Chronotype Individuals Research Articles

Pressure Pain Sensitivity and Chronotype: A Population-based Study of Middle-aged Finns

Evening chronotype individuals experience pain more often than morning chronotypes, but relationships with pain sensitivity have rarely been studied. We examined whether chronotype is associated with pressure pain sensitivity, with special reference to mental health disorders, insomnia, and chronic musculoskeletal (MSK) pain as potential moderating factors. The study sample consisted of members of the Northern Finland Birth Cohort 1966 aged 46. Pressure pain threshold and tolerance were measured via the standardized protocol, categorized as lowest quartile versus others. Chronotype (morning [M; the reference], intermediate [I], and evening [E]) was defined using the Short Morningness-Eveningness questionnaire. Sex-stratified binary logistic regression models were separately adjusted for education, body mass index, long-term diseases (fully adjusted model), and for mental health disorders, insomnia, and chronic MSK pain (a residual confounding analysis). Interaction terms (Chronotype × Mental health/insomnia/chronic MSK pain) were tested. The study had 2,132 males and 2,830 females. The E-type males had 1.5-fold odds of having a low pain threshold (fully adjusted odds ratio [OR] 1.45, 95% confidence interval 1.05–2.00) and pressure pain tolerance (fully adjusted OR 1.47, 1.07–2.02), in comparison to M-types. Having a mental health disorder intensified the association with low pain threshold fourfold (4.06, 1.56–10.6). Being an E-type female was also associated with a low pain threshold, but the association was statistically nonsignificant (fully adjusted OR 1.18, .90–1.53). No statistically significant interactions were found among females. These results emphasize the role of chronotype in pain sensitivity and add an understanding of pain experience in light of innate circadian types. PerspectiveMale evening chronotypes are more sensitive to pain than morning chronotypes. Diagnosed mental health disorders in particular indicate a low pain threshold for evening chronotype males.

Chronotype, circadian rhythm, and psychiatric disorders: Recent evidence and potential mechanisms.

The circadian rhythm is crucial for physiological and behavioral functions. Chronotype, which represents individual preferences for activity and performance, is associated with human health issues, particularly psychiatric disorders. This narrative review, which focuses on the relationship between chronotype and mental disorders, provides an insight into the potential mechanism. Recent evidence indicates that (1) the evening chronotype is a risk factor for depressive disorders and substance use disorders, whereas the morning chronotype is a protective factor. (2) Evening chronotype individuals with bipolar disorder tend to have more severe symptoms and comorbidities. (3) The evening chronotype is only related to anxiety symptoms. (4) The relationship between chronotype and schizophrenia remains unclear, despite increasing evidence on their link. (5) The evening chronotype is significantly associated with eating disorders, with the majority of studies have focused on binge eating disorders. Furthermore, the underlying mechanisms or influence factors are described in detail, including clock genes, brain characteristics, neuroendocrinology, the light/dark cycle, social factors, psychological factors, and sleep disorders. These findings provide the latest evidence on chronotypes and psychiatric disorders and serve as a valuable reference for researchers.

Comparison of Sleep, Perceived Health, and Job Stress According to Symptoms of Shift Work Disorder in Shift Nurses

Objectives: This study aimed to investigate the prevalence of symptoms of shift work disorder (SSWD) and its related factors in rapidly rotating three-shift nurses. Methods: We enrolled 344 nurses (mean age, 28.7 years) without prior history of sleep disturbance before starting shift work in a university-affiliated hospital. SSWD were defined using self-reported sleep questionnaires (insomnia severity index >14 and/or Epworth Sleepiness Scale ≥10) and without any sleep problem before shift work. Sleep pattern in each of the three shifts was measured using the Munich Chronotype Questionnaire for Shift-Workers. Mood (anxiety, depression) and job stress were also measured using self-reported questionnaires. Results: Our results showed that 62.2% of the participants presented SSWD. Compared to the non-SWD group, the SSWD group showed worse sleep hygiene, lower total sleep time (TST) during workdays, higher anxiety and depressive mood, and higher job stress. In the SSWD group, the evening chronotype individuals presented the shortest TST during day shifts, while the morning chronotype individuals presented the shortest TST during evening shifts. Conclusions: SSWD is highly prevalent in fast rotating three-shift nurses. This study suggests that intensive education on sleep hygiene and appropriate scheduling of shift work while considering individual chronotypes may improve sleep patterns and sleep quality of shift workers and minimize SSWD.

Snacking behavior differs between evening and morning chronotype individuals but no differences are observed in overall energy intake, diet quality, or food cravings

ABSTRACT There is a growing body of literature that links chronotype to certain undesirable eating behaviors. However, the relationship between chronotype and dietary intake is poorly characterized among adults in the United States (U.S.). This cross-sectional study examined the associations among chronotype, snacking habits, dietary intake and quality, and food cravings. One-hundred adults living in the U.S. completed the study. Based on the Horne-Östberg Morningness-Eveningness Questionnaire score, an individual was categorized as having either a morning (M)-type, intermediate (I)-type, or evening (E)-type chronotype. Snack intake was assessed using a previously published specialized food frequency questionnaire. Sugar-sweetened beverage (SSB) intake was assessed using the updated version of the Beverage Intake Questionnaire-15. Alcohol misuse was measured using the Alcohol Use Disorders Identification Test-Consumption. Diet quality was obtained using the Diet History Questionnaire III. The validated General Food Cravings Questionnaire-Trait measured participants’ food cravings. E-type individuals reported consuming snacks more often over the course of a week than M-types (p = .002) but not I-types. In terms of timing of snacking, E-type individuals consumed more snacks after dinner than M-types (p < .001). E-type individuals consumed more energy-dense snacks (p = .005), especially candies (p = .005), than M-types. However, there were no significant differences in healthy snack frequency, diet quality, energy and macronutrient intake, SSB consumption, alcohol misuse, or food cravings among chronotypes (p > .05, for all). In conclusion, E-type individuals consumed snacks more frequently and later than M-types; however, chronotype was not associated with an individual’s energy intake, diet quality, and food cravings, which suggests that chronotype is negligibly associated with weight gain-related behaviors in this population.

Association between Chronotype and Type 2 Diabetes: A Literature Review

Chronotype is an individual attribute of a person regarding circadian rhythm. Past literature denotes that the evening chronotype individuals are more prone to obesity, sleep problems, unhealthy diet and lifestyles. This review investigates original research studies on association between chronotype and diabetes. Total 28 articles were reviewed which were published in four research databases. Evening or later chronotype was associated with diabetes and poor glycemic control. Dietary practices like breakfast skipping, percentage of calories consumed at night to total daily calories were found to partially mediate the association. There is need to study how several risk factors of diabetes and the circadian disruptors influence this association. The abstracts of the shortlisted articles were further studied and relevant articles were shortlisted. Finally, total 28 articles were selected for the review. Articles published in English language only were included. The decision to include or exclude a study; was taken by agreement of all authors.

Cognitive functions and underlying parameters of human brain physiology are associated with chronotype

Circadian rhythms have natural relative variations among humans known as chronotype. Chronotype or being a morning or evening person, has a specific physiological, behavioural, and also genetic manifestation. Whether and how chronotype modulates human brain physiology and cognition is, however, not well understood. Here we examine how cortical excitability, neuroplasticity, and cognition are associated with chronotype in early and late chronotype individuals. We monitor motor cortical excitability, brain stimulation-induced neuroplasticity, and examine motor learning and cognitive functions at circadian-preferred and non-preferred times of day in 32 individuals. Motor learning and cognitive performance (working memory, and attention) along with their electrophysiological components are significantly enhanced at the circadian-preferred, compared to the non-preferred time. This outperformance is associated with enhanced cortical excitability (prominent cortical facilitation, diminished cortical inhibition), and long-term potentiation/depression-like plasticity. Our data show convergent findings of how chronotype can modulate human brain functions from basic physiological mechanisms to behaviour and higher-order cognition.

Snacking Behavior Differs Between Evening and Morning Chronotype Individuals but Chronotype Is Not Associated With Energy Intake and Diet Quality

Abstract Objectives There is a growing body of literature that links a person's preferred time for activities and sleep cycle, or chronotype, to eating behaviors and the risk of becoming overweight or obese. However, the relationships among chronotype, snacking behavior, diet quality, and food cravings are poorly characterized among US adults. This cross-sectional study examined the associations among chronotype, snacking habits, dietary intake and quality, and food cravings these relationships. Methods One-hundred adults (mean age: 28.4 ± 7.3 y; 63% female) living in the United States completed the study. Based on their score on the HorneÖstberg Morningness-Eveningness Questionnaire, an individual was categorized into morning-type (M-type), intermediate-type (I-type), or evening-type (E-type). Snack intake was assessed using a previously published specialized food frequency questionnaire. Diet quality was obtained using the Diet History Questionnaire III. The validated General Food Cravings Questionnaire-Trait measured cravings. General linear regression was used to assess differences in outcomes among chronotypes. Results Over the course of a week, E-type individuals consumed snacks more often than the M-type (E-type: 13.9 ± 4.5, M-type: 11.2 ± 4.6; P = 0.002), but not the I-type (10.1 ± 4.1; P = 0.086). In terms of timing of snacking, E-type individuals consumed more snacks after dinner than the M-type (E-type: 5.3 ± 1.6; M-type: 3.7 ± 2.2; P &amp;lt; 0.001). E-type individuals consumed more energy-dense snacks (E-type: 14.4 ± 4.4; M-type: 11.3 ± 4.7; P = 0.005), especially candies (E-type: 2.0 ± 1.0; M-type: 1.1 ± 0.9, P = 0.005), than the M-type. However, there were no significant differences in healthy snack frequency, food cravings, diet quality, and energy and macronutrient intake among chronotypes (P &amp;gt; 0.05, for all). Conclusions In this relatively young population, E-type individuals consumed snacks more frequently than M-types. However, chronotypes were not associated with an individual's energy intake, diet quality, and food cravings, which suggests that chronotype negligibly influences weight gain risk in this young adult population. Funding Sources USDA NIFA and Michigan AgBioResearch.

Ideal Time of Day for Risky Decision Making: Evidence from the Balloon Analogue Risk Task.

BackgroundPrevious studies have demonstrated that individuals showed higher risk preference in the afternoon than in the morning. However, few studies aimed to explore the alteration of feedback learning effect during risky decision making, which is one of the important psychological processes of real risk behaviors. Moreover, cognitive function altered at the off-peak time due to impaired inhibitory control. The present study is to investigate the time-of-day effect on risky decision making and inhibitory control and whether the alteration of inhibitory control causes the differences in risky decision making across one day.Participants and MethodsWe adopted a within-participants design without extremely chronotype individuals to measure the time-of-day (9 am vs 3 pm) effect on risky decision making by using the Balloon Analogue Risk Task. At the same time, we measured the inhibitory control by using the Go/no-go task.ResultsOur results confirmed that individuals showed higher risk preference in the afternoon than in the morning. In addition, we found that individuals were insensitive to loss and the previous negative feedback in the afternoon. Critically, the results did not reveal any significant correlation between risky decision making and inhibitory control under the regulation of the time-of-day effects, although individuals performed worse on inhibitory control in the afternoon.ConclusionThe current findings revealed that the time-of-day effect regulated risky decision making and inhibitory control. Individuals act with higher risk preference, less sensitivity to loss as negative feedback, and lower inhibitory control in the afternoon than in the morning. This may reflect the effects of time-of-day on risk propensity and inhibitory control is relatively independent.

Impairment of sleep quality and quality of life in bimodal chronotype individuals

ABSTRACTThere is still insufficient data about the characteristics and clinical significance of the bimodal chronotype. We evaluated more than 1000 students with Morningness-Eveningness Questionnaire, Munich Chronotype Questionnaire (MCTQ), Pittsburgh Sleep Quality Index and 36-item Short Form Health Survey. Twelve percent of the sample was bimodal and they showed similar results to intermediate chronotype in MCTQ-chronotype and social jetlag, both different from morning and evening chronotypes. However, their quality of life and sleep quality were similar to evening types, both different from morning and intermediate types. We discuss if being bimodal would be a maladaptive aspect of circadian preference

Altered resting-state connectivity within default mode network associated with late chronotype

Current evidence suggests late chronotype individuals have an increased risk of developing depression. However, the underlying neural mechanisms of this association are not fully understood. Forty-six healthy, right-handed individuals free of current or previous diagnosis of depression, family history of depression or sleep disorder underwent resting-state functional Magnetic Resonance Imaging (rsFMRI). Using an Independent Component Analysis (ICA) approach, the Default Mode Network (DMN) was identified based on a well validated template. Linear effects of chronotype on DMN connectivity were tested for significance using non-parametric permutation tests (applying 5000 permutations). Sleep quality, age, gender, measures of mood and anxiety, time of scan and cortical grey matter volume were included as covariates in the regression model. A significant positive correlation between chronotype and functional connectivity within nodes of the DMN was observed, including; bilateral PCC and precuneus, such that later chronotype (participants with lower rMEQ scores) was associated with decreased connectivity within these regions. The current results appear consistent with altered DMN connectivity in depressed patients and weighted evidence towards reduced DMN connectivity in other at-risk populations which may, in part, explain the increased vulnerability for depression in late chronotype individuals. The effect may be driven by self-critical thoughts associated with late chronotype although future studies are needed to directly investigate this.

F97. Late Chronotype is Associated With Enhanced Amygdala Reactivity and Reduced Fronto-Limbic Functional Connectivity to Fearful Versus Happy Facial Expressions

Evidence suggests late chronotype individuals are at increased risk of developing depression. However, the underlying neural mechanisms that confer risk are not fully understood.

Exploring the effect of chronotype on hippocampal volume and shape: A combined approach

ABSTRACTCurrent evidence suggests that acute depression is associated with reduced total hippocampal volume and regional atrophy. Here, using structural magnetic resonance imaging, we assayed linear effects of chronotype on total hippocampal volume and morphology. Later chronotype was associated with localised atrophy in the subiculum region of the right hippocampus in the absence of changes in total volume. The hippocampus forms a key node in a network of brain regions implicated in emotional regulation and alterations in the structure of this region may underpin, in part, the increased vulnerability for depression in late chronotype individuals.

Identifying shift worker chronotype: implications for health.

Shift workers are at risk for developing serious health issues due to short sleep. One cause of short sleep is circadian misalignment: sleep time is not synchronized with the body’s natural circadian rhythms. Although circadian rhythms are strongly driven by the light/dark cycle, humans have individualized sleep time preferences (chronotypes) based on genetics, development, and external influences. Evening chronotype individuals fall asleep later than average and have a higher risk for developing various noncommunicable diseases. What is unclear is the association between chronotype, shift work, and risks for acquiring chronic conditions. This review is focused on shift worker chronotype and associations with obesity. Because of the paucity of research, other health issues connected with circadian misalignment were included, allowing for a total of 21 research studies. Evidence from this review supports chronotype and certain health issues are associated with shift work, even after adjusting for short sleep duration. In addition, there is evidence to support future research on how shift worker chronotype matched with shift timing impacts worker health. Through better understanding of this interface, occupational health providers can provide more comprehensive worker education on the risks associated with shift work and sleep disturbances.

Reduced Effective Emotion Regulation in Night Owls

Previous research has demonstrated a clear link between late chronotype and depression. The vulnerability factors underpinning this link, however, are unclear. Here the relationship between two specific emotion regulation strategies, cognitive reappraisal and expressive suppression, and chronotype was investigated using multiple regression. Two hundred and forty participants (age range 18-80, 189 females) completed validated self-report questionnaires assaying chronotype, neuroticism, depressive symptomatology, sleep quality, and emotion regulation. Eveningness was associated with increased expressive suppression, and morningness was associated with increased cognitive reappraisal after controlling for age, gender, depressive symptomatology, neuroticism, and sleep quality. Trait expressive suppression and reduced cognitive reappraisal are known to increase depression risk. Our results suggest that eveningness is associated with impaired emotion regulation, which may confer risk for future depression. These findings suggest modifiable markers that could be therapeutically targeted to prevent the onset of depression in late chronotype individuals.

Negative emotional biases in late chronotypes

Increasing evidence suggests evening chronotypes are at increased risk for developing depression. Here, we examined if, similar to acutely depressed patients, evening chronotype individuals display biases in emotional face recognition. Two hundred and twenty-six individuals completed an online survey including measures of sleep quality, depression/anxiety and chronotype followed by a simple emotion recognition task presenting male and female faces morphed in 10 steps between 0 (neutral) and 100% sad or happy. Evening chronotype was associated with increased recognition of sad facial expressions independently of sleep quality, mood, age and gender. The current results extend previous work indicating that negative biases in emotional processing are present in evening chronotypes and may have important implications for the prevention and treatment of depression in these vulnerable individuals.