Acute effects of transdermal nicotine on sleep architecture, snoring, and sleep-disordered breathing in nonsmokers

Poor sleep duration and E-cigarette/Cigarette use among US adults with cardiovascular diseases: findings from the 2022 BRFSS cross-sectional study

BACKGROUND

Studies have explored the connections between tobacco use, sleep and cardiovascular disease (CVD) risks in adults, but no study has examined the link between tobacco use and sleep among adults with CVDs. This study explores the association between tobacco use (cigarette only, e-cigarette only, and dual use) and poor sleep duration among adults with CVDs.

METHODS

A sample of 47,180 US adults with CVDs (myocardial infarction, coronary heart disease, or stroke) was drawn from the 2022 Behavioral Risk Factor Surveillance System (BRFSS) cross-sectional survey. Poor/inadequate sleep (< 7 h/24-hour) was defined based on National Sleep Foundation recommendations. Logistic regression models assessed tobacco use status across seven categories (i.e., non-use [reference], current [past-month use] cigarette only, current e-cigarettes only, current dual use, former cigarette only, former e-cigarette only, and former dual use) with inadequate sleep, adjusting for demographics and health conditions.

RESULTS

Overall, 40% of US adults with a history of CVD reported inadequate sleep. Current cigarette, e-cigarette, and dual use were associated with a relatively higher proportion of inadequate sleep duration. Unweighted findings revealed a significant association between current cigarette use (OR = 1.35, 95%CI: 1.26-1.44), e-cigarette use (1.40 [1.19-1.63]) and dual use (1.50 [1.27-1.77]) and increased odds of reporting inadequate sleep among adults with CVDs. Weighted analysis showed only a significant link between current cigarette use and inadequate sleep (1.34 [1.17-1.54]).

CONCLUSIONS

Current cigarette use is associated with poor sleep in adults with CVDs. Unweighted findings suggested a similar association for e-cigarettes. Interventions targeting smoking cessation may offer promising avenues for improving sleep health and reducing the burden on adults with CVDs.

Tobacco Smoke Exposure and Sleep Duration among U.S. Adolescents

OBJECTIVES

Tobacco smoke exposure (TSE) and poor sleep are public health problems with their own set of consequences. This study assessed whether TSE was associated with sleep duration among U.S. adolescents.

METHOD

We conducted a secondary analysis of 2013-2018 National Health and Nutrition Examination Survey data including 914 nontobacco-using adolescents ages 16-19 years. TSE measures included cotinine and self-reported home TSE groups including no home TSE, thirdhand smoke (THS) exposure, and secondhand smoke (SHS)+THS exposure. Sleep duration was assessed in hours and categorically as insufficient sleep (recommended hours). Weighted multiple linear regression and multinomial regression models were conducted.

RESULTS

Adolescents with higher log-cotinine levels had higher number of sleep hours (β = 0.31, 95%CI = 0.02,0.60) and were at increased odds of reporting excess sleep (AOR = 1.41, 95%CI = 1.40,1.42), but were at reduced odds of reporting insufficient sleep (AOR = 0.88, 95%CI = 0.87,0.89). Compared to adolescents with no home TSE, adolescents with home THS exposure and home SHS+THS exposure were at increased odds of reporting insufficient sleep (AOR = 2.27, 95%CI = 2.26,2.29; AOR = 2.75, 95%CI = 2.72,2.77, respectively) and excess sleep (AOR = 1.89, 95%CI = 1.87,1.90; AOR = 5.29, 95%CI = 5.23,5.34, respectively).

CONCLUSIONS

TSE may affect insufficient and excess sleep duration among adolescents. Eliminating TSE may promote adolescent respiratory and sleep health.

Associations between e-cigarette use and sleep health among adults in the United States, NHANES 2015-2018

OBJECTIVE

To examine the associations between e-cigarette use or dual (e-cigarette and combustible cigarette) use and short sleep duration and trouble sleeping among U.S. adults.

METHODS

We used 2015-2018 data from the National Health and Nutrition Examination Survey (NHANES) (n = 11,659). E-cigarette use and dual use were categorized as current, former, and never use. Short sleep duration was defined as sleep duration ≤6 h. Trouble sleeping was self-reported. Weighted logistic regression analyses were performed.

RESULTS

Among those with current e-cigarette use, 53.9 % were with current dual use and 23.8 % were with former dual use. Compared to never e-cigarette use, current e-cigarette use was associated with significantly higher odds of trouble sleeping (OR = 2.16, 95 % CI: 1.49-3.13), adjusting for potential confounders. Significant associations were also observed for former e-cigarette use versus never use with trouble sleeping (OR = 1.54, 95 % CI: 1.15-2.07) after full adjustment. Current cigarette use was associated with both short sleep duration (OR = 1.65, 95 % CI: 1.28-2.14) and trouble sleeping (OR = 1.36, 95 % CI: 1.03-1.79) after full adjustment. Additionally, the fully adjusted ORs for short sleep duration and trouble sleeping were 1.64 (95 % CI: 1.06-2.54) and 2.14 (95 % CI: 1.34-3.42) among those with current dual use, and 1.46 (95 % CI: 1.17-1.81) and 2.11 (95 % CI: 1.66-2.67) among those with former dual use, compared to those without dual use.

CONCLUSIONS

Current cigarette use or dual use is associated with significantly higher odds of short sleep duration and trouble sleeping. Moreover, former e-cigarette use or dual use is associated with increased odds of trouble sleeping.

Obstructive Sleep Apnea and Smoking Increase the Risk of Cardiovascular Disease: Smoking Cessation Pharmacotherapy

Tobacco smoking has been a recognized risk factor for cardiovascular diseases (CVD). Smoking is a chronic relapsing disease and pharmacotherapy is a main component of smoking cessation. Obstructive sleep apnea (OSA) and smoking both increase the risk of CVD and are associated with significant morbidity and mortality. There are few existing data examining how pharmacological treatment, such as nicotine replacement therapy (NRT), bupropion, and varenicline, affect smokers suffering with OSA and especially their cardiovascular effects. The aim of this review was to evaluate the effects of smoking cessation pharmacotherapy on OSA with a special emphasis on the cardiovascular system. Results: Only small studies have assessed the effect of NRTs on OSA. Nicotine gum administration showed an improvement in respiratory events but with no permanent results. No specific studies were found on the effect of bupropion on OSA, and a limited number evaluated varenicline's effects on sleep and specifically OSA. Varenicline administration in smokers suffering from OSA reduced the obstructive respiratory events, especially during REM. Studies on second-line medication (nortriptyline, clonidine, cytisine) are even more limited. There are still no studies evaluating the cardiovascular effects of smoking cessation medications on OSA patients. Conclusions: Sleep disturbances are common withdrawal effects during smoking cessation but could be also attributed to pharmacotherapy. Smokers should receive personalized treatment during their quitting attempts according to their individual needs and problems, including OSA. Future studies are needed in order to evaluate the efficacy and safety of smoking cessation medications in OSA patients.

Nicotine, alcohol, and caffeine use among individuals with untreated obstructive sleep apnea

BACKGROUND

Psychoactive substance use (i.e., nicotine, alcohol, and caffeine) has substantial effects on sleep architecture in healthy individuals, but their effects in those with obstructive sleep apnea (OSA) have not been well described. We aimed to describe the association between psychoactive substance use and sleep characteristics and daytime symptoms in individuals with untreated OSA.

METHODS

We performed a secondary, cross-sectional analysis of The Apnea Positive Pressure Long-term Efficacy Study (APPLES). Exposures included current smoking, alcohol and caffeine use in individuals with untreated OSA. Outcome domains included subjective and objective sleep characteristics, daytime symptoms, and comorbid conditions. Linear or logistic regression assessed the association between substance use and each domain (e.g., self-reported sleep duration, total polysomnographic sleep time, sleepiness, and anxiety).

RESULTS

Of the 919 individuals with untreated OSA, 116 (12.6%) were current cigarette smokers, 585 (63.7%) were moderate or heavy alcohol users, and 769 (83.7%) were moderate or heavy caffeine users. Participants were on average 52.2±11.9 years old, 65.2% were male with a median BMI of 30.6 (IQR: 27.2, 35.9, kg/m2). Current smokers exhibited lower sleep duration (0.3 h), longer sleep latency (5 min) compared with non-smokers (all p-values < 0.05). People with heavy or moderate alcohol use exhibited more REM sleep (2.5 and 5% of total sleep time respectively), as did those with moderate caffeine use (2%, p-values < 0.05). The combined smoker plus caffeine group exhibited shorter sleep duration (0.4 h, p-value < 0.05) and higher risk for chronic pain [Odds Ratio (95%CI) = 4.83 (1.57, 14.9) compared with non-users.

CONCLUSIONS

Psychoactive substance use is associated with sleep characteristics and clinically relevant correlates in people with untreated OSA. Further investigation into the effects that various substances have on this population may present opportunities to understand disease mechanisms more fully and increase the effectiveness of treatment in OSA.

Turning Over a New Leaf-Pharmacologic Therapy in Obstructive Sleep Apnea

Despite extensive research, there is currently no approved drug for obstructive sleep apnea (OSA) treatment. OSA is a heterogeneous condition that involves multiple dominating pathophysiological traits. Drug development in this field needs to address both pathophysiological mechanisms and associated comorbid conditions in order to meet requirements for long-term therapy in OSA. Several drug candidates have been proposed and ongoing phase II trials that target various forms of sleep-disordered breathing have been initiated. The field is moving toward tailored therapeutic approaches in patients with OSA.

Does Smoking Affect OSA? What about Smoking Cessation?

The connection between smoking and Obstructive sleep apnea (OSA) is not yet clear. There are studies that have confirmed the effect of smoking on sleep disordered breathing, whereas others did not. Nicotine affects sleep, as smokers have prolonged total sleep and REM latency, reduced sleep efficiency, total sleep time, and slow wave sleep. Smoking cessation has been related with impaired sleep. The health consequences of cigarette smoking are well documented, but the effect of smoking cessation on OSA has not been extensively studied. Smoking cessation should improve OSA as upper airway oedema may reduce, but there is limited data to support this hypothesis. The impact of smoking cessation pharmacotherapy on OSA has been studied, especially for nicotine replacement therapy (NRT). However, there are limited data on other smoking cessation medications as bupropion, varenicline, nortriptyline, clonidine, and cytisine. The aim of this review was to explore the current evidence on the association between smoking and OSA, to evaluate if smoking cessation affects OSA, and to investigate the possible effects of different pharmacologic strategies offered for smoking cessation on OSA.

The impact of cigarette smoking on the quality of sleep in Polish men

Quality of sleep directly impacts quality of life, whilst lifestyle significantly impacts night rest. Cigarette smoking is a serious threat to overall health, including sleep. Nicotine in cigarettes affects the nervous system, whilst the respiratory system is impacted by carcinogenic substances, such as dusts and tarred substances, inhaled with smoke. Cigarettes are assumed to be a risk factor in sleep disorders, including breathing sleep disorders.

This study’s aim was to analyze the impact of cigarette smoking on adult men’s polysomnographic parameters.

Polysomnographic records for 94 adult men were obtained from the polysomnography laboratory in Opolskie Province, Poland. Additionally co-morbidities, height, weight and frequency of smoking were also noted. Three groups of men were categorised according to the frequency with which they smoked: non-smokers, smoking less than a pack a day, smoking more than a pack a day.

Compared to non-smokers and mild smokers, men who were heavy smokers also exhibited the longest sleepless time (H=8.11; p=0.017), the maximum waking time following the onset of sleep (H=7.99; p= 0.018), the lowest sleep efficiency across the three groups (H=7.96; p=0.019), the greatest number of apnea events per hour of sleep (H=6.23; p= 0.045), the lowest Oxygen Level Nadir (H=11.44; p= 0.003) and the highest rate of limb movements per hour of sleep (H=9.81; p=0.007).

The dose effect was identified, which correlated more cigarettes men smoked per day with lower sleep quality.

Smoking and Obstructive Sleep Apnea: Is There An Association between These Cardiometabolic Risk Factors?-Gender Analysis

Background and Objectives: Studies have tried to establish a relationship between Obstructive Sleep Apnea syndrome (OSA) and smoking but data still remain controversial. We aimed: 1. To evaluate the relationship between smoking and OSA; 2. To explore potential differences according to gender, and 3. To analyze the prevalence of cardiovascular disease (CVD) co-morbidities according to gender and smoking status. Materials and Methods: This retrospective study included 3791 (70.6% males) adult patients who visited a Sleep Clinic. All participants underwent nocturnal polysomnography. Daytime somnolence and insomnia were assessed by using the Epworth Sleepiness Scale (ESS) and the Athens Insomnia Scale (AIS). Ever-smokers completed the Fagerstrom Test for Nicotine Dependence (FTND). Results: OSA was confirmed in 72.1% of participants with 62.2% suffering from moderate-to-severe disease. The number of cigarettes/day, Pack/Years, and FTND were significantly higher in patients with more severe OSA. The prevalence of current smokers was higher in those without OSA or with mild disease, whereas the prevalence of former smokers was higher in moderate and severe OSA. In univariate analysis, current smokers were found to be 1.2 times more likely to have OSA compared with never and former smokers combined and former smokers 1.49 times more likely compared with never smokers. In the multiple regression analysis, after adjusting for BMI, gender, age and number of alcoholic drinks per week, smoking was not found to be significantly associated with OSA. In gender stratified multivariate analyses, no significant associations were observed. CVD co-morbidities were more frequent in more severe OSA. Hypertension, coronary disease and diabetes were more prevalent in former smokers with AHI ≥ 15, compared with current smokers, especially in men. Conclusions: Even if an independent effect of smoking on OSA was not found, the number of cigarettes/day, Pack/Years, and FTND were higher in patients with more severe OSA with more prevalent CVD co-morbidities.

Varenicline administration for smoking cessation may reduce apnea hypopnea index in sleep apnea patients

OBJECTIVE/BACKGROUND

Varenicline (VAR) is used for smoking cessation as it inhibits nicotine for binding on its receptors reducing nicotine dependence. VAR administration has been reported to affect sleep. The aim of this study was to evaluate possible changes in polysomnography (PSG) during VAR treatment (SmokeFreeBrain) in healthy smokers and smokers with obstructive sleep apnea (OSA).

PATIENTS/METHODS

Thirty smokers (21 men) with 15.3 ± 10.2 PY, aged 32.8 ± 4.5 years, with BMI 28.6 ± 4 kg/m², 16 without and 14 with OSA (92% males) were studied with PSG (Embletta MPR-Master) before treatment with VAR while smoking and 20-30 days during VAR administration and smoking cessation for at least 5 days.

RESULTS

No significant differences were observed in sleep macro architecture (N1, N2, N3, REM, Sleep Efficiency, Total Sleep Time) during VAR treatment apart from prolongation of sleep latency, N2 and N3 latency in both smokers with and without OSA. Apnea hypopnea index (AHI) was reduced in OSA smokers and especially during REM with a borderline increase of arousal index (ArI) and reduction of sleep efficiency (SE).

CONCLUSION

VAR treatment worsened sleep quality as a prolongation of sleep latency, N2 and N3 latency was observed. A marginal reduction of AHI was found in OSA patients, more significantly during REM. Due to the small sample size, further studies are needed to distinguish between the adverse reactions of VAR treatment and smoking cessation effects and to evaluate whether VAR may play a role in OSA treatment.

Smoking and incidence of insomnia: a systematic review and meta-analysis of cohort studies

OBJECTIVE

This study investigated the impact of smoking on the incidence of insomnia.

STUDY DESIGN

Systematic review and meta-analysis of cohort studies.

METHODS

PubMed, EMBASE, Web of Science, Cochrane Library, and OVID were searched through March 2020. Cohort studies reporting the effect of smoking on the incidence of insomnia were included. We quantitatively analyzed the basic framework and study characteristics and then pooled estimate effects with 95% confidence intervals (CIs) of outcomes of each included study using fixed-effects meta-analyses.

RESULTS

This systematic review included six cohort studies involving 12,445 participants. Quantitatively summarized results suggested that smoking could significantly increase the incidence of insomnia (odds ratio [OR]: 1.07, 95% CI: 1.02, 1.13). Regular smoking was significantly associated with the incidence of insomnia (OR = 1.07, 95% CI: 1.01, 1.13). As for occasional smokers and ex-smokers, the pooled analysis did not indicate a significant association (occasional smoker: OR = 2.09, 95% CI: 0.44, 9.95; ex-smoker; OR = 1.02, 95% CI: 0.67, 1.54). Subgroup analysis by age, gender ratio, and region showed a statistically significant relationship between smoking and the incidence of insomnia in specific groups.

CONCLUSIONS

Integrated longitudinal observational evidence identified smoking as a significant risk factor of insomnia. Considering the limited amount of available studies, more high-quality and prospective cohort studies of large sample sizes are needed to explore details of this association.

Tobacco smoke exposure and inadequate sleep among U.S. school-aged children

OBJECTIVE/BACKGROUND

Inadequate sleep and tobacco smoke exposure (TSE) have been separately linked to adverse childhood health consequences. Our objective was to assess the association between home TSE status and inadequate sleep among U.S. school-aged children.

METHODS

We analyzed 2018-2019 National Survey of Children's Health data, and included 17,851 children ages 6-11 years. Children were classified into three parent-report TSE groups: (1) did not live with a smoker (no TSE at home); (2) lived with a smoker who did not smoke inside the home (thirdhand smoke (THS) exposure only); and (3) lived with a smoker who smoked inside the home (secondhand smoke (SHS) and THS exposure). Parent-report of inadequate sleep on most weeknights was defined as <9 h, following age-specific national guidelines. We fitted a weighted multivariable logistic model to assess the association between TSE groups and inadequate sleep, adjusting for child covariates (sociodemographics, overweight status, health status, physical activity, and screen time).

RESULTS

About 13% and 1% of school-aged children were exposed to home THS only and home SHS and THS, respectively; approximately 36% overall had inadequate sleep. Compared to children with no TSE at home, children who were exposed to home THS only had higher odds of inadequate sleep (AOR = 1.44, 95%CI = 1.20-1.73); those exposed to home SHS and THS had higher odds of inadequate sleep (AOR = 1.83, 95%CI = 1.20-2.78).

CONCLUSIONS

TSE is associated with school-aged children having inadequate sleep, even when smokers did not smoke inside the home. Promoting parental smoking cessation is essential to fully protect children from related risks.

Sleep disturbances are associated with cortical and subcortical atrophy in alcohol use disorder

Sleep disturbances are prominent in patients with alcohol use disorder (AUD) and predict relapse. So far, the mechanisms underlying sleep disruptions in AUD are poorly understood. Because sleep-related regions vastly overlap with regions, where patients with AUD showed pronounced grey matter (GM) reduction; we hypothesized that GM structure could contribute to sleep disturbances associated with chronic alcohol use. We combined sleep EEG recording and high-resolution structural brain imaging to examine the GM-sleep associations in 36 AUD vs. 26 healthy controls (HC). The patterns of GM-sleep associations differed for N3 vs. REM sleep and for AUD vs. HC. For cortical thickness (CT), CT-sleep associations were significant in AUD but not in HC and were lateralized such that lower CT in right hemisphere was associated with shorter N3, whereas in left hemisphere was associated with shorter REM sleep. For the GM density (GMD), we observed a more extensive positive GMD-N3 association in AUD (right orbitofrontal cortex, cerebellum, dorsal cingulate and occipital cortex) than in HC (right orbitofrontal cortex), and the GMD-REM association was positive in AUD (midline, motor and paralimbic regions) whereas negative in HC (the left supramarginal gyrus). GM structure mediated the effect of chronic alcohol use on the duration of N3 and the age by alcohol effect on REM sleep. Our findings provide evidence that sleep disturbances in AUD were associated with GM reductions. Targeting sleep-related regions might improve sleep in AUD and enhance sleep-induced benefits in cognition and emotional regulation for recovery.

Smoke at night and sleep worse? The associations between cigarette smoking with insomnia severity and sleep duration

OBJECTIVE

Insomnia is a clinically verified nicotine withdrawal symptom. As nicotine is a stimulant, it is plausible that smoking at night could disturb sleep more than smoking at earlier times of the day, but this remains empirically unclear. This study examined smoking status and its associations with insomnia severity and sleep duration while considering the potential role of smoking time.

METHODS

Data were derived from the Sleep and Healthy Activity Diet Environment and Socialization study, a community-based study of 1007 adults (nnonsmokers = 818; nsmokers = 189) aged 22-60 from the Philadelphia area. Smoking status and time of smoking were self-reported. Insomnia was assessed with the Insomnia Severity Index and categorized as none, mild, and moderate-to-severe. Sleep duration was assessed with one item from the National Health and Nutrition Examination Survey and categorized as very short, short, normal, and long. Ordinal and multinomial logistic regressions were used to determine the association of smoking status including smoking time with insomnia severity and sleep duration controlling for sociodemographic covariates.

RESULTS

Compared to nonsmoking, smoking was associated with experiencing increased insomnia (odds ratio = 2.5, 95% confidence interval [CI] 1.9, 3.4, P < .001) as well as very short (relative risk ratio = 1.9, 95% CI 1.1, 3.3) and short (relative risk ratio = 1.5, 95% CI 1.0, 2.3) sleep (vs normal sleep duration). Night-time smoking was significantly associated with greater insomnia and shorter sleep duration.

CONCLUSIONS

Findings provide evidence that smoking is associated with increased insomnia severity and shorter sleep duration, particularly nightly smoking. Sleep health should be considered in smoking cessation efforts.

Smoking and risk of sleep-related issues: a systematic review and meta-analysis of prospective studies

OBJECTIVES

Smoking has many deleterious consequences on health, one of which can be sleep-related issues. Therefore, a meta-analysis was performed with the aim of pooling results from studies on the relationship between smoking and sleep-related issues.

METHODS

The present study follows PRISMA guidelines. Databases were searched by both researchers to find the articles. The review was done up to December 2018. In order to analyze the results of the screened articles, statistical indexes were converted to logarithms and the studies were combined with each other. Finally, several analyses were conducted with respect to various subgroups. In the subgroup analysis, the pool index of the studies was determined and the degree of heterogeneity in each subgroup was presented. Meta-regression was also used.

RESULTS

Smoking is associated with a risk of developing sleep-related issues. Risk ratio (1.47; 1.20-1.79) for smokers was higher than for non-smokers. Egger's test and Begg's test indicated publication bias.

CONCLUSIONS

Smoking is associated with sleep-related issues. Informing smokers about the effects of smoking on sleep issues can be effective in reducing and preventing its consequences.

Sleep Duration and Efficiency Associated With Better Functional Exercise Capacity in Black Smokers at Risk for COPD

BACKGROUND

Black smokers have earlier development of lung disease as well as poorer sleep health than whites.

RESEARCH QUESTION

In a sample of black smokers, to what extent does sleep health modify the association between smoking level and functional exercise capacity?

DESIGN AND METHODS

Cross-sectional data from 209 black smokers (≥ 1 cigarette in last month), aged 40 to 65 years with no evidence of sleep-disordered breathing (apnea-hypopnea index < 15) or severe COPD (FEV₁ > 50%), were used for the current study. Self-reported smoking rate, objectively measured sleep efficiency (SE), total sleep time (TST), and the 6-min walk test (6MWT) for functional exercise capacity were the key assessments.

RESULTS

The mean age was 54.8 years (SD, 5.96), and mean cigarettes smoked per day (cpd) was 8.71 (SD, 6.78). Mean SE was 69.9% (SD, 12.3%), and mean TST was 307.99 min (SD 92.2). In adjusted linear regression models of the 6MWT (meters), TST (slope estimate, -0.14; P = .14) and SE (slope estimate, -1.0; P = .19) were negatively associated with 6MWT. The smoking rate × SE interaction was highly significant (slope estimate, 0.18; P = .007) such that in individuals who smoked ≥ 10 cpd, every additional percentage of SE garnered an additional distance of 0.83 to 6.62 m. Similarly, the smoking rate × TST interaction was significant (slope estimate, 0.019; P = .03) such that in smokers who smoked ≥ 10 cpd, every additional minute of TST garnered an additional distance of 0.04 to 0.60 m.

INTERPRETATION

Higher SE and, to a lesser extent, longer TST, in black adults who smoke ≥ 10 cpd is associated with better 6MWT performance.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT03534076; URL: www.clinicaltrials.gov.

The efficacy of a dose-escalated application of transdermal nicotine plus sulpiride in Tourette’s syndrome

The addition of a dose-escalated regimen of transdermal nicotine patches (TNP) improved tics of a non-smoker patient with Tourette's syndrome, whose tics did not respond to sulpiride. This improvement, as assessed by the Yale Global Tic Severity Scale, lasted for up to 8 weeks, but not 16 weeks. An explanation for the efficacy of TNP is presented.

Apnea-Hypopnea Event Duration Predicts Mortality in Men and Women in the Sleep Heart Health Study

RATIONALE

Obstructive sleep apnea is a risk factor for mortality, but its diagnostic metric-the apnea-hypopnea index-is a poor risk predictor. The apnea-hypopnea index does not capture the range of physiological variability within and between patients, such as degree of hypoxemia and sleep fragmentation, that reflect differences in pathophysiological contributions of airway collapsibility, chemoreceptive negative feedback loop gain, and arousal threshold.

OBJECTIVES

To test whether respiratory event duration, a heritable sleep apnea trait reflective of arousal threshold, predicts all-cause mortality.

METHODS

Mortality risk as a function of event duration was estimated by Cox proportional hazards in the Sleep Heart Health Study, a prospective community-based cohort. Gender-specific hazard ratios were also calculated.

MEASUREMENTS AND MAIN RESULTS

Among 5,712 participants, 1,290 deaths occurred over 11 years of follow-up. After adjusting for demographic factors (mean age, 63 yr; 52% female), apnea-hypopnea index (mean, 13.8; SD, 15.0), smoking, and prevalent cardiometabolic disease, individuals with the shortest-duration events had a significant hazard ratio for all-cause mortality of 1.31 (95% confidence interval, 1.11-1.54). This relationship was observed in both men and women and was strongest in those with moderate sleep apnea (hazard ratio, 1.59; 95% confidence interval, 1.11-2.28).

CONCLUSIONS

Short respiratory event duration, a marker for low arousal threshold, predicts mortality in men and women. Individuals with shorter respiratory events may be predisposed to increased ventilatory instability and/or have augmented autonomic nervous system responses that increase the likelihood of adverse health outcomes, underscoring the importance of assessing physiological variation in obstructive sleep apnea.

Targeting Endotypic Traits with Medications for the Pharmacological Treatment of Obstructive Sleep Apnea. A Review of the Current Literature

Obstructive sleep apnea (OSA) is a highly prevalent condition with few therapeutic options. To date there is no approved pharmacotherapy for this disorder, but several attempts have been made in the past and are currently ongoing to find one. The recent identification of multiple endotypes underlying this disorder has oriented the pharmacological research towards tailored therapies targeting specific pathophysiological traits that contribute differently to cause OSA in each patient. In this review we retrospectively analyze the literature on OSA pharmacotherapy dividing the medications tested on the basis of the four main endotypes: anatomy, upper airway muscle activity, arousal threshold and ventilatory instability (loop gain). We show how recently introduced drugs for weight loss that modify upper airway anatomy may play an important role in the management of OSA in the near future, and promising results have been obtained with drugs that increase upper airway muscle activity during sleep and reduce loop gain. The lack of a medication that can effectively increase the arousal threshold makes this strategy less encouraging, although recent studies have shown that the use of certain sedatives do not worsen OSA severity and could actually improve patients' sleep quality.

Relationships Between Smoking and Sleep Problems in Black and White Adolescents

Study Objectives

The relationship between sleeping and smoking during adolescence remains unclear and is likely complex. We aim to evaluate the longitudinal reciprocal associations between sleep problems, sleep duration, and smoking among non-Hispanic white (NHW) and non-Hispanic black (NHB) youth.

Design

Prospective cohort study.

Setting

NEXT Generation Health Study.

Participants

A national sample (N = 1394) of NHB and NHW 10th graders were surveyed annually between 2009 (Wave 1) and 2012 (Wave 3).

Interventions

N/A.

Measurements and Results

Past 30-day smoking, chronic difficulty falling asleep, recent difficulty falling asleep, difficulty staying asleep, and weekday and weekend sleep duration were measured at each wave. Using structural equation models, we observed significant autocorrelations over time for sleep problems and sleep duration. We found significant reciprocal, prospective relationships between smoking and sleep problems. The strengths of the relationships differed by race, with a stronger association between sleep problems and subsequent smoking for NHB than NHW youth. Conversely, a stronger association between smoking and subsequent sleep problems for NHW than NHB youth was observed. These association were independent of demographics, snoring or sleep apnea, body mass index, depressive symptoms, alcohol use, and soda consumption.

Conclusions

Reciprocal and prospective relationships exist for youth smoking and sleep problems and duration in both NHW and NHB youth. Further research is needed to unravel the complex relationship between the direct effects of nicotine, lifestyle choices that may link smoking and sleep problems, and racial differences.

Transdermal Nicotine Patch Effects on EEG Power Spectra and Heart Rate Variability During Sleep of Healthy Male Adults

OBJECTIVE

The effect of transdermal nicotine patch on sleep physiology is not well established. The current study aimed to examine the influence of nicotine patch on homeostatic sleep propensity and autonomic nervous system.

METHODS

We studied 16 non-smoking young healthy volunteers with nocturnal polysomnography in a double blind crossover design between sleep with and without nicotine patch. We compared the sleep variables, sleep EEG power spectra, and heart rate variability.

RESULTS

The night with nicotine patch showed significant increase in sleep latency, wake after sleep onset, and stage 1 sleep; and decrease in total sleep time, sleep efficiency, and percentage of REM sleep. Also, spectral analysis of the sleep EEG in the night with nicotine patch revealed decreased slow wave activity in stage 2 and REM sleep and increased alpha activity in the first NREM-REM sleep cycle. Heart rate variability showed no differences between the 2 nights, but the low to high ratio (a parameter indicative of sympathetic nervous system activity) positively correlated with wake after sleep onset in night with nicotine patch.

CONCLUSION

Transdermal nicotine patch significantly disrupts sleep continuity, sleep architecture, and homeostatic sleep propensity. The overactivation of the sympathetic nervous system may be responsible for these changes.

Relationships Between Smoking and Sleep Problems in Black and White Adolescents

Study Objectives

The relationship between sleeping and smoking during adolescence remains unclear and is likely complex. We aim to evaluate the longitudinal reciprocal associations between sleep problems, sleep duration, and smoking among non-Hispanic white (NHW) and non-Hispanic black (NHB) youth.

Design

Prospective cohort study.

Setting

NEXT Generation Health Study.

Participants

A national sample (N = 1394) of NHB and NHW 10th graders were surveyed annually between 2009 (Wave 1) and 2012 (Wave 3).

Interventions

N/A.

Measurements and Results

Past 30-day smoking, chronic difficulty falling asleep, recent difficulty falling asleep, difficulty staying asleep, and weekday and weekend sleep duration were measured at each wave. Using structural equation models, we observed significant autocorrelations over time for sleep problems and sleep duration. We found significant reciprocal, prospective relationships between smoking and sleep problems. The strengths of the relationships differed by race, with a stronger association between sleep problems and subsequent smoking for NHB than NHW youth. Conversely, a stronger association between smoking and subsequent sleep problems for NHW than NHB youth was observed. These association were independent of demographics, snoring or sleep apnea, body mass index, depressive symptoms, alcohol use, and soda consumption.

Conclusions

Reciprocal and prospective relationships exist for youth smoking and sleep problems and duration in both NHW and NHB youth. Further research is needed to unravel the complex relationship between the direct effects of nicotine, lifestyle choices that may link smoking and sleep problems, and racial differences.

Impact of concomitant medications on obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is characterized by repeated episodes of apnoea and hypopnoea during sleep. Little is known about the potential impact of therapy drugs on the underlying respiratory disorder. Any influence should be taken into account and appropriate action taken, including drug withdrawal if necessary. Here, we review drugs in terms of their possible impact on OSA; drugs which (1) may worsen OSA; (2) are unlikely to have an impact on OSA; (3) those for which data are scarce or contradictory; and (4) drugs with a potentially improving effect. The level of evidence is ranked according to three grades: A - randomized controlled trials (RCTs) with high statistical power; B - RCTs with lower power, non-randomized comparative studies and observational studies; C - retrospective studies and case reports. Our review enabled us to propose clinical recommendations. Briefly, agents worsening OSA or inducing weight gain, that must be avoided, are clearly identified. Drugs such as 'Z drugs' and sodium oxybate should be used with caution as the literature contains conflicting results. Finally, larger trials are needed to clarify the potential positive impact of certain drugs on OSA. In the meantime, some, such as diuretics or other antihypertensive medications, are helpful in reducing OSA-associated cardiovascular morbidity.

Sleep disturbances among Swedish soldiers after military service abroad

Aims Since 1956, more than 100,000 Swedish soldiers have served abroad on various international missions. The aim of this paper was to determine whether there was a connection between military service abroad and sleep disorders among Swedish soldiers. Methods The prevalence of sleep disturbances among 1,080 veterans from Kosovo and Afghanistan was compared with almost 27,000 Swedes from a general population sample, using propensity score matching and logistic regression. The sleep disturbances studied were habitual snoring, difficulty inducing sleep (DIS), difficulty maintaining sleep (DMS), early morning awakenings (EMA), and excessive daytime sleepiness (EDS). Insomnia was defined as having at least one of DIS, DMS, or EMA. The covariates used in the matching and adjustments were age, gender, smoking habits, BMI, education, ever having had asthma, moist snuff, and exercise habits. Results The veterans had a significantly lower prevalence of insomnia (26.2% versus 30.4%) and EDS (22.7% versus 29.4%) compared with a matched group from the reference population, using propensity score matching. Analyses with logistic regression showed that belonging to the military population was related to a lower risk of having DMS (adjusted OR (95% CI) 0.77 (0.64-0.91)), insomnia (OR 0.82 (0.71-0.95)), and EDS (OR 0.74 (0.63-0.86)), whereas no significant difference was found for snoring, DIS, and EMA. Conclusion Swedish veterans have fewer problems with insomnia and daytime sleepiness than the general Swedish population. The explanation of our findings may be the selection processes involved in becoming a soldier and when sampling personnel for military assignments abroad.

Obstructive sleep apnea: management considerations in psychiatric patients

Psychiatric disorders and obstructive sleep apnea (OSA) are often comorbid. However, there is limited information on the impact of psychotropic medications on OSA symptoms, on how to manage psychiatric pharmacotherapy in patients presenting with OSA, or on the effectiveness and challenges of OSA treatments in patients with comorbid mental illness. As such, the objective of this article is to provide an overview of some epidemiological aspects of OSA and treatment considerations in the management of OSA in individuals with comorbid psychiatric disorders. Predefined keywords were used to search for relevant literature in electronic databases. Data show that OSA is particularly prevalent in patients with psychiatric disorders. The medical care that patients with these comorbidities require can be challenging, as some of the psychiatric medications used by these patients may exacerbate OSA symptoms. As such, continuous positive airway pressure continues to be the first-line treatment, even in patients with psychiatric comorbidity. However, more controlled studies are required, particularly to determine continuous positive airway pressure compliance in patients with mental illness, the impact of treating OSA on psychiatric symptoms, and the impact of the use of psychotropic medications on OSA symptoms.

Where there is smoke…there is sleep apnea: exploring the relationship between smoking and sleep apnea

Smoking and OSA are widely prevalent and are associated with significant morbidity and mortality. It has been hypothesized that each of these conditions adversely affects the other, leading to increased comorbidity while altering the efficacy of existing therapies. However, while the association between smoking and OSA is plausible, the evidence is less than conclusive. Cigarette smoking may increase the severity of OSA through alterations in sleep architecture, upper airway neuromuscular function, arousal mechanisms, and upper airway inflammation. Conversely, some evidence links untreated OSA with smoking addiction. Smoking cessation should improve OSA, but the evidence to support this is also limited. This article reviews the current evidence linking both conditions and the efficacy of various treatments. Limitations of the current evidence and areas in need of future investigation are also addressed.

Medication effects on sleep and breathing

Sleep respiration is regulated by circadian, endocrine, mechanical and chemical factors, and characterized by diminished ventilatory drive and changes in Pao2 and Paco2 thresholds. Hypoxemia and hypercapnia are more pronounced during rapid eye movement. Breathing is influenced by sleep stage and airway muscle tone. Patient factors include medical comorbidities and body habitus. Medications partially improve obstructive sleep apnea and stabilize periodic breathing at altitude. Potential adverse consequences of medications include precipitation or worsening of disorders. Risk factors for adverse medication effects include aging, medical disorders, and use of multiple medications that affect respiration.

Impaired sleep quality and sleep duration in smokers-results from the German Multicenter Study on Nicotine Dependence

Cigarette smoking is a severe health burden being related to a number of chronic diseases. Frequently, smokers report about sleep problems. Sleep disturbance, in turn, has been demonstrated to be involved in the pathophysiology of several disorders related to smoking and may be relevant for the pathophysiology of nicotine dependence. Therefore, determining the frequency of sleep disturbance in otherwise healthy smokers and its association with degree of nicotine dependence is highly relevant. In a population-based case-control study, 1071 smokers and 1243 non-smokers without lifetime Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Axis I disorder were investigated. Sleep quality (SQ) of participants was determined by the Pittsburgh Sleep Quality Index. As possible confounders, age, sex and level of education and income, as well as depressiveness, anxiety, attention deficit hyperactivity, alcohol drinking behaviour and perceived stress, were included into multiple regression analyses. Significantly more smokers than non-smokers (28.1% versus 19.1%; P < 0.0001) demonstrated a disturbed global SQ. After controlling for the confounders, impaired scores in the component scores of sleep latency, sleep duration and global SQ were found significantly more often in smokers than non-smokers. Consistently, higher degrees of nicotine dependence and intensity of smoking were associated with shorter sleep duration. This study demonstrates for the first time an elevated prevalence of sleep disturbance in smokers compared with non-smokers in a population without lifetime history of psychiatric disorders even after controlling for potentially relevant risk factors. It appears likely that smoking is a behaviourally modifiable risk factor for the occurrence of impaired SQ and short sleep duration.

Update on obstructive sleep apnea and its relation to COPD

Chronic obstructive pulmonary disease (COPD) is a common and preventable lung disease that affects millions of people in the United States. Sleep disorders including obstructive sleep apnea (OSA) are also common. It is not surprising that many people with COPD also suffer from OSA. This relationship, however, puts people at risk for more nocturnal desaturations and potential complications related to this, including pulmonary hypertension and heart rhythm disturbances. This update focuses on the physiology of sleep disturbances in COPD as well as the clinical implications of OSA in COPD.

Interactions between disordered sleep, post-traumatic stress disorder, and substance use disorders

Disordered sleep is associated with a number of adverse health consequences and is an integral component of many psychiatric disorders. Rates of substance use disorders (SUDs) are markedly higher among individuals with post-traumatic stress disorder (PTSD), and this relationship may be partly mediated by disturbed sleep. Sleep disturbances (e.g. insomnia, daytime sleepiness, vivid nightmares) are hallmark features of PTSD and there is evidence that individuals with PTSD engage in substance use as a means of coping with these symptoms. However, prolonged substance use can lead to more severe sleep disturbances due to the development of tolerance and withdrawal. Behavioural or pharmacological treatment of disordered sleep is associated with improved daytime symptoms and psychosocial functioning among individuals who have developed PTSD. Initial research also suggests that improving sleep could be similarly beneficial in reducing coping oriented substance use and preventing relapse among those seeking treatment for SUDs. Together, these findings suggest that ameliorating sleep disturbance among at-risk individuals would be a viable target for the prevention and treatment of PTSD and associated SUDs, but prospective research is needed to examine this hypothesis. Enhanced understanding of the interrelation between sleep, PTSD, and SUDs may yield novel prevention and intervention approaches for these costly, prevalent and frequently co-occurring disorders.

Outcomes from a patient-centered residential treatment plan for tobacco dependence

St. Helena Hospital launched the first US residential stop-smoking program, The St. Helena Center for a Smoke-Free Life, in 1969. This observational report describes the center's treatment outcome rate for using a patient-centered approach to the use of tobacco dependence medications and behavioral treatment for patients who participated in the program from January 1, 2005 through December 31, 2007. A total of 284 patients used long-acting (nicotine patch, bupropion, and varenicline) and/or short-acting medications (nicotine nasal spray, nicotine gum, nicotine lozenge, and nicotine oral inhaler) alone or in combination during treatment and after discharge. Seven patients chose to use no medications. Patients using nicotine patch received a mean ± SD dose of 33.3±15.7 mg of nicotine in 16 hours (range, 5-90 mg). The 12-month 7-day point prevalence smoking abstinence rate after participation in the intensive, 1-week, residential program was 57.0%. Recommendations are discussed for future research and for implementing aspects of the St. Helena program in other treatment settings.

Drug therapy for obstructive sleep apnoea in adults

BACKGROUND

The treatment of choice for moderate to severe obstructive sleep apnoea (OSA) is continuous positive airways pressure (CPAP) applied via a mask during sleep. However, this is not tolerated by all individuals and its role in mild OSA is not proven. Drug therapy has been proposed as an alternative to CPAP in some patients with mild to moderate sleep apnoea and could be of value in patients intolerant of CPAP. A number of mechanisms have been proposed by which drugs could reduce the severity of OSA. These include an increase in tone in the upper airway dilator muscles, an increase in ventilatory drive, a reduction in the proportion of rapid eye movement (REM) sleep, an increase in cholinergic tone during sleep, an increase in arousal threshold, a reduction in airway resistance and a reduction in surface tension in the upper airway.

OBJECTIVES

To determine the efficacy of drug therapies in the specific treatment of sleep apnoea.

SEARCH METHODS

We searched the Cochrane Airways Group Specialised Register of trials. Searches were current as of July 2012.

SELECTION CRITERIA

Randomised, placebo controlled trials involving adult patients with confirmed OSA. We excluded trials if continuous positive airways pressure, mandibular devices or oxygen therapy were used. We excluded studies investigating treatment of associated conditions such as excessive sleepiness, hypertension, gastro-oesophageal reflux disease and obesity.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by The Cochrane Collaboration.

MAIN RESULTS

Thirty trials of 25 drugs, involving 516 participants, contributed data to the review. Drugs had several different proposed modes of action and the results were grouped accordingly in the review. Each of the studies stated that the participants had OSA but diagnostic criteria were not always explicit and it was possible that some patients with central apnoeas may have been recruited.Acetazolamide, eszopiclone, naltrexone, nasal lubricant (phosphocholinamine) and physiostigmine were administered for one to two nights only. Donepezil in patients with and without Alzheimer's disease, fluticasone in patients with allergic rhinitis, combinations of ondansetrone and fluoxetine and paroxetine were trials of one to three months duration, however most of the studies were small and had methodological limitations. The overall quality of the available evidence was low.The primary outcomes for the systematic review were the apnoea hypopnoea index (AHI) and the level of sleepiness associated with OSA, estimated by the Epworth Sleepiness Scale (ESS). AHI was reported in 25 studies and of these 10 showed statistically significant reductions in AHI.Fluticasone in patients with allergic rhinitis was well tolerated and reduced the severity of sleep apnoea compared with placebo (AHI 23.3 versus 30.3; P < 0.05) and improved subjective daytime alertness. Excessive sleepiness was reported to be altered in four studies, however the only clinically and statistically significant change in ESS of -2.9 (SD 2.9; P = 0.04) along with a small but statistically significant reduction in AHI of -9.4 (SD 17.2; P = 0.03) was seen in patients without Alzheimer's disease receiving donepezil for one month. In 23 patients with mild to moderate Alzheimer's disease donepezil led to a significant reduction in AHI (donepezil 20 (SD 15) to 9.9 (SD 11.5) versus placebo 23.2 (SD 26.4) to 22.9 (SD 28.8); P = 0.035) after three months of treatment but no reduction in sleepiness was reported. High dose combined treatment with ondansetron 24 mg and fluoxetine 10 mg showed a 40.5% decrease in AHI from the baseline at treatment day 28. Paroxetine was shown to reduce AHI compared to placebo (-6.10 events/hour; 95% CI -11.00 to -1.20) but failed to improve daytime symptoms.Promising results from the preliminary mirtazapine study failed to be reproduced in the two more recent multicentre trials and, moreover, the use of mirtazapine was associated with significant weight gain and sleepiness. Few data were presented on the long-term tolerability of any of the compounds used.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend the use of drug therapy in the treatment of OSA. Small studies have reported positive effects of certain agents on short-term outcomes. Certain agents have been shown to reduce the AHI in largely unselected populations with OSA by between 24% and 45%. For donepezil and fluticasone, studies of longer duration with a larger population and better matching of groups are required to establish whether the change in AHI and impact on daytime symptoms are reproducible. Individual patients had more complete responses to particular drugs. It is possible that better matching of drugs to patients according to the dominant mechanism of their OSA will lead to better results and this also needs further study.

Orexin receptors in the developing piglet hypothalamus, and effects of nicotine and intermittent hypercapnic hypoxia exposures

Orexin and its receptors (OxR1 and OxR2) play a significant role in arousal and sleep regulation. Using developing piglets, we aimed to determine the effects of nicotine and Intermittent Hypercapnic Hypoxia (IHH), alone or in combination, on orexin receptor expression in the hypothalamus. Four piglet groups were studied: control (n=14), nicotine (n=14), IHH (n=10) and nic+IHH (n=14). Applying immunohistochemistry for OxR1 and OxR2 expression, eight nuclei/areas of the hypothalamus: dorsal medial nucleus (DMN), arcuate nucleus (ARC), perifornical area (PFA), paraventricular nucleus (PVN), lateral hypothalamic area (LHA), ventral medial nucleus (VMN), supraoptic nucleus, retrochiasmatic part (SONr) and tuberal mammillary nucleus (TMN), were studied. Compared to controls, OxR1 and OxR2 were increased due to exposures, however this was region dependent. Nicotine increased OxR1 in the DMN (P<0.001) and SONr (P=0.036), and OxR2 in the DMN (P<0.001), VMN (P=0.014) and the TMN (P=0.026). IHH increased OxR1 in the DMN, PVN, VMN and SONr (P<0.01 for all), and OxR2 in DMN (P<0.001), PFA (P=0.001), PVN (P=0.004), VMN (P=0.041) and the TMN (P<0.001). The nic+IHH exposure increased OxR1 expression in all nuclei (TMN excluded) however, the changes were not significantly different from IHH alone. For OxR2, the increased expression after nic+IHH was significant compared to IHH in the DMN, ARC and SONr. These results show that nicotine increases orexin receptor expression in a region dependent manner. IHH induced increases were specific to arousal and stress related regions and nic+IHH results suggest that for OxR1, nicotine has no additive effect whereas for OxR2 it does, and is region dependent.

Asthma symptoms and nasal congestion as independent risk factors for insomnia in a general population: results from the GA(2)LEN survey

BACKGROUND

Asthma and rhinitis have been related to insomnia. The aim of this study was to further analyse the association between asthma, nasal symptoms and insomnia and to identify risk factors for sleep disturbance among patients with asthma, in a large population-based set of material.

METHOD

In 2008, a postal questionnaire was sent to a random sample of 45 000 adults in four Swedish cities. The questionnaire included questions on insomnia, asthma, rhinitis, weight, height, tobacco use and physical activity.

RESULTS

Twenty-five thousand six hundred and ten subjects participated. Asthma was defined as either current medication for asthma or at least one attack of asthma during the last 12 months, and 1830 subjects (7.15%) were defined as asthmatics. The prevalence of insomnia symptoms was significantly higher among asthmatics than non-asthmatics (47.3% vs 37.2%, <0.0001). In the subgroup reporting both asthma and nasal congestion, 55.8% had insomnia symptoms compared with 35.3% in subjects without both asthma and nasal congestion. The risk of insomnia increased with the severity of asthma, and the adjusted OR for insomnia was 2.65 in asthmatics with three symptoms compared with asthmatics without symptoms. Nasal congestion (OR 1.50), obesity (OR 1.54) and smoking (OR 1.71) also increased the risk of insomnia.

CONCLUSION

Insomnia remains a common problem among asthmatics. Uncontrolled asthma and nasal congestion are important, treatable risk factors for insomnia. Lifestyle factors, such as smoking and obesity, are also risk factors for insomnia among asthmatics.

Narcolepsy with cataplexy masked by the use of nicotine

This report describes a case of narcolepsy with cataplexy masked by the chronic use of cigarettes and nicotine patches. It has been described that narcoleptic smokers report relief of symptoms by smoking tobacco cigarettes. In addition, a case describing partial treatment of sleepiness using a nicotine patch in an adolescent with narcolepsy was recently reported in this journal. Our case adds to the growing literature that nicotine may be used to manage symptoms associated with narcolepsy.

Sleep neurobiology from a clinical perspective

Many neurochemical systems interact to generate wakefulness and sleep. Wakefulness is promoted by neurons in the pons, midbrain, and posterior hypothalamus that produce acetylcholine, norepinephrine, dopamine, serotonin, histamine, and orexin/hypocretin. Most of these ascending arousal systems diffusely activate the cortex and other forebrain targets. NREM sleep is mainly driven by neurons in the preoptic area that inhibit the ascending arousal systems, while REM sleep is regulated primarily by neurons in the pons, with additional influence arising in the hypothalamus. Mutual inhibition between these wake- and sleep-regulating regions likely helps generate full wakefulness and sleep with rapid transitions between states. This up-to-date review of these systems should allow clinicians and researchers to better understand the effects of drugs, lesions, and neurologic disease on sleep and wakefulness.

Associations between secondhand smoke exposure and sleep patterns in children

OBJECTIVES

The objective of this study was to investigate the relationship between exposure to secondhand smoke (SHS) and child sleep patterns among a group of children with asthma who were exposed regularly to tobacco smoke at home.

METHODS

We studied 219 children who were enrolled in an asthma intervention trial and were exposed regularly to SHS. Serum cotinine levels were used to measure exposure to tobacco smoke, and sleep patterns were assessed through parent reports using the Children's Sleep Habits Questionnaire. Covariates in adjusted analyses included gender, age, race, maternal marital status, education, and income, prenatal tobacco exposure, maternal depression, Home Observation for Measurement of the Environment total score, household density, asthma severity, and use of asthma medications.

RESULTS

Exposure to SHS was associated with sleep problems, including longer sleep-onset delay (P = .004), sleep-disordered breathing (P = .02), parasomnias (P = .002), daytime sleepiness (P = .022), and overall sleep disturbance (P = .0002).

CONCLUSIONS

We conclude that exposure to SHS is associated with increased sleep problems among children with asthma.

Pathophysiology of sleep apnea

Sleep-induced apnea and disordered breathing refers to intermittent, cyclical cessations or reductions of airflow, with or without obstructions of the upper airway (OSA). In the presence of an anatomically compromised, collapsible airway, the sleep-induced loss of compensatory tonic input to the upper airway dilator muscle motor neurons leads to collapse of the pharyngeal airway. In turn, the ability of the sleeping subject to compensate for this airway obstruction will determine the degree of cycling of these events. Several of the classic neurotransmitters and a growing list of neuromodulators have now been identified that contribute to neurochemical regulation of pharyngeal motor neuron activity and airway patency. Limited progress has been made in developing pharmacotherapies with acceptable specificity for the treatment of sleep-induced airway obstruction. We review three types of major long-term sequelae to severe OSA that have been assessed in humans through use of continuous positive airway pressure (CPAP) treatment and in animal models via long-term intermittent hypoxemia (IH): 1) cardiovascular. The evidence is strongest to support daytime systemic hypertension as a consequence of severe OSA, with less conclusive effects on pulmonary hypertension, stroke, coronary artery disease, and cardiac arrhythmias. The underlying mechanisms mediating hypertension include enhanced chemoreceptor sensitivity causing excessive daytime sympathetic vasoconstrictor activity, combined with overproduction of superoxide ion and inflammatory effects on resistance vessels. 2) Insulin sensitivity and homeostasis of glucose regulation are negatively impacted by both intermittent hypoxemia and sleep disruption, but whether these influences of OSA are sufficient, independent of obesity, to contribute significantly to the "metabolic syndrome" remains unsettled. 3) Neurocognitive effects include daytime sleepiness and impaired memory and concentration. These effects reflect hypoxic-induced "neural injury." We discuss future research into understanding the pathophysiology of sleep apnea as a basis for uncovering newer forms of treatment of both the ventilatory disorder and its multiple sequelae.

Approaches to measuring the effects of wake-promoting drugs: a focus on cognitive function

OBJECTIVES

In clinical drug development, wakefulness and wake-promotion may be assessed by a large number of scales and questionnaires. Objective assessment of wakefulness is most commonly made using sleep latency/maintenance of wakefulness tests, polysomnography and/or behavioral measures. The purpose of the present review is to highlight the degree of overlap in the assessment of wakefulness and cognition, with consideration of assessment techniques and the underlying neurobiology of both concepts.

DESIGN

Reviews of four key areas were conducted: commonly used techniques in the assessment of wakefulness; neurobiology of sleep/wake and cognition; targets of wake promoting and/or cognition enhancing drugs; and ongoing clinical trials investigating wake promoting effects.

RESULTS

There is clear overlap between the assessment of wakefulness and cognition. There are common techniques which may be used to assess both concepts; aspects of the neurobiology of both concepts may be closely related; and wake-promoting drugs may have nootropic properties (and vice versa). Clinical trials of wake-promoting drugs often, though not routinely, assess aspects of cognition.

CONCLUSIONS

Routine and broad assessment of cognition in the development of wake-promoting drugs may reveal important nootropic effects, which are not secondary to alertness/wakefulness, whilst existing cognitive enhancers may have underexplored or unknown wake promoting properties.