The effect of sleep–wake intraindividual variability in digital cognitive behavioral therapy for insomnia: a mediation analysis of a large-scale RCT

Study ObjectivesDigital cognitive behavioral therapy for insomnia (dCBT-I) is an effective treatment for insomnia. However, less is known about mediators of its benefits. The aim of the present study was to test if intraindividual variability in sleep (IIV) was reduced with dCBT-I, and whether any identified reduction was a mediator of dCBT-I on insomnia severity and psychological distress.MethodsIn a two-arm randomized controlled trial (RCT), 1720 adults with insomnia (dCBT-I = 867; patient education about sleep = 853) completed the Insomnia Severity Index (ISI), the Hospital Anxiety and Depression Scale (HADS) and sleep diaries, at baseline and 9-week follow-up. Changes in IIV were analyzed using linear mixed modeling followed by mediation analyses of ISI, HADS, and IIV in singular sleep metrics and composite measures (behavioral indices (BI-Z) and sleep disturbance indices (SI-Z)).ResultsdCBT-I was associated with reduced IIV across all singular sleep metrics, with the largest between-group effect sizes observed for sleep onset latency (SOL). Reduced IIV for SOL and wake after sleep onset had the overall greatest singular mediating effect. For composite measures, SI-Z mediated change in ISI (b = −0.74; 95% confidence interval (CI) −1.04 to −0.52; 13.3%) and HADS (b = −0.40; 95% CI −0.73 to −0.18; 29.2%), while BI-Z mediated minor changes.ConclusionReductions in IIV in key sleep metrics mediate significant changes in insomnia severity and especially psychological distress when using dCBT-I. These findings offer important evidence regarding the therapeutic action of dCBT-I and may guide the future development of this intervention.Clinical trials Name: Overcoming Insomnia: Impact on Sleep, Health and Work of Online CBT-I Registration number: NCT02558647 URL: https://clinicaltrials.gov/ct2/show/NCT02558647?cond=NCT02558647&draw=2&rank=1     

Associations of insomnia symptoms with subsequent health services use among community-dwelling U.S. older adults

Study ObjectivesDetermine the association of insomnia symptoms with subsequent health services use, in a representative sample of U.S. older adults.MethodsParticipants were 4,289 community-dwelling Medicare beneficiaries who had continuous fee-for-service Medicare coverage 30 days before, and 1 year after the National Health and Aging Trends Study (NHATS) Round 1 interview. Participants reported past-month insomnia symptoms (i.e. sleep onset latency >30 min, difficulty returning to sleep) which we categorized as 0, 1, or 2 symptoms. Outcomes were health services use within 1 year of interviews from linked Medicare claims: emergency department (ED) visits, hospitalizations, 30-day readmissions, home health care (all measured as yes/no), and number of hospitalizations and ED visits.ResultsOverall, 18.5% of participants were hospitalized, 28.7% visited the ED, 2.5% had a 30-day readmission, and 11.3% used home health care. After adjustment for demographics, depressive and anxiety symptoms, medical comorbidities, and BMI, compared to participants with no insomnia symptoms, those with two insomnia symptoms had a higher odds of ED visits (odds ratio [OR) = 1.60, 95% confidence interval [CI] = 1.24–2.07, p < 0.001), hospitalizations (OR = 1.29, 95% CI = 1.01–1.65, p < 0.05), and 30-day readmissions (OR = 1.88, 95% CI = 1.88–3.29, p < 0.05). Reporting 2 insomnia symptoms, versus no insomnia symptoms, was associated with a greater number of ED visits and hospitalizations (incidence rate ratio (IRR) = 1.52, 95% CI = 1.23–1.87, p < 0.001; IRR = 1.21, 95% CI = 1.02–1.44, p < 0.05, respectively) after adjusting for demographic and health characteristics.ConclusionsAmong older adults, insomnia symptoms are associated with greater health services use, including emergency department use, hospitalization, and 30-day readmission. Targeting insomnia may lower health services use.     

Mendelian randomization highlights insomnia as a risk factor for pain diagnoses

Study ObjectiveInsomnia has been linked to acute and chronic pain conditions; however, it is unclear whether such relationships are causal. Recently, a large number of genetic variants have been discovered for both insomnia and pain through genome-wide association studies (GWASs) providing a unique opportunity to examine the evidence for causal relationships through the use of the Mendelian randomization paradigm.MethodsTo elucidate the causality between insomnia and pain, we performed bidirectional Mendelian randomization analysis in FinnGen, where clinically diagnosed ICD-10 categories of pain had been evaluated. In addition, we used measures of self-reported insomnia symptoms. We used endpoints for pain in the FinnGen Release 5 (R5) (N = 218,379), and a non-overlapping sample for insomnia (UK Biobank (UKBB) and 23andMe, N = 1,331,010 or UKBB alone N = 453,379). We assessed the robustness of results through conventional Mendelian randomization sensitivity analyses.ResultsGenetic liability to insomnia symptoms increased the odds of reporting pain (odds ratio (OR) [95% confidence interval (CI)] = 1.47 [1.38–1.58], p = 4.12 × 10⁻²⁸). Manifested pain had a small effect on increased risk for insomnia (OR [95% CI] = 1.04 [1.01–1.07], p < 0.05). Results were consistent in sensitivity analyses.ConclusionsOur findings support a bidirectional causal relationship between insomnia and pain. These data support a further clinical investigation into the utility of insomnia treatment as a strategy for pain management and vice versa.     

Mode of delivery of Cognitive Behavioral Therapy for Insomnia: a randomized controlled non-inferiority trial of digital and face-to-face therapy

Study ObjectivesDigital Cognitive Behavioral Therapy for Insomnia (dCBT-I) has demonstrated efficacy in reducing insomnia severity in self-referred and community samples. It is unknown, however, how dCBT-I compares to individual face-to-face (FtF) CBT-I for individuals referred to clinical secondary services. We undertook a randomized controlled trial to test whether fully automated dCBT-I is non-inferior to individual FtF CBT-I in reducing insomnia severity.MethodsEligible participants were adult patients with a diagnosis of insomnia disorder recruited from a sleep clinic provided via public mental health services in Norway. The Insomnia Severity Index (ISI) was the primary outcome measure. The non-inferiority margin was defined a priori as 2.0 points on the ISI at week 33.ResultsIndividuals were randomized to FtF CBT-I (n = 52) or dCBT-I (n = 49); mean baseline ISI scores were 18.4 (SD 3.7) and 19.4 (SD 4.1), respectively. At week 33, the mean scores were 8.9 (SD 6.0) and 12.3 (SD 6.9), respectively. There was a significant time effect for both interventions (p < 0.001); and the mean difference in ISI at week 33 was −2.8 (95% CI: −4.8 to −0.8; p = 0.007, Cohen’s d = 0.7), and −4.6 at week 9 (95% CI −6.6 to −2.7; p < 0.001), Cohen’s d = 1.2.ConclusionsAt the primary endpoint at week 33, the 95% CI of the estimated treatment difference included the non-inferiority margin and was wholly to the left of zero. Thus, this result is inconclusive regarding the possible inferiority or non-inferiority of dCBT-I over FtF CBT-I, but dCBT-I performed significantly worse than FtF CBT-I. At week 9, dCBT-I was inferior to FtF CBT-I as the 95% CI was fully outside the non-inferiority margin. These findings highlight the need for more clinical research to clarify the optimal application, dissemination, and implementation of dCBT-I. Clinicaltrials.gov: NCT02044263: Cognitive Behavioral Therapy for Insomnia Delivered by a Therapist or on the Internet: a Randomized Controlled Non-inferiority Trial.     

Insomnia with objective short sleep duration is associated with cognitive impairment: a first look at cardiometabolic contributors to brain health

Study ObjectivesInsomnia with objective short sleep duration has been previously associated with adverse cardiometabolic health outcomes as well as poorer cognitive performance in otherwise noncognitively impaired adults. However, studies demonstrating an increased prevalence of cognitive impairment (CI) in this insomnia phenotype are lacking.MethodsWe analyzed data from Penn State Adult Cohort (N = 1,524; 48.9 ± 13.4 years; 53.4% women). Self-reported sleep difficulty was defined as normal sleep (n = 899), poor sleep (n = 453), and chronic insomnia (n = 172). Objective short sleep duration was defined as less than 6-h of sleep, based on in-lab, 8-h polysomnography. CI (n = 155) and possible vascular cognitive impairment (pVCI, n = 122) were ascertained using a comprehensive neuropsychological battery. Analyses adjusted for age, sex, race, education, body mass index, apnea/hypopnea index, smoking, alcohol, psychoactive medication, and mental and physical health problems.ResultsParticipants who reported poor sleep or chronic insomnia and slept objectively less than 6 hours were associated with a 2-fold increased odds of CI (OR = 2.06, 95% confidence limits [CL] = 1.15–3.66 and OR = 2.18, 95% CL = 1.07–4.47, respectively) and of pVCI (OR = 1.94, 95% CL = 1.01–3.75 and OR = 2.33, 95% CL = 1.07–5.06, respectively). Participants who reported poor sleep or chronic insomnia and slept objectively more than 6 hours were not associated with increased odds of either CI (OR = 0.72, 95% CL = 0.30–1.76 and OR = 0.75, 95% CL = 0.21–2.71, respectively) or pVCI (OR = 1.08, 95% CL = 0.42–2.74 and OR = 0.76, 95% CL = 0.16–3.57, respectively).ConclusionsInsomnia with objective short sleep duration is associated with an increased prevalence of CI, particularly as it relates to cardiometabolic health (i.e. pVCI). These data further support that this insomnia phenotype may be a more biologically severe form of the disorder associated with cardiovascular, cerebrovascular, and neurocognitive morbidity.     

Racial disparities in sleep-related cardiac function in young,healthy adults: implications for cardiovascular-related health

Study ObjectivesConsiderable evidence shows that individuals from marginalized racial/ethnic groups in the United States experience greater rates of sleep disturbance and cardiovascular complications. Because sleep is a modifiable factor that is critically involved in cardiovascular health, improved understanding of the association between sleep and cardiovascular health during early adulthood can prevent cardiovascular disparities. This study examined racial/ethnic differences in cardiovascular function during sleep using heart rate and heart-rate-variability analyses.MethodsParticipants in this laboratory-based sleep study included healthy, “good sleepers” who were in early adulthood and resided in the United States at the time of participation (14 non-Hispanic Black [NHB; age = 30.9 (6.6), 57% female], 12 Asian [Asian, age = 26.0 (5.2), 42% female], and 24 non-Hispanic white [NHW; age = 24.6 (5.8), 79% female]).ResultsAfter adjusting for demographic factors and an apnea–hypopnea index, we found significantly higher heart rate within NREM Stage 2 (N2) (b = −22.6, p = .04) and REM sleep (b = −25.8, p =.048) and lower heart rate variability during N2 sleep (b = −22.6, p = .04) among NHB individuals compared with NHW individuals. Furthermore, NHB and Asian participants demonstrated significantly lower percent of time in slow wave sleep (SWS) compared with NHW participants (NHB: b = −22.6, p =.04; Asian: b = −22.6, p = .04). Individuals’ percent of time in SWS significantly mediated differences in heart rate during N2 (indirect = 0.94, 95% CI [0.03, 2.68]) and REM sleep (indirect = 1.02, 95% CI [0.04, 3.04]).ConclusionsOur results showed disparities in sleep-related cardiovascular function in early adulthood that are mediated by SWS. These data suggest targeting sleep health in early adulthood might help reduce cardiovascular disease burden on individuals from marginalized groups.     

Associations between longitudinal trajectories of insomnia symptoms and sleep duration with objective physical function in postmenopausal women: the Study of Women’s Health Across the Nation

Study ObjectivesExamine the association between trajectories of self-reported insomnia symptoms and sleep duration over 13 years with objective physical function.MethodsWe utilized data from 1,627 Study of Women’s Health Across the Nation participants, aged 61.9 ± 2.7 years at the end of the 13-year follow-up. Latent class growth models identified trajectories of insomnia symptoms (trouble falling asleep, frequent night-time awakenings, and/or early morning awakening) and sleep duration over 13 years. Physical function tests were performed at the end of the 13-year period: 40-ft walk, 4-m walk, repeated chair stand, grip strength, and balance. Multivariable regression analyses examined each physical function measure according to the insomnia symptom or sleep duration trajectory group.ResultsFive insomnia symptom trajectories and two sleep duration trajectories were identified. Women with a consistently high likelihood of insomnia symptoms and women with a decreased likelihood of insomnia symptoms (i.e. improving) had slower gait speed (3.5% slower 40-ft walk [consistently high], 3.7% slower 4-m walk [improving]; each p ≤ .05) than those with a consistently low likelihood of insomnia symptoms. In contrast, women with a steep increase in the likelihood of insomnia symptoms over time and women with persistent insufficient sleep duration had lower odds of having a balance problem (odds ratio [OR] = 0.36 and OR = 0.61, respectively; each p < .02) compared to those with a consistently low likelihood of insomnia symptoms and those with persistent sufficient sleep duration, respectively.ConclusionThese results suggest that women’s sleep during midlife has important implications for maintaining physical function during the transition into older adulthood.     

Sleep during menopausal transition: a 10-year follow-up

Study ObjectivesA 10-year observational follow-up study to evaluate the changes in sleep architecture during the menopausal transition.MethodsFifty-seven premenopausal women (mean age 46 years, SD 0.9) were studied at baseline and after a 10-year follow-up. At both time points, polysomnography (PSG) was performed, and the serum follicle-stimulating hormone (S-FSH) concentration was measured. Linear regression models were used to study the effects of aging and menopause (assessed as change in S-FSH) on sleep.ResultsAfter controlling for body mass index, vasomotor, and depressive symptoms, higher S-FSH level was associated with longer sleep latency (B 0.45, 95% confidence interval [CI]: 0.07 to 0.83). Aging of 10 years was associated with shorter sleep latency (B −46.8, 95% CI: −77.2 to −16.4), shorter latency to stage 2 sleep (B −50.6, 95% CI: −85.3 to −15.9), decreased stage 2 sleep (B −12.4, 95% CI: −21.4 to −3.4), and increased slow-wave sleep (B 12.8, 95% CI: 2.32 to 23.3) after controlling for confounding factors.ConclusionsThis study suggests that PSG measured sleep of middle-aged women does not worsen over a 10-year time span due to the menopausal transition. The observed changes seem to be rather age- than menopause-dependent.     

Aerobic and resistance exercise improve patient-reported sleep quality and is associated with cardiometabolic biomarkers in Hispanic and non-Hispanic breast cancer survivors who are overweight or obese: results from a secondary analysis

Study ObjectivesPoor sleep quality affects nearly one-third of breast cancer survivors and is associated with insulin resistance. The purpose of this secondary analysis was to examine the effects of a 16-week exercise intervention on patient-reported sleep quality among breast cancer survivors and assess whether changes in patient-reported sleep quality were associated with cardiometabolic biomarkers. We explored Hispanic ethnicity as a moderator of the effects of exercise on patient-reported sleep quality.MethodsBreast cancer survivors who were overweight or obese were randomized to exercise (n = 50) or usual care (n = 50). The 16-week intervention included aerobic and resistance exercise. Patient-reported sleep quality (Pittsburgh Sleep Quality Index [PSQI]) and biomarkers of cardiometabolic health were assessed at baseline and post-intervention. Within- and between-group differences were assessed using general linear models repeated-measures analyses of variance and mixed-model repeated-measure analysis, respectively. Associations between changes in PSQI and cardiometabolic biomarkers were computed using Pearson correlations. Linear mixed-models were used to evaluate effect modification by ethnicity.ResultsParticipants were 52 ± 10.4 years old, and over half were of Hispanic ethnicity. As compared to usual care, PSQI global scores improved significantly in the exercise group (mean between-group difference −2.2; 95% CI −3.2 to −0.6). Change in PSQI was inversely associated with changes in all cardiometabolic biomarkers (p < 0.01) among the exercise group. Ethnicity was found to moderate the effects of exercise training on global sleep quality (p < 0.001).ConclusionsAn aerobic and resistance exercise intervention effectively improved patient-reported sleep quality in breast cancer survivors. Hispanic ethnicity as a moderator showed greater improvement in patient-reported sleep indicating Hispanic versus non-Hispanic breast cancer survivors may derive larger sleep benefits.Clinical Trail Information{"type":"clinical-trial","attrs":{"text":"NCT01140282","term_id":"NCT01140282"}}NCT01140282.     

Associations of the residential built environment with adolescent sleep outcomes

Study ObjectivesOver 75% of US high school students obtain insufficient sleep, placing them at risk for adverse health outcomes. Identification of modifiable determinants of adolescent sleep is needed to inform prevention strategies, yet little is known about the influence of the built environment on adolescent sleep.MethodsIn this prospective study, actigraphy was used to assess sleep outcomes among 110 adolescents for 14 days each in eighth and ninth grades: duration (hours/night), onset and offset, and sleeping ≥8 hours. Home addresses were linked to built environment exposures: sound levels, tree canopy cover, street density, intersection density, population density, and housing density. Mixed-effects regression estimated associations of built environment measures with sleep outcomes, adjusting for sex, race, parent education, household income, household size, grade, weeknight status, and neighborhood poverty.ResultsA 1-standard deviation (SD) increase in neighborhood sound was associated with 16 minutes later sleep onset (β = 0.28; 95% confidence interval (CI): 0.06, 0.49) and 25% lower odds of sleeping for ≥8 hours (odds ratio (OR) = 0.75, 95% CI: 0.59, 0.96). A 1-SD increase in neighborhood tree canopy was associated with 18 minutes earlier sleep onset (β = −0.31, 95% CI: −0.49, −0.13) and 10 minutes earlier sleep offset (β= −0.17, 95% CI: −0.28, −0.05). No associations were observed for density-based exposures.ConclusionsHigher neighborhood sound level was associated with lower odds of sufficient sleep, while higher tree canopy cover was associated with more favorable sleep timing. Neighborhood sound levels and tree canopy cover are potential targets for policies and interventions to support healthier sleep among adolescents.     

Once-nightly sodium oxybate (FT218) demonstrated improvement of symptoms in a phase 3 randomized clinical trial in patients with narcolepsy

Study ObjectivesTo assess the efficacy and safety of FT218, a novel once-nightly formulation of sodium oxybate (ON-SXB), in patients with narcolepsy in the phase 3 REST-ON trial.MethodsNarcolepsy patients aged ≥16 years were randomized 1:1 to uptitration of ON-SXB (4.5, 6, 7.5, and 9 g) or placebo. Three coprimary endpoints were change from baseline in mean sleep latency on the Maintenance of Wakefulness Test, Clinical Global Impression-Improvement rating, and weekly cataplexy attacks at 9, 7.5, and 6 g. Secondary endpoints included change from baseline on the Epworth Sleepiness Scale. Safety included adverse drug reactions and clinical laboratory assessments.ResultsIn total, 222 patients were randomized; 212 received ≥1 dose of ON-SXB (n = 107) or placebo (n = 105). For the three coprimary endpoints and Epworth Sleepiness Scale, all three doses of ON-SXB demonstrated clinically meaningful, statistically significant improvement versus placebo (all p < 0.001). For ON-SXB 9 g versus placebo, increase in mean sleep latency was 10.8 versus 4.7 min (Least squares mean difference, LSMD [95% CI], 6.13 [3.52 to 8.75]), 72.0% versus 31.6% were rated much/very much improved on Clinical Global Impression-Improvement (OR [95% CI], 5.56 [2.76 to 11.23]), change in mean weekly number of cataplexy attacks was –11.5 versus –4.9 (LSMD [95% CI], –6.65 [–9.32 to –3.98]), and change in Epworth Sleepiness Scale was –6.5 and –2.7 (LSMD [95% CI], –6.52 [–5.47 to –2.26]). Common adverse reactions included nausea, vomiting, headache, dizziness, and enuresis.ConclusionsON-SXB significantly improved narcolepsy symptoms; its safety profile was consistent with SXB. ON-SXB conferred efficacy with a clearly beneficial single nighttime dose.Clinical Trial Registration ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT02720744","term_id":"NCT02720744"}}NCT02720744, https://clinicaltrials.gov/ct2/show/{"type":"clinical-trial","attrs":{"text":"NCT02720744","term_id":"NCT02720744"}}NCT02720744.     

Perceived home sleep environment: associations of household-level factors and in-bed behaviors with actigraphy-based sleep duration and continuity in the Jackson Heart Sleep Study

Study ObjectivesIn an older African-American sample (n = 231) we tested associations of the household environment and in-bed behaviors with sleep duration, efficiency, and wakefulness after sleep onset (WASO).MethodsOlder adult participants completed a household-level sleep environment questionnaire, a sleep questionnaire, and underwent 7-day wrist actigraphy for objective measures of sleep. Perceived household environment (self-reported) was evaluated using questions regarding safety, physical comfort, temperature, noise, and light disturbances. In-bed behaviors included watching television, listening to radio/music, use of computer/tablet/phone, playing video games, reading books, and eating. To estimate the combined effect of the components in each domain (perceived household environment and in-bed behaviors), we calculated and standardized a weighted score per sleep outcome (e.g. duration, efficiency, WASO), with a higher score indicating worse conditions. The weights were derived from the coefficients of each component estimated from linear regression models predicting each sleep outcome while adjusting for covariates.ResultsA standard deviation increase in an adverse household environment score was associated with lower self-reported sleep duration (β = −13.9 min, 95% confidence interval: −26.1, −1.7) and actigraphy-based sleep efficiency (β = −0.7%, −1.4, 0.0). A standard deviation increase in the in-bed behaviors score was associated with lower actigraphy-based sleep duration (β = −9.7 min, −18.0, −1.3), sleep efficiency (β = −1.2%, −1.9, −0.6), and higher WASO (5.3 min, 2.1, 8.6).ConclusionIntervening on the sleep environment, including healthy sleep practices, may improve sleep duration and continuity among African-Americans.     

Inhaled Corticosteroid and Secondary Glaucoma: A Meta-analysis of 18 Studies

PurposeGuidelines and systematic reviews frequently warn of inhaled corticosteroid (ICS)-induced glaucoma. However, most of the published studies deny it.MethodsWe performed a systematic review of randomized, cohort, nested-case control, cross-sectional studies by using Meta-analyses of Observational Studies in Epidemiology statement. Four major databases, PubMed, EMBASE, Cochrane Search Manager, and the Web of Science Core Collection as well as meta-analysis were used. Studies comparing incidence, prevalence and intraocular pressure (IOP) between patients who were treated with and without ICSs were included. A random-model meta-analysis was performed using the inverse variance method.ResultsOut of 623 studies screened, 18 with 31,665 subjects were finally included. No significant difference between the 2 groups was observed for crude glaucoma incidence (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.86–1.04; P = 0.26; I ² = 0%; P for heterogeneity = 0.57) as a primary endpoint, adjusted glaucoma incidence (OR, 0.90; 95% CI, 0.65–1.24; P = 0.64), crude prevalence (OR, 1.82; 95% CI, 0.23–14.19; P = 0.57), adjusted prevalence (OR, 1.22; 95% CI, 0.50–2.96; P = 0.66), IOP change during ICS treatment (mean difference [MD] +0.01 mmHg; 95% CI, −0.19–0.20; P = 0.95), and single measurement IOP (MD +0.37 mmHg; 95% CI, −0.24–0.97; P = 0.23). Time-to-event analysis for glaucoma development as one of the secondary endpoints (adjusted hazard ratio, 0.52; 95% CI, 0.28–0.96) suggested a reverse association between ICS and glaucoma.ConclusionsThe ophthalmological side effects of ICSs, such as glaucoma and intraocular hypertension, should not be exaggerated.Trial RegistrationUniversity Hospital Medical Information Network Center Clinical Trial Registry Identifier: UMIN000040351     

Sleep changes following statin therapy: a systematic review and meta-analysis of randomized placebo-controlled polysomnographic trials

Introduction

Statin use might be associated with an increased risk of sleep disturbances including insomnia, but the evidence regarding sleep changes following statin therapy has not been conclusive. Therefore we assessed the impact of statin therapy on sleep changes through a systematic review and meta-analysis of available randomized controlled trials (RCTs).

Material and methods

We searched MEDLINE and SCOPUS up to October 1, 2014 to identify placebo-controlled RCTs investigating the effect of statin therapy on sleep changes. A meta-analysis was performed using either a fixed-effects or a random-effect model according to the I2 statistic. Effect size was expressed as weighted mean difference (WMD) and 95% confidence interval (CI).

Results

Overall, the impact of statin therapy on polysomnography (PSG) indices of sleep was reported in 5 trials comprising 9 treatment arms. Overall, statin therapy had no significant effect on total sleep duration (WMD: –7.75 min, 95% CI: –18.98, 3.48, p = 0.176), sleep efficiency (WMD: 0.09%, 95% CI: –2.27, 2.46, p = 0.940), entries to stage I (WMD: 0.36, 95% CI: –0.91, 1.63, p = 0.580), or latency to stage I (WMD: –1.92 min, 95% CI: –4.74, 0.89, p = 0.181). In contrast, statin therapy significantly reduced wake time (WMD: –4.43 min, 95% CI: –7.77, –0.88, p = 0.014) and number of awakenings (WMD: –0.40, 95% CI: –0.46, –0.33, p < 0.001). Meta-regression did not suggest any correlation between changes in wake time and awakening episodes with duration of treatment and LDL-lowering effect of statins.

Conclusions

The results indicated that statins have no significant adverse effect on sleep duration and efficiency, entry to stage I, or latency to stage I sleep, but significantly reduce wake time and number of awakenings.     

Intraindividual variability in sleep schedule: effects of an internet-based cognitive-behavioral therapy for insomnia program and its relation with symptom remission

Study ObjectivesSleep schedule consistency is fundamental to cognitive-behavioral therapy for insomnia (CBT-I), although there is limited evidence suggesting whether it predicts treatment response. This analysis tested whether: (1) an Internet-based CBT-I program affects intraindividual variability (IIV) in sleep schedule and (2) sleep schedule IIV predicts insomnia symptom remission.MethodsThis secondary analysis compares participants (N = 303) randomized to an Internet-based CBT-I program (SHUTi—Sleep Healthy Using the Internet) or Internet-based patient education (PE). Participants reported daily bedtimes and rising times on 10 online sleep diaries collected over 2 weeks at baseline and 9-week post-intervention assessment. Participants completed the Insomnia Severity Index (ISI) at post-assessment and 6-month follow-up; symptom remission was defined by ISI < 8. Mixed effects location scale modeling was used to examine the effect of SHUTi on bedtime and rising time IIV; a novel two-staged analysis examined the effect of bedtime and rising time IIV on insomnia symptom remission.ResultsAt post-assessment, SHUTi participants reported about 30% less bedtime and 32% less rising time variability compared to PE (ps < 0.03). Bedtime and rising time IIV was not independently associated with likelihood of insomnia symptom remission at the subsequent time point (ps > 0.18), nor did sleep schedule IIV moderate treatment response (ps > 0.12).ConclusionsFindings demonstrate that an Internet-delivered CBT-I program can effectively increase users’ sleep schedule consistency relative to an educational control. This consistency, however, was not related to treatment outcome when defined by insomnia symptom remission, suggesting that enforcing rigid sleep schedules for patients may not be necessary for treatment success.Clinical Trial Registration{"type":"clinical-trial","attrs":{"text":"NCT00328250","term_id":"NCT00328250"}}NCT00328250     

Dynamics of sleep,sedentary behavior,and moderate-to-vigorous physical activity on school versus nonschool days

Study ObjectivesStudies examining time-use activity behaviors (sleep, sedentary behavior, and physical activity) on school days compared with nonschool days have examined these behaviors independently, ignoring their interrelated nature, limiting our ability to optimize the health benefits of these behaviors. This study examines the associations of school-day (vs. nonschool day) with time-use activity behaviors.MethodsTime series data (6,642 days) from Fitbits (Charge-2) were collected (n = 196, 53% female, 5–10 years). We used a variable-centered dynamic structural equation modeling approach to estimate day-to-day associations of time-use activity behaviors on school days for each child. We then used person-centered cluster analyses to group individuals based on these estimates.ResultsWithin-participant analysis showed that on school days (vs. nonschool days), children (1) slept less (β = −0.17, 95% CI = −0.21, −0.13), (2) were less sedentary (β = −0.05, 95% CI = −0.09, −0.02), and (3) had comparable moderate-to-vigorous physical activity (MVPA; β = −0.05, 95% CI = −0.11, 0.00). Between-participant analysis showed that, on school days, children with higher sleep carryover experienced greater decreases in sleep (β = 0.44, 95% CI = 0.08, 0.71), children with higher body mass index z-score decreased sedentary behavior more (β = −0.41, 95% CI = −0.64, −0.13), and children with lower MVPA increased MVPA more (β = −0.41, 95% CI −0.64, −0.13). Cluster analysis demonstrated four distinct patterns of connections between time-use activity behaviors and school (High Activity, Sleep Resilient, High Sedentary, and Dysregulated Sleep).ConclusionsUsing a combination of person-centered and more traditional variable-centered approaches, we identified patterns of interrelated behaviors that differed on school, and nonschool days. Findings can inform targeted intervention strategies tailored to children’s specific behavior patterns.     

Insomnia in the context of short sleep increases suicide risk

Study ObjectivesThe relationship between insomnia and suicide risk is not completely understood. We aimed to investigate the influence of insomnia on suicide risk, taking both sleep duration and depression into consideration.MethodsThe present study is based on a Swedish prospective cohort study of 38,786 participants with a mean follow-up time of 19.2 years. Cox proportional hazards models with attained age as time-scale were used to estimate hazard ratios (HRs) of death by suicide with 95% confidence intervals (CI) for participants categorized by frequency of insomnia symptoms. Causal mediation analysis was performed to assess to what extent the relationship between insomnia and suicide risk is mediated by depression.ResultsInsomnia was only associated with suicide risk among short sleepers, whereas no significant association was observed among those who slept 7 h/night or more. The total effect of insomnia in the context of short sleep on suicide risk, expressed on the HR scale, was 2.85 (95% CI 1.42–5.74). The direct effect was 2.25 (95% CI 1.12–4.54) and the indirect effect, mediated by depression, was 1.27 (95% CI 1.05–1.53). Of the total effect, 32% was mediated by depression. The association between insomnia and suicide risk became more pronounced with decreasing depressive symptoms (p value for trend <0.05).ConclusionsInsomnia in the context of short sleep increases suicide risk, both directly and indirectly by affecting the risk of depression. Abnormalities of sleep duration and insomnia symptoms should be evaluated when assessing suicide risk.     

Effects of nocturnal wearing of dentures on the quality of sleep and oral-health-related quality in edentate elders with untreated sleep apnea: a randomized cross-over trial

Study ObjectivesThis study aims to assess whether the nocturnal wear of dentures has an effect on the quality of sleep and oral-health-related quality of life of the edentulous elderly with untreated sleep apnea.MethodsA single-blind randomized cross-over design with two sequences and two periods was used. Participants (n = 77) were randomly assigned either to sequence 1 (nocturnal wear followed by nocturnal nonwear of the denture for 30–30 days) or sequence 2 (nocturnal nonwear followed by nocturnal wear of denture for 30–30 days). The primary sleep outcome was the quality of sleep, assessed through sleep fragmentation measured as Apnea–Hypopnea Index (AHI) and respiratory arousal from portable polysomnography. Secondary outcomes were daytime sleepiness, sleep quality (Pittsburgh Sleep Quality Index, PSQI) and oral-health-related quality of life measured by validated questionnaires.ResultsThe mean paired difference in AHI scores for the period of wearing versus not wearing dentures at night was small 1.0 event per hour (p = 0.50; 95% confidence interval (CI) = −2.0 to 4.1). The mean respiratory arousal index was higher when wearing dentures at night than when not wearing dentures at night, with a mean paired difference of 2.3 events per hour (p = 0.05; 95% CI = 0.0 to 4.6). No difference in sleepiness and PSQI were noted. Wearing dentures at night resulted in a statistically significantly higher mean score of psychological discomfort when compared to not wearing dentures at night.ConclusionsThe results provide some support to usual practice guidelines to remove dentures at night in edentulous elders suffering from sleep apnea.Clinical trial registrationNCT01868295.     

The acute effects of aerobic exercise on sleep in patients with unipolar depression: a randomized controlled trial

Study ObjectivesInsomnia increases the risk of negative disease trajectory, relapse, and suicide in patients with depression. We aimed at investigating the effects of a single bout of aerobic exercise, performed after 02:00 pm, on the subsequent night’s sleep in patients with depression.MethodsThe study was designed as a two-arm parallel-group, randomized, outcome assessor-blinded, controlled, superiority trial. Patients between 18 and 65 years of age with a primary diagnosis of unipolar depression were included. The intervention was a single 30-minute bout of moderate aerobic exercise. The control group sat and read for 30 minutes. The primary outcome was sleep efficiency measured by polysomnography. Secondary outcomes were other polysomnographic variables, subjective sleep quality, daytime sleepiness, mood states, and adverse events.ResultsNinety-two patients were randomized to the exercise (N = 46) or control group (N = 46). There were no clinically relevant differences at baseline. Intent-to-treat analysis ANCOVA of follow-up sleep efficiency, adjusted for baseline levels and minimization factors, did not detect a significant effect of the allocation (β = −0.93, p = 0.59). There was no evidence for significant differences between both groups in any other objective or subjective sleep outcomes, daytime sleepiness, or adverse events. The intervention had an immediate positive effect on mood states, including depressiveness (β = −0.40, p = 0.003).ConclusionsThis is the first trial to study the effects of a single bout of aerobic exercise on sleep in patients with depression to the best of our knowledge. Aerobic exercise had no effect on sleep efficiency but had a strong beneficial effect on mood and did not increase adverse outcomes. These results add to the growing body of evidence that, contrary to sleep hygiene recommendations, exercise after 02:00 pm is not detrimental for sleep.Clinical Trial RegistrationClinicaltrials.gov, https://clinicaltrials.gov/ct2/show/NCT03673397. Protocol registered on September 17, 2018.     

Cooling Capacity of Transpulmonary Cooling and Cold-Water Immersion After Exercise-Induced Hyperthermia

ContextCold-water immersion (CWI) may not be feasible in some remote settings, prompting the identification of alternative cooling methods as adjunct treatment modalities for exertional heat stroke (EHS).ObjectiveTo determine the differences in cooling capacities between CWI and the inhalation of cooled air.DesignRandomized controlled clinical trial.SettingLaboratory.Patients or Other ParticipantsA total of 12 recreationally active participants (7 men, 5 women; age = 26 ± 4 years, height = 170.6 ± 10.1 cm, mass = 76.0 ± 18.0 kg, body fat = 18.5% ± 9.7%, peak oxygen uptake = 42.7 ± 8.9 mL·kg⁻¹·min⁻¹).Intervention(s)After exercise in a hot environment (40°C and 40% relative humidity), participants were randomized to 3 cooling conditions: cooling during passive rest (PASS; control), CWI, and the Polar Breeze thermal rehabilitation machine (PB) with which participants inspired cooled air (22.2°C ± 1.0°C).Main Outcome Measure(s)Rectal temperature (T_REC) and heart rate were continuously measured throughout cooling until T_REC reached 38.25°C.ResultsCooling rates during CWI (0.18°C·min⁻¹ ± 0.06°C·min⁻¹) were greater than those during PASS (mean difference [95% CI] of 0.16°C·min⁻¹ [0.13°C·min⁻¹, 0.19°C·min⁻¹]; P < .001) and PB (0.15°C·min⁻¹ [0.12°C·min⁻¹, 0.16°C·min⁻¹]; P < .001). Elapsed time to reach a T_REC of 38.25°C was also faster with CWI (9.71 ± 3.30 minutes) than PASS (−58.1 minutes [−77.1, −39.9 minutes]; P < .001) and PB (−46.8 minutes [−65.5, −28.2 minutes]; P < .001). Differences in cooling rates and time to reach a T_REC of 38.25°C between PASS and PB were not different (P > .05).ConclusionsTranspulmonary cooling via cooled-air inhalation did not promote an optimal cooling rate (>0.15°C·min⁻¹) for the successful treatment of EHS. In remote settings where EHS is a risk, access and use of treatment methods via CWI or cold-water dousing are imperative to ensuring survival.Trial RegistryClinicalTrials.gov (NCT0419026).