Do hot flashes disturb sleep?

A re vasomotor symptoms (VMS) associated with sleep characteristics among symptomatic women? The current issue of Menopause features the answer that Thurston et al give this controversial question. Others offer conflicting answers. One group initially reported that objective VMS do not disturb sleep but thereafter reported that VMS did disturb sleep. An earlier study had evidenced that women with VMS have relatively poor objective sleep, but then a highly regarded study of 412 epidemiologically sampled, laboratory-studied Wisconsin women 30 to 60 years of age found that women who thought that hot flashes disturbed their sleep slept no differently from other women. Women who suffer hot flashes often disagree with such research results. Indeed, women have found researchers’ failure to confirm their subjective complaints Ba source of particular frustration. [ Their distress got Polo to write an editorial that asked, BCan millions of women be wrong? [ The controversy over whether VMS, also known as hot flashes or night sweats, disturb sleep arises in part because subjective and objective VMS are not the same. Researchers generally find that although objective hot flashes may correlate with worse sleep, subjective hot flashes do not. A rose may be a rose, but a self-reported, subjectively felt hot flash is not necessarily an objectively measured, publically observable hot flash. Just as the answer to a question depends on how the question is asked, any phenomenon depends on the instrument that measures it. Subjective and objective hot flashes can never be the same. Confusion follows when the single term hot flashes is used to denote discomfort instantiated in brain limbic system stimulus processing while at the same time it also represents vasodilatation and sweat secretion from dysfunctional thermoregulation. Bothersome hot flashes probably represent an important third phenomenon, namely, the general tendency to be bothered. Women may not notice most of their objectively metered hot flashes. A group of 52 women monitored during their normal everyday lives reportedly detected only 30% to 50% of their metered hot flashes. These women were breast cancer survivors who had volunteered for a hot flash study, so they could have been relatively sensitized to hot flashes, but neither the number nor the intensity of their self-reported hot flashes was related to metered hot flashes Bin any meaningful way. [ In other words, with respect to hot flashes, researchers’ meters and women’s self-reports represent two distinctly different things. Although objective hot flashes measured in a thermoregulatory physiology laboratory pose little information about the hot flashes that women seek clinical relief from, some researchers contend that only objective hot flashes are reliable enough to judge the worth of hot flash treatments. However, using skin electrical conductance to objectively measure VMS is not as simple as it may seem. A hot flash meter records moments when resistance to electric current diminishes because of increased sweat on the skin, but the hot flashes that women actually detect do not highly correlate with skin conductance. A woman’s sensitivity to hot flashes depends on her sensory threshold, the meaning of VMS in her culture, and whether her attitude toward menopause or her affects are generally negative. A similar disparity between subjective and objective measurements also bedevils sleep research. Subjective and objective versions of sleep correlate too little to consider them the same thing. People and polysomnographs differently record the amount of time it takes to fall asleep, nocturnal wakefulness, total sleep, and so on. Those people who say that they sleep poorly produce sleep self-recordings that differ relatively more from what polysomnographs record. Furthermore, only sleepers, and not machines, can report the most clinically salient measure of sleep, namely, sleep misery. Sleep researchers previously considered any self-reported poor sleep that proved inconsistent with sleep laboratory results Bpseudo-insomnia. [ They thought that the inconsistencies continually found between sleepers and polygraphs Bcast serious doubts once again on the validity of patients’ estimations of sleep. [ These researchers might have validly concluded that laboratory results do not accurately capture the construct of interest, like Thurston et al have concluded. Subsequent sleep laboratory studies involving the use of alternative electroencephalographic (EEG) measures found that participants whose problems met criteria for what by then was termed sleep stage misperception retain an abnormal degree of consciousness during sleep. In other words, researchers using alternative EEG measures uncovered abnormalities that confirmed patients’ self-reports, which experts had previously dismissed as invalid because their measures had failed to detect these. An expert’s judgment represents a decision-making process that is ultimately derived from the expert’s intentions. Clinicians who deal with individual patients tend to prioritize subjective measures, whereas researchers advocate conventional objective measures because they must have common terms for clear communication within a scholarly field. Experts’ judgments that women saying that their objectively normal sleep is poor are Bwrong[ are judgments as