Circadian clock genes and circadian phenotypes in patients with myocardial infarction

PurposeHuman physiological activities and diseases are under the control of the circadian rhythm. There are strong epidemiological associations between disrupted circadian rhythms, sleep duration and diseases. Sleep disorders are associated with vascular outcomes, such as myocardial infarction (MI).MethodsWe conducted an association study of genotype-phenotype interaction, to determine which circadian clock gene variants might be associated with the circadian phenotypes in patients with MI. In the present study, we analyzed the allele frequencies of 10 single nucleotide polymorphisms in four circadian clock genes in two independent samples: MI patients and controls. Chronotype was assessed using the Morningness - Eveningness Questionnaire (MEQ) and daytime sleepiness using the Epworth Sleepiness Scale (ESS).ResultsChronotype was associated with the ARNTL genetic variant rs12363415 in MI patients. The polymorphisms rs11932595 of the CLOCK gene and rs934945 of the PER2 gene were associated with daytime sleepiness in the patient group.ConclusionOur data suggest that genetic variations in some circadian clock genes might be related to circadian phenotype (i.e., chronotype and daytime sleepiness) in patients with myocardial infarction.     

Morning chronotype is associated with higher adherence to the Mediterranean diet in a sample of Italian adults

Background and aimsA growing body of evidence has associated subjects with an evening chronotype with worse eating behaviours and poorer diet quality. However, only few studies have investigated the relationship between chronotype and Mediterranean diet (MD). The aim of this study was to better understand the chronotype influence on dietary habits and MD adherence in a large sample of Italian adults.Methods and resultsA total of 1247 participants (66.7% women) with a mean age of 36.1 ± 14.6 years were included in the analysis. Chronotype was classified as morning in 35.6% of subjects, intermediate in 56.7%, and evening in 7.1%. Regarding meal frequency, evening subjects showed a significantly (p < 0.05) greater tendency to skip breakfast (20.5%) than morning (6.9%) and intermediate (12%) subjects. Similarly, evening subjects were found to skip mid-morning snack more often than morning subjects (59.1% vs. 47.1%; p = 0.04), and lunch more often than intermediate subjects (8% vs. 2.8%; p = 0.01). In addition, all meals were eaten by evening subjects at a significantly delayed time, except for lunch. As to MD adherence a significant (p < 0.001) higher adherence in morning subjects (10.1 ± 2.2) compared to intermediate (9.5 ± 2.1) and evening (9.5 ± 2.2) subjects was observed. At a logistic regression analysis adjusted for possible confounding factors, morning subjects showed an increased probability (OR 1.54, 95%CI 1.19–1.99; p < 0.001) of being in the highest MD adherence tertile.ConclusionChronotype was associated with MD adherence. In particular, morning subjects showed higher MD adherence than intermediate and evening subjects.     

Evaluation of Two Circadian Rhythm Questionnaires for Screening for the Delayed Sleep Phase Disorder

Objective

Delayed sleep phase disorder (DSPD) is a condition in which patients often fall asleep some hours after midnight and have difficulty waking up in the morning. Circadian chronotype questionnaires such as Horne-Östberg Morningness-Eveningness Questionnaire (MEQ) and Basic Language Morningness (BALM) scale have been used for screening for DSPD. This study was to evaluate these two chronotype questionnaires for screening of DSPD.

Methods

The study samples were 444 DSPD and 438 controls. Cronbach''s alpha coefficient was calculated to evaluate for internal consistency. An exploratory factor analysis was conducted using principal-axis factoring. The diagnostic performance of a test was evaluated using Receiver Operating Characteristic (ROC) curve analysis. A discriminant function analysis was also performed.

Results

For internal consistency, Cronbach''s alpha of 0.898 for BALM was higher than the 0.837 for MEQ, though both have acceptable internal consistency. BALM has better construct validity than the MEQ because some MEQ items measure different dimensions. However, when we evaluated the efficiency of two questionnaires for DSPD diagnosis by using the ROC curve, the BALM was similar to the MEQ. In a discriminant analysis with the BALM to classify the two groups (DSPD vs. normal), 6 items were identified that resulted in good classification accuracy. Upon examination of the classification procedure, 94.2% of the originally grouped cases were classified correctly.

Conclusion

These findings suggest that the BALM has better psychometric properties than the MEQ in screening and discriminating DSPS.     

Age and gender variations of sleep in subjects without sleep disorders

Objective. Although sleep is a biomarker for general health and pathological conditions, its changes across age and gender are poorly understood.

Methods. Subjective evaluation of sleep was assessed by questionnaires in 5,064 subjects, and 2,966 were considered without sleep disorders. Objective evaluation was performed by polysomnography in 2,160 subjects, and 1,147 were considered without sleep disorders. Only subjects without sleep disorders were included (aged 40–80 years).

Results. Aging was strongly associated with morning preference. Older subjects, especially women, complained less about sleepiness, and pathological sleepiness was significantly lower than in younger subjects. Self-reported sleep quality and daytime functioning improved with aging. Sleep latency increased with age in women, while sleep efficiency decreased with age in both genders. Deep slow-wave sleep decreased with age, but men were more affected. Spectral power densities within slow waves (< 5 Hz) and fast spindles (14–14.75 Hz) decreased, while theta-alpha (5-1 Hz) and beta (16.75–25 Hz) power in non-rapid eye movement sleep increased with aging. In REM sleep, aging was associated with a progressive decrease in delta (1.25–4.5 Hz) and increase in higher frequencies.

Conclusions. Our findings indicate that sleep complaints should not be viewed as part of normal aging but should prompt the identification of underlying causes.     

Sleep duration and timing are nonlinearly associated with depressive symptoms among older adults

BackgroundGeriatric depression is a common but preventable psychiatric disorder; however, its association with specific sleep patterns remains unclear. Therefore, we examined the association of self-reported sleep duration and sleep timing with depressive symptoms in the older population.MethodsA total of 1068 older Taiwanese adults (52.7% women; 72.2 ± 5.7 y) responded to a telephone survey during 2019–2020. Self-reported data on sociodemographic characteristics, sleep duration, bedtime, wake-up time (adapted items from Pittsburgh Sleep Quality Index), and depressive symptoms (five-item Center for Epidemiological Studies–Depression scale) were included. Generalized additive models were used to examine the nonlinear associations of sleep duration and midpoint sleep time (ie, the midpoint of bedtime and wake-up time) with depressive symptoms.ResultsThe means of sleep duration and midpoint sleep time in the participants were 6 h per night and 02:13 h, respectively. The results showed marked nonlinear associations of sleep patterns with depressive symptoms. Sleep duration shorter than 4 h per night was associated with a relatively higher level of depressive symptoms, with the highest risk (coefficient = 3.41; 95% confidence interval [CI] = 2.12, 4.70) while sleeping 2.06 h per night. The midpoint sleep time was positively associated with depressive symptom scores after 01:00 h.ConclusionsThe results showed that sleep duration and fitting sleep timing were nonlinearly associated with the risks of depressive symptoms in the general older adult population. These findings have implications for targeting nonpharmacological approaches by tackling modifiable behaviors, such as adequate sleep duration and timing, with decreased risks of depressive symptoms in the older adult population.     

Sleep quality among adults with attention deficit hyperactivity disorder or autism spectrum disorder: which is the role of gender and chronotype?

Both Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) present increased prevalence rates of sleep difficulties, which persist into adulthood. However, it is still unclear whether in adults these disorders show specific sleep patterns and which role is played by comorbidities, circadian preferences and gender. This study aimed to describe and compare subjective measures of sleep in adults with ADHD and high-functioning ASD, in relation to the levels of anxiety and depression, chronotype and gender. In a sample of 136 adults (43 ADHD, 43 high-functioning ASD, 50 controls) subjective sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI), and clinical scales were used to assess chronotype and the levels of anxiety and depression. The three groups showed a significant difference in the distribution of chronotypes, with greater prevalence of an Evening chronotype among ASD compared to controls. The MANCOVA using PSQI subscale scores as dependent variables and MEQ-SA score and depression range as covariates showed that the three groups significantly differ in quality, latency, efficiency, and dysfunction scores with a significant differences between ASD and ADHD in efficiency and dysfunction. Compared to men, women showed higher scores on PSQI total and quality subscale across the three groups and higher duration scores only within ASD group. Our results indicate that both ADHD and ASD adults show unique sleep disturbances and suggest that ASD patients, especially women, may display more pronounced disordered sleep.     

Owls and larks do not exist: COVID-19 quarantine sleep habits

BackgroundThe coronavirus pandemic presented a unique opportunity to study the daily temporal patterns and sleep habits of humans. The question to be explored was: Are there discernible differences in sleep between the normal operational environment and the stay-at-home condition?MethodsThis international prospective study analyzed results from the sleep-wake patterns questionnaire, daily logs, and interviews. Surveys were administered to the healthy volunteers (age 15–60 y) with stay-at-home for a month or more, without previous sleep disorders and mood-related complaints; volunteers were not involved in online education/work daily timetable-related activities.ResultsWe analyzed 3787 subjects with average stay-at-home of 65 ± 9 days. The most significant changes in sleep occurred during the first ten days when the difference between weekdays and weekends disappeared and changes occurred in napping habits. The majority of the participants (66.8%) shifted toward eveningness when the self-selected sleep was possible and 1869 volunteers appeared to be owls (49.4%), 823 (21.7%) exercised “typical” sleep, 478 (12.6%) were larks, and 617 (16.3%) participants were completely desynchronized to the end of stay-at-home. In addition, 497 participants (13.1%) alternated their sleep habits. The most of the desynchronized participants (n = 414) were older than 50 years (age correlation r = 0.80), and predominantly males (n = 297, r = 0.76).ConclusionIn self-selected sleep conditions, the timing of sleep and sleep habits significantly differ from those of socially and economically fixed daily routine conditions. The changes in daily temporal patterns of humans during a prolonged stay-at-home situation indicate that human sleep habits may change according to existing living conditions.     

Further support for higher salivary cortisol levels in "morning" compared to "evening" persons

We analyzed free cortisol daytime levels in a "3-days-7-samples-a-day" protocol in relation to morningness in 112 middle-aged male and female adults derived from the first year of data of the Trier Teacher Stress Study using a one-item proxy for the assessment of chronotype. First, log-transformed cortisol levels were analyzed by a repeated-measures approach controlling for relevant covariates. Results yielded an almost significant main effect of morningness (P=.06). Subsequent within-day analyses, additionally controlling for awakening time, resulted in (marginally) significant main effects of morningness at Day 1 (P=.06) and Day 3 (P=.05) and a significant interaction of sample-by-morningness at Day 2 (P=.04). In sum, the present data seem to corroborate the idea of higher daytime cortisol levels in morning relative to evening types in a sample of healthy middle-aged male and female adults.