Evening physical activity alters wrist temperature circadian rhythmicity

The adequate time to perform physical activity (PA) to maintain optimal circadian system health has not been defined. We studied the influence of morning and evening PA on circadian rhythmicity in 16 women with wrist temperature (WT). Participants performed controlled PA (45?min continuous-running) during 7 days in the morning (MPA) and evening (EPA) and results were compared with a no-exercise-week (C). EPA was characterized by a lower amplitude (evening: 0.028?±?0.01?°C versus control: 0.038?±?0.016?°C; p?<?0.05) less pronounced second-harmonic (power) (evening: 0.41?±?0.47 versus morning: 1.04?±?0.59); and achrophase delay (evening: 06:35?±?02:14?h versus morning: 04:51?±?01:11?h; p?<?0.05) as compared to MPA and C. Performing PA in the late evening might not be as beneficial as in the morning.     

Short and long-term effects of unguided internet-based cognitive behavioral therapy for chronic insomnia in morning and evening persons: a post-hoc analysis

ABSTRACT

A post-hoc analysis comparing morning and evening persons with insomnia on sleep and mental health characteristics was conducted in order to investigate whether an Internet-based cognitive behavioral therapy for insomnia (ICBTi) was effective both for morning and evening persons. Adult patients (N = 178, mean age = 44.8, 67% females) with insomnia were randomized to either ICBTi (N = 92; morning persons = 41; evening persons = 51) or a web-based patient education condition (N = 86; morning persons = 44; evening persons = 42). All patients were assessed with sleep diaries, the Insomnia Severity Index (ISI), the Bergen Insomnia Scale (BIS), the Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16), the Hospital Anxiety and Depression Scale (HADS) and the Chalder Fatigue Scale (CFQ). Patients were characterized as morning or evening persons based on a median split on the Horne-Östberg Morningness Eveningness Questionnaire. Short and long-term effects of treatment were examined with mixed-model repeated-measures analyses. Morning and evening persons did not differ in terms of age, gender or educational status. At baseline, morning persons had more wake time after sleep onset (d= 0.54, p < .001) and more early morning awakening (d= 0.38, p < .05) compared to evening persons, while evening persons reported longer sleep onset latency (d= 0.60, p < .001), more time in bed (d= 0.56, p < .001), longer total sleep time (d= 0.45, p < .01), more fatigue (d= 0.31, p < .05) and more dysfunctional beliefs and attitudes about sleep (d= 0.47, p < .01). Despite these differences at baseline, both morning and evening persons receiving ICBTi benefitted more across most measures compared to morning and evening persons who received patient education. For morning persons in the ICBTi group, ISI scores were reduced from 17.3 at baseline to 8.8 (d_pre-post = 2.48, p < .001) at post-assessment, and to 10.0 at 18-month follow up (d_pre-post18m = 2.13, p < .001). Comparable results were found for evening persons in the ICBTi group, with a reduction in ISI scores from 17.4 at baseline to 8.6 (d_pre-post = 2.24, p < .001) at post-assessment, and to 8.7 at 18-month follow up (d_pre-post18m = 2.19, p < .001). Similar results were found on the BIS, DBAS, HADS, CFQ and sleep diary data. Despite different insomnia symptomatology between the two groups, the current study suggests that ICBTi is effective across scores on the morningness-eveningness dimension. The study was pre-registered at: ClinicalTrials.gov Identifier: NCT02261272.     

Effects of Acute Endurance Exercise Performed in the Morning and Evening on Inflammatory Cytokine and Metabolic Hormone Responses

Purpose

To compare the effects of endurance exercise performed in the morning and evening on inflammatory cytokine responses in young men.

Methods

Fourteen healthy male participants aged 24.3 ± 0.8 years (mean ± standard error) performed endurance exercise in the morning (0900–1000 h) on one day and then in the evening (1700–1800 h) on another day with an interval of at least 1 week between each trial. In both the morning and evening trials, the participants walked for 60 minutes at approximately 60% of the maximal oxygen uptake (V·O2max) on a treadmill. Blood samples were collected to determine hormones and inflammatory cytokines at pre-exercise, immediately post exercise, and 2 h post exercise.

Results

Plasma interleukin (IL)-6 and adrenaline concentrations were significantly higher immediately after exercise in the evening trial than in the morning trial (P < 0.01, both). Serum free fatty acids concentrations were significantly higher in the evening trial than in the morning trial at 2 h after exercise (P < 0.05). Furthermore, a significant correlation was observed between the levels of IL-6 immediately post-exercise and free fatty acids 2 h post-exercise in the evening (r = 0.68, P < 0.01).

Conclusions

These findings suggest that the effect of acute endurance exercise in the evening enhances the plasma IL-6 and adrenaline concentrations compared to that in the morning. In addition, IL-6 was involved in increasing free fatty acids, suggesting that the evening is more effective for exercise-induced lipolysis compared with the morning.     

Effects of morning vs. evening combined strength and endurance training on physical performance,sleep and well-being

The aim of the present study was to examine how combined strength and endurance training in the morning and evening influences the adaptations in strength and endurance performance, perception of time management, psychological well-being and sleep. The combined training period lasted for 24 weeks and the participants were divided into the morning training (MG, n = 18), evening training (EG, n = 24) and control groups (CG, n = 10). Isometric leg press force (iLP), maximal oxygen consumption (VO₂max), sleep behavior, fatigue, time management, motivation, self-esteem and health-related quality of life (HRQoL) were assessed. Morning to evening difference in iLP was observed in both MG and EG at Pre and Post, with higher force values in the evening, but not for VO₂max. iLP force increased significantly in EG in the morning (p < 0.001) and evening (p = 0.010). VO₂max increased in MG and EG both in the morning (both p < 0.001) and in the evening (MG: p < 0.001; EG: p = 0.003). Participants of the present study slept 7–8 h per night and the self-reported sleep duration, get-up time and the average time to go to bed were similar between the groups and did not change from Pre to Post. From HRQoL dimensions, the score for bodily pain decreased in MG (p = 0.029) and significant between-group differences were observed for Pre-Post changes in MG and EG (p = 0.001) as well as between MG and CG (p < 0.001). In vitality, a significant between-group difference was observed for Pre to Post changes in MG and EG (p = 0.014). Perception of time management decreased in EG (p = 0.042) but stayed unchanged for MG and CG. For the intrinsic motivation to participate, significant between-group differences were observed for MG and EG (p = 0.033) and between MG and CG (p = 0.032) for Pre to Post changes. Self-esteem improved in MG (p = 0.029) and EG (p = 0.024). The present combined strength and endurance training program performed in the morning and in the evening led to similar improvements in strength and endurance performance. Training in the morning or in the evening did not disrupt the already good sleep behavior and it was able to further increase the self-esteem. Although training in the morning hours may leave more time for free time activities or social life (i.e. family and friends) compared to the evening training, it might be more challenging to stay motivated to participate in prolonged training programs in the morning hours.     

Effects of sequential feeding with low- and high-protein diets on growth performances and plasma metabolite levels in geese

This study was conducted by two trials to investigate effects of sequential feeding with low- and high-protein diets on growth traits and plasma metabolites in geese. In Trial I, the effect of sequential feeding under time-restricted feeding system was investigated. Seventy-two White Roman goslings were randomly allotted into either sequential feeding (S1) or control feeding (C1) group. All goslings were fed for 1 h at morning and at evening, respectively, from 2 to 8 weeks of age. S1 group was offered 13% CP diet at morning and 19% CP diet at evening. C1 group was offered the same diet (16% CP; mixed equally with the two diets mentioned above) at both morning and evening. Blood samples were hourly collected for 4 h after feeding at both morning and evening for the determination of the postprandial plasma levels of glucose, triacylglycerol and uric acid at the end of experiment. Results showed that BW, average daily gain (ADG), and daily feed intake (FI) were not different between groups, but the feed efficiency (FE) in S1 group was significantly higher than that in C1 group (P<0.05). The areas under curve (AUC) of plasma postprandial levels of glucose, triacylglycerol and uric acid were not affected by treatment, but the AUC of triacylglycerol and uric acid in morning were lower than those in evening (P<0.05). In Trial II, the effect of sequential feeding under ad libitum feeding system was investigated. Twenty-four goslings were randomly allotted into either sequential feeding (S2) or control feeding (C2) group. Diets were altered at 0600 and 1800 h, respectively, and geese were fed ad libitum from 4 to 8 weeks of age. S2 group was offered 14% CP diet at morning and 20% CP diet at evening. C2 group was supplied the same diet (mixed with the two diets according to the ratio of diets consumed by S2 group on the preceded day) at both morning and evening. Results showed that the ADG in S2 group was higher than those in C2 group (P<0.05). Summarized data from both trials showed that sequential feeding improves daily gain and FE in growing geese.     

Effect of Time of Day on Performance,Hormonal and Metabolic Response during a 1000-M Cycling Time Trial

The aim of this study was to determine the effect of time of day on performance, pacing, and hormonal and metabolic responses during a 1000-m cycling time-trial. Nine male, recreational cyclists visited the laboratory four times. During the 1^st visit the participants performed an incremental test and during the 2^nd visit they performed a 1000-m cycling familiarization trial. On the 3^rd and 4^th visits, the participants performed a 1000-m TT at either 8 am or 6 pm, in randomized, repeated-measures, crossover design. The time to complete the time trial was lower in the evening than in the morning (88.2±8.7 versus 94.7±10.9 s, respectively, p<0.05), but there was no significant different in pacing. However, oxygen uptake and aerobic mechanical power output at 600 and 1000 m tended to be higher in the evening (p<0.07 and 0.09, respectively). There was also a main effect of time of day for insulin, cortisol, and total and free testosterone concentration, which were all higher in the morning (+60%, +26%, +31% and +22%, respectively, p<0.05). The growth hormone, was twofold higher in the evening (p<0.05). The plasma glucose was ∼11% lower in the morning (p<0.05). Glucagon, norepinephrine, epinephrine and lactate were similar for the morning and evening trials (p>0.05), but the norepinephrine response to the exercise was increased in the morning (+46%, p<0.05), and it was accompanied by a 5-fold increase in the response of glucose. Muscle recruitment, as measured by electromyography, was similar between morning and evening trials (p>0.05). Our findings suggest that performance was improved in the evening, and it was accompanied by an improved hormonal and metabolic milieu.     

The Relationship of Dream Content and Changes in Daytime Mood in Traumatized vs. Non-Traumatized Children

The study examined how the mood changes from night to morning, and how dysphoric dream contents associate with this change among children who live in traumatic environment and their controls from peaceful area. The sample consisted of 413 Palestinian boys and girls of 6–15 years of age, the mean age being 11.22 ± 2.64. The participants filled in a seven-day dream diary in which they recorded their recalled dreams every morning. First, the results, confirmed that mood change from evening to morning is a general dream function: age and gender are not related to the change. The mood chance was rather associated with what and whom the children dreamt about. Second, the hypothesis of the trauma group showing less change in dysphoric dream content and in the intensity of negative morning mood across a period of time of seven days was not confirmed. On the contrary, the results showed that both dreams incorporating dysphoric themes and negative morning mood decreased only among children living in traumatic conditions. Third, it was hypothesized that there is a stronger association between presleep negative mood and dysphoric dreams, as well as between the dysphoric dreams and negative morning mood among children living in traumatic environment than among children from peaceful area. Contrary to the hypothesis, results for the trauma group revealed a reverse association between evening mood and dream contents: the more afraid, angry and worried children felt in the evening, the more Happy recreation dreams they reported, and the happier evening mood they reported, the more Threatening stranger dreams they had. However, concurring with the hypothesis, a direct association was found between dysphoric dreams and negative morning mood in the trauma group. The more children dreamt about Threatening strangers, the more afraid, angry and worried they felt in the morning. The discussion proposes a model of the correcting or balancing dream function that is characterized by an reverse assimilation of incorporating evening mood into dreams, and by a direct accommodation of dream content into morning mood.     

Comparison of the Efficacy of Morning versus Evening Administration of Olmesartan in Uncomplicated Essential Hypertension

A total of 18 diurnally active subjects with uncomplicated, mild to moderate, essential hypertension were studied to compare the efficacy of the morning versus evening administration of an oral olmesartan medication. After a two‐week, wash‐out/placebo run‐in period, subjects with clinic diastolic blood pressure (DBP) ≥90 mm Hg and <110 mm Hg began 12 weeks of 20 mg olmesartan medoxomil tablet therapy at 08:00 h daily. Four of the 18 subjects required dose escalation to 40 mg at eight weeks because of clinic DBP≥90 mm Hg. After the 12‐week period of once‐a‐day 08:00 h treatment, subjects were immediately switched to an evening (20:00 h) drug‐ingestion schedule for another 12‐week period without change in dose. Subjects underwent 24 h ambulatory blood pressure monitoring (ABPM) before the initiation of morning treatment and at the end of both the 12‐week morning and evening treatment arms. Dosing time did not exert statistically significant differences on the efficacy of olmesartan: the reduction from baseline in the 24 h mean systolic (SBP) and DBP was, respectively, 18.8 and 14.6 mm Hg with morning dosing and 16.1 and 13.2 mm Hg with evening dosing (p>0.152 between groups). The amplitude of the BP 24 h pattern did not vary with dosing time, indicating full 24 h BP reduction no matter the clock hour of treatment. Although, the BP‐lowering effect was somewhat better with morning dosing, the results of this study suggest that the studied olmesartan medoxomil preparation efficiently reduces BP when ingested in the morning (08:00 h) or evening (20:00 h) in equivalent manner, based on statistical testing, throughout the 24 h.     

The effects of time of day-specific resistance training on adaptations in skeletal muscle hypertrophy and muscle strength: A systematic review and meta-analysis

The present paper endeavored to elucidate the topic on the effects of morning versus evening resistance training on muscle strength and hypertrophy by conducting a systematic review and a meta-analysis of studies that examined time of day-specific resistance training. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines with searches conducted through PubMed/MEDLINE, Scopus, and SPORTDiscus databases. The Downs and Black checklist was used for the assessment of the methodological quality of the included studies. Studies that examined the effects of time of day-specific resistance training (while equating all other training variables, such as training frequency and volume, between the groups) on muscle strength and/or muscle size were included in the present review. The random effects model was used for the meta-analysis. Meta-analyses explored (1) the differences in strength expression between morning and evening hours at baseline; (2) the differences in strength within the groups training in the morning and evening by using their post-intervention strength data from the morning and evening strength assessments; (3) the overall differences between the effects of morning and evening resistance training (with subgroup analyses conducted for studies that assessed strength in the morning hours and for the studies that assessed strength in the evening hours). Finally, a meta-analysis was also conducted for studies that assessed muscle hypertrophy. Eleven studies of moderate and good methodological quality were included in the present review. The primary findings of the review are as follows: (1) at baseline, a significant difference in strength between morning and evening is evident, with greater strength observed in the evening hours; (2) resistance training in the morning hours may increase strength assessed in the morning to similar levels as strength assessed in the evening; (3) training in the evening hours, however, maintains the general difference in strength across the day, with greater strength observed in the evening hours; (4) when comparing the effects between the groups training in the morning versus in the evening hours, increases in strength are similar in both groups, regardless of the time of day at which strength assessment is conducted; and (5) increases in muscle size are similar irrespective of the time of day at which the training is performed.     

Chronotype and Breast Cancer Risk in a Cohort of US Nurses

The aim of this study was to examine the relation between chronotype and breast cancer risk. We analyzed the association between chronotype (definite morning type, probable morning type, probable evening type, definite evening type, or neither morning nor evening type) and breast cancer risk among 72 517 women in the Nurses’ Health Study II (NHS II). Chronotype was self-reported in 2009, and 1834 breast cancer cases were confirmed among participants between 1989 and 2007; a 2-yr lag period was imposed to account for possible circadian disruptions related to breast cancer diagnosis. Age- and multivariable-adjusted logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Participants who self-reported as neither morning nor evening type had a 27% increased risk of breast cancer (multivariable-adjusted OR?=?1.27, 95% CI?=?1.04–1.56), compared with definite morning types. None of the other chronotypes were significantly associated with breast cancer risk (multivariable-adjusted OR?=?0.99, 95% CI?=?0.87–1.12 for probable morning versus definite morning types; OR?=?0.96, 95% CI?=?0.84–1.09 for probable evening versus definite morning types; and OR?=?1.15, 95% CI?=?0.98–1.34 for definite evening versus definite morning types). Overall, chronotype was not associated with breast cancer risk in our study. A modestly increased risk among neither morning nor evening types may indicate circadian disruption as a potentially underlying mechanism; however, more studies are needed to confirm our results.     

Effect of the time of day on central and peripheral fatigue during 2-min maximal voluntary contractions in persons with multiple sclerosis: gender differences

There is a lack of data on fatigue changes within 24 h among patients with multiple sclerosis. The purpose of this study was to evaluate the effect of time of day on central and peripheral fatigue during a continuous 2-min maximal voluntary contraction of the quadriceps muscle in women and men with multiple sclerosis (MS). We studied age-matched MS patients (range, 40–50 years). The inclusion criteria for patients were: a Kurtzke Expanded Disability Status score and a Fatigue Severity Scale score. We found a significant gender difference in central activation ratio (CAR) in the evening. At the end of the 2-min maximal voluntary contraction (MVC), the voluntary torque decreased by about 65% in men and women with MS in both the morning and evening. We also observed that, in women, CAR decreased markedly during the first 30 s in the evening test. The most interesting finding of our study is that central fatigue increased, whereas peripheral fatigue decreased markedly in the evening only in women. It remains unclear why women’s central fatigue is greater in the evening than in the morning.     

Meteorological factors affecting beginning and end of foraging activities of Camponotus maculatus aegyptiacus emery (HYM., formicidae)

Summary It is to be concluded that the nocturnal ant C. maculatus aegyptiacus Emery starts foraging with the sun-set and its field activities are stopped with the sun-rise. The level of foraging activity showed two peaks at 1–3 hours after evening start and before morning stop.The differences in temperature and relative humidity at evening initiation and morning cessation of foraging activities suggest that both temperature and relative humidity have a marked effect on the evening start and morning stop of field activities.Although the atmospheric pressure, wind velocity and dew may have affected the rate of trail activity they appeared to have, within the ranges obtained, a very slight influence upon the evening start or morning stop of foraging activity.Cloud cover is not involved in the evening initiation or morning cessation of trail activity since it happened that the sky was almost always very clear at both evenings and mornings of all the nights of investigation from May to October but, the probability that the rate of nocturnal foraging activity of C. maculatus aegyptiacus might be affected by the cloud cover through the reduction of the moonlight exists. It is hoped to examine this in more detail at a later date.Zur Zeit: Zoologisches Institüt, 8 München 2, Luisenstraße 14.     

Association between Time of Day of Sports-Related Physical Activity and the Onset of Acute Myocardial Infarction in a Chinese Population

Objective

To investigate the association between the time of day of sports-related physical activity and the onset of acute myocardial infarction (AMI) in a coronary artery disease (CAD) population in China.

Methods

Between February 2014 and March 2015, a total of 696 patients from Nanjing, China, who had CAD were studied and divided into two groups (Non-AMI and AMI groups). The work-related activity and sports-related physical activity information were obtained from a self-reporting predesigned patient questionnaire.

Results

Sports-related physical activity was associated with a lower risk of the onset of AMI, after adjusting the established and potential confounders, with an adjusted odds ratio (OR) of 0.67 (95% CI, 0.47–0.94) compared with those who did not have any sports-related physical activity. A dose–response relationship was observed for intensity, duration, and frequency of sports-related physical activity. Further stratification analysis revealed that the protective effects of sports-related physical activity were significant in the morning and evening groups, and patients who exercised in the evening were at a lower risk of AMI than those doing sports-related physical activity in the morning. The adjusted ORs for doing sports-related physical activity in the morning and evening groups were 0.60(0.36–0.98) and 0.56(0.37–0.87), respectively, compared with inactivity (all P<0.05). On the occurrence of AMI, doing sports-related physical activity in the evening had an adjusted OR of 0.93 (95% CI, 0.54–1.64, P = 0.824) compared with in the morning group.

Conclusions

Sports-related physical activity is associated with a lower risk of onset of AMI than inactivity in Chinese people. For CAD patients, we suggest they participate in sports-related physical activity of high intensity, long duration, and high frequency. Doing sports-related physical activity in the evening and in the morning have similar benefits on the prevention of the onset of AMI.     

Efficacy in asthma of once-daily treatment with fluticasone furoate: a randomized,placebo-controlled trial

Background

Fluticasone furoate (FF) is a novel long-acting inhaled corticosteroid (ICS). This double-blind, placebo-controlled randomized study evaluated the efficacy and safety of FF 200 mcg or 400 mcg once daily, either in the morning or in the evening, and FF 200 mcg twice daily (morning and evening), for 8 weeks in patients with persistent asthma.

Methods

Asthma patients maintained on ICS for ≥ 3 months with baseline morning forced expiratory volume in one second (FEV₁) 50-80% of predicted normal value and FEV₁ reversibility of ≥ 12% and ≥ 200 ml were eligible. The primary endpoint was mean change from baseline FEV₁ at week 8 in pre-dose (morning or evening [depending on regimen], pre-rescue bronchodilator) FEV₁.

Results

A total of 545 patients received one of five FF treatment groups and 101 patients received placebo (intent-to-treat population). Each of the five FF treatment groups produced a statistically significant improvement in pre-dose FEV₁ compared with placebo (p < 0.05). FF 400 mcg once daily in the evening and FF 200 mcg twice daily produced similar placebo-adjusted improvements in evening pre-dose FEV₁ at week 8 (240 ml vs. 235 ml). FF 400 mcg once daily in the morning, although effective, resulted in a smaller improvement in morning pre-dose FEV₁ than FF 200 mcg twice daily at week 8 (315 ml vs. 202 ml). The incidence of oral candidiasis was low (0-4%) and UC excretion was comparable with placebo for all FF groups.

Conclusions

FF at total daily doses of 200 mcg or 400 mcg was significantly more effective than placebo. FF 400 mcg once daily in the evening had similar efficacy to FF 200 mcg twice daily and all FF regimens had a safety tolerability profile generally similar to placebo. This indicates that inhaled FF is an effective and well tolerated once-daily treatment for mild-to-moderate asthma.

Trial registration

NCT00398645     

Does Lowering Evening Rectal Temperature to Morning Levels Offset the Diurnal Variation in Muscle Force Production?

Muscle force production and power output in active males, regardless of the site of measurement (hand, leg, or back), are higher in the evening than the morning. This diurnal variation is attributed to motivational, peripheral, and central factors and higher core and, possibly, muscle temperatures in the evening. This study investigated whether decreasing evening resting rectal temperatures to morning values, by immersion in a water tank, leads to muscle force production and power output becoming equal to morning values in motivated subjects. Ten healthy active males (mean?±?SD: age, 22.5?±?1.3 yrs; body mass, 80.1?±?7.8?kg; height, 1.72?±?0.05?m) completed the study, which was approved by the local ethics committee of the university. The subjects were familiarized with the techniques and protocol and then completed three sessions (separated by at least 48?h): control morning (07:30?h) and evening (17:30?h) sessions (with an active 5-min warm-up on a cycle ergometer at 150?W) and then a further session at 17:30?h but preceded by an immersion in cold water (～16.5?°C) to lower rectal temperature (T_rec) to morning values. During each trial, three measures of grip strength, isokinetic leg strength measurements (of knee flexion and extension at 1.05 and 4.19?rad?s^?1 through a 90° range of motion), and three measures of maximal voluntary contraction (MVC) on an isometric dynamometer (utilizing the twitch-interpolation technique) were performed. T_rec, rating of perceived exertion (RPE), and thermal comfort (TC) were also measured after the subjects had reclined for 30?min at the start of the protocol and prior to the measures for grip, isokinetic, and isometric dynamometry. Muscle temperature was taken after the warm-up or water immersion and immediately before the isokinetic and MVC measurements. Data were analyzed using general linear models with repeated measures. T_rec values were higher at rest in the evening (by 0.37?°C; p?<?0.05) than the morning, but values were no different from morning values immediately after the passive pre-cooling. However, T_rec progressively decreased throughout the experiments, this being reflected in the subjects’ ratings of thermal comfort. Muscle temperatures also displayed significant diurnal variation, with higher values in the evening (by 0.39?°C; p?<?0.05). Right grip strength, isometric peak power, isokinetic knee flexion and extension for peak torque and peak power at 1.05?rad?s^?1, and knee extension for peak torque at 4.19?rad?s^?1 all showed higher values in the evening (a range of 3–14%), and all other measures of strength or power showed a statistical trend to be higher in the evening (0.10?>?p?>?0.05). Pre-cooling in the evening significantly reduced force or power variables towards morning values. In summary, effects of time of day were seen in some measures of muscle performance, in agreement with past research. However, in this population of motivated subjects, there was evidence that decreasing evening T_rec to morning values by coldwater immersion decreased muscle strength to values similar to those found in the morning. It is concluded that diurnal changes in muscle performance are linked to diurnal changes in T_rec. (Author correspondence: B.J.Edwards@ljmu.ac.uk)     

Chronopharmacology of Oral Nitrates in Healthy Subjects

The pharmacokinetics and the hemodynamic effects (blood pressure, heart rate) of oral organic nitrates have been investigated in healthy subjects after oral single-dose application either in the morning or in the evening. Isosorbide-5- monitrate (IS-SMN, 60 rng) was administered as an immediate-release tablet or as a slow-release formulation. Isosorbide dinitrate (ISDN, 20 mg) was ingested as an immediate-release tablet. After administration of IS-5-MN as an immediate-release tablet, the drug was more rapidly absorbed in the morning (t_max of 0.9 h) than in the evening (t_max of 2.1 h). The rapid absorption led to more pronounced effects in the morning, at which time maximum drug concentrations occurred at the same time as peak effects were observed. After evening administration, however, peak effects were in advance of the maximum drug concentrations. No chronokinetics were observed after application of the slow-release formulation of IS-5- MN. In accordance with the results of the immediate-release formulation, peak effects of the slow-release preparation occurred significantly earlier than peak drug concentrations after evening than after morning dosing. ISDN bioavailability was higher after morning than after evening administration and hemodynamic effects were more pronounced in the evening than in the morning. These results show that daily variations in pharmacokinetics and/or hemodynamic effects can be observed with oral nitrates. In addition, galenic formulation can influence the time-specified pharmacokinetics of IS-5-MN.     

Associations Between Chronotypes,Psychopathology, and Personality Among Incoming College Students

Chronotye is associated with age, sex, personality, and parental monitoring during childhood. The evening type is associated with poor school performance, sleep problems, anxious/depressive symptoms, tobacco smoking, caffeine consumption, alcohol drinking, and suicidality in adolescents. The present study tested the relationships between chronotype and a wide range of psychopathology and personality traits among 2919 incoming undergraduate students. Each participant completed a self-administered questionnaire that included demographics, plus the Morningness-Eveningness (M-E) scale, Brief Symptom Rating Scale (BSRS), Tridimensional Personality Questionnaire, and Maudesley Personality Inventory. The t-score distribution of the M-E scale was used to form the morning (t-score >60, n?=?419), evening (t-score <40, n?=?371), and intermediate (40?≤?t-score?≤?60, n?=?2129) groups. Multivariable regression was employed for data analysis. For males, the evening type scored higher on all subscales of the BSRS than the morning type, except phobic anxiety. For females, the evening type had higher scores than the other two types on all subscales, except in obsession/compulsion and phobic anxiety, where the evening type only scored higher than the intermediate type. The evening type of both sexes also scored higher than the morning type in novelty seeking, harm avoidance, and neurotic personality characteristics, but lower than the morning type in extraversion and social desirability. In reward dependence, the evening type scored lowest for males, but there was no difference for females. The findings of the evening type being associated with possible psychopathology and certain types of personality have public health implications, that is, chronotype needs to be taken into account in the development of mental health prevention programs and assessment of and intervention for mental problems in young adults. (Author correspondence: gaushufe@ntu.edu.tw)     

Low-dose oral risperidone lengthened sleep duration in healthy participants

We examined the effects of low-dose oral risperidone (RIS) on nocturnal sleep in healthy participants. This study was performed in a placebo-controlled manner in 10 healthy male volunteers (mean age, 23.6 years), with administration of 0.5 mg of RIS oral solution or a placebo in the morning or evening for 2 consecutive days. Each night, polysomnography (PSG) was performed, and PSG data during non-rapid-eye movement (REM) sleep were processed by power spectral analysis. An evening administration of 0.5 mg RIS significantly increased total sleep time, sleep efficiency and sleep stage 3, and significantly decreased total waking time and waking after sleep onset (P < 0.05). A morning administration of 0.5 mg RIS significantly increased sleep stage 3 (P < 0.05). According to power spectral analysis, the evening administration of RIS significantly increased the theta power (P < 0.05) and decreased the beta power (P < 0.05) during non-REM sleep. The administration of 0.5 mg oral RIS increases sleep stage 3 and increases total sleep time following evening administration.

     

Light activates output from evening neurons and inhibits output from morning neurons in the Drosophila circadian clock

Animal circadian clocks are based on multiple oscillators whose interactions allow the daily control of complex behaviors. The Drosophila brain contains a circadian clock that controls rest–activity rhythms and relies upon different groups of PERIOD (PER)–expressing neurons. Two distinct oscillators have been functionally characterized under light-dark cycles. Lateral neurons (LNs) that express the pigment-dispersing factor (PDF) drive morning activity, whereas PDF-negative LNs are required for the evening activity. In constant darkness, several lines of evidence indicate that the LN morning oscillator (LN-MO) drives the activity rhythms, whereas the LN evening oscillator (LN-EO) does not. Since mutants devoid of functional CRYPTOCHROME (CRY), as opposed to wild-type flies, are rhythmic in constant light, we analyzed transgenic flies expressing PER or CRY in the LN-MO or LN-EO. We show that, under constant light conditions and reduced CRY function, the LN evening oscillator drives robust activity rhythms, whereas the LN morning oscillator does not. Remarkably, light acts by inhibiting the LN-MO behavioral output and activating the LN-EO behavioral output. Finally, we show that PDF signaling is not required for robust activity rhythms in constant light as opposed to its requirement in constant darkness, further supporting the minor contribution of the morning cells to the behavior in the presence of light. We therefore propose that day–night cycles alternatively activate behavioral outputs of the Drosophila evening and morning lateral neurons.     

Light Activates Output from Evening Neurons and Inhibits Output from Morning Neurons in the Drosophila Circadian Clock

Animal circadian clocks are based on multiple oscillators whose interactions allow the daily control of complex behaviors. The Drosophila brain contains a circadian clock that controls rest–activity rhythms and relies upon different groups of PERIOD (PER)–expressing neurons. Two distinct oscillators have been functionally characterized under light-dark cycles. Lateral neurons (LNs) that express the pigment-dispersing factor (PDF) drive morning activity, whereas PDF-negative LNs are required for the evening activity. In constant darkness, several lines of evidence indicate that the LN morning oscillator (LN-MO) drives the activity rhythms, whereas the LN evening oscillator (LN-EO) does not. Since mutants devoid of functional CRYPTOCHROME (CRY), as opposed to wild-type flies, are rhythmic in constant light, we analyzed transgenic flies expressing PER or CRY in the LN-MO or LN-EO. We show that, under constant light conditions and reduced CRY function, the LN evening oscillator drives robust activity rhythms, whereas the LN morning oscillator does not. Remarkably, light acts by inhibiting the LN-MO behavioral output and activating the LN-EO behavioral output. Finally, we show that PDF signaling is not required for robust activity rhythms in constant light as opposed to its requirement in constant darkness, further supporting the minor contribution of the morning cells to the behavior in the presence of light. We therefore propose that day–night cycles alternatively activate behavioral outputs of the Drosophila evening and morning lateral neurons.