The effect of experimentally-induced sleep fragmentation and estradiol suppression on neurobehavioral performance and subjective sleepiness in pre-menopausal women.

STUDY OBJECTIVES: Menopause is associated with nighttime sleep fragmentation, declining estradiol and impaired cognition. In a model of pharmacologically-induced estradiol suppression mimicking menopause, we examined the impact of menopause-pattern sleep fragmentation on daytime neurobehavioral performance and sleepiness in premenopausal women. METHODS: Twenty premenopausal women completed two 5-night inpatient studies in the mid-to-late follicular phase (estrogenized) and after pharmacological estradiol suppression (hypo-estrogenized). During each study, participants had an uninterrupted 8-hour sleep opportunity for two nights, followed by three nights where sleep was experimentally fragmented to mimic menopause-pattern sleep disturbance, and during which the sleep opportunity was extended to prevent shortening of the sleep duration. Neurobehavioral performance and subjective sleepiness were measured using the Psychomotor Vigilance Task and Karolinska Sleepiness Scale (KSS). RESULTS: Compared to unfragmented sleep, sleep fragmentation increased attentional lapses (+0.6 lapses, p<0.05), slowed reaction time (+9.4 milliseconds, p<0.01), and increased daytime sleepiness (+0.5 KSS score, p<0.001). Estradiol suppression increased attentional lapses (+0.8; p<0.001) and reaction time (+12.3, p<0.01) but did not significantly affect daytime sleepiness. The effect of sleep fragmentation on neurobehavioral performance differed by estradiol state, such that the adverse effects of sleep fragmentation on attentional lapses (+0.9, trend p=0.06) and reaction time (+15, p<0.05) were observed only when estrogenized. CONCLUSIONS: Menopause-pattern sleep fragmentation and estradiol suppression worsened neurobehavioral performance and daytime sleepiness, even while sleep duration was not reduced. The adverse effects of sleep fragmentation in the context of an adequate sleep duration highlight the importance of sleep continuity as a vital aspect of good sleep health.

Effects of Sleep Fragmentation and Estradiol Decline on Cortisol in a Human Experimental Model of Menopause.

CONTEXT: Perturbations to the hypothalamic-pituitary-adrenal (HPA) axis have been hypothesized to increase postmenopausal cardiometabolic risk. Although sleep disturbance, a known risk factor for cardiometabolic disease, is prevalent during the menopause transition, it is unknown whether menopause-related sleep disturbance and estradiol decline disturb the HPA axis. OBJECTIVE: We examined the effect of experimental fragmentation of sleep and suppression of estradiol as a model of menopause on cortisol levels in healthy young women. METHODS: Twenty-two women completed a 5-night inpatient study during the mid-to-late follicular phase (estrogenized). A subset (n = 14) repeated the protocol after gonadotropin-releasing hormone agonist-induced estradiol suppression. Each inpatient study included 2 unfragmented sleep nights followed by 3 experimental sleep fragmentation nights. This study took place with premenopausal women at an academic medical center. Interventions included sleep fragmentation and pharmacological hypoestrogenism, and main outcome measures were serum bedtime cortisol levels and cortisol awakening response (CAR). RESULTS: Bedtime cortisol increased 27% (P = .03) and CAR decreased 57% (P = .01) following sleep fragmentation compared to unfragmented sleep. Polysomnographic-derived wake after sleep-onset (WASO) was positively associated with bedtime cortisol levels (P = .047) and negatively associated with CAR (P < .01). Bedtime cortisol levels were 22% lower in the hypoestrogenized state compared to the estrogenized state (P = .02), while CAR was similar in both estradiol conditions (P = .38). CONCLUSION: Estradiol suppression and modifiable menopause-related sleep fragmentation both independently perturb HPA axis activity. Sleep fragmentation, commonly seen in menopausal women, may disrupt the HPA axis, which in turn may lead to adverse health effects as women age.

C-reactive protein and affective inhibition in bipolar disorder.

BACKGROUND: Individuals with bipolar disorder (BD) experience cognitive and affective processing deficits that often persist beyond the remission of acute mood symptoms. One possible biological mechanism for these deficits involves the potential effects of chronic low-grade peripheral inflammation on brain function. Peripheral inflammation has been associated with reduced executive functioning and memory performance, as well as altered reward processing in BD, but whether it is also implicated in cognitive-affective processing remains unknown. METHOD: Peripheral inflammation was measured by serum C-reactive protein (CRP) in 119 adults with BD I or II, age 18-65. All participants completed the Affective Go/No-Go Task, a measure of cognitive-emotional processing. Correlations of CRP with discrimination of and response times to Negative, Positive, and Neutral words were performed before and after adjustment for severity of residual depressive symptoms and other demographic and clinical characteristics associated with inflammation. RESULTS: Increased CRP was significantly associated with reduced negative target discriminability, which was also significantly reduced compared to positive and neutral target conditions. Additionally, greater CRP was associated with faster response times for both negative hits and commissions, as well as positive commissions. CONCLUSIONS: This study adds to existing research demonstrating associations between inflammation and cognition or reward sensitivity and motivation separately in BD, by raising the possibility that inflammation is also implicated in the integration of cognitive-affective processing. Assessment of these associations over time is warranted to determine involvement of inflammation and cognitive-emotional processing in course of illness and identify critical periods for possible modulation of inflammation.

Brain-derived neurotrophic factor and mood in perimenopausal depression.

BACKGROUND: Previous work implicates high pro-inflammatory biomarkers in mood disturbance and low brain-derived neurotrophic factor (BDNF) levels in major depression. However, in hormonally-sensitive premenstrual dysphoric disorder (PMDD), BDNF levels are higher when mood is worse. Perimenopausal depression has not been studied to date. We evaluated whether BDNF and inflammatory cytokines predict mood symptoms across the menstrual cycle in hormonally-sensitive perimenopausal depression symptoms. METHODS: Data from 49 time points derived from mid-to-late follicular phase [M/L-FP] and peri­menstrual assessments of 14 perimenopausal women ages 38-52 with ovulatory menstrual cycles 24-35 days long across 1-2 cycles for mood symptoms, BDNF levels, cytokines, gonadal steroids. Depression was assessed with Montgomery-Åsberg Depression Rating Scale (MADRS), Beck Depression Inventory (BDI); irritability with Kellner Symptom Questionnaire Anger-Hostility subscale (SQ); overall psychological distress with Profile of Mood States (POMS). Mixed models were run on dependent measures of MADRS (primary endpoint) and other mood outcomes (BDI, POMS, SQ) with independent variables of interest (each biomarker, cycle phase), controlling for cycle number and participant. RESULTS: After FDR adjustment, BDNF levels showed consistent significant positive relationships to MADRS (ß=0.00053; p = 0.0028), POMS (ß=0.00153; p = 0.0394), SQ (ß=0.00053; p = 0.0067), and BDI (ß=0.00039; p = 0.0231). Cycle phase did not affect this relationship. No other biomarker consistently predicted affective symptom severity. LIMITATIONS: Small sample size and large number of comparisons. CONCLUSION: In women with perimenopausal depression symptoms, BDNF is elevated in association with more severe mood symptomatology, resembling the pattern in hormonally-sensitive PMDD and suggesting a hormonally-sensitive mood disorder biomarker profile distinct from that of major depression.

A double-blind, randomized, placebo-controlled trial of suvorexant for the treatment of vasomotor symptom-associated insomnia disorder in midlife women.

STUDY OBJECTIVES: The neuropeptide orexin promotes wakefulness, modulates thermoregulation, increases after menopause, and is normalized in women receiving estrogen therapy, suggesting a role for orexin antagonism as a treatment for the vasomotor symptom (VMS)-associated insomnia disorder. We tested the efficacy of the dual orexin receptor antagonist suvorexant for chronic insomnia related to nighttime VMS. METHODS: In a double-blind, placebo-controlled trial, 56 women with chronic insomnia associated with nighttime VMS, Insomnia Severity Index (ISI) scores ≥15, and >30 min of diary-rated wake after sleep-onset (WASO) were randomized to receive oral suvorexant 10-20 mg (n = 27) or placebo (n = 29) nightly for 4 weeks. Analysis of within-person change in ISI was adjusted for baseline ISI and race. RESULTS: Mean baseline ISI scores were 18.1 (95% CI, 16.8 to 19.4) and 18.3 (95% CI, 17.2 to 19.5) in the suvorexant and placebo groups, respectively (p = .81). The average 4-week ISI within-person decrease from baseline was greater on suvorexant (-8.1 [95% CI, -10.2 to -6.0]) compared to placebo (-5.6 [95% CI, -7.4 to -3.9], p = .04). Compared to placebo, nighttime diary-rated VMS frequency was significantly reduced with suvorexant (p < .01). While diary-rated WASO and total sleep time trended toward improvement on suvorexant, findings were not significant after adjustment for multiple comparisons. Daytime VMS and other sleep-related outcomes did not differ between groups. Suvorexant was well tolerated. CONCLUSION: These results suggest that suvorexant is likely a well-tolerated and efficacious treatment for VMS-associated insomnia disorder and reduces nighttime VMS. Antagonism of orexin receptors could provide a novel therapeutic option for midlife women with VMS-associated chronic insomnia. CLINICAL TRIAL INFORMATION: Efficacy of Suvorexant in the Treatment of Hot Flash-associated Insomnia, https://clinicaltrials.gov/ct2/show/NCT03034018, ClinicalTrials.gov Identifier: NCT03034018.

Sleep Fragmentation and Estradiol Suppression Decrease Fat Oxidation in Premenopausal Women.

CONTEXT: Body fat gain associated with menopause has been attributed to estradiol (E2) withdrawal. Hypoestrogenism is unlikely to be the only contributing factor, however. OBJECTIVE: Given the links between sleep and metabolic health, we examined the effects of an experimental menopausal model of sleep fragmentation on energy metabolism. METHODS: Twenty premenopausal women (age 21-45 years) underwent a 5-night inpatient study during the mid-to-late follicular phase (estrogenized; n = 20) and the same protocol was repeated in a subset of the participants (n = 9) following leuprolide-induced E2 suppression (hypo-estrogenized). During each 5-night study, there were 2 nights of unfragmented sleep followed by 3 nights of fragmented sleep. Indirect calorimetry was used to assess fasted resting energy expenditure (REE) and substrate oxidation. RESULTS: Sleep fragmentation in the estrogenized state increased the respiratory exchange ratio (RER) and carbohydrate oxidation while decreasing fat oxidation (all P < 0.01). Similarly, in the hypo-estrogenized state without sleep fragmentation, RER and carbohydrate oxidation increased and fat oxidation decreased (all P < 0.01); addition of sleep fragmentation to the hypo-estrogenized state did not produce further effects beyond that observed for either intervention alone (P < 0.05). There were no effects of either sleep fragmentation or E2 state on REE. CONCLUSION: Sleep fragmentation and hypoestrogenism each independently alter fasting substrate oxidation in a manner that may contribute to body fat gain. These findings are important for understanding mechanisms underlying propensity to body fat gain in women across the menopause transition.