohosh reduced hot flashes more than the placebo.

Adult↗

PubMed2006

Genetic polymorphisms, hormone levels, and hot flashes in midlife women.

OBJECTIVE: Hot flashes disrupt the lives of millions of women each year. Although hot flashes are a public health concern, little is known about risk factors that predispose women to hot flashes. Thus, the objective of this study was to examine whether sex steroid hormone levels and genetic polymorphisms in hormone biosynthesis and degradation enzymes are associated with the risk of hot flashes. METHODS: In a cross-sectional study design, midlife women aged 45-54 years (n=639) were recruited from Baltimore and its surrounding counties. Participants completed a questionnaire and donated a blood sample for steroid hormone analysis and genotyping. The associations between genetic polymorphisms and hormone levels, as well as the associations between genetic polymorphisms, hormone levels, and hot flashes were examined using statistical models. RESULTS: A polymorphism in CYP1B1 was associated with lower dehydroepiandrosterone-sulfate (DHEA-S) and progesterone levels, while a polymorphism in CYP19 (aromatase) was associated with higher testosterone and DHEA-S levels. Lower progesterone and sex hormone binding globulin levels, lower free estradiol index, and a higher ratio of total androgens to total estrogens were associated with the experiencing of hot flashes. A polymorphism in CYP1B1 and a polymorphism in 3betaHSD were both associated with hot flashes. CONCLUSION: Some genetic polymorphisms may be associated with altered levels of hormones in midlife women. Further, selected genetic polymorphisms and altered hormone levels may be associated with the risk of hot flashes in midlife women.

Aryl Hydrocarbon Hydroxylases↗

PubMed1999

Reduced thermoregulatory null zone in postmenopausal women with hot flashes.

OBJECTIVE: Most menopausal hot flashes are preceded by small elevations in core body temperature. If the thermoneutral zone between the thresholds for sweating and shivering is reduced in women with symptoms, the triggering mechanism for hot flashes could be explained. STUDY DESIGN: We studied 12 postmenopausal women with symptoms and 8 without symptoms. We measured body temperatures with a rectal probe, an ingested telemetry pill, and a weighted average of rectal and skin temperatures. Each woman underwent 3 experimental sessions: determination of the sweating threshold by body heating, determination of the shivering threshold by body cooling, and replication of the sweating threshold with exercise. RESULTS: The women with symptoms had significantly smaller interthreshold zones than did the symptom-free women for all 3 measures of body temperature: rectal temperature, 0.0 degrees C +/- 0.06 degrees C versus 0.4 degrees C +/- 0.18 degrees C (P <.005); telemetry pill temperature, 0.0 degrees C +/- 0.11 degrees C versus 0.4 degrees C +/- 0.18 degrees C (P <.005); and mean body temperature, 0.8 degrees C +/- 0.09 degrees C versus 1.5 degrees C +/- 0.20 degrees C (P <. 0006). Sweat rates were significantly higher among the women with symptoms (0.06 +/- 0.002 mg. cm(-2). min(-1)) than among the women without symptoms (0.03 +/- 0.001 mg. cm(-2). min(-1), P <.05). Sweating thresholds during exercise did not significantly differ from those during body heating. During exercise all the women with symptoms and none of the women without symptoms had hot flashes. CONCLUSIONS: Menopausal hot flashes in women with symptoms may be triggered by small elevations in body temperature acting within a reduced thermoneutral zone.

Body Temperature↗

PubMed1995

The hot flash: pathophysiology and treatment.

Hot flashes are the most frequent somatic complaint of women going through the menopause. Although the exact pathophysiology of the hot flash remains unknown, it appears to be related to an alteration in the set point of the hypothalamic thermoregulatory center. With the withdrawal of estrogen, some event parallel to the release of GnRH (and subsequent release of LH) causes a decrease in the set point of the thermoregulatory center. The hot flash, with its characteristic sweating and vasodilation, represents the attempt to decrease the body core temperature and restore equilibrium. Estrogen therapy reliably treats hot flashes in the majority of women in addition to its proven beneficial effect on heart disease and osteoporosis. It is rare that health care providers can so reliably and safely positively impact on a patient's symptoms and overall health.

Body Temperature Regulation↗

PubMed1994

Risk factors for menopausal hot flashes.

OBJECTIVE: To find predictors of hot flashes at natural menopause. METHODS: A cross-sectional sample of 334 black and white, naturally menopausal women was selected from a control group in a population-based study of reproductive cancers in central North Carolina. Women reported whether they had experienced hot flashes at the time of menopause. Life-style factors and reproductive histories of those with and without hot flashes were compared. RESULTS: Compared to women who were older at menopause, those reporting natural menopause before age 52 years had a significantly increased probability of having hot flashes (prevalence ratio 1.5, P = .04). Less than a high school education was significantly related to an increased probability of hot flashes (prevalence ratio 1.4, P = .20). There was significant interaction between cigarette smoking and body mass index (BMI), so that thin women who smoked in the premenopausal period were most likely to experience hot flashes (prevalence ratio 1.9, P = .03). Among non-smokers, BMI appeared to have no effect on the probability of hot flashes. Alcohol use, although not statistically significant, suggested a positive relation with hot flashes over and above that incurred from smoking. In addition, menarche before the age of 12 (prevalence ratio 0.6, P = .08) and a history of irregular menstrual cycles (prevalence ratio 0.6, P = .08) were marginally related to a decreased prevalence of hot flashes. Race, parity, and age at first and last pregnancy had no relation to hot flashes. CONCLUSION: Socioeconomic factors and those related to the decline of estrogen production are related to the occurrence of hot flashes at the time of menopause.

Adult↗

PubMedDate not supplied

Hot flashes in breast cancer survivors.

Hot flashes can be a major problem for patients with a history of breast cancer. The precipitation of menopause in premenopausal women who undergo chemotherapy for breast cancer can lead to the rapid onset of hot flash symptoms that are more frequent and more severe than those associated with natural menopause. In addition, tamoxifen, historically the most commonly prescribed pharmacologic agent for the treatment of breast cancer, is associated with hot flashes in more than 50% of its users. Although estrogen relieves hot flashes in 80-90% of women who initiate treatment, its use in women with a history of breast cancer is controversial, and most physicians in the community will not use this treatment modality. In addition, the results of the long-awaited Women's Health Initiative study and other recent studies suggest that long-term estrogen therapy should not be recommended for most women for a variety of reasons. However, hot flashes in breast cancer survivors should no longer be considered untreatable, as there are many pharmacologic and nonpharmacologic treatments that can help alleviate this problem. This article reviews the current strategies for the management of hot flashes in breast cancer survivors and the evidence supporting their use.

Antidepressive Agents↗

PubMed1998

Pilot evaluation of venlafaxine hydrochloride for the therapy of hot flashes in cancer survivors.

PURPOSE: Hot flashes can be a prominent clinical problem for breast cancer survivors and men who undergo androgen-deprivation therapy. Anecdotal information suggested a low dose of a relatively new antidepressant, venlafaxine, could abrogate this clinical problem. MATERIALS AND METHODS: This study included 28 consecutive assessable patients entered onto a phase II clinical trial. Hot flash data were collected by daily diary questionnaires during a 1-week baseline period and then for 4 weeks, during which time patients received venlafaxine 12.5 mg orally twice daily. RESULTS: Fifty-eight percent of patients who completed the study had a greater than 50% reduction in hot flash scores (frequency times severity) during the fourth treatment week as compared with the baseline week. Median weekly hot flash scores were reduced by 55% from baseline during the fourth week of venlafaxine therapy. Therapy was generally well tolerated and appeared to alleviate fatigue, sweating, and trouble sleeping. CONCLUSION: Venlafoxine appears to represent an efficacious new method to alleviate hot flashes. Further evaluation of this compound for alleviating hot flashes is indicated.

Adult↗

PubMed2004

Lack of sleep disturbance from menopausal hot flashes.

OBJECTIVE: To determine whether hot flashes produce disordered sleep in symptomatic postmenopausal women. DESIGN: Controlled laboratory study. SETTING: Healthy volunteers in a university medical center. PATIENT(S): Symptomatic and asymptomatic postmenopausal women and premenopausal women, all of similar ages (46-51 years). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Sleep electroencephalogram recordings, sternal skin conductance to record hot flashes, multiple sleep latency test to assess sleepiness, simple and divided attention performance tests, sleep and fatigue questionnaires. RESULT(S): Nineteen women were not selected for the following reasons: seven failed the drug screen, two had sleep apnea and periodic limb movements, one had periodic limb movements alone, two had body mass index (BMI) >30, one had hypertension, and six asymptomatic women had hot flashes in the laboratory. There were no significant group differences on any sleep stage measure. For example, for cycling vs. symptomatic vs. asymptomatic women: total sleep time, 6.9 +/- 0.7, 7.0 +/- 0.4, 7.0 +/- 0.4 hours; percentage stage 1 (light) sleep, 9.3% +/- 4.2%, 10.4% +/- 2.5%, 10.5% +/- 3.9%; number of brief arousals, 89.6 +/- 30.1, 111.9 +/- 45.8, 99.4 +/- 22.2; number of awakenings, 4.8 +/- 3.3, 6.7 +/- 2.1, 6.9 +/- 3.5. An average of 5.2 +/- 2.9 (+/-SD, range 1-18) hot flashes/night occurred in the symptomatic women. Of arousals occurring within 2 minutes of a hot flash, 46.7% occurred before, 46.7% occurred after, and 5.6% occurred simultaneously. Of awakenings occurring within 2 minutes of a hot flash, 55.2% occurred before, 40.0% after, and 5% simultaneously. There were no significant group differences on the multiple sleep latency test or any performance test or questionnaire measure. CONCLUSION(S): These data provide no evidence that hot flashes produce sleep disturbance in symptomatic postmenopausal women. Previous reports of increased sleep disturbance at menopause may be due to disorders that were screened out, such as sleep apnea and drug use.

Arousal↗

PubMed1995

Core body temperature and circadian rhythm of hot flashes in menopausal women.

Postmenopausal hot flashes are characterized by sweating and peripheral vasodilation and occur more frequently during increased heat loads. The circadian rhythm of core body temperature (TC) is well known and suggests that hot flashes will be most frequent when core temperature is highest. This hypothesis has not been tested previously. Ten symptomatic and six asymptomatic postmenopausal women were recruited from advertisements and screened. Each received 24-h ambulatory monitoring of sternal skin conductance levels to detect hot flashes, ambient temperature, skin temperature, and TC. The last measure was recorded using an ingested radiotelemetry pill. Cosinor analysis demonstrated a circadian rhythm (P < 0.02) of hot flashes with a peak at about 1825 h. TC values of the symptomatic women were lower than those of the asymptomatic women (P < .05) from 0000-0400 h and at 1500 and 2200 h. The majority of hot flashes were preceded by elevations in TC. Thus, elevated TC may serve as one trigger of menopausal hot flashes.

Body Temperature↗

PubMed2005

Menopausal hot flashes and development of cognitive impairment.

Hot flashes have a negative influence on the quality of life in hypogonadal women. There seem to be many regulators of hot flashes that add to the complexity of these profound vasomotor symptoms. In this paper, focus is placed on selected factors that may be involved in the relationship between hot flashes and cognitive status. During the hypogonadal state, the brain becomes relatively deprived of glucose. Hot flashes were found to be associated with transient inadequacies in brain levels of glucose. Neuroglucopenia was shown to initiate a cascade of immediate and delayed reactions leading to neuronal damage. Estrogen is known to diminish neuroglucopenia. In a pilot study on postmenopausal women, it was observed that cognitive performance of women who reported having hot flashes during their menopausal years was better than in women who did not experience hot flashes. It is hypothesized that a hot flash triggers a counterregulatory mechanism of the central nervous system to the insufficiency of glucose delivery to the brain and may have a beneficial effect on cognitive health in postmenopausal women. Possible therapeutic implications of this hypothesis are discussed in the light of current knowledge.

Aging↗

PubMed1992

Effect of fever on menopausal hot flashes.

Some women report that they have fewer hot flashes when they have a fever. This is the first case of physiological monitoring of hot flashes during fever in a subject with a well documented pattern of frequent hot flashes when afebrile. During fever, there were fewer hot flashes than during afebrile periods, and these hot flashes also tended to be less intense. For most of the period of reduced hot flashes, internal (core) temperature was elevated, above 37.5 degrees C. When the fever broke, hot flashes resumed in a pattern similar to that of afebrile periods. Possible explanations for the reduction in hot flashes during a fever include: (1) a hot flash is triggered, but the characteristic physiological changes do not occur due to competing thermoregulatory drives, (2) the febrile core temperature inhibits whatever it is that triggers a hot flash; or (3) some product of the fever process inhibits the hot flash trigger or masks the physiological changes that occur during hot flashes.

Body Temperature↗

PubMed1998

Prospective evaluation of vitamin E for hot flashes in breast cancer survivors.

PURPOSE: Hot flashes represent a substantial clinical problem for some breast cancer survivors. Although estrogen or progesterone preparations can alleviate these symptoms in many patients, concern remains regarding the use of hormonal preparations in such women. Thus, there is a perceived need for nonhormonal treatments for hot flashes for breast cancer survivors. Based on anecdotal evidence that vitamin E was helpful, we designed a trial to investigate this matter. METHODS: We developed and conducted a placebo-controlled, randomized, crossover trial where, after a 1 week baseline period, patients received 4 weeks of vitamin E 800 IU daily, then 4 weeks of an identical-appearing placebo, or vice versa. Diaries were used to measure potential toxicities and hot flashes during the baseline week and the two subsequent 4-week treatment periods. RESULTS: The 120 patients evaluated for toxicity failed to show any. The 105 patients who finished the first treatment period showed a similar reduction in hot flash frequencies (25% v 22%; P = .90) for the two study arms. A crossover analysis, however, showed that vitamin E was associated with a minimal decrease in hot flashes (one less hot flash per day than was seen with a placebo) (P < or = .05). At the study end, patients did not prefer vitamin E over the placebo (32% v 29%, respectively). CONCLUSION: Although this trial was able to show a statistically significant hot flash reduction with vitamin E compared to a placebo, the clinical magnitude of this reduction was marginal.

Adolescent↗

PubMedDate not supplied

What we know about managing menopausal hot flashes: navigating without a compass.

Hot flashes and night sweats are frequently experienced as the cardinal symptoms of menopause. However, their physiological basis has not been explained; nor have any potential risks been explored. Current knowledge and theoretical perspectives regarding hot flashes will be presented and contrasted with evidence for an emerging hypothesis of altered brain glucose availability as the hot flash trigger. Perspectives regarding hormone therapy and alternative therapies for treatment of hot flashes will be presented and directions for future research reviewed.

Brain Chemistry↗

PubMed2005

Geographical distribution of hot flash frequencies: considering climatic influences.

Laboratory studies suggest that hot flashes are triggered by small elevations in core body temperature acting within a reduced thermoneutral zone, i.e., the temperature range in which a woman neither shivers nor sweats. In the present study, it was hypothesized that women in different populations develop climate-specific thermoneutral zones, and ultimately, population-specific frequencies of hot flashes at menopause. Correlations were predicted between hot flash frequencies and latitude, elevation, and annual temperatures. Data on hot flash frequencies were drawn from 54 studies. Pearson correlation analyses and simple linear regressions were applied, first using all studies, and second using a subset of studies that included participants only to age 60 (n = 36). Regressions were repeated with all studies, controlling for method of hot flash assessment. When analyses were restricted to studies that included women up to age 60, average temperature of the coldest month was a significant predictor of hot flash frequency (P < 0.01), explaining 29.2% of the variation in hot flash frequency. In a separate equation, the difference between hottest and coldest temperatures was also a significant predictor (P < 0.01), explaining 26.4% of the variation in hot flash frequency. When regressions used all studies but controlled for method of hot flash assessment, average temperature of the coldest month, difference between hottest and coldest temperatures, and mean annual temperature were significant predictors of hot flash frequency. Women reported fewer hot flashes in warmer temperatures, and more hot flashes with increasing seasonality. These results suggest that acclimatization to coldest temperatures or sensitivity to seasonality may explain part of the population variation in hot flash frequency.

Body Temperature Regulation↗

PubMed2006

Severe hot flashes are associated with chronic insomnia.

BACKGROUND: Because hot flashes can occur during the night, their presence has been frequently associated with insomnia in women with symptoms of menopause. However, many factors other than hot flashes or menopause can be responsible for insomnia, and several factors associated with insomnia in the general population are also commonly observed in perimenopausal and postmenopausal women who have hot flashes. METHODS: A random sample of 3243 subjects (aged > or =18 years) representative of the California population was interviewed by telephone. Included were 982 women aged 35 to 65 years. Women were divided into 3 groups according to menopausal status: premenopause (57.2%), perimenopause (22.3%), and postmenopause (20.5%). Hot flashes were counted if they were present for at least 3 days per week during the last month and were classified as mild, moderate, or severe according to their effect on daily functioning. Chronic insomnia was defined as global sleep dissatisfaction, difficulty initiating sleep, difficulty maintaining sleep, or nonrestorative sleep, for at least 6 months. Diagnoses of insomnia were assessed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, classification. RESULTS: Prevalence of hot flashes was 12.5% in premenopause, 79.0% in perimenopause, and 39.3% in postmenopause. Prevalence of chronic insomnia was reported as 36.5% in premenopause, 56.6% in perimenopause, and 50.7% in postmenopause (P<.001). Prevalence of symptoms of chronic insomnia increased with the severity of hot flashes, reaching more than 80% in perimenopausal women and postmenopausal women who had severe hot flashes. In multivariate analyses, severe hot flashes were significantly associated with symptoms and a diagnosis of chronic insomnia. Poor health, chronic pain, and sleep apnea were other significant factors associated with chronic insomnia. CONCLUSIONS: Severe hot flashes are strongly associated with chronic insomnia in midlife women. The presence of hot flashes should be systematically investigated in women with insomnia. Treating hot flashes could improve sleep quality and minimize the deleterious consequences of chronic insomnia.

Adult↗