Health implications of sleep and circadian rhythm research in 2017

UPLC-MS/MS simultaneous quantification of urinary circadian rhythm hormones and related metabolites: Application to air traffic controllers

Civil aviation flight crew and civil aviation air traffic controllers are prone to circadian rhythm abnormalities, which can lead to a slew of other maladies. It could endanger people's health and provide a serious threat to the safety of civil aviation flights if it is not appropriately evaluated and addressed. Early detection of rhythm irregularities and prompt treatment for particular populations that are vulnerable to rhythm disorders are crucial for enhancing civil aviation safety. In general, monitoring of the classical circadian rhythm biomarkers (melatonin or cortisol) in plasma or saliva is an effective way to evaluate the rhythm status. Due to the challenging sample procedure and the trauma of plasma, urine sample testing has received an increasing amount of attention. While, urine circadian rhythm biomarkers have seldom been examined, and the relationship between urinary steroid hormones and melatonin is still poorly understood. In most cases, hormones are determined by immunoassays respectively, mainly enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay (RIA). There are also reports describing the liquid chromatography with tandem mass spectrometry (LC-MS/MS) technique as a method of melatonin or few steroid hormones quantification, however, the simultaneous detection of multiple rhythmic hormones in human urine is rarely reported. For the quantification of the rhythmic hormones in human urine, an accurate approach using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was devised in this work. Nine endogenous hormones (melatonin, 6-hydroxymelatonin, 6-sulfatoxymelatonin, cortisol, corticosterone, cortisone, testosterone, epitestosterone and androsterone), in human overnight urine, were quantified after solid phase extraction (SPE). A reverse phase HSS C18 column was used for chromatographic separation with a 9-minute gradient elution and deuterated analogues of each analyte were applied as internal standards. This method was successfully applied to the analysis of 596 overnight urine samples (23:00-9:00) collected from 84 air traffic controllers in the Beijing area during shift work. This study's findings showed a clear correlation not only between melatonin and its metabolites; cortisol-related metabolites, but also between melatonin metabolites and endogenous metabolites upstream and downstream of cortisol, implying that these two categories of hormones can be used as potential biological rhythm indicators to provide circadian rhythm data support for future studies on circadian rhythm disorders.

Effect of healthy lifestyle index and lifestyle patterns on the risk of mortality: A community-based cohort study

Background

Limited evidence was available on the association of the integrated effect of multidimensional lifestyle factors with mortality among Chinese populations. This cohort study was to examine the effect of combined lifestyle factors on the risk of mortality by highlighting the number of healthy lifestyles and their overall effects.

Methods

A total of 11,395 participants from the Guangzhou Heart Study (GZHS) were followed up until 1 January 2020. Individual causes of death were obtained from the platform of the National Death Registry of China. The healthy lifestyle index (HLI) was established from seven dimensions of lifestyle, and lifestyle patterns were extracted from eight dimensions of lifestyle using principal component analysis (PCA). Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using the Cox proportional hazard regression model.

Results

During 35,837 person-years of follow-up, 184 deaths (1.61%) were observed, including 64 from cardiovascular disease. After adjustment for confounders, HLI was associated with a 50% (HR: 0.50, 95% CI: 0.25–0.99) reduced risk of all-cause mortality when comparing the high (6–7 lifestyle factors) with low (0–2 lifestyle factors) categories. Three lifestyle patterns were defined and labeled as pattern I, II, and III. Lifestyle pattern II with higher factor loadings of non-smoking and low-level alcohol drinking was associated with a decreased risk of all-cause mortality (HR: 0.63, 95% CI: 0.43–0.92, P_–trend = 0.023) when comparing the high with low tertiles of pattern score, after adjustment for confounders. Every 1-unit increment of pattern II score was associated with a decreased risk (HR: 0.97, 95% CI: 0.95–0.99) of all-cause mortality. The other two patterns were not associated with all-cause mortality, and the association of cardiovascular mortality risk was observed with neither HLI nor any lifestyle pattern.

Conclusion

The results suggest that the more dimensions of the healthy lifestyle the lower the risk of death, and adherence to the lifestyle pattern characterized with heavier loading of non-smoking and low-level alcohol drinking reduces the risk of all-cause mortality. The findings highlight the need to consider multi-dimensional lifestyles rather than one when developing health promotion strategies.

Altered insular functional connectivity correlates to impaired vigilant attention after sleep deprivation: A resting-state functional magnetic resonance imaging study

Objectives

This study used resting-state functional magnetic resonance imaging (rs-fMRI) scans to assess the dominant effects of 36 h total sleep deprivation (TSD) on vigilant attention and changes in the resting-state network.

Materials and methods

Twenty-two healthy college students were enrolled in this study. Participants underwent two rs-fMRI scans, once in rested wakefulness (RW) and once after 36 h of TSD. We used psychomotor vigilance tasks (PVT) to measure vigilant attention. The region-of-interest to region-of-interest correlation was employed to analyze the relationship within the salience network (SN) and between other networks after 36 h of TSD. Furthermore, Pearson’s correlation analysis investigated the relationship between altered insular functional connectivity and PVT performance.

Results

After 36 h of TSD, participants showed significantly decreased vigilant attention. Additionally, TSD induced decreased functional connectivity between the visual and parietal regions, whereas, a significant increase was observed between the anterior cingulate cortex and insula. Moreover, changes in functional connectivity in the anterior cingulate cortex and insula showed a significant positive correlation with the response time to PVT.

Conclusion

Our results suggest that 36 h of TSD impaired vigilant visual attention, resulting in slower reaction times. The decrease in visual-parietal functional connectivity may be related to the decrease in the reception of information in the brain. Enhanced functional connectivity of the anterior cingulate cortex with the insula revealed that the brain network compensation occurs mainly in executive function.

Associations of sleep duration and quality with incident cardiovascular disease, cancer, and mortality: a prospective cohort study of 407,500 UK biobank participants

OBJECTIVE

Few studies have investigated the associations of sleep duration and sleep quality with incident cardiovascular diseases (CVDs), cancer, and mortality in the same large population. This study aimed at estimating the independent risk factors of long or short sleep durations and several typical characteristics of poor sleep quality for incident CVDs, cancer, and mortality.

METHODS

In this prospective cohort study, 407 500 individuals were enrolled. Cox proportional hazards models were used to calculate the adjusted hazard ratios and 95% confidence intervals (HR, 95%CI) of associations of sleep duration and quality with incident CVDs, cancer, and mortality.

RESULTS

Compared with the sleep duration of 7 h, sleep duration of ≤5 h and ≥9 h were both associated with higher risk of all-cause mortality (HR = 1.25, 95% CI: 1.16-1.34 and HR = 1.30, 95% CI: 1.22-1.38, respectively), CVD mortality (HR = 1.27, 95% CI: 1.09-1.49 and HR = 1.32, 95% CI: 1.16-1.50, respectively), and CVD incidence (HR = 1.23, 95% CI: 1.16-1.31 and HR = 1.08, 95% CI: 1.02-1.15, respectively). Additionally, long sleep duration (≥9 h) was associated with a higher risk of cancer mortality (HR = 1.19, 95% CI: 1.10-1.30) and cancer incidence (HR = 1.08, 95% CI: 1.04-1.12). Moreover, CVD incidence was significantly associated with snoring, insomnia and narcolepsy, increasing the risk by 7%, 26%, and 20%, respectively.

CONCLUSION

Long sleep durations may substantially increase the risk of mortality and morbidity. Snoring, insomnia, and narcolepsy were independent risk factors for incident CVD.

Mass spectrometric quantification of urinary 6-sulfatoxymelatonin: age-dependent excretion and biological variation

Objectives

Regulators of circadian rhythm, including melatonin, influence fundamental biological processes. Measuring the melatonin metabolite 6-sulfatoxymelatonin in urine can estimate melatonin production. 6-sulfatoxymelatonin is mainly analyzed by immunoassays, but these methods are hampered by cross-reactivity and poor reproducibility when used to analyze small molecules. Therefore, we validated a high-throughput liquid chromatography with tandem mass spectrometry (LC–MS/MS) method to quantify 6-sulfatoxymelatonin in urine. We evaluated age-dependent 24-h excretion of 6-sulfatoxymelatonin into urine and the biological variation of urinary excretion in healthy individuals.

Methods

The online solid phase extraction method combined with LC–MS/MS was validated according to international guidelines, and used to measure the excretion of 6-sulfatoxymelatonin into urine of 240 healthy individuals. Biological variation of 6-sulfatoxymelatonin excretion was examined in 10 healthy individuals.

Results

Urinary 6-sulfatoxymelatonin results were well within the validation criteria (interassay coefficient of variation: <5.4%, quantification limit: 0.2 nmol/L). There was an age-related decrease in 6-sulfatoxymelatonin excretion into 24-h urine [F(5, 234)=13.9; p<0.001]. Within-subject variation of 6-sulfatoxymelatonin was 39.2% in day urine, 15.1% in night urine, and 12.2% in 24-h urine. Between-subject variation was 39.1% in day urine, 37.9% in night urine, and 36.8% in 24-h urine.

Conclusions

This MS-based method enables straightforward, reproducible, and sensitive quantification of 6-sulfatoxymelatonin in urine. Urinary 6-sulfatoxymelatonin levels decreased with age. Biological variation of 6-sulfatoxymelatonin excretion into urine was high between subjects and lower within subjects, indicating that repeated measurements of 6-sulfatoxymelatonin in 24-h urine are needed in future studies.

Gaining Insights Into the Estimation of the Circadian Rhythms of Social Activity in Older Adults From Their Telephone Call Activity With Statistical Learning: Observational Study

Background

Understanding the social mechanisms of the circadian rhythms of activity represents a major issue in better managing the mechanisms of age-related diseases occurring over time in the elderly population. The automated analysis of call detail records (CDRs) provided by modern phone technologies can help meet such an objective. At this stage, however, whether and how the circadian rhythms of telephone call activity can be automatically and properly modeled in the elderly population remains to be established.

Objective

Our goal for this study is to address whether and how the circadian rhythms of social activity observed through telephone calls could be automatically modeled in older adults.

Methods

We analyzed a 12-month data set of outgoing telephone CDRs of 26 adults older than 65 years of age. We designed a statistical learning modeling approach adapted for exploratory analysis. First, Gaussian mixture models (GMMs) were calculated to automatically model each participant’s circadian rhythm of telephone call activity. Second, k-means clustering was used for grouping participants into distinct groups depending on the characteristics of their personal GMMs.

Results

The results showed the existence of specific structures of telephone call activity in the daily social activity of older adults. At the individual level, GMMs allowed the identification of personal habits, such as morningness-eveningness for making calls. At the population level, k-means clustering allowed the structuring of these individual habits into specific morningness or eveningness clusters.

Conclusions

These findings support the potential of phone technologies and statistical learning approaches to automatically provide personalized and precise information on the social rhythms of telephone call activity of older individuals. Futures studies could integrate such digital insights with other sources of data to complete assessments of the circadian rhythms of activity in elderly populations.

Novel statistical approach for assessing the persistence of the circadian rhythms of social activity from telephone call detail records in older adults

How circadian rhythms of activity manifest themselves in social life of humans remains one of the most intriguing questions in chronobiology and a major issue for personalized medicine. Over the past years, substantial advances have been made in understanding the personal nature and the robustness—i.e. the persistence—of the circadian rhythms of social activity by the analysis of phone use. At this stage however, the consistency of such advances as their statistical validity remains unclear. The present paper has been specifically designed to address this issue. To this end, we propose a novel statistical procedure for the measurement of the circadian rhythms of social activity which is particularly well-suited for the existing framework of persistence analysis. Furthermore, we illustrate how this procedure works concretely by assessing the persistence of the circadian rhythms of telephone call activity from a 12-month call detail records (CDRs) dataset of adults over than 65 years. The results show the ability of our approach for assessing persistence with a statistical significance. In the field of CDRs analysis, this novel statistical approach can be used for completing the existing methods used to analyze the persistence of the circadian rhythms of a social nature. More importantly, it provides an opportunity to open up the analysis of CDRs for various domains of application in personalized medicine requiring access to statistical significance such as health care monitoring.

Effect of Transcranial Alternating Current Stimulation for the Treatment of Chronic Insomnia: A Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Clinical Trial

BACKGROUND

Not all adults with chronic insomnia respond to the recommended therapeutic options of cognitive behavioral therapy and approved hypnotic drugs. Transcranial alternating current stimulation (tACS) may offer a novel potential treatment modality for insomnia.

OBJECTIVES

This study aimed to examine the efficacy and safety of tACS for treating adult patients with chronic insomnia.

METHODS

Sixty-two participants with chronic primary insomnia received 20 daily 40-min, 77.5-Hz, 15-mA sessions of active or sham tACS targeting the forehead and both mastoid areas in the laboratory on weekdays for 4 consecutive weeks, followed by a 4-week follow-up period. The primary outcome was response rate measured by the Pittsburgh Sleep Quality Index (PSQI) at week 8. Secondary outcomes were remission rate, insomnia severity, sleep onset latency (SOL), total sleep time (TST), sleep efficiency, sleep quality, daily disturbances, and adverse events at the end of the 4-week intervention and at the 4-week follow-up.

RESULTS

Of 62 randomized patients, 60 completed the trial. During the 4-week intervention, 1 subject per group withdrew due to loss of interest and time restriction, respectively. Based on PSQI, at 4-week follow-up, the active group had a higher response rate compared to the sham group (53.4% [16/30] vs. 16.7% [5/30], p = 0.009), but remission rates were not different between groups. At the end of the 4-week intervention, the active group had higher response and remission rates than the sham group (p < 0.001 and p = 0.026, respectively). During the trial, compared with the sham group, the active group showed a statistically significant decrease in PSQI total score, a shortened SOL, an increased TST, improved sleep efficiency, and improved sleep quality (p < 0.05 or p < 0.001). Post hoc analysis revealed that, in comparison with the sham group, the active group had improved symptoms, except for daily disturbances, at the end of the 4-week intervention, and significant improvements in all symptoms at the 4-week follow-up. No adverse events or serious adverse responses occurred during the study.

CONCLUSION

The findings show that the tACS applied in the present study has potential as an effective and safe intervention for chronic insomnia within 8 weeks.

Circadian Rhythms in the Telephone Calls of Older Adults: Observational Descriptive Study

Background

Recent studies have thoughtfully and convincingly demonstrated the possibility of estimating the circadian rhythms of young adults’ social activity by analyzing their telephone call-detail records (CDRs). In the field of health monitoring, this development may offer new opportunities for supervising a patient’s health status by collecting objective, unobtrusive data about their daily social interactions. However, before considering this future perspective, whether and how similar results could be observed in other populations, including older ones, should be established.

Objective

This study was designed specifically to address the circadian rhythms in the telephone calls of older adults.

Methods

A longitudinal, 12-month dataset combining CDRs and questionnaire data from 26 volunteers aged 65 years or older was used to examine individual differences in the daily rhythms of telephone call activity. The study used outgoing CDRs only and worked with three specific telecommunication parameters: (1) call recipient (alter), (2) time of day, and (3) call duration. As did the studies involving young adults, we analyzed three issues: (1) the existence of circadian rhythms in the telephone call activity of older adults, (2) their persistence over time, and (3) the alter-specificity of calls by calculating relative entropy.

Results

We discovered that older adults had their own specific circadian rhythms of outgoing telephone call activity whose salient features and preferences varied across individuals, from morning until night. We demonstrated that rhythms were consistent, as reflected by their persistence over time. Finally, results suggested that the circadian rhythms of outgoing telephone call activity were partly structured by how older adults allocated their communication time across their social network.

Conclusions

Overall, these results are the first to have demonstrated the existence, persistence, and alter-specificity of the circadian rhythms of the outgoing telephone call activity of older adults. These findings suggest an opportunity to consider modern telephone technologies as potential sensors of daily activity. From a health care perspective, these sensors could be harnessed for unobtrusive monitoring purposes.

Effectiveness of non-pharmacological interventions for insomnia in children with Autism Spectrum Disorder: A systematic review and meta-analysis

Background

Autism spectrum disorders (ASD) are a set of neurodevelopmental disorders characterised by behavioural, communication and social impairments. The prevalence of sleep disturbances in children with ASD is 40–80%, with significant effects on quality of life for the children and carers.

This systematic review aimed to synthesise evidence of the effects of behavioural interventions to improve sleep among children with ASD.

Methods

Databases (MEDLINE, PsycINFO, CINAHL, ScienceDirect, Autism Data, CENTRAL, ClinicalTrials.gov and Current Controlled Trials) were searched for published, unpublished and ongoing randomised controlled trials evaluating the effect of non-pharmacological interventions for insomnia in children with autism spectrum conditions.

Results

Three studies met the inclusion criteria, one provided actigraphy data, one Children’s Sleep Habits Questionnaire (CSHQ) data, and one both actigraphy and CSHQ data for use in meta-analyses. There were significant differences between the behavioural intervention and comparison groups (actigraphy data) for total sleep time (24.41 minutes, 95% CI 5.71, 43.11, P = 0.01), sleep latency (-18.31 minutes, 95% CI -30.84, -5.77, P = 0.004) and sleep efficiency (5.59%, 95% CI 0.87, 10.31, P = 0.02). There was also a favourable intervention effect evident for the subjective CSHQ data (-4.71, 95% CI -6.70, -2.73, P<0.00001). Risk of bias was low across several key domains (randomisation, allocation concealment and reporting), with some studies being unclear due to poor reporting.

Conclusions

There are very few high quality randomised controlled trials in this area. Here we provide initial synthesised quantitative evidence of the effectiveness of behavioural interventions for treating sleep problems in children with ASD.

Trial registration

Protocol was registered (CRD42017081784) on the International Prospective Register of Systematic Reviews (http://www.crd.york.ac.uk/PROSPERO).

The effects of individual circadian rhythm differences on insomnia, impulsivity, and food addiction

PURPOSE

Individuals can generally be divided into morning, neither and evening types according to behavioral, psychological, and biological variables including appetite levels, usual meal times, sleep times, and melatonin secretion. These factors together identify a person as being part of a certain chronotype, i.e., as feeling more efficient either in the morning (morning type) or later in the day (evening type). Food addiction is defined as addictive behavior toward palatable foods and is thought to be one of the underlying risk factors for obesity. Our aim in this study was to investigate the relationship between circadian rhythm differences and food addiction via insomnia and impulsivity in university students.

METHOD

Participants were 1323 university students, filled out a package of psychological tools, including the Morningness-Eveningness Questionnaire, Insomnia Severity Index, Barratt Impulsiveness Scale Short Form, and Yale Food Addiction Scale. Logistic regression analysis was used to investigate direct relation of food addiction with insomnia, impulsivity and obesity, and mediation regression analysis was used to investigate the indirect effect of circadian rhythm differences on food addiction.

RESULTS

Our findings indicated that evening types were more prone to insomnia and impulsivity, and also insomnia and impulsivity significantly contributed to the variance of food addiction. Although there was no significant linear relationship between circadian rhythm differences and food addiction, evening-type circadian preferences were indirectly associated with higher food addiction scores mediated by insomnia and impulsivity.

CONCLUSION

The most remarkable result of our work was that circadian rhythm differences seem to indirectly effect on food addiction through elevated insomnia and impulsivity.

LEVEL OF EVIDENCE

Level V, descriptive cross-sectional survey.

Modulation of thermogenesis and metabolic health: a built environment perspective

Lifestyle interventions, obviating the increasing prevalence of the metabolic syndrome, generally focus on nutrition and physical activity. Environmental factors are hardly covered. Because we spend on average more that 90% of our time indoors, it is, however, relevant to address these factors. In the built environment, the attention has been limited to the (assessment and optimization of) building performance and occupant thermal comfort for a long time. Only recently well-being and health of building occupants are also considered to some extent, but actual metabolic health aspects are not generally covered. In this review, we draw attention to the potential of the commonly neglected lifestyle factor 'indoor environment'. More specifically, we review current knowledge and the developments of new insights into the effects of ambient temperature, light and the interaction of the two on metabolic health. The literature shows that the effects of indoor environmental factors are important additional factors for a healthy lifestyle and have an impact on metabolic health.

Mitochondrial function and autophagy: integrating proteotoxic, redox, and metabolic stress in Parkinson's disease

Parkinson's disease (PD) is a movement disorder with widespread neurodegeneration in the brain. Significant oxidative, reductive, metabolic, and proteotoxic alterations have been observed in PD postmortem brains. The alterations of mitochondrial function resulting in decreased bioenergetic health is important and needs to be further examined to help develop biomarkers for PD severity and prognosis. It is now becoming clear that multiple hits on metabolic and signaling pathways are likely to exacerbate PD pathogenesis. Indeed, data obtained from genetic and genome association studies have implicated interactive contributions of genes controlling protein quality control and metabolism. For example, loss of key proteins that are responsible for clearance of dysfunctional mitochondria through a process called mitophagy has been found to cause PD, and a significant proportion of genes associated with PD encode proteins involved in the autophagy-lysosomal pathway. In this review, we highlight the evidence for the targeting of mitochondria by proteotoxic, redox and metabolic stress, and the role autophagic surveillance in maintenance of mitochondrial quality. Furthermore, we summarize the role of α-synuclein, leucine-rich repeat kinase 2, and tau in modulating mitochondrial function and autophagy. Among the stressors that can overwhelm the mitochondrial quality control mechanisms, we will discuss 4-hydroxynonenal and nitric oxide. The impact of autophagy is context depend and as such can have both beneficial and detrimental effects. Furthermore, we highlight the potential of targeting mitochondria and autophagic function as an integrated therapeutic strategy and the emerging contribution of the microbiome to PD susceptibility.