Effects of hormone replacement therapy on perceptual and cognitive event-related potentials in menopausal insomnia

Inhibitory Deficits of Insomnia Disorder: A Meta-Analysis on Event Related Potentials in Auditory Oddball Task

BACKGROUND

Despite numerous studies on auditory event-related potentials (ERPs) in insomnia disorder (ID), the results are inconsistent across different ERP components (e.g. N1, P2, P3, and N350), types of auditory stimuli (e.g. standard and deviant), and stages of sleep (e.g. wakefulness, NREM sleep, and REM sleep). In light of this variability, we conducted a systematic meta-analysis of previous auditory ERP studies in ID to provide a quantitative review of the existing literature.

METHODS

Relevant literatures were searched on the Embase, PubMed/MEDLINE, PsycINFO and Cochrane Library. A total of 12 studies comprising 497 participants were finally included in this meta-analysis. The study protocol was registered with PROSPERO under the registration number CRD42022308348.

RESULTS

We found that patients with ID have significantly decreased N1 (Hedges' g = 0.34, 95%CI [0.04, 0.65]) and P3 (Hedges'g = -1.21, 95%CI [-2.37, -0.06]) amplitudes during wakefulness. In addition, decreases in P2 (Hedges'g = -0.57, 95%CI [-0.96, -0.17]) amplitude during wakefulness and N350 (Hedges' g = 0.73, 95%CI [0.36, 1.09]) amplitude during NREM.

CONCLUSIONS

This meta-analysis represents the first systematic investigation of ERP features across different stages of sleep in individuals with ID. Our results suggest that in patients with insomnia, the absence or deficiency of arousal inhibition during the nighttime sleep initiation or maintenance process may interfere with the normal process of sleep.

Blunted Flanker P300 Demonstrates Specificity to Depressive Symptoms in Females during Adolescence

Recent research suggests that depressive disorders in adults are characterized by reductions in flanker P300 amplitude, and that a reduced flanker P300 may also predict worst depressive trajectories over time. The current study extended this work to adolescence-and to evaluate the specificity of the relationship between flanker P300 to depressive symptoms versus anxiety symptoms, and whether the association between flanker P300 and depressive symptoms was moderated by biological sex. To this end, P300 amplitude, depression, anxiety, and sex were assessed in a large sample of 619 adolescents aged 11 to 14. Participants completed a speeded response flanker task while EEG was recorded, as well as self-reported measures of current depression and anxiety symptoms. Reduced P300 amplitude was related to both heightened depression and anxiety symptoms in zero-order correlations. Regression-based analyses suggest that reduced P300 was uniquely related to depressive symptoms. Furthermore, this negative association between P300 and depression was apparent in female adolescents, but not male adolescents. In sum, the current study suggests that flanker P300 amplitude may potentially serve as a neural marker specific to depression in females during adolescence.

Slow electroencephalographic oscillations and behavioral measures as predictors of high executive processing in early postmenopausal females: A discriminant analysis approach

Decline in cognitive function is frequent in early postmenopause. There are postmenopausal females who show high performance while others display low performance in executive function, modulated by the prefrontal cortex. These differences have led to confusing and inconclusive results, which have not been explained entirely by the decline in estrogens, which affect the prefrontal cortex functions. An analysis of brain function and the application of a discriminant analysis can help to clarify the deficits in executive function shown by some postmenopausal females. The objective was to examine electroencephalographic recording during the performance of an executive function test in early postmenopausal females, ten with a high level of performance and ten with a low level of performance. Absolute power of delta, theta, alpha1, alpha2, beta1 and beta2 and the numbers of completed categories, trials, perseverative errors and overall errors were submitted to stepwise discriminant analysis to identify predictor variables. Four predictors emerged as significant of group membership based on cognitive performance, with the high-performance group characterized by more completed categories, more delta power, less theta power and more alpha1 power. These findings suggest that postmenopausal females classified in the high-performance group displayed appropriate temporary activation in slow oscillations during executive processing.

Gender effects on auditory P300: A systematic review

The evidence suggests that gender-related effects could influence the electrophysiological P300 parameters and stand as an additional source of variation for both clinical and non-clinical subjects. The aim of this paper is to characterize gender-related differences in P300 potential as elicited with simple auditory paradigms. This knowledge (1) is important for the practical assessment of P300 potential in normal and clinical populations, and (2) can provide an insight into the understanding of gender differences in pathophysiology, particularly those with differential risk or prevalence in males and females. With this review it is shown that a limited number of studies encounter possible gender effects on parameters of auditory P300, and the findings need to be read with caution due to methodological limitations of the studies. Nevertheless, evidence supports that the P300 amplitude could be significantly modulated by gender, with greater amplitude in females relative to males. Noteworthy, gender has a minimal effect on the P300 latency, and it is often comparable between males and females. Furthermore, the effect of gender on P300 could be modulated by hormonal background, anatomy and some methodological aspects.

Sex differences in extinction to negative stimuli: Event-related brain potentials

There are controversial observations regarding whether females have a longer time to extinction than men, which may be related to different levels of conditioning acquisition and/or the influence of the menstrual cycle. We explored the electrophysiological evidence of sex differences in extinction.In this study, females in the luteal phase and menstrual phase were examined for event-related potential (ERP) and evidence of attention allocation in the conditioning model using electroencephalogram recordings. A group of male participants was also included and compared.Women in the luteal phase had a higher difference waveform of P3 amplitude to conditioned stimulus (CS) in the extinction phase than women in the menstrual phase and men. There was a shorter latency of P3 to CS+ in men than in women in the extinction phase, suggesting that men react faster than women to unconditioned stimulus (US) expectation. Our study revealed that women in the luteal phase allocated more attentive resources to the expectation of a US. In contrast, men displayed faster expectation of the extinguished US than women. Our results support the superiority of ERP technology in documenting the neural mechanism of the extinction process.

Differential effects of estrogen and testosterone on auditory sensory gating in rats

RATIONALE

Estrogen has been shown to have beneficial effects in patients with schizophrenia. However, the mechanisms involved in this protective effect are unclear. Schizophrenia is associated with deficits in sensory gating, a filtering mechanism which normally prevents sensory overload. In rodent models, acute treatment with drugs such as the dopamine D1/D2 receptor agonist, apomorphine; the dopamine releaser, amphetamine; and the glutamate NMDA receptor antagonists, phencyclidine or MK-801, can induce a phenotype similar to that seen in schizophrenia.

OBJECTIVES

Given the putative protective action of estrogen in schizophrenia, here we investigated the effect of ovariectomy (OVX) and estrogen replacement in female rats on drug-induced auditory gating deficits. For comparison, we also assessed the effects of castration (CAST) and dihydrotestosterone (DHT) replacement in male rats.

METHODS

Rats were instrumented with cortical surface electrodes. Test sessions comprised of 150 presentations of paired clicks, 500 ms apart (S1 and S2).

RESULTS

Administration of all drugs increased the ratio of responses to S2/S1 in sham-operated female and male rats. OVX reduced event-related potential amplitudes but did not alter S2/S1 ratio or drug effects. In OVX rats with 17β-estradiol implants, the effect of apomorphine was abolished, but there was no change in that of amphetamine and phencyclidine. There were no effects of CAST or DHT replacement in male rats.

CONCLUSIONS

Chronic estrogen replacement in OVX rats protected against sensory gating deficits caused by direct dopamine D1/D2 receptor stimulation. These data could indicate a possible mechanism by which estrogen exerts a protective action in schizophrenia.

Sex differences in brain maturation as measured using event-related potentials

Little is known about how sex influences functional brain maturation. The current study investigated sex differences in the maturation of event-related potential (ERP) amplitudes during an auditory oddball task (N = 170; age = 6-17 years). Performance improved with age. N200 amplitude declined with age: parietal sites showed earlier development than temporal and frontal locations. Girls showed greater bilateral frontal P300 amplitude development, approaching the higher values observed in boys during childhood. After controlling for age, right frontal P300 amplitude was associated with reaction time in girls. The findings demonstrate sex differences in ERP maturation in line with behavioral and neuroimaging studies.

P300 auditory event-related potentials in children with obesity: is childhood obesity related to impairment in cognitive functions?

OBJECTIVE

To investigate alterations in P300 auditory event-related potentials in children with obesity to detect changes in cognitive functions.

METHOD

A total of 50 children with obesity and 23 age- and sex-matched healthy control subjects were included in the study. Laboratory tests were performed to detect dislipidemia and insulin resistance (IR). The latencies and amplitudes of P300 waves were measured in healthy and obese subjects with or without IR. The oddball paradigm was used in recordings of P300 auditory event-related potentials.

RESULTS

A significant difference was observed between groups regarding latency and amplitude of P300 component obtained from central (Cz) electrode. The grand means of P300 latency were longer, and amplitude decreased significantly in obese group compared to that of healthy controls. When the obese group was divided into two different subgroups, those with IR and without IR, the grand means of P300 latency were longer and the amplitude decreased significantly in subjects with IR compared to those without IR.

CONCLUSION

Both decreased amplitude and prolonged latency of P300 are associated with IR in children with obesity, which shows the impairment of neural activity associated with sensory and cognitive information processing in these children. Further studies are necessary to strengthen the current findings and to determine the exact mechanism of cognitive impairment in obese children.

Evaluation of cognitive performance by using P300 auditory event related potentials (ERPs) in patients with growth hormone (GH) deficiency and acromegaly

CONTEXT

Impaired cognitive performance has been demonstrated in adults with GH deficiency and acromegaly by using different neuropsychological tests. P300 event related potential (ERP) application is a well established neurophysiological approach in the assessment of cognitive performance.

OBJECTIVES

Evaluation of cognitive performance by using P300 ERPs has not been reported in acromegaly, and the comparisons of the P300 ERPs between the patients with GH deficiency and GH excess have not been done yet. Therefore present study was designed to investigate the effects of GH deficiency and GH excess on cognitive performance by using P300 ERPs.

DESIGN AND METHODS

The study comprised 19 patients with severe GH deficiency, 18 acromegalic patients and 16 age, education and sex matched healthy controls. Baseline auditory ERPs were obtained at Fz (frontal), Cz (central), Pz (parietal) and Oz (occipital) electrode sites in GH deficient group, GH excess group and control group.

RESULTS

There was a significant difference between mean serum IGF-I levels in the GH deficient and acromegalic patients (48+/-38 ng/ml and 742+/-272 ng/ml, respectively) (P=0.01). The mean P300 latency of the patients with GH deficiency was significantly (P=0.0001) prolonged when compared with that of normal controls and acromegalic patients at all electrode sites. The mean P300 amplitude of the patients with acromegaly was significantly (P=0.005) lower when compared with that of normal controls and GH deficient patients at all electrode sites.

CONCLUSIONS

Using ERPs recordings, the present study indicates the prolongation of P300 latencies in patients with severe GH deficiency and reduction of P300 amplitudes in patients with acromegaly. This study provides the electrophysiological evidence for the presence of cognitive dysfunction in both GH deficiency and GH excess, and different components of the cognitive performance are impaired in these conditions.

The use of evoked potentials in sleep research

Averaged event-related potentials (ERPs) represent sensory and cognitive processing of stimuli during wakefulness independent of behavioral responses, and reflect the underlying state of the CNS (central nervous system) during sleep. Components measured during wakefulness which are reflective of arousal state or the automatic switching of attention are sensitive to prior sleep disruption. Components reflecting active attentional influences during the waking state appear to be preserved in a rudimentary form during REM sleep, but in a way that highlights the differences in the neurochemical environment between wakefulness and REM sleep. Certain ERP components only appear within sleep. These begin to emerge at NREM sleep onset and may reflect inhibition of information processing and thus have utility as markers of the functional status of sleep preparatory mechanisms. These large amplitude NREM components represent synchronized burst firing of large number of cortical cells and are a reflection of the nervous system's capacity to generate delta frequency EEG activity. As such they are useful in assessing the overall integrity of the nervous system in populations not showing substantial amounts of SWS as measured using traditional criteria. While requiring care in their interpretation, ERPs nonetheless provide a rich tool to investigators interested in probing the nervous system to evaluate daytime functioning in the face of sleep disruption, the ability of the sleeping nervous system to monitor the external environment, and the ability of the nervous system to respond to stimuli in a manner consistent with the initiation or maintenance of sleep.

Low-dose estradiol alters brain activity

Although several studies have examined the effects of estrogen replacement therapy (ERT) on neural activity associated with tasks of learning and memory, no study has examined such effects on a sustained attention task. This study examined the effect of low-dose estrogen replacement therapy on hemodynamic activity elicited by a visual three-stimulus oddball task recorded using event-related functional magnetic resonance imaging (fMRI). Participants included 16 women between the ages of 73 and 84 who were part of a randomized controlled double-blind study to evaluate the effect of an ultralow dose micronized estradiol on bone. No significant differences in behavioral performance were found with ERT. However, there was evidence that ERT group participants had both reductions and increases in the amplitude of hemodynamic response in a variety of subcortical and cortical brain regions. These included regions involved in perception and attention such as the occipital and parietal lobes, motor cortex, anterior cingulate and prefrontal cortex. These findings suggest that estrogen may facilitate the efficiency of brain function during the performance of sustained attention tasks in post-menopausal elderly women.

Age-related cognitive decline in the menopause: effects of hormone replacement therapy on cognitive event-related potentials

OBJECTIVE

Although epidemiological and clinical studies suggest that hormone replacement therapy (HRT) may protect against cognitive disorders and neurodegenerative diseases, the relation between estrogen and cognition in postmenopausal women remains controversial.

METHODS

In a double-blind placebo-controlled, parallel group design study the effects of HRT with the estrogen-progestogen combination Presomen 1.25 compositum((R)) (1.25mg equine conjugated estrogens administered for 21 days plus the progestogen 5mg medrogeston given for 11 days) on event-related potentials (ERPs) in postmenopausal patients with age-related cognitive decline (DSM-IV code 780.9, ICD-10 code R 41.8) were investigated. After a pre-drug comparison with age-matched normal postmenopausal controls, 48 psychotropic drug-free patients aged 60 +/- 6 years were randomized to receive either placebo or verum for 4 months. ERPs were recorded before as well as on the 91-92 days of the study, which thus fell into the estrogen phase of the treatment during the fourth cycle.

RESULTS

At baseline, patients showed a lengthening of P300 latency and an attenuation of P300 amplitudes as compared with normal controls. After HRT with Presomen, a significant shortening of P300 latency as compared with placebo was observed.

CONCLUSIONS

The baseline P300 differences suggest that in the patient group the aging process was advanced, while after HRT with Presomen a significant improvement and normalization of information processing as indexed by P300 was observed.

No changes in event-related potentials with estrogen or estrogen plus progesterone treatment in healthy older hysterectomized women: results from a double-blind, placebo-controlled study

RATIONALE

The potential to improve cognition in older women with estrogen or estrogen/progesterone therapy is currently a matter of intense debate. Only a few studies conducted so far have used electrophysiological indicators of cognitive information processing as outcome measures in randomised placebo controlled studies.

OBJECTIVES

This study was undertaken to measure changes in event-related potentials (ERPs) after short (4 weeks) or prolonged (24 weeks) hormone treatment in older women.

METHODS

A randomised, double-blind, placebo-controlled study in hysterectomized older women (aged 58-75 years) was performed (n = 51). The participants received orally estradiol (2 mg estradiol valerate), estradiol plus progesterone (100 mg micronized progesterone) or placebo for 24 weeks. Using four different paradigms, early and late ERPs were assessed at baseline and after 4 and 24 weeks of treatment.

RESULTS

Strong hormone increases were observed in the two active treatment groups. However, no significant effects on any of the assessed ERPs were observed in either of the two treatment groups. Similar non-significant findings were obtained for reaction time and error rate.

CONCLUSIONS

Estradiol or estradiol/progesterone treatment appears to have no strong effects on several ERP markers of information processing in older hysterectomized women. The current negative findings might suggest a reduced sensitivity of the aged brain to gonadal steroids.

Acute neurophysiological effects of the hypnotic zolpidem in healthy volunteers

INTRODUCTION

The imidazopyridine zolpidem is a hypnotic drug with relative selectivity for the benzodiazepine (BZP) type 1 receptor subtypes displaying a different biochemical structure to that of BZPs. Little is known of its electrophysiological effects.

PURPOSE

The aim of the present study was to investigate the acute neurophysiological effects of clinical oral doses of zolpidem.

METHODS

This was a double blind, independent group design study. Thirty-six young, healthy volunteers were randomly allocated to one of three groups--zolpidem (5 mg and 10 mg) and placebo. In addition to ERPs, behavioural measures were used to examine sedative effects of the drug.

RESULTS

ERPs were affected in a similar way to that described after sedative/hypnotic drug ingestion: increased N2 and P3 latencies and decreased N2 and P3 amplitudes. However, contrary to what is expected of a hypnotic drug, there was no change with N1 while P2 amplitude increased after the highest dose.

CONCLUSIONS

Because zolpidem showed different effects in different components, it seems to first enhance or preserve initial orienting (no change in N1), after an increase of P2 and then drastically diminish resource allocation (affecting N2 and P3 latencies and amplitudes). The study with ERPs, therefore, allows a more direct "moment to moment" investigation of finer mechanisms of changes in cerebral processes underlying the acute ingestion of the drug in question. The effects on N2 and P3 amplitudes and latencies were similar to those of other sedative/hypnotic drugs. However, zolpidem led to an unexpected increase in P2 amplitude; this effect may be related to its selective receptor binding profile and warrants further research.

Identifying target regions for vigilance improvement under hormone replacement therapy in postmenopausal syndrome patients by means of electroencephalographic tomography (LORETA)

RATIONALE

Daytime fatigue, which at the neurophysiological level is due to vigilance decrements, is a frequent complaint in postmenopausal women.

OBJECTIVES

In a three-arm, 2-month, parallel group-design study, vigilance-promoting effects of a novel continuous combination (=Climodien 2/3) of estradiol valerate (EV; 2 mg) and dienogest (DNG; 3 mg) were compared with the effects of both EV alone and placebo in 55 insomniac, postmenopausal syndrome patients.

METHODS

Low-resolution brain electromagnetic tomography (LORETA) was undertaken to identify the cerebral target regions of hormone replacement therapy.

RESULTS

An omnibus significance test revealed Climodien to increase activity in 882 of 2,394 voxels in the alpha-2 band, followed by 733, 706, and 664 voxels in the beta-2, beta-1, and beta-3 bands, and 509 voxels in the delta band, whereas 2 mg EV alone did not produce a significant suprathreshold activity. Current density increased predominantly in the right hemisphere, which had already been described in the literature as the center of the vigilance system. In the fast alpha range, which plays a major role in the context of vigilance, increased activity was found in the right prefrontal, temporal, and superior parietal cortices, i.e., those brain areas of the right-sided fronto-parietal neuronal network that are responsible for sustained attention. A further activity increase was seen in the anterior cingulate gyrus associated with attentional control and conflict monitoring. The right temporal lobe showed increased current density in all frequency bands.

CONCLUSIONS

Electroencephalographic tomography (LORETA) identified the right-hemispheric vigilance system as the target region of Climodien.

Role of progestins with partial antiandrogenic effects

An experts' meeting on the 'Role of progestins with partial antiandrogenic effects' was held in Berlin from January 19 to 22, 2001. The meeting was chaired by Dr R. Sitruk-Ware (New York, USA) and participants included Ms F. Fruzzetti (Pisa, Italy), J. Hanker (Trier, Germany), J. Huber (Vienna, Austria), F. Husmann (Bad Sassendorf, Germany), S. O. Skouby (Copenhagen, Denmark), J. H. H. Thijssen (Utrecht, The Netherlands), and R. Druckmann (Nice, France). The present paper reports the conclusions of the meeting. However, the publication of the Women's Health Initiative study, which appeared after the meeting, led to additional comments and revisions.

Brain regions activated during an auditory discrimination task in insomniac postmenopausal patients before and after hormone replacement therapy: low-resolution brain electromagnetic tomography applied to event-related potentials

Electrical sources of auditory event-related potentials (ERPs) determined by means of low-resolution brain electromagnetic tomography (LORETA) in 48 unmedicated insomniac postmenopausal patients aged between 46 and 67 years were compared with those obtained in 48 age-matched normal female controls. Subsequently, the patients were included in a double-blind, placebo-controlled, comparative, randomized 3-arm trial phase - Climodien 2/3 [estradiol valerate (EV) 2 mg + the progestin dienogest 3 mg] was compared with EV 2 mg and placebo - followed by an open-label phase in which all of them received Climodien 2/2 (EV 2 mg + dienogest 2 mg). The double-blind and the open-label phase lasted 2 months. ERPs were recorded from 19 EEG leads in a two-tone oddball paradigm and electrical sources of standard N1 and P2 as well as target N2 and P300 components were estimated. In both patients and controls, LORETA revealed an activation of the superior temporal gyrus [auditory cortex, Brodmann areas (BA) 41, 42, 22] for all four components. For standard P2, an additional activation was observed medially parietally in the precuneus (BA 7, 5). For target N2, also a medial frontal source (BA 9, 10, 32) was identified. Finally, for the target P300 component - in addition to the aforementioned sources - activations in the prefrontal cortex (BA 9, 10, 46, 47), the inferior parietal cortex (supramarginal gyrus, BA 40, 39) and the posterior cingulum (BA 31) were found. Thus, patients and controls did not differ in the structural processes engaged in these fundamental aspects of information processing. However, patients demonstrated significantly reduced source strength - for standard ERP components predominantly in the temporal lobe and for target components predominantly in the frontal lobe, indicating reduced energetic resources available for perceptual and cognitive demands of the discrimination task. While, as compared with placebo, estrogen alone had only minor effects on ERP source strength, Climodien generally increased the impressed current density at the ERP peak latencies, predominantly in the temporal lobe, indicating an increased stimulus-induced cortical arousal in the primary and higher-order auditory cortex. Specifically, Climodien enhanced P300 source strength in the left middle temporal gyrus and in the left superior frontal gyrus, brain regions that on the one hand have been shown to be affected by hormone therapy in positron emission tomography and functional magnetic resonance neuroimaging studies and that on the other hand are among those critical for encoding and memory processes.

Abnormalities of P300 cortical current density in unmedicated depressed patients revealed by LORETA analysis of event-related potentials

The purpose of the present study was to investigate the neural substrates underlying event-related potential (ERP) abnormalities, with respect to the generators of the ERP components in depressed patients. Using an oddball paradigm, ERP from auditory stimuli were recorded from 22 unmedicated patients with current depressive episodes and compared with those from 22 age- and gender-matched normal controls. Cortical current densities of the N100 and P300 components were analyzed using low-resolution electromagnetic tomography (LORETA). Group differences in cortical current density were mapped on a 3-D cortex model. The results revealed that N100 cortical current densities did not differ between the two groups, while P300 cortical current densities were significantly lower in depressed patients over the bilateral temporal lobes, the left frontal region, and the right temporal-parietal area. Furthermore, the cortical area in which the group difference in P300 current density had been identified was remarkably larger over the right than the left hemisphere, thus supporting the hypothesis of right hemisphere dysfunction in depression.

Insomnia related to postmenopausal syndrome and hormone replacement therapy: sleep laboratory studies on baseline differences between patients and controls and double-blind, placebo-controlled investigations on the effects of a novel estrogen-progestogen combination (Climodien, Lafamme) versus estrogen alone

Differences in sleep and awakening quality between 51 insomniac postmenopausal syndrome patients and normal controls were evaluated. In a subsequent double-blind, placebo-controlled, comparative, randomized, three-arm trial (Climodien 2/3 = estradiol valerate 2 mg + the progestogen dienogest 3 mg = regimen A, estradiol valerate 2 mg = regimen EV, and placebo = regimen P), the effects of 2 months of hormone replacement therapy were investigated, followed by a 2-month open-label phase in which all patients received Climodien 2/2 (EV 2 mg + dienogest 2 mg = regimen A*). Polysomnography at baseline demonstrated significantly deteriorated sleep initiation and maintenance, increased S1 and decreased S2 in patients. Subjective sleep and awakening quality, well-being, morning drive, wakefulness, memory and reaction time performance were deteriorated too. Treatment with both regimen A and regimen EV induced a moderate, although nonsignificant, improvement in the primary efficacy variable wakefulness during the total sleep period compared with baseline, while under placebo no changes occurred. Secondary efficacy variables concerning sleep initiation and maintenance, and sleep architecture showed similar findings. The apnea and apnea-hypopnea indices improved significantly under regimen A, compared with both baseline and placebo. Subjective sleep and awakening quality improved significantly after regimen A and EV compared with baseline, with the drug-induced changes being superior to those induced by placebo. In the open-label phase, subjective sleep quality improved further, significantly in the former regimen A group. Awakening quality, somatic complaints and morning thymopsyche did not yield any significant findings. Concerning morning noopsychic performance, memory improved significantly after regimen A compared with baseline, fine motor activity after regimen EV. Reaction time performance increased with all three compounds. In conclusion, Climodien significantly improved subjective sleep quality, the apnea and apnea-hypopnea indices of insomniac postmenopausal syndrome patients, while it only marginally improved variables concerning objective sleep and awakening quality.

Hormone replacement therapy and vigilance: double-blind, placebo-controlled EEG-mapping studies with an estrogen-progestogen combination (Climodien, Lafamme) versus estrogen alone in menopausal syndrome patients

The aim of the double-blind, placebo-controlled study was to investigate the effects of a continuous combined estrogen-progestogen treatment (Climodien, Lafamme) as compared with estrogen alone on vigilance in insomniac postmenopausal syndrome patients, objectified by EEG mapping.

METHODS

In a 3-arm, 2-month parallel group design phase, patients received a combination of estradiol valerate 2 mg and the novel progestogen dienogest 3 mg (Climodien 2/3) or estradiol valerate 2 mg alone or placebo. In a subsequent open-label phase, all patients received estradiol valerate 2 mg+dienogest 2 mg (Climodien 2/2). EEG mapping was carried out before and after the 2-month double-blind phase as well as after the 2-month open-label treatment.

RESULTS

As compared with placebo, Climodien 2/3 induced a marked and highly significant increase in absolute power in all frequency bands, specifically in alpha-2 activity. Moreover, a significant increase in relative alpha-2 power, a decrease in relative delta and beta power as well as an acceleration of the dominant frequency and of the delta and alpha centroids suggested a marked improvement in vigilance. In contrast, under estradiol valerate 2 mg alone, only a slight augmentation of alpha and attenuation of relative delta and beta power occurred, suggesting only a slight vigilance improvement as compared with placebo. Thus, dienogest 2 mg increased the estrogen effect, which was also confirmed by a statistical evaluation of the differences between Climodien 2/3 and estradiol valerate alone (augmentation of alpha-2, attenuation of relative beta, acceleration of the dominant frequency). Moreover, Climodien 2/2 also markedly increased alpha-2 power, decreased relative beta-2 power and accelerated the alpha centroid. Finally, comparing Climodien 2/3 with Climodien 2/2, there was even a dose-efficacy relation.

CONCLUSIONS

Estradiol valerate 2 mg improves vigilance slightly, thereby confirming previous findings. The additional administration of dienogest does not minimize the effect of estrogen, but on the contrary increases it, which makes the combination superior to both placebo and estradiol valerate alone. Vigilance improvement may be of great therapeutic benefit to menopausal syndrome patients at a time when increased adaptability is needed to adjust to increasing sexual, marital, occupational and social difficulties known to occur specifically in this period of life.