Evidence for Genetic Correlations and Bidirectional, Causal Effects Between Smoking and Sleep Behaviors

Network analysis of smoking-related sleep characteristics in Chinese adults

The associations between multiple sleep characteristics and smoking behavior are inconsistent, and it is unclear which sleep characteristics are most crucial for tobacco prevention. This study aimed to explore the associations between smoking status/intensity and multiple sleep characteristics and to identify the potential core domain of smoking-related sleep using network analysis. Data were obtained from a survey of cancer-related risk factors among Chinese adults. Logistic regression models were used to quantify the associations between sleep characteristics and smoking status/intensity. Network analyses were employed to identify the core sleep characteristics. A total of 5,228 participants with a median age of 44 years old were included in the study. Current smoking was significantly positively associated with long nap time, difficulty falling asleep, late bedtime, getting up after 7 am, and waking up earlier than expected. There was significant positive association between current smoking and short sleep duration in young adults under 45 years old. Late bedtime and getting up after 7 am were only associated with current heavy smoking, but not current light smoking. Network analyses showed that multiple smoking-related sleep characteristics were interconnected, with difficulty falling asleep and late bedtime as central characteristics in the network. The study found that the associations between sleep characteristics and smoking varied by age and smoking intensity and highlights the potential benefits of sleep health promotion in smoking cessation, with a particular focus on difficulty falling asleep and late bedtime.

Causal relationship between insomnia and thyroid disease: A bidirectional Mendelian randomization study

OBJECTIVE

Some correlations between thyroid disorders and insomnia have been found in previous studies; however, the causal relationship between them is unclear. The aim of this study was to investigate the causal relationship between insomnia and five thyroid disorders (hyperthyroidism, hypothyroidism, thyroiditis, thyroid nodules, and thyroid cancer).

METHODS

We assessed the causal relationship between insomnia and thyroid disorders using inverse variance weighted, weighted median, and Mendelian randomization (MR)-Egger analyses in MR analyses and then used inverse MR analyses to assess the causal relationship between thyroid disorders and insomnia.

RESULTS

MR analysis showed that insomnia did not increase the risk of hyperthyroidism, hypothyroidism, thyroiditis, thyroid nodules, and thyroid cancer. However, reverse MR analysis showed that thyroid cancer increased the risk of insomnia (OR = 1.01, 95%CI: 1.00-1.02, p = .01), and the other four thyroid disorders had no direct causal relationship with insomnia. Sensitivity analyses indicated that the results were robust and no pleiotropy or heterogeneity was detected.

CONCLUSION

This study did not find evidence of a bidirectional causal relationship between genetically predicted insomnia and hyperthyroidism, hypothyroidism, thyroiditis, and thyroid nodules. However, we found that although insomnia does not increase the risk of thyroid cancer, thyroid cancer does increase the risk of insomnia.

Behavioral Sleep Interventions and Cardiovascular Risk Factors: Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND/OBJECTIVES

Chronic sleep disturbance has been consistently associated with cardiovascular disease. We sought to determine whether behavioral interventions to improve sleep have been associated with improvements in 4 common cardiovascular disease risk factors: hypertension, diabetes mellitus (DM), obesity, and smoking.

METHODS

Randomized controlled trials evaluating the prospective effect of behavioral sleep interventions on ( a ) blood pressure in participants with hypertension/prehypertension, ( b ) glycemic control in participants with DM/pre-DM, ( c ) anthropometrics in participants who were overweight/obese, and ( d ) smoking status in smokers were eligible. Where feasible, we undertook random-effects meta-analyses of standardized mean differences in cardiovascular disease risk factor change.

RESULTS

Overall, 3 trials met the inclusion criteria for blood pressure, 4 for glycemic control, 9 for overweight/obesity, and 2 for smoking. On meta-analysis, interventions with sleep as the sole behavioral target were associated with a significant reduction in hemoglobin A 1c % (-0.84; 95% confidence interval [CI], -1.34 to -0.34), but not a significant reduction in systolic blood pressure (-0.18; 95% CI, -0.55 to 0.20) versus controls. In addition, any interventions with sleep as a behavioral target were associated with significant reductions in hemoglobin A 1c % (-0.71; 95% CI, -1.01 to -0.42) and weight (-0.78; 95% CI, -1.11 to -0.45), but not systolic blood pressure (-0.72; 95% CI, -1.82 to 0.37). Trials evaluating smoking status were not amenable to meta-analysis.

CONCLUSION

Behavioral interventions to improve sleep were associated with improved glycemic control in patients with DM. It is also possible that these interventions improve weight in individuals who were overweight/obese. A low number of trials and small sample sizes indicate that further large, well-designed randomized controlled trials of interventions are warranted.

The Interactions between Smoking and Sleep

Smoking a cigarette before bed or first thing in the morning is a common habit. In this review, the relationship between smoking and sleep is investigated based on the existing literature. Out of 6504 unique items that were identified via a PubMed search related to smoking and sleep, 151 were included in this review. Tobacco smoking disrupts sleep architecture by reducing slow wave and rapid eye movement (REM) sleep and undermining sleep quality. Furthermore, smoking affects sleep-related co-morbidities, such as obstructive sleep apnea-hypopnea syndrome (OSAHS), insomnia, parasomnias, arousals, bruxism, and restless legs, as well as non-sleep-related conditions such as cardiovascular, metabolic, respiratory, neurologic, psychiatric, inflammatory, gynecologic and pediatric issues, while poor sleep quality also seems to worsen the chances of successful smoking cessation. In conclusion, the existing literature suggests that there is a wicked relation between smoking and sleep.

Insomnia symptom prevalence in England: a comparison of cross-sectional self-reported data and primary care records in the UK Biobank

OBJECTIVES

We aimed to use a large dataset to compare self-reported and primary care measures of insomnia symptom prevalence in England and establish whether they identify participants with similar characteristics.

DESIGN

Cross-sectional study with linked electronic health records (EHRs).

SETTING

Primary care in England.

PARTICIPANTS

163 748 UK Biobank participants in England (aged 38-71 at baseline) with linked primary care EHRs.

OUTCOME MEASURES

We compared the percentage of those self-reporting 'usually' having insomnia symptoms at UK Biobank baseline assessment (2006-2010) to those with a Read code for insomnia symptoms in their primary care records prior to baseline. We stratified prevalence in both groups by sociodemographic, lifestyle, sleep and health characteristics.

RESULTS

We found that 29% of the sample self-reported having insomnia symptoms, while only 6% had a Read code for insomnia symptoms in their primary care records. Only 10% of self-reported cases had an insomnia symptom Read code, while 49% of primary care cases self-reported having insomnia symptoms. In both primary care and self-reported data, prevalence of insomnia symptom cases was highest in females, older participants and those with the lowest household incomes. However, while snorers and risk takers were more likely to be a primary care case, they were less likely to self-report insomnia symptoms than non-snorers and non-risk takers.

CONCLUSIONS

Only a small proportion of individuals experiencing insomnia symptoms have an insomnia symptom Read code in their primary care record. However, primary care data do provide a clinically meaningful measure of insomnia prevalence. In addition, the sociodemographic characteristics of people attending primary care with insomnia were consistent with those with self-reported insomnia, thus primary care records are a valuable data source for studying risk factors for insomnia. Further studies should replicate our findings in other populations and examine ways to increase discussions about sleep health in primary care.

Insomnia and parasomnia induced by validated smoking cessation pharmacotherapies and electronic cigarettes: a network meta-analysis

We aim to assess the relationship between validated smoking cessation pharmacotherapies and electronic cigarettes (e-cigarettes) and insomnia and parasomnia using a systematic review and a network meta-analysis. A systematic search was performed until August 2022 in the following databases: PUBMED, COCHRANE, CLINICALTRIAL. Randomized controlled studies against placebo or validated therapeutic smoking cessation methods and e-cigarettes in adult smokers without unstable or psychiatric comorbidity were included. The primary outcome was the presence of "insomnia" and "parasomnia." A total of 1261 studies were selected. Thirty-seven studies were included in the quantitative analysis (34 for insomnia and 23 for parasomnia). The reported interventions were varenicline (23 studies), nicotine replacement therapy (NRT, 10 studies), bupropion (15 studies). No studies on e-cigarettes were included. Bayesian analyses found that insomnia and parasomnia are more frequent with smoking cessation therapies than placebo except for bupropion. Insomnia was less frequent with nicotine substitutes but more frequent with bupropion than the over pharmacotherapies. Parasomnia are less frequent with bupropion but more frequent with varenicline than the over pharmacotherapies. Validated smoking cessation pharmacotherapies can induce sleep disturbances with different degrees of frequency. Our network meta-analysis shows a more favorable profile of nicotine substitutes for insomnia and bupropion for parasomnia. It seems essential to systematize the assessment of sleep disturbances in the initiation of smoking cessation treatment. This could help professionals to personalize the choice of treatment according to sleep parameters of each patient. Considering co-addictions, broadening the populations studied and standardizing the measurement are additional avenues for future research.

Association of the combination of obstructive sleep apnea risk and sleep duration with ideal cardiovascular health metrics in patients undergoing hemodialysis

BACKGROUND

The purpose of this study was to explore the separate and combined associations of obstructive sleep apnea (OSA) risk and sleep duration with ideal cardiovascular health metrics in hemodialysis (HD) patients.

METHODS

470 HD participants (average: 59.48 ± 12.89 y, 281 men) were included in this study. Sleep duration was measured as self-reported average sleep time during the previous month. The OSA risk was assessed using the STOP-BANG questionnaire. Participants were divided into three groups based on the number of ideal cardiovascular health (CVH) metrics: 0-2,3-4, and 5-7. Ordinal logistic regression was conducted to model the associations of CVH metrics with sleep duration, OSA risk, and their combined effects by adjusting for specific covariates.

RESULTS

After adjusting for covariates, short sleep duration (< 7 h) (OR = 0.53; 95% CI [ 0.30, 0.92]) and OSA risk (OR = 0.58; 95% CI [0.32, 0.83]) were negatively associated with better CVH (ideal vs. intermediate; intermediate vs. poor), respectively. For HD patients with both short sleep duration and OSA risk, the odds of ideal CVH metrics were reduced by 72% (odds ratio 0.28 [95% CI 0.13, 0.60]).

CONCLUSIONS

Short sleep duration and OSA risk are separately and jointly associated with poor CVH in hemodialysis patients. Suitable interventions for sleep may minimize the risk of developing cardiovascular disease.

Sleep Health at the Genomic Level: Six Distinct Factors and Their Relationships With Psychopathology

Background

Poor sleep is associated with many negative health outcomes, including multiple dimensions of psychopathology. In the past decade, sleep researchers have advocated for focusing on the concept of sleep health as a modifiable health behavior to mitigate or prevent these outcomes. Sleep health dimensions often include sleep efficiency, duration, satisfaction, regularity, timing, and daytime alertness. However, there is no consensus on how to best operationalize sleep health at the phenotypic and genetic levels. In some studies, specific sleep health domains were examined individually, while in others, sleep health domains were examined together (e.g., with an aggregate sleep health score).

Methods

Here, we compared alternative sleep health factor models using genomic structural equation modeling on summary statistics from previously published genome-wide association studies of self-reported and actigraphic sleep measures with effective sample sizes up to 452,633.

Results

Our best-fitting sleep health model had 6 correlated genetic factors pertaining to 6 sleep health domains: circadian preference, efficiency, alertness, duration, noninsomnia, and regularity. All sleep health factors were significantly correlated (|rgs| = 0.11-0.51), except for the circadian preference factor with duration and noninsomnia. Better sleep health was generally significantly associated with lower genetic liability for psychopathology (|rgs| = 0.05-0.48), yet the 6 sleep health factors showed divergent patterns of associations with different psychopathology factors, especially when controlling for covariance among the sleep health factors.

Conclusions

These results provide evidence for genetic separability of sleep health constructs and their differentiation with respect to associations with mental health.

Identifying the potential causal role of insomnia symptoms on 11,409 health-related outcomes: a phenome-wide Mendelian randomisation analysis in UK Biobank

BACKGROUND

Insomnia symptoms are widespread in the population and might have effects on many chronic conditions and their risk factors but previous research has focused on select hypothesised associations/effects rather than taking a systematic hypothesis-free approach across many health outcomes.

METHODS

We performed a Mendelian randomisation (MR) phenome-wide association study (PheWAS) in 336,975 unrelated white-British UK Biobank participants. Self-reported insomnia symptoms were instrumented by a genetic risk score (GRS) created from 129 single-nucleotide polymorphisms (SNPs). A total of 11,409 outcomes from UK Biobank were extracted and processed by an automated pipeline (PHESANT) for the MR-PheWAS. Potential causal effects (those passing a Bonferroni-corrected significance threshold) were followed up with two-sample MR in MR-Base, where possible.

RESULTS

Four hundred thirty-seven potential causal effects of insomnia symptoms were observed for a diverse range of outcomes, including anxiety, depression, pain, body composition, respiratory, musculoskeletal and cardiovascular traits. We were able to undertake two-sample MR for 71 of these 437 and found evidence of causal effects (with directionally concordant effect estimates across main and sensitivity analyses) for 30 of these. These included novel findings (by which we mean not extensively explored in conventional observational studies and not previously explored using MR based on a systematic search) of an adverse effect on risk of spondylosis (OR [95%CI] = 1.55 [1.33, 1.81]) and bronchitis (OR [95%CI] = 1.12 [1.03, 1.22]), among others.

CONCLUSIONS

Insomnia symptoms potentially cause a wide range of adverse health-related outcomes and behaviours. This has implications for developing interventions to prevent and treat a number of diseases in order to reduce multimorbidity and associated polypharmacy.

Factors associated with poor sleep quality in patients with pre-dialysis chronic kidney disease: A systematic review

AIMS

To determine factors associated with poor sleep quality among patients with pre-dialysis chronic kidney disease.

DESIGN

This is a systematic review study guided by Preferred Reporting Items for Systematic Reviews and Meta-Analyses statements and checklist.

DATA SOURCES

Empirical evidence was sought in major electronic databases, including Embase, MEDLINE, CINAHL and Airiti library from March to September 2022.

REVIEW METHODS

Studies investigating factors associated with poor sleep quality among adult patients with chronic kidney disease were included. Study participants who received renal replacement therapy and had sleep disorders and serious illnesses such as cancer were excluded. Of the 526 studies that resulted from the search after removing duplicate articles, 20 studies were assessed for quality by using Joanna Briggs Institute and Newcastle-Ottawa Scale by two doctorial prepared nursing scientists.

RESULTS

A total of 20 studies were included in this review. The prevalence of poor sleep quality in these studies ranged from 11% to 97.5%. Demographics (older age and female), physiological conditions (higher body mass index, higher hip circumferences, higher systolic blood pressure, poor cardiovascular function, dyspnoea, pain, cramps, itchiness or moderate to extreme pruritus, lower fasting plasma glucose, electrolyte imbalance, higher total cholesterol and gastrointestinal symptoms), depression, smoking, arousal-related and cognitive arousal behaviours were associated with poor sleep quality.

CONCLUSION

Poor sleep quality was prevalent and influenced kidney function, increased mortality as well as decreased quality of life in patients with pre-dialysis chronic kidney disease. This review synthesizes factors associated with poor sleep quality. Managing these factors can mitigate and prevent poor sleep quality.

IMPACT

Healthcare providers, especially nurses, can assess the risk factors of poor sleep quality and reinforce patients' self-management. Future research should elucidate the assessment and management of risk factors and transfer these into widespread use in the routine care of patients with chronic kidney disease.

Tobacco use and incident sleep parameters among a rural ageing population in South Africa

INTRODUCTION

Tobacco use may be associated with incident insomnia. The aim of the study was to investigate the association between tobacco use and incident sleep parameters in a longitudinal study in South Africa.

METHODS

Longitudinal data from two consecutive waves of middle-aged and older adults in 2014-2015 (n=5059) and 2018-2019 (n=4176) in rural South Africa were analyzed. Tobacco use and sleep parameters were assessed by self-report. The associations between tobacco use and incident sleep parameters were estimated with multivariable logistic regression.

RESULTS

The prevalence of baseline sleep parameters was poor sleep quality 6.5%, sleep disturbance 13.6%, restless sleep 32.9%, and breathing stops 7.0%. In the fully adjusted model for people without poor sleep quality at baseline, daily tobacco smoking, smoking ≥10 units of tobacco products, current tobacco use and current smokeless tobacco use did not increase the odds of incident poor sleep quality. Smoking ≥10 units of tobacco products in a day (AOR=3.83; 95% CI: 1.77-8.28), current tobacco use (AOR=1.65; 95% CI: 1.09-2.51), and daily tobacco smoking (AOR=2.16; 95% CI: 1.15-4.07), were significantly positively associated with incident sleep disturbance. Furthermore, incident restless sleep was significantly positively associated with smoking ≥10 units of tobacco products in a day (AOR=3.97; 95% CI: 1.18-13.37), current smokeless tobacco use (AOR=2.78; 95% CI: 1.17-6.62) and current tobacco use (AOR=2.00; 95% CI: 1.00-4.00). Incident breathing stops were significantly positively associated with daily smoking tobacco (AOR=2.08; 95% CI: 1.11-3.34), smoking 1-9 units of tobacco products in a day (AOR=2.17; 95% CI: 1.20-3.94), and current tobacco use (AOR=1.77; 95% CI: 1.16-2.72).

CONCLUSIONS

Higher tobacco use was independently associated with incident sleep disturbance, incident restless sleep, and incident breathing stops, but not with incident poor sleep quality.

The circadian preferences in the context of sociodemographic indicators and lifestyle

Circadian preferences are frequently used as a synonym for chronotype. Both terms are based on different principles and are measured by a variant questionnaire. We focused on circadian preferences, delimited as an individual preference for the timing of various activities, and their relationship to the selected sociodemographic factors. All participants (n = 2068) filled out online questionnaires including MEQ, MCTQ, and sociodemographic information (age, sex, place of residence, marital status, childcare, education, financial security, physical and mental health). Although the concept of chronotype and circadian preference differ, the mutual correlation was high. Our results of the observed variables are similar to other studies. We revealed evening preference is related to a higher probability of living in a big city, having a single life, a higher risk of smoking, worse health status, and worse financial security. We observed a higher social jet lag among them. Our research complies with previous studies, which found that in some areas, people with evening preferences evince worse results. Due to the evening preference, these people are at a disadvantage, and the society's setting for morning operations can lead to a deepening of these differences. We recommend further research, which would focus on the practical application of results to the everyday life of participants to create preventive programs aimed at reducing the negative impact of evening preferences on life.

Insomnia Severity Mediates the Association between COVID-19 Related Anxiety and Increase in Tobacco Smoking During the COVID-19 Pandemic among Adults

OBJECTIVES

Examining the associations of COVID-19 related anxiety and insomnia with increased smoking following the outbreak of the COVID-19 pandemic, and investigating whether increased insomnia severity mediates the association between COVID-19 related anxiety and increased smoking.

METHODS

598 participants, aged 18-40, out of whom 140 self-identified as smokers, completed online questionnaires during the third wave of the COVID-19 pandemic. Measures included two items assessing COVID-19 related anxiety, the Pittsburgh Sleep Quality Index, and the Insomnia Severity Index, which included a pre-pandemic retrospective report.

RESULTS

Compared with nonsmokers, smokers reported lower sleep quality and more severe symptoms of insomnia. Among smokers, more severe symptoms of insomnia were associated with greater odds of increased smoking during the COVID-19 outbreak. COVID-19 related anxiety was indirectly associated with greater odds of increased smoking through greater insomnia severity during the COVID-19 outbreak, after controlling for pre-pandemic levels of insomnia.

CONCLUSIONS

Smokers experienced more sleep difficulties during the COVID-19 pandemic than nonsmokers. The results also lend support to the suggestion that anxiety, such that was experienced during the COVID-19 pandemic, may lead to further exacerbation of sleep difficulties, leading in turn to increase in smoking. These findings have important clinical implications that may be particularly relevant to attempts to minimize smoking during stressful circumstances.

Impact of smoking intensities on sleep quality in young Saudi males: a comparative study

This study aimed to compare various components of sleep quality between cigarette smokers of various intensities and non-smokers in young Saudi males. In total, 73 healthy male participants (31 smokers and 42 non-smokers) aged 17-33 years were recruited over three months (August 2018 to October 2018). All participants completed the Pittsburgh Sleep Quality Index (PSQI) questionnaire. The smokers were then divided into three groups, according to their Smoking Index* (SI) (Cigarettes Per Day (CPD) X Years of Tobacco Use), into mild, moderate, and heavy smokers. The PSQI was significantly higher in heavy smokers than in mild smokers (P=0.022) or non-smokers (p=0.013). A significant positive correlation was observed between the PSQI and the smoking index (p=0.005). Sleep duration was significantly longer in heavy smokers compared to mild (p=0.032) and nonsmokers (p=0.047). Sleep disturbance was significantly higher in moderate than nonsmokers (p=0.035) and moderate than mild smokers (p=0.028). Sleep latency was significantly longer in heavy than nonsmokers (p=0.011). Daytime dysfunction was significantly higher in moderate than mild smokers (p=0.041). Habitual sleep efficiency was significantly greater in moderate than in either mild (p=0.013) or nonsmokers (p=0.021). The use of sleep medication was significantly higher in moderate than nonsmokers (p=0.041). The findings suggest that poorer sleep quality is positively associated with smoking intensity among young Saudi males. Considering the importance of sleep quality for well-being and health, these results suggest exploring how improving sleep quality could inform future smoking cessation interventions.

The association between cotinine-measured smoking intensity and sleep quality

INTRODUCTION

METHODS

RESULTS

CONCLUSIONS

Characterisation of the genetic relationship between the domains of sleep and circadian-related behaviours with substance use phenotypes

Sleep problems and substance use frequently co-occur. While substance use can result in specific sleep deficits, genetic pleiotropy could explain part of the relationship between sleep and substance use and use disorders. Here we use the largest publicly available genome-wide summary statistics of substance use behaviours (N = 79,729-632,802) and sleep/activity phenotypes to date (N = 85,502-449,734) to (1) assess the genetic overlap between substance use behaviours and both sleep and circadian-related activity measures, (2) estimate clusters from genetic correlations and (3) test processes of causality versus genetic pleiotropy. We found 31 genetic correlations between substance use and sleep/activity after Bonferroni correction. These patterns of overlap were represented by two genetic clusters: (1) tobacco use severity (age of first regular tobacco use and smoking cessation) and sleep health (sleep duration, sleep efficiency and chronotype) and (2) substance consumption/problematic use (drinks per day and cigarettes per day, cannabis use disorder, opioid use disorder and problematic alcohol use) and sleep problems (insomnia, self-reported short sleep duration, increased number of sleep episodes, increased sleep duration variability and diurnal inactivity) and measures of circadian-related activity (L5, M10 and sleep midpoint). Latent causal variable analyses determined that horizontal pleiotropy (rather than genetic causality) underlies a majority of the associations between substance use and sleep/circadian related measures, except one plausible genetically causal relationship for opioid use disorder on self-reported long sleep duration. Results show that shared genetics are likely a mechanism that is at least partly responsible for the overlap between sleep and substance use traits.

Tobacco cigarette smokers who endorse greater intolerance for nicotine withdrawal also report more severe insomnia symptoms

It has been suggested that nighttime nicotine withdrawal may help to explain why tobacco cigarette smokers are more likely than nonsmokers to experience clinically significant insomnia. There is also reason to believe that intolerance for withdrawal symptoms could play a role in withdrawal-related sleep disturbance. However, we are not aware of any previous research that examined whether smokers who endorse greater intolerance for smoking abstinence also report greater difficulty initiating and/or maintaining sleep. To address this question, 224 adult cigarette smokers (42.9% female, Mcigarettes per day = 21.3) completed the baseline portion of an experimental study that included assessment of current/historical smoking behavior, perceived intolerance for smoking abstinence, and insomnia severity and impact on functioning. The results indicated that, after accounting for general distress intolerance and sociodemographic factors, smokers who endorsed greater intolerance for nicotine withdrawal also reported greater insomnia severity and impact. Logistic regression further revealed that, for every 1-point increase in nicotine withdrawal intolerance scores, smokers were nearly twice as likely to score above threshold for clinically significant insomnia (p = .001). Collectively, these initial findings suggest that intolerance for nicotine withdrawal may warrant consideration as a potentially modifiable mechanistic factor in comorbid insomnia and nicotine/tobacco dependence. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Sleep, substance misuse and addictions: a nationwide observational survey on smoking, alcohol, cannabis and sleep in 12,637 adults

For a good night's sleep, we consensually recommend avoiding alcohol, smoking and drugs. However, these addictions are highly prevalent in the general population, and it is difficult to estimate their real impact on sleep. The aim of this study is to clarify the association between sleep habits and disorders, and addictions. The design was a telephone crossover national recurrent health poll survey (Santé publique France, Baromètre santé, 2017; Questionnaire, pp. 53; Saint Maurice) in a representative sample of French adults. There were 12,367 subjects (18-75 years old) who answered the survey. Sleep log items assessed sleep schedules (total sleep time) on work and leisure days: at night, while napping, and over 24 hr using a sleep log. Retained items include: (1) short sleep (≤ 6 hr/24 hr); (2) chronic insomnia (International Classification of Sleep Disorders, 3^rd edition criteria); and (3) chronotype (evening-morning-neutral). Psychoactive substances retained included tobacco (current or former users), alcohol (daily consumption and weekly binge drinking), cannabis (Cannabis Abuse Screening Test), and other drugs (consumption during the past year). We found that: (1) daily smokers (lightly or heavily dependent) were more frequently short sleepers than occasional smokers and non-smokers; (2) heavily dependent daily smokers were more likely to suffer from insomnia than other smokers or non-smokers; (3) short sleep and insomnia were not significantly associated with the consumption of alcohol, cannabis or any other drug; (4) the evening chronotype was significantly associated with the consumption of tobacco, alcohol and cannabis. In conclusion, our study highlights significant relationships between the use of psychoactive substances and sleep characteristics among adults, emphasizing the need to take into account each subject individually.

Genetic Liability to Insomnia and Lung Cancer Risk: A Mendelian Randomization Analysis

Lung cancer is the second most frequently diagnosed cancer and the leading cause of cancer death worldwide, making its prevention an urgent issue. Meanwhile, the estimated prevalence of insomnia was as high as 30% globally. Research on the causal effect of insomnia on lung cancer incidence is still lacking. In this study, we aimed to assess the causality between the genetic liability to insomnia and lung cancer. We performed a two-sample Mendelian randomization analysis (inverse variance weighted) to determine the causality between the genetic liability to insomnia and lung cancer. Subgroup analysis was conducted, which included lung adenocarcinoma and lung squamous cell carcinoma. In the sensitivity analysis, we conducted heterogeneity test, MR Egger, single SNP analysis, leave-one-out analysis, and MR PRESSO. There were causalities between the genetic susceptibility to insomnia and increased incidence of lung cancer [odds ratio (95% confidence interval), 1.35 (1.14-1.59); P, < 0.001], lung adenocarcinoma [odds ratio (95% confidence interval), 1.35 (1.07-1.70); P, 0.01], and lung squamous cell carcinoma [odds ratio (95% confidence interval), 1.35 (1.06-1.72), P, 0.02]. No violation of Mendelian randomization assumptions was observed in the sensitivity analysis. There was a causal relationship between the genetic susceptibility to insomnia and the lung cancer, which was also observed in lung adenocarcinoma and lung squamous cell carcinoma. The underlying mechanism remains unknown. Effective intervention and management for insomnia were recommended to improve the sleep quality and to prevent lung cancer. Moreover, regular screening for lung cancer may be beneficial for patients with insomnia.

Risky Behaviours of Spanish University Students: Association with Mediterranean Diet, Sexual Attitude and Chronotype

The most common drugs that are consumed by young people are alcohol and tobacco, which are especially prevalent in universities. These risk behaviours can be determined by a series of intrinsic and extrinsic factors. The aim of this study was to evaluate the consumption of alcohol and tobacco by Spanish university students and the relationship between the Mediterranean diet, sexual attitudes and opinions, and chronotype. A multicentre observational study enrolled 457 students from two public universities in Spain. The study period was from December 2017 to January 2018. The majority of the participants consumed alcohol (90.2%), tobacco consumption was low (27.2%), with a high percentage of students (78.6%) having a low dependence on nicotine. The surveyed students demonstrated a high adherence to the Mediterranean diet, which was shown to be associated with less risky alcohol consumption. The Mediterranean diet is a part of healthy lifestyle, and avoiding heavy drinking results in the intention to maintain such a lifestyle. In addition, unhealthy eating habits (skipping breakfast, eating sweets and pastries daily, and fast-food consumption) had a tendency to induce risky alcohol consumption. Therefore, to promote healthy lifestyle habits, it is considered important to establish programs that promote healthy diets in university settings and to evaluate them periodically.

Sleeping, Smoking, and Kidney Diseases: Evidence From the NHANES 2017-2018

Study Objectives: Smoking and sleep are modifiable factors associated with the chronic kidney diseases. However, the interaction of smoking and sleep on the renal function are still unclear. Therefore, we aimed to evaluate the interactive impacts of smoking and sleep on the renal function. Methods: Data were obtained from the National Health and Nutrition Examination Survey. The study population were categorized into nine subgroups by smoking (smoking every day, sometimes, and non-smokers recently) and sleep duration (short duration ≤ 6 h, normal duration 6-9 h, and longer duration ≥ 9 h on the weekdays). Results: The study group with a short sleep duration had significantly higher serum cotinine and hydrocotinine levels compared with the other two sleep groups. After adjusting the demographic characteristics (age, race, body mass index, and marital status), sleep quality (snoring or breathing cessation), and comorbidities (diabetes mellitus, hypertension, high cholesterol, anemia, congestive heart failure, coronary heart disease, and stroke), non-smokers with short or long sleep duration had significant lower estimated glomerular filtration rate (eGFR) levels than the study group who smoked every day and slept ≤ 6 h. The effects of sleep duration on eGFR levels varied with smoking status. For the study group smoking every day, eGFR levels increased as sleep duration decreased, whereas for the study group smoking sometimes, eGFR levels increased as sleep duration increased. The U-shaped effects of eGFR levels were observed among non-smokers whose normal sleep duration was associated with better eGFR levels. Normal sleep duration was an important protective factor of the renal function for non-smokers than smokers. Conclusions: The effects of sleep duration on eGFR levels varied with smoking status. Normal sleep duration was a protective factor and more crucial for non-smokers than for smokers.

A Causal Web between Chronotype and Metabolic Health Traits

Observational and experimental evidence has linked chronotype to both psychological and cardiometabolic traits. Recent Mendelian randomization (MR) studies have investigated direct links between chronotype and several of these traits, often in isolation of outside potential mediating or moderating traits. We mined the EpiGraphDB MR database for calculated chronotype–trait associations (p-value < 5 × 10⁻⁸). We then re-analyzed those relevant to metabolic or mental health and investigated for statistical evidence of horizontal pleiotropy. Analyses passing multiple testing correction were then investigated for confounders, colliders, intermediates, and reverse intermediates using the EpiGraphDB database, creating multiple chronotype–trait interactions among each of the the traits studied. We revealed 10 significant chronotype–exposure associations (false discovery rate < 0.05) exposed to 111 potential previously known confounders, 52 intermediates, 18 reverse intermediates, and 31 colliders. Chronotype–lipid causal associations collided with treatment and diabetes effects; chronotype–bipolar associations were mediated by breast cancer; and chronotype–alcohol intake associations were impacted by confounders and intermediate variables including known zeitgebers and molecular traits. We have reported the influence of chronotype on several cardiometabolic and behavioural traits, and identified potential confounding variables not reported on in studies while discovering new associations to drugs and disease.

Using Mendelian randomization analysis to better understand the relationship between mental health and substance use: a systematic review

BACKGROUND

Poor mental health has consistently been associated with substance use (smoking, alcohol drinking, cannabis use, and consumption of caffeinated drinks). To properly inform public health policy it is crucial to understand the mechanisms underlying these associations, and most importantly, whether or not they are causal.

METHODS

In this pre-registered systematic review, we assessed the evidence for causal relationships between mental health and substance use from Mendelian randomization (MR) studies, following PRISMA. We rated the quality of included studies using a scoring system that incorporates important indices of quality, such as the quality of phenotype measurement, instrument strength, and use of sensitivity methods.

RESULTS

Sixty-three studies were included for qualitative synthesis. The final quality rating was '-' for 16 studies, '- +' for 37 studies, and '+'for 10 studies. There was robust evidence that higher educational attainment decreases smoking and that there is a bi-directional, increasing relationship between smoking and (symptoms of) mental disorders. Another robust finding was that higher educational attainment increases alcohol use frequency, but decreases binge-drinking and alcohol use problems, and that mental disorders causally lead to more alcohol drinking without evidence for the reverse.

CONCLUSIONS

The current MR literature increases our understanding of the relationship between mental health and substance use. Bi-directional causal relationships are indicated, especially for smoking, providing further incentive to strengthen public health efforts to decrease substance use. Future MR studies should make use of large(r) samples in combination with detailed phenotypes, a wide range of sensitivity methods, and triangulate with other research methods.

Tobacco and Nervous System Development and Function-New Findings 2015-2020

Tobacco is a one of the most common addictive stimulants used by people around the world. The smoke generated during tobacco combustion is a toxic mixture of more than 5000 chemicals of which over 30 are known human carcinogens. While its negative effects on the human body are well understood, it remains a serious public health problem. One of the multiple effects of smoking is tobacco’s effect on the nervous system—its development and function. This review aims to summarize the progress made in research on the effects of tobacco on the nervous system both of the perinatal period and adults and both in animals and humans in 2015–2020. The 1245 results that corresponded to the keywords “tobacco, cigarette, nervous system, brain, morphology, function” were reviewed, of which 200 abstracts were considered significant. Most of those articles broadened the knowledge about the negative effects of smoking on the human nervous system. Tobacco has a significant negative impact on the development of nervous structures, neurotransmission and cognitive functions, and promotes the development of neurodegenerative diseases, insomnia and cerebrovascular diseases. The only exception is the protective effect of the dopaminergic system in Parkinson’s disease. In conclusion, in recent years much effort has been devoted to describing, revealing and uncovering new aspects of tobacco detrimental to human life. The nicotine contained in tobacco smoke affects the human body in a multidimensional way, including a serious impact on the broadly understood neurological health.

Sleep deficits and cannabis use behaviors: an analysis of shared genetics using linkage disequilibrium score regression and polygenic risk prediction

STUDY OBJECTIVES

Estimate the genetic relationship of cannabis use with sleep deficits and an eveningness chronotype.

METHODS

We used linkage disequilibrium score regression (LDSC) to analyze genetic correlations between sleep deficits and cannabis use behaviors. Secondly, we generated sleep deficit polygenic risk score (PRS) and estimated their ability to predict cannabis use behaviors using linear and logistic regression. Summary statistics came from existing genome-wide association studies of European ancestry that were focused on sleep duration, insomnia, chronotype, lifetime cannabis use, and cannabis use disorder (CUD). A target sample for PRS prediction consisted of high-risk participants and participants from twin/family community-based studies (European ancestry; n = 760, male = 64%; mean age = 26.78 years). Target data consisted of self-reported sleep (sleep duration, feeling tired, and taking naps) and cannabis use behaviors (lifetime ever use, number of lifetime uses, past 180-day use, age of first use, and lifetime CUD symptoms).

RESULTS

Significant genetic correlation between lifetime cannabis use and an eveningness chronotype (rG = 0.24, p < 0.001), as well as between CUD and both short sleep duration (<7 h; rG = 0.23, p = 0.017) and insomnia (rG = 0.20, p = 0.020). Insomnia PRS predicted earlier age of first cannabis use (OR = 0.92, p = 0.036) and increased lifetime CUD symptom count (OR = 1.09, p = 0.012).

CONCLUSION

Cannabis use is genetically associated with both sleep deficits and an eveningness chronotype, suggesting that there are genes that predispose individuals to both cannabis use and sleep deficits.

Vitamin D status and its longitudinal association with changes in patterns of sleep among middle-aged urban adults

OBJECTIVE

We examined relationships of vitamin D status with over time changes in patterns of sleep in a longitudinal study of Whites and African-American urban middle-aged adults, while further testing effect modification by age group, sex and race and the potential roles of dietary and supplemental vitamin D.

METHODS

Data on 1,760 middle-aged participants in the Healthy Aging in Neighborhoods of Diversity Across the Life Span (HANDLS study: Age range at v₂: 33-71y, mean±SD:53.0±8.8, % women: 58.4%, % African-American:60.3%) were used, with complete baseline 25-hydroxyvitamin D [25(OH)D] serum concentration data, initial selected covariates and mediators, and initial and/or follow-up data on five sub-scales (sleep duration, daytime dysfunction, sleep disturbance, sleep latency and sleep quality) of the Pittsburgh Sleep Quality Index. Mean±SD time between initial and follow-up visits: 4.1±1.5 years. Time-interval multiple mixed-effects linear regression models were used.

RESULTS

Upon multiple testing adjustment, among Whites, initial 25(OH)D was associated with better sleep duration [25(OH)D × TIME γ±SE: -0.027±0.011, P=0.017] and sleep quality [25(OH)D × TIME γ±SE: -0.026±0.010, P=0.008] over time, with heterogeneity by race found for both relationships (P<0.05 for 25(OH)D × TIME × Race in the un-stratified model). These relationships remained unaltered after further adjustment for dietary and supplemental vitamin D, indicating that this association may be largely explained by sunlight exposure.

LIMITATIONS

Limitations included small sample size, selection bias, residual confounding and lack of objective sleep measures. Conclusions Vitamin D status, possibly through mechanisms involving sunlight exposure, was linked to a potential improvement in sleep duration and quality among White urban adults.

Active smoking, sleep quality and cerebrospinal fluid biomarkers of neuroinflammation

BACKGROUNDS

Cigarette smoking has been shown to be associated with sleep disorders and the related neuropathogenesis including neuroinflammation. Previous studies showed that pro- and anti-inflammatory cytokines are physiologically important in maintaining circadian function. In addition, sleep deprivation leads to immune dysregulations. However, no study has been published yet by using cerebrospinal fluid (CSF) biomarkers of neuroinflammation to investigate the relationship between active cigarette smoking and sleep disorders.

METHODS

CSF tissues from subjects of 191 male subjects (non-smokers n = 104; active smokers n = 87) receiving local anesthesia before surgery for anterior cruciate ligament injuries were obtained after the assessment of clinical information and Pittsburgh Sleep Quality Index (PSQI). The levels of tumor necrosis factor alpha (TNFα), Interleukin (IL) 1 beta (IL1β), IL2, IL4, IL6 and IL10 were measured using radioimmunoassay and ELISA.

RESULTS

PSQI scores were significantly higher in active smokers than that in non-smokers (p < 0.001, Cohen's d = 0.63). Significantly higher levels of CSF TNFα were found in active smokers compared to non-smokers (28 ± 1.97 vs. 22.97 ± 2.48, p < 0.05, Cohen's d = 2.23). There was a positive correlation between CSF IL1β levels and PSQI scores in non-smokers (r = 0.31, p = 0.01, adjustment R-Squared = 0.11).

DISCUSSION

This is the first study to reveal the association between higher CSF TNFα levels and poorer sleep quality in active smoking. In addition, CSF IL1β levels might be a potential biomarker in central nervous system for circadian dysregulation.

Causal relationships between substance use and insomnia

BACKGROUND

Poor sleep quality and insomnia have been associated with the use of tobacco, alcohol, and cannabis, but it is unclear if there is a causal link. In this Mendelian Randomization (MR) study we examine if insomnia causes substance use and/or if substance use causes insomnia.

METHODS

MR uses summary effect estimates from a genome-wide association study (GWAS) to create a genetic instrumental variable for a proposed 'exposure' variable and then identifies that same genetic instrument in an 'outcome' GWAS. Using GWASs of insomnia, smoking (initiation, heaviness, cessation), alcohol use (drinks per week, dependence), and cannabis initiation, bi-directional causal effects were tested. Multiple sensitivity analyses were applied to assess the robustness of the findings.

RESULTS

There was strong evidence for positive causal effects of liability to insomnia on all substance use phenotypes (smoking traits, alcohol dependence, cannabis initiation), except alcohol per week. In the other direction, there was strong evidence that smoking initiation increased insomnia risk (smoking heaviness and cessation could not be tested as exposures). We found no evidence that alcohol use per week, alcohol dependence, or cannabis initiation causally affect insomnia risk.

CONCLUSIONS

There were unidirectional effects of liability to insomnia on alcohol dependence and cannabis initiation, and bidirectional effects between liability to insomnia and smoking measures. Bidirectional effects between smoking and insomnia might give rise to a vicious circle. Future research should investigate if interventions aimed at insomnia are beneficial for substance use treatment.

The interrelation of sleep and mental and physical health is anchored in grey-matter neuroanatomy and under genetic control

Humans need about seven to nine hours of sleep per night. Sleep habits are heritable, associated with brain function and structure, and intrinsically related to well-being, mental, and physical health. However, the biological basis of the interplay of sleep and health is incompletely understood. Here we show, by combining neuroimaging and behavioral genetic approaches in two independent large-scale datasets (HCP (n = 1106), age range: 22-37, eNKI (n = 783), age range: 12-85), that sleep, mental, and physical health have a shared neurobiological basis in grey matter anatomy; and that these relationships are driven by shared genetic factors. Though local associations between sleep and cortical thickness were inconsistent across samples, we identified two robust latent components, highlighting the multivariate interdigitation of sleep, intelligence, BMI, depression, and macroscale cortical structure. Our observations provide a system-level perspective on the interrelation of sleep, mental, and physical conditions, anchored in grey-matter neuroanatomy.

Weekday and weekend sleep duration and mortality among middle-to-older aged White and Black adults in a low-income southern US cohort

INTRODUCTION

Both short and long sleep have been associated with higher mortality. However, most studies are conducted in predominantly White or Asian populations and little is known about the sleep-mortality relationship in Blacks. Given the high prevalence of short and long sleep in Blacks, it is important to examine the health effects of sleep in this population.

METHODS

We studied sleep duration in relation to all-cause, cardiovascular and cancer mortality in 55,375 participants age 40-79 at enrollment in the Southern Community Cohort Study, of whom ∼2/3 are Black. Weekday and weekend sleep durations were self-reported. Mortality follow up started at baseline (2002-2009) and was regularly updated until 2015 via linkage to Social Security Administration and the National Death Index. We used Cox proportional hazards model adjusting for multiple covariates to estimate relative risks associated with sleep duration.

RESULTS

We found U-shaped relationships between weekday and weekend sleep duration and all-cause mortality, with the effects stronger in Whites than Blacks. Risks for all-cause mortality were significantly elevated by about 25% among Whites and about 10% among Blacks reporting either less than 5 hours or more than 9 hours of sleep compared with those reporting 8 hours of sleep. The associations among Whites but not Blacks were even stronger for cardiovascular disease mortality, whereas no association between sleep duration and cancer mortality was found in either group.

CONCLUSIONS

Our results suggest that short and long sleep durations may be weaker predictors of total and cardiovascular mortality in Blacks than in Whites.

Association of sleep characteristics with cardiovascular health among women and differences by race/ethnicity and menopausal status: findings from the American Heart Association Go Red for Women Strategically Focused Research Network

BACKGROUND AND OBJECTIVE

Sleep is an emerging risk factor for cardiovascular disease (CVD) that is not currently included as a cardiovascular health (CVH) metric in the American Heart Association's Life's Simple 7 (AHA LS7). Our objective was to evaluate the association of sleep with CVH in women and examine differences by menopausal status and race/ethnicity.

METHODS

Baseline data from the Columbia University AHA Go Red for Women Strategically Focused Research Network were examined. Sleep habits were self-reported using validated questionnaires. A CVH score was computed using AHA LS7 criteria for smoking, diet, physical activity, BMI, blood pressure(BP), total cholesterol, and fasting glucose. Women received a score of 2 (ideal), 1 (intermediate), or 0 (poor) based on their level of meeting each AHA LS7 metric. Multivariable-adjusted regression models were used to evaluate associations of sleep with meeting overall and individual CVH metrics.

RESULTS

The analytical sample consisted of n = 507 women (62% minority/Hispanic, mean age:37 y). Participants with adequate sleep duration (≥7 h), good sleep quality, no insomnia nor snoring, and low risk for OSA were more likely to meet >4 of the AHA LS7 metrics (P < .01). Poorer sleep quality (β = -0.08, P = .002), higher insomnia severity (β = -0.05, P = .002), snoring (β = -0.77, P = .0001), and higher risk for OSA (β = -1.63, P < .0001) were associated with poorer CVH. Insomnia, snoring, and high OSA risk were associated with 69% to >300% higher odds of having poor CVH (P ≤ .03). Associations were stronger in post-menopausal and racial/ethnic minority women.

CONCLUSIONS

Better sleep habits were associated with more favorable CVH among women, suggesting that there may be benefit in incorporating sleep assessment into CVD risk screening.

MR-pheWAS with stratification and interaction: Searching for the causal effects of smoking heaviness identified an effect on facial aging

Mendelian randomization (MR) is an established approach to evaluate the effect of an exposure on an outcome. The gene-by-environment (GxE) study design can be used to determine whether the genetic instrument affects the outcome through pathways other than via the exposure of interest (horizontal pleiotropy). MR phenome-wide association studies (MR-pheWAS) search for the effects of an exposure, and can be conducted in UK Biobank using the PHESANT package. In this proof-of-principle study, we introduce the novel GxE MR-pheWAS approach, that combines MR-pheWAS with the use of GxE interactions. This method aims to identify the presence of effects of an exposure while simultaneously investigating horizontal pleiotropy. We systematically test for the presence of causal effects of smoking heaviness-stratifying on smoking status (ever versus never)-as an exemplar. If a genetic variant is associated with smoking heaviness (but not smoking initiation), and this variant affects an outcome (at least partially) via tobacco intake, we would expect the effect of the variant on the outcome to differ in ever versus never smokers. We used PHESANT to test for the presence of effects of smoking heaviness, instrumented by genetic variant rs16969968, among never and ever smokers respectively, in UK Biobank. We ranked results by the strength of interaction between ever and never smokers. We replicated previously established effects of smoking heaviness, including detrimental effects on lung function. Novel results included a detrimental effect of heavier smoking on facial aging. We have demonstrated how GxE MR-pheWAS can be used to identify potential effects of an exposure, while simultaneously assessing whether results may be biased by horizontal pleiotropy.

E-cigarette use and sleep-related complaints among youth

INTRODUCTION

E-cigarette use is highly prevalent among adolescents. However, little research has examined the relationship between e-cigarette use and sleep-related complaints in this population. The objective of this study was to assess whether exclusive e-cigarette, exclusive combusted cigarette, and dual-product use are associated with sleep-related complaints among adolescents.

METHODS

Participants were 9,588 U.S. adolescents from the Population Assessment of Tobacco and Health Study, a nationally representative cohort, followed from 2013 through 2015. Using logistic regression, we examined the cross-sectional association between past-year e-cigarette, combusted cigarette, or dual-product use and past-year sleep-related complaints (bad dreams, sleeping restlessly, or falling asleep during the day), both measured at Wave 2. We controlled for Wave 1 demographic characteristics, emotional and behavioral health, and prior history of e-cigarette use, combusted cigarette use, and sleep-related complaints.

RESULTS

In unadjusted analyses, e-cigarette, combusted cigarette, and dual-product use were significantly associated with greater odds of sleep-related complaints, compared to use of neither product (e-cigarettes: OR = 1.61, 95% CI 1.34-1.94; combusted cigarettes: OR = 1.62, 95% CI 1.26-2.09; dual-product use: OR = 2.00, 95% CI 1.63-2.46). Associations between e-cigarette and dual-product use and sleep-related complaints remained significant in fully adjusted analyses (e-cigarettes: aOR = 1.29, 95% CI 1.05-1.59; dual-product use: aOR = 1.57, 95% CI 1.24-1.99), whereas associations with combusted cigarette use were significant in all models except the fully adjusted model (aOR = 1.30, 95% CI 0.98-1.71).

CONCLUSIONS

E-cigarette and dual-product use are significantly associated with greater odds of reporting sleep-related complaints among adolescents. Future research should evaluate whether this association may be causal.

Longitudinal change of sleep timing: association between chronotype and longevity in older adults

Evening-oriented sleep timing preferences have been associated with risk of diabetes, cardiovascular diseases, obesity, psychiatric disorders, and increased mortality. This research aims to explore the relationship between diurnal preferences (chronotype), daily habits, metabolic health, and mortality, using longitudinal data from The University of Manchester Longitudinal Study of Cognition in Normal Healthy Old Age (6375 participants at inception, recruited in the North of England) with a long follow-up period (up to 35.5 years). Mixed models were used to investigate the influence of aging, socio-demographic, and seasonal factors on sleep timing. Results show that sleep timing shifted towards earlier time with aging. Test seasons influence chronotype of older adults but working schedules challenge seasonality of sleep timing. Moreover, the season of birth may set chronotype in adulthood. Individual chronotype trajectories were clustered using latent class analysis and analyzed against metabolic health and mortality. We observed a higher risk of hypertension in the evening-type cluster compared to morning-type individuals (Odds ratio = 1.88, 95%CI = 1.02/3.47, p = .04). Evening-type cluster was also associated with traits related to lower health such as reduced sport participation, increased risk of depression and psychoticism personality, late eating, and increased smoking and alcohol usage. Finally, Cox regression of proportional hazards was used to study the effects of chronotype on longevity after adjusting for sleep duration, age, gender, smoking, alcohol usage, general health, and social class. The survival analysis (82.6% censored by death) revealed that evening-type chronotype increased the likelihood of mortality (Hazard ratio = 1.15, 95%CI = 1.04/1.26, p = .005). Taken together, chronotype is influenced by aging and seasonal effects. Evening-type preference may have detrimental outcomes for human well-being and longevity.