Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials

Sleep, Nutrition, and Health Maintenance in Cardiothoracic Surgery

Cardiothoracic surgeons work in high-intensity environments starting in surgical training and throughout their careers. They deal with critical patients. Their routine procedures are delicate, require extensive attention to detail, and can have detrimental effects on patients' lives. Cardiothoracic surgeons are required to perform at their best capacity incessantly. To do this, they must safeguard their mental and physical well-being. Preserving health through sleep, nutrition, exercise, and routine medical checkups ensures a cardiothoracic surgeon's well-being. Great personal effort and discipline is required to maintain health in a busy schedule. We offer our best recommendations from expert peers in the field.

Device-estimated sleep metrics do not mediate the relation between race and blood pressure dipping in young black and white women

Short, disturbed, and irregular sleep may contribute to blunted nocturnal blood pressure (BP) dipping, a predictor of cardiovascular disease. Black women (BLW) demonstrate less BP dipping and poorer sleep health than White women (WHW). However, it remains unclear whether device-estimated sleep health metrics mediate the relation between race and BP dipping in young women. We hypothesized that the relation between race and BP dipping would be partly mediated by sleep health metrics of sleep duration, sleep efficiency, and sleep regularity. Participants (20 BLW, 17 WHW) were 18-29 years old, normotensive, nonobese, and without evidence of sleep disorders. Systolic and diastolic BP dipping were derived from 24-h ambulatory BP monitoring. Habitual sleep duration and sleep efficiency were estimated via 14 days of wrist actigraphy. Sleep duration regularity was calculated as the standard deviation (SD) of nightly sleep duration (SDSD). Sleep timing regularity metrics were calculated as the SD of sleep onset and sleep midpoint (SMSD). Mediation analysis tested the mediating effect of each sleep metric on the relation between race and BP dipping. BLW experienced less systolic (P = .02) and diastolic (P = .01) BP dipping. Sleep duration (P = .14) was not different between groups. BLW had lower sleep efficiency (P < .01) and higher SDSD (P = .02), sleep onset SD (P < .01) and SMSD (P = .01). No sleep metrics mediated the relation between race and BP dipping (all indirect effects P > .38). In conclusion, mediation pathways of sleep health metrics do not explain racial differences in nocturnal BP dipping between young BLW and WHW.

Caffeine Boosts Weight-Lifting Performance in Rats: A Pilot Study

Caffeine is a well-described ergogenic aid used to enhance athletic performance. Using animal models can greatly increase our understanding of caffeine's mechanisms in performance. Here, we adapted an animal weight-lifting exercise model to demonstrate caffeine's ergogenic effect in rats. Male Wistar rats (315 ± 35 g) were randomly divided into two groups: one group received 5 mg·kg-1 of caffeine (0.5 mL; CEx; n = 5) and the other 0.9% NaCl (0.5 mL; PEx; n = 4) through an orogastric probe (gavage) one hour before exercise. Weight-lifting exercise sessions were performed over three subsequent days, and the number of complete squats performed was counted. Analyses of the area under the curve in all three experiments showed that the CEx group responded more to stimuli, performing more squats (1.7-, 2.0-, and 1.6-fold; p < 0.05) than the control group did. These three days' data were analyzed to better understand the cumulative effect of this exercise, and a hyperbolic curve was fitted to these data. Data fitting from the caffeine-supplemented group, CEx, also showed larger Smax and Kd (2.3-fold and 1.6-fold, respectively) than the PEx group did. Our study demonstrated an acute ergogenic effect of caffeine in an animal weight-lifting exercise model for the first time, suggesting potential avenues for future research.

Predictors for poor daily weight gain in preterm neonates exposed to different dose regimens of caffeine in ICU- a retrospective cohort study

BACKGROUND

With a wide therapeutic index, efficacy, ease of use, and other neuroprotective and respiratory benefits, caffeine citrate(CC) is currently the drug of choice for preterm neonates (PTNs). Caffeine-induced excessive energy expenditure, diuresis, natriuresis, and other CC-associated potential side-effects (CC-APSEs) result in lower daily-weight gain (WG) in premature neonates. This study aimed to evaluate the risk factors for daily-WG in neonates exposed to different dose regimens of caffeine in ICU.

METHOD

This retrospective cohort study included neonates of ≤ 36weeks gestational age (GA) and received CC-therapy. The same participants were followed for data analysis in two postnatal phases: 15-28 and 29-42 days of life (DOL). Based on daily CC-dose, formed group-I (received; standard-doses = 5 mg/kg/day), group-II (received;>5-7 mg/kg/day), and group-III (received;>7 mg/kg/day). Prenatal and postnatal clinical characteristics, CC-regimen, daily-WG, CC-APSEs, and concomitant risk-factors, including daily-caloric intake, Parenteral-Nutrition duration, steroids, diuretics, and ibuprofen exposure, were analyzed separately for group-II and group-III using group-I as standard. Regression analysis was performed to evaluate the risk factors for daily-WG.

RESULTS

Included 314 PTNs. During 15-28 DOL, the mean-daily-WG(MD-WG) was significantly higher in group-I than group-II [19.9 ± 0.70 g/kg/d vs. 17.7 ± 0.52 p = 0.036] and group-III [19.9 ± 0.70 g/kg/d vs. 16.8 ± 0.73 p < 0.001]. During 29-42 DOL the MD-WG of group-I was only significantly higher than group-III [21.7 ± 0.44 g/kg/d vs. 18.3 ± 0.41 g/kg/d p = 0.003] and comparable with group-II. During 15-28 DOL, observed CC-APSEs was significantly higher in group-II and III but during 29-42 DOL it was only significant in group-III. In the adjusted regression analysis for daily-WG during 15-28DOL, with respect to standard-dose, 5-7 mg/kg/day (β=-1.04; 95%CI:-1.62,-0.93) and > 7-10 mg/kg/day (β=-1.36; 95%CI:-1.56,-1.02) were associated with a lower daily-WG. However, during 29-42DOL, this association was present only for > 7-10 mg/kg/day (β=-1.54; 95%CI:-1.66,-1.42). The GA ≤ 27weeks (β=-1.03 95%CI:-1.24, -0.88) was associated with lower daily-WG only during 15-28DOL. During both periods of therapy, higher cumulative-caffeine dose and presence of culture proven sepsis, tachypnea, hyponatremia, and feeding intolerance were significantly associated with lower daily-WG. Conversely, daily kcal intake was found to be linked with an increase in daily-WG in both periods.

CONCLUSION

In this study cohort exposure to higher caffeine daily and cumulative doses is associated with lower postnatal daily-WG in PTNs than standard-daily doses, which may be due to its catabolic effects and CC-APSEs.

Combined Effect of Red Wine and Mocha Pot Coffee in Mild Vascular Cognitive Impairment

OBJECTIVES

Moderate daily mocha pot coffee intake has been associated with better mood and cognition in patients with mild vascular cognitive impairment (VCI). Similarly, moderate red wine consumption has shown protective effects on cognitive disorders, including Alzheimer's disease and vascular dementia. The aim of this study was to explore the synergistic relation between red wine and coffee intake on mood and cognitive status in mild VCI patients at risk for dementia.

METHODS

A total of 300 non-demented older patients with mild VCI were asked for coffee and red wine consumption and administered with the 17-items Hamilton Depression Rating Scale (HDRS), the Mini Mental State Examination (MMSE), and the Stroop Color-Word Interference Test (Stroop T), as well as the Activities of Daily Living (ADL) and the Instrumental ADL to measure their mood status, cognitive performance, and functional independence. Linear regression models were used to test the association between variables.

RESULTS

Moderate wine drinkers tended to show the best Stroop T score at any level of coffee consumption; conversely, heavy wine consumers performed worse at the Stroop T, especially in patients reporting high coffee intake. Moderate drinkers of both coffee and wine showed the lowest HDRS scores. Finally, a progressive increase in MMSE score was evident with increasing coffee consumption, which peaks when combined with a moderate wine consumption.

CONCLUSIONS

Daily mocha pot coffee and red wine intake seem to be synergistically associated with global cognition, executive functioning, and mood status in patients with mild VCI; the association was not linear, resulting in a protective direction for moderate intake and detrimental for heavy consumption. Future studies are needed to further corroborate the present findings and the potential long-term protective effects of these dietary compounds over time.

Unmasking the triad of burnout, absenteeism, and poor sleep among healthcare workers during the third wave of COVID-19 pandemics. Results from the national AMADEUS study

BACKGROUND

Burnout and absenteeism are prevalent among healthcare workers, reflecting prolonged work-related stress and dissatisfaction with their job. Identifying poor sleep as a contributing factor can assist in developing targeted interventions. This study explored the relationship between burnout, absenteeism, and sleep among healthcare workers.

METHODS

A nationwide online cross-sectional study was conducted among healthcare professionals in France during the third wave of COVID-19, from May 2021 to June 2021. Recruitment strategies included outreach through social and professional networks and email invitations. Burnout was assessed using the Maslach Burnout Inventory, absenteeism through self-reported days absent in the preceding 12 months, and sleep quality using the Pittsburgh Sleep Quality Index. The association between burnout, absenteeism, and poor sleep was analyzed using multivariate logistic regression, accounting for individual and professional variables. The study also explored various sleep dimension abnormalities.

RESULTS

Of 10,087 healthcare workers, 55.2 % reported burnout, 20.5 % absenteeism, and 64.8 % poor sleep. Burnout and absenteeism were more frequent in individuals with poor sleep compared to those with good sleep (74.2 % vs. 25.8 % and 75.6 % vs. 24.4 %, respectively). The multivariate analyses confirmed the associations between burnout, absenteeism, and poor sleep (Adjusted Odds Ratio [aOR] = 2.15, 95 % CI [1.97-2.35], p < 0.001; and aOR = 1.49, 95 % CI [1.32-1.67], p < 0.001, respectively).

INTERPRETATION

The study highlighted the intricate relationship between burnout, absenteeism, and poor sleep among healthcare professionals, informing workforce management and policy decisions to foster a supportive work environment and enhance their well-being.

Dietary patterns and insomnia symptoms: A systematic review and meta-analysis

We aimed to systematically review and synthesize the available evidence regarding the link between dietary patterns and insomnia symptoms among the general population using observational studies. We reviewed 16,455 references, of which 37 studies met inclusion criteria with a total sample size of 591,223. There was a significant association of the Mediterranean diet (OR: 0.86; 95 % CI, 0.79, 0.93; P < 0.001; I2 = 32.68 %), a high-quality diet (OR: 0.66; 95 % CI, 0.48, 0.90; P = 0.010; I2 = 84.62 %), and an empirically-derived healthy dietary pattern (OR: 0.91; 95 % CI, 0.85, 0.98; P = 0.010; I2 = 57.14 %) with a decreased risk of insomnia symptoms. Moreover, the dietary glycemic index (OR: 1.16; 95 % CI, 1.08, 1.25; P < 0.001; I2 = 0.0 %), the dietary glycemic load (OR: 1.10; 95 % CI, 1.01, 1.20; P = 0.032; I2 = 74.36 %), and an empirically-derived unhealthy dietary pattern (OR: 1.20; 95 % CI, 1.01, 1.42; P = 0.040; I2 = 68.38 %) were linked with a higher risk of insomnia symptoms. Most individual studies were of good quality (NOS) but provided very low certainty of evidence (GRADE). Consistent data reveals that following healthy diets is associated with decreased insomnia symptoms prevalence, while adherence to an unhealthy pattern is associated with an increased prevalence of insomnia symptoms.

Targeting the adenosinergic system in restless legs syndrome: A pilot, "proof-of-concept" placebo-controlled TMS-based protocol

Restless Legs Syndrome (RLS) is a common sleep disorder characterized by an urge to move the legs that is responsive to movement (particularly during rest), periodic leg movements during sleep, and hyperarousal. Recent evidence suggests that the involvement of the adenosine system may establish a connection between dopamine and glutamate dysfunction in RLS. Transcranial magnetic stimulation (TMS) is a non-invasive electrophysiological technique widely applied to explore brain electrophysiology and neurochemistry under different experimental conditions. In this pilot study protocol, we aim to investigate the effects of dipyridamole (a well-known enhancer of adenosinergic transmission) and caffeine (an adenosine receptor antagonist) on measures of cortical excitation and inhibition in response to TMS in patients with primary RLS. Initially, we will assess cortical excitability using both single- and paired-pulse TMS in patients with RLS. Then, based on the measures obtained, we will explore the effects of dipyridamole and caffeine, in comparison to placebo, on various TMS parameters related to cortical excitation and inhibition. Finally, we will evaluate the psycho-cognitive performance of RLS patients to screen them for cognitive impairment and/or mood-behavioral dysfunction, thus aiming to correlate psycho-cognitive findings with TMS data. Overall, this study protocol will be the first to shed lights on the neurophysiological mechanisms of RLS involving the modulation of the adenosine system, thus potentially providing a foundation for innovative "pharmaco-TMS"-based treatments. The distinctive TMS profile observed in RLS holds indeed the potential utility for both diagnosis and treatment, as well as for patient monitoring. As such, it can be considered a target for both novel pharmacological (i.e., drug) and non-pharmacological (e.g., neuromodulatory), "TMS-guided", interventions.

Insomnia-related rodent models in drug discovery

Despite the widespread prevalence and important medical impact of insomnia, effective agents with few side effects are lacking in clinics. This is most likely due to relatively poor understanding of the etiology and pathophysiology of insomnia, and the lack of appropriate animal models for screening new compounds. As the main homeostatic, circadian, and neurochemical modulations of sleep remain essentially similar between humans and rodents, rodent models are often used to elucidate the mechanisms of insomnia and to develop novel therapeutic targets. In this article, we focus on several rodent models of insomnia induced by stress, diseases, drugs, disruption of the circadian clock, and other means such as genetic manipulation of specific neuronal activity, respectively, which could be used to screen for novel hypnotics. Moreover, important advantages and constraints of some animal models are discussed. Finally, this review highlights that the rodent models of insomnia may play a crucial role in novel drug development to optimize the management of insomnia.

Caffeine and Sleep in Preventing Post-spinal Headache: Which One is More Effective?

OBJECTIVE

The study aimed to determine the effects of caffeine consumption and sleep on post-spinal headache after spinal anesthesia.

BACKGROUND

Post-spinal headache is among the most well-known and common complications of spinal anesthesia. Although caffeine consumption is recommended to prevent headache after spinal anesthesia, caffeine does not prevent headache and causes sleep-related problems. No study in the literature found a correlation between sleep and caffeine consumption after spinal anesthesia and post-spinal headache.

METHODS

The research is a descriptive and cross-sectional study. The study sample comprised 425 patients who underwent elective surgery in a research hospital. The research data were collected by face-to-face interviews between April 2021 and December 2023. The "Sociodemographic and Clinical Characteristics Form," "Richard-Campbell Sleep Scale," "Insomnia Severity Index," and "Visual Analog Scale" were used in data collection. Factors affecting post-spinal headache were determined using binary logistic regression analysis.

RESULTS

According to the binary logistic regression, the insomnia severity score (OR = 1.234; p < .001), sleep quality score (OR = .992; p < .01), postoperative sleep duration (OR = .619; p < .05), and not consuming coffee (OR = .035; p < .001) are statistically significant predictors of post-spinal headache and explain 57.7% of the variance. A one-unit increase in patients' insomnia severity increased the probability of experiencing a post-spinal headache by 23.4%. With a one-unit increase in sleep quality, there was an 8% decrease in the probability of experiencing spinal headache, and a 3.81% decrease in the probability of experiencing post-spinal headache with an increase in sleep duration after surgery. The probability of experiencing post-spinal headache was 0.35 times higher in individuals who did not consume caffeine after surgery than in those who consumed it.

CONCLUSION

The present study demonstrated that insomnia severity and sleep quality were more effective than caffeine consumption in preventing post-spinal headache. Insomnia and decreased sleep quality may cause a significant burden in developing post-spinal headache in patients and may cause post-spinal headache to be observed more frequently. Therefore, the use of caffeine in preventing or reducing post-spinal headache may adversely affect the duration and quality of sleep and increase the severity of insomnia.

Dose-Response Study of Caffeine on Postnatal Weight Gain in Premature Neonates-A Retrospective Cohort Study

Background

Caffeine citrate (CC)-induced excessive energy expenditure, diuresis, natriuresis, and other CC-associated potential side effects (CC-APSEs) result in lower daily weight gain (WG) in premature neonates. This study aimed to assess higher CC-doses' effect on the mean daily-WG (MD-WG) and CC-APSE development, considering 5 mg/kg/day as the standard regimen.

Method

This retrospective cohort study included neonates of ≤36 weeks gestational age and received CC-therapy. The same participants were followed for data analysis in two postnatal phases: 15-28 and 29-42 days of life (DOL). Based on daily CC-dose, formed group-I=(5 mg/kg/day), group-II=(>5-7 mg/kg/day), and group-III=(>7 mg/kg/day). Data was analyzed separately for group-II and group-III using group-I as the standard.

Results

The study included 284 neonates. During phase-I, the MD-WG was significantly higher in group-I than group-II (19.9 ± .88 g/kg/d vs 17.5 ± .49, P = .031) and group-III (19.9 ± .88 g/kg/d vs 16.7 ± .71, P < .001). During 29-42 DOL, the MD-WG of group-I was only significantly higher than group-III (21.5 ± .42 g/kg/d vs 18.1 ± .39 g/kg/d, P = .003) and comparable with group-II. During 15-28 DOL, CC-APSEs were significantly higher in group-II and group-III but during 29-42 DOL was significant only in group-III.

Conclusion

Exposure to higher caffeine doses in this study cohort is associated with lower postnatal WG in preterm neonates than standard daily doses may be due to its catabolic effects and CC-APSEs.

Assessing the daily association of sleep hygiene behaviours with sleep: A between and within persons approach

Sleep hygiene behaviours are recommendations given to both clinical and non-clinical populations with a focus on modifying behaviours to maximise sleep outcomes. However, methodological issues present in sleep hygiene research make it difficult to conclusively determine the impact of each behaviour. This study aimed to address these issues by adopting a two-week, repeated measures design which incorporated objective sleep measures and used linear mixed effect modelling to assess the daily association of a wide range of sleep hygiene behaviours on sleep in a non-clinical, university sample. Between-persons effects revealed that bedtime and frequency of daytime napping, alcohol use, and social media use were negatively related to sleep duration while waketime and frequency of too much water consumption were positively related to sleep duration. Within-person effects revealed that later than usual bedtime, earlier than usual waketime, no sunlight exposure, poor ventilation, having an unpleasant conversation before bed were negatively associated with sleep duration whereas using alcohol to deliberately help full asleep was positively related to sleep duration. In contrast, disproportionately more behaviours were not significantly related to either sleep outcome, only some of which could be explained by individual differences, which suggests that more research is needed to determine the conditions under which these behaviours affect sleep, if at all.

Problematic coffee use and associated factors among medical and health science students in Dilla University, Ethiopia

Objective

Coffee holds a cherished place in Ethiopian culture, its consumption among students raises concerns despite its perceived benefits for alertness and productivity. Moderate caffeine intake remains unproblematic, but exceeding 400 mg daily can trigger detrimental health effects such as fatigue, memory impairment, and even attention-deficit disorder. Research on problematic coffee use among young adults, specifically Ethiopian students, remains limited, hindering our understanding of its potential scope and impact. To address this knowledge gap, researchers at Dilla University, Ethiopia, undertook a comprehensive study in 2022, focusing on the university's student population. This investigation holds significant potential to unveil the previously obscured landscape of excessive coffee consumption in this demographic and inform future research and potential interventions.

Methodology

An institutional-based cross-sectional study design was conducted in August-July, 2022. To measure problematic coffee use, this study used the Diagnostic Statistical Manual five criteria for substance use disorder. Those who scored >2 out of 11 criteria were considered to have problematic coffee use. To measure a significant association between the outcome and independent variable, a multivariable logistic regression analysis at p < 0.05 and 95% confidence interval was employed.

Result

This study included 414 respondents. More than half of the respondents, 347 (59.7%) were male. Out of all respondents, 182 (44.0%) had a boy/girlfriend. Nearly half of the respondents, 218 (52.7%) were orthodox, Christian religion followers. According to this study's findings, 137 (33.1%) respondents were considered to have problematic coffee use. Multivariable logistic regression analysis showed that 5-10 years duration of coffee use (AOR = 4.62, 95% CI: 2.96-7.85; p = 0.001), start to use coffee before joining university (AOR = 2.977, 95% CI: 1.332-6.653; p = 0.008) and 6-9 cups of daily coffee use (AOR = 3.26, 95% CI: 2.14-5.89; p = 0.00) were associated with problematic coffee use.

Conclusion

This study showed that one-third of the respondents had problematic coffee use. The starting point, duration, and amount of use had a strong association with problematic coffee use. Hence, focusing on addressing the mental health challenges associated with problematic/excessive coffee consumption among higher education students is advisable. Additionally, promoting awareness of problematic/excessive coffee use and its potential remedies is recommended.

Modifiable dietary factors in adolescent sleep: A systematic review and meta-analysis

OBJECTIVE

Sleep problems are prevalent during adolescence, and modifying dietary factors may contribute to better sleep outcomes in adolescents. This systematic review and meta-analysis aimed to evaluate the impact of modifiable dietary factors on sleep health among adolescents.

METHODS

A systematic search of records from six databases including MEDLINE, PubMed, Embase, Scopus, CINAHL, and the CENTRAL from inception up to November 2023, identified 33 peer-reviewed publications that assessed the relationship between modifiable dietary factors and sleep outcomes in adolescents aged 12-18 years. The NIH Quality Assessment Tools were used to assess the quality of the included studies. Meta-analysis was performed on a sub-group of studies (n = 6) to ascertain the effect of dietary factors on sleep health.

RESULTS

Although the included studies were predominantly cross-sectional and exhibited heterogeneity, relying mainly on self-reported measures, it was observed that consumption of healthy foods was consistently linked with improved sleep outcomes among adolescents, whereas higher intake of fat-rich or sugar-rich foods and red meats or processed food was associated with poorer sleep features. The meta-analysis further substantiated that adolescents with higher caffeine intake faced increased odds of sleep problems (OR = 1.67, 95% CI: 1.28-2.17), while alcohol consumption was significantly associated with insomnia (OR = 1.17, 95% CI: 1.07-1.27).

CONCLUSION

Overall, despite high heterogeneity among studies, this systematic review underscores the promising role of healthy dietary factors in enhancing both the quality and quantity of sleep in adolescents. The meta-analysis results also highlight that reducing caffeine and alcohol intake holds potential for supporting better sleep in this population. However, further validation through intervention studies is warranted.

Molecular docking targeting autophagy pathway mediate abrogation of NASH by specific functional foods: update review

Autophagy is a very well-conserved self-digestive mechanism that transports unwanted or disposable cytoplasmic debris to lysosomes for destruction, including misfolded proteins and damaged organelles. Advanced liver illnesses can develop from the prevalent clinical condition known as non-alcoholic steatohepatitis (NASH). There is no effective treatment, is still unclear. Therefore, in order to create novel therapeutics, it is necessary to comprehend the pathogenic pathways causing disease onset and progression. Natural components from medicinal plants are currently the subject of a larger number of studies since they provide fresh promise for NASH. This review provided an overview of the aetiology of NASH, in addition the role of natural products as alternative or complementary therapeutic agent for management of NASH via autophagy induction. It was concluded that, alternative and complementary supplement of natural functional food as Arabica coffee that rich with chlorogenic acid targeting autophagy mechanism mediate amelioration effect of NASH.

The timing of energy intake

The aim of the paper is to review the current evidence on the impact of 'the timing of energy intake' on the risk of developing obesity and obesity-related metabolic diseases. The prevalence of obesity is currently increasing worldwide thus becoming a severe health burden for most countries. Indeed, obesity represents a risk factor for several non-communicable diseases such as cancer, type 2 diabetes, dyslipidaemia, CVD and overall mortality. In order to treat obesity, several pharmacological approaches have been developed and are indicated for subjects with obesity with a BMI ≥ 30 kg/m2 or ≥ 27 kg/m2 and obesity-related comorbidities. For severe obesity (BMI ≥ 40 kg/m2), bariatric surgery represents a promising approach. The most common bariatric surgical procedures are represented by the Roux-en-Y gastric bypass, laparoscopic adjustable band, laparoscopic gastric sleeve and biliopancreatic diversion with duodenal switch. Both anti-obesity pharmacological and surgical treatments require change in lifestyle. When a nutritional plan is established, attention is usually paid to macronutrient composition and energy intake, while 'the time of food' is not taken into account. Chronotype, which is the attitude of a subject to carry out most of their daily activities in the first (morning chronotype) or second half (evening chronotype) of the day, has been reported to have a role in the pathogenesis of obesity and obesity-related cardiometabolic diseases as well as eating speed. Thus, adopting a physiological timing of energy intake could be an additional strategy to potentiate the current anti-obesity approaches.

Impact of Medical School on the Relationship between Nutritional Knowledge and Sleep Quality-A Longitudinal Study of Students at Wroclaw Medical University in Poland

The aim of this study was to investigate the impact of the first year of medical school on the relationship between nutritional knowledge and sleep. To achieve this, first-year medical students at Wroclaw Medical University were invited to participate in the study during both the initial and final months of their first academic year. The study included 570 students in the initial period and 705 in the latter. The research questionnaire comprised the KomPAN, assessing nutritional knowledge, and the Pittsburgh Sleep Quality Index (PSQI), evaluating sleep quality. The majority of students demonstrated at least sufficient nutritional knowledge, while approximately two-thirds of students experienced poor sleep in both periods. Notably, sleep quality further deteriorated in the second period (PSQI total score: 6.86 vs. 7.38, p = 0.0157). This change was influenced mainly by a decrease in sleep duration and an increase in the use of sleep medications (both p < 0.0001). The significant difference in overall sleep quality between different nutritional knowledge levels emerged only in the second semester, where students with the highest nutritional knowledge slept the best, while those with the lowest slept the worst (p = 0.0001). Crucially, in both periods, the use of sleep medications was highest among individuals with insufficient nutritional knowledge. Throughout the academic year, the usage increased for all except those with the highest nutritional knowledge, who exhibited the best sleep (p < 0.0001). The escalating use of sleep medications among medical students warrants greater attention, and leveraging the relationship between nutritional knowledge and sleep could prove beneficial, as positive habits in one domain may positively influence the other.

Concentration-effect relationships of plasma caffeine on EEG delta power and cardiac autonomic activity during human sleep

Acute caffeine intake affects brain and cardiovascular physiology, yet the concentration-effect relationships on the electroencephalogram and cardiac autonomic activity during sleep are poorly understood. To tackle this question, we simultaneously quantified the plasma caffeine concentration with ultra-high-performance liquid chromatography, as well as the electroencephalogram, heart rate and high-frequency (0.15-0.4 Hz) spectral power in heart rate variability, representing parasympathetic activity, with standard polysomnography during undisturbed human sleep. Twenty-one healthy young men in randomized, double-blind, crossover fashion, ingested 160 mg caffeine or placebo in a delayed, pulsatile-release caffeine formula at their habitual bedtime, and initiated a 4-hr sleep opportunity 4.5 hr later. The mean caffeine levels during sleep exhibited high individual variability between 0.2 and 18.4 μmol L-1 . Across the first two non-rapid-eye-movement (NREM)-rapid-eye-movement sleep cycles, electroencephalogram delta (0.75-2.5 Hz) activity and heart rate were reliably modulated by waking and sleep states. Caffeine dose-dependently reduced delta activity and heart rate, and increased high-frequency heart rate variability in NREM sleep when compared with placebo. The average reduction in heart rate equalled 3.24 ± 0.77 beats per minute. Non-linear statistical models suggest that caffeine levels above ~7.4 μmol L-1 decreased electroencephalogram delta activity, whereas concentrations above ~4.3 μmol L-1 and ~ 4.9 μmol L-1 , respectively, reduced heart rate and increased high-frequency heart rate variability. These findings provide quantitative concentration-effect relationships of caffeine, electroencephalogram delta power and cardiac autonomic activity, and suggest increased parasympathetic activity during sleep after intake of caffeine.

Better characterizing sleep beliefs for personalized sleep health promotion: the French sleep beliefs scale validation study

Background

The Sleep Beliefs Scale (SBS) is a well-known tool to design and monitor personalized sleep health promotion at an individual and population level. The lack of an established French version limits the development of effective interventions targeting these populations. Thus, the aim of this study was to validate the French version of the SBS in a representative sample of the general population.

Methods

Quota sampling was used to recruit 1,004 participants (18-65 years, mean age: 43 years, 54% of female) who underwent an online survey to complete the SBS, and to assess sleep schedules, sleep quality and disorders, and mental health. Cronbach's α coefficient, confirmatory factor analysis, item-internal consistency (IIC), and item discriminant validity (IDV) of the SBS were computed to assess internal validity while bivariate associations with sleep schedules, sleep quality and disorders, and mental health were used to assess external convergent and discriminant validity.

Results

The mean score on the SBS was 12.3 ± 4.9. Item 19 ("Quiet & Dark") showed the highest rate of correct answers (n = 801, 79.8%), while item 20 ("Recovering sleep") showed the lowest rate of correct answers (n = 246, 24.5%). Overall, the SBS showed satisfactory internal consistency (α = 0.87) and confirmed the three-factor structure proposed by the original study. All items were found consistent (IIC > 0.4) and discriminant (IIC > IDV) except for item 20 ("recovering lost sleep by sleeping for a long time"). Females, older participants, and subjects with short time-in-bed, poor sleep quality, insomnia, and circadian rhythm disorder had higher SBS scores while participants with depressive symptoms had lower SBS scores.

Conclusion

We successfully translated and validated the French version of the SBS in a representative sample, making it a reliable instrument for researchers and clinicians to assess and target sleep beliefs. Correct answers vary from 25 to 80% which underlines the importance of continuing sleep health promotion campaigns by targeting poorly understood behaviors. Our findings also shed light on the fickleness of beliefs that are prone to vary within individuals across time, in step with societal changes. Several associated factors were identified, thus contributing to our understanding of sleep beliefs and offering insights for personalized approaches to enhance sleep health and overall well-being.

Multi-omics reveals changed energy metabolism of liver and muscle by caffeine after mice swimming

In recent years, numerous studies have investigated the effects of caffeine on exercise, and provide convincing evidence for its ergogenic effects on exercise performance. However, the precise mechanisms underlying these ergogenic effects remain unclear. In this study, an exercise swimming model was conducted to investigate the effects of orally administered with caffeine before swimming on the alterations of proteome and energy metabolome of liver and muscle after swimming. We found proteins in liver, such as S100a8, S100a9, Gabpa, Igfbp1 and Sdc4, were significantly up-regulated, while Rbp4 and Tf decreased after swimming were further down-regulated in caffeine group. The glycolysis and pentose phosphate pathways in liver and muscle were both significantly down-regulated in caffeine group. The pyruvate carboxylase and amino acid levels in liver, including cysteine, serine and tyrosine, were markedly up-regulated in caffeine group, exhibiting a strong correlation with the increased pyruvic acid and oxaloacetate levels in muscle. Moreover, caffeine significantly decreased the lactate levels in both liver and muscle after swimming, potentially benefiting exercise performance.

Well-being therapy and sleep hygiene in a non-clinical population of adults reporting poor sleep quality and distress: A remote pilot randomized controlled study

OBJECTIVES

This pilot randomized controlled study evaluates the feasibility and preliminary efficacy of a 7-week remote intervention combining well-being therapy and sleep hygiene to improve sleep and psychological outcomes among adults reporting poor sleep and distress.

METHODS

Thirty-one participants (81% women, 40.2 ± 13.0 y, 48% racial/ethnic minority) were recruited from the community during the COVID-19 pandemic through online and local advertisement, and randomized to well-being therapy+sleep hygiene or sleep hygiene-only. Study outcomes were evaluated by self-reported questionnaires administered at baseline and post-intervention and a daily sleep diary.

RESULTS

Compared to sleep hygiene-only, well-being therapy+sleep hygiene led to greater improvements in wake after sleep onset (time-by-group interaction: 3.6 ± 1.5 min, p = .017), personal growth (β -3.0, 95%CI -5.2, -0.8, p = .01), and purpose in life (β -3.5, 95%CI -6.1, -0.9, p = .009). Anxiety, perceived stress, sleep quality, and insomnia symptoms improved similarly in both groups (between-group differences, p > .05). Improvements in sleep quality, insomnia, and sleep duration were associated with reductions in multiple measures of psychological distress (all p < .05).

CONCLUSIONS

These findings suggest that, in a non-clinical setting of individuals suffering from combined poor sleep and psychological distress, the addition of well-being therapy to sleep hygiene may provide additional benefits for sleep by promoting sleep continuity and well-being.

Multi-omics microsampling for the profiling of lifestyle-associated changes in health

Current healthcare practices are reactive and use limited physiological and clinical information, often collected months or years apart. Moreover, the discovery and profiling of blood biomarkers in clinical and research settings are constrained by geographical barriers, the cost and inconvenience of in-clinic venepuncture, low sampling frequency and the low depth of molecular measurements. Here we describe a strategy for the frequent capture and analysis of thousands of metabolites, lipids, cytokines and proteins in 10 μl of blood alongside physiological information from wearable sensors. We show the advantages of such frequent and dense multi-omics microsampling in two applications: the assessment of the reactions to a complex mixture of dietary interventions, to discover individualized inflammatory and metabolic responses; and deep individualized profiling, to reveal large-scale molecular fluctuations as well as thousands of molecular relationships associated with intra-day physiological variations (in heart rate, for example) and with the levels of clinical biomarkers (specifically, glucose and cortisol) and of physical activity. Combining wearables and multi-omics microsampling for frequent and scalable omics may facilitate dynamic health profiling and biomarker discovery.

Transcranial Direct Current Stimulation and Aviator Performance During Simulated Flight

INTRODUCTION: Transcranial direct current stimulation (tDCS) is a promising method for maintaining cognitive performance. Anticipated changes in rotary-wing aircraft are expected to alter aviator performance.METHODS: A single-blind, randomized, sham-controlled study evaluated effects of 2-mA anodal tDCS to the right posterior parietal cortex on aviator performance within a Black Hawk simulator. A mixed design with one between-subjects factor was assessed: stimulation prior to flight (20 constant min) and during flight (two timepoints for 10 min each). The within-subjects factor included active vs. sham stimulation. Randomly assigned to each stimulation group were 22 aviators. Aircraft state metrics derived from the simulator were used to evaluate performance. Subjects completed two flights (active stimulation and sham stimulation) with an in-flight emergency introduced at the end to assess whether the timing of tDCS application (prior or during flight) affected the ability to maintain attention and respond to an unexpected event.RESULTS: Results found active stimulation during flight produced statistically significant improvements in performance during the approach following the in-flight emergency. Subjects maintained a more precise approach path with glideslope values closer to zero (M = 0.05) compared to the prior-to-flight group (M = 0.15). The same was found for localizer values (during flight, M = 0.07; prior to flight, M = 0.17). There were no statistically significant differences between groups on secondary outcome measures.DISCUSSION: These findings suggest stimulation during flight may assist in maintaining cognitive resources necessary to respond to an unexpected in-flight emergency. Moreover, blinding efficacy was supported with 32% of subjects correctly guessing when active stimulation was being delivered (52% correctly guessed the sham condition).Feltman KA, Kelley AM. Transcranial direct current stimulation and aviator performance during simulated flight. Aerosp Med Hum Perform. 2024; 95(1):5-15.

The Association between Caffeine Consumption from Coffee and Tea and Sleep Health in Male and Female Older Adults: A Cross-Sectional Study

Poor sleep health is common in older adults and is associated with negative health outcomes. However, the relationship between caffeine consumption and sleep health at an older age is poorly understood. This study investigated the association between caffeine consumption and sleep health in community-dwelling older males and females in The Netherlands. Cross-sectional analyses were performed using data from 1256 participants aged 61-101 years from the Longitudinal Ageing Study Amsterdam. Self-reported questions assessed sleep disturbances (including sleep latency, continuity, and early awakening), sleep duration, and perceived sleep quality. Caffeine consumption was determined with questions about frequency, quantity, and type of coffee and tea consumption. Logistic and linear regression models were used, controlling for potential confounders, and interaction by sex and age was tested. Caffeine consumption showed significant interactions with sex (p < 0.005) in association with sleep health outcomes. Older females who abstained from caffeine consumption reported more sleep disturbances (β = 0.64 [95%CI 0.13; 1.15]) and had greater odds of short sleep duration (<7 h/day) (OR = 2.26 [95% CI 1.22; 4.20]) compared to those who consumed caffeine. No associations were observed for long sleep duration (>8 h/day) and perceived sleep quality. No associations were observed in older males. Caffeine abstinence was associated with more sleep disturbances and short sleep duration in older females, but not in males. The observed association in older females may reflect reverse causation, suggesting that females may have different motivations for discontinuing caffeine consumption than males.

Effectiveness of caffeine and blue-enriched light on cognitive performance and electroencephalography correlates of alertness in a spaceflight robotics simulation

Human cognitive impairment associated with sleep loss, circadian misalignment and work overload is a major concern in any high stress occupation but has potentially catastrophic consequences during spaceflight human robotic interactions. Two safe, wake-promoting countermeasures, caffeine and blue-enriched white light have been studied on Earth and are available on the International Space Station. We therefore conducted a randomized, placebo-controlled, cross-over trial examining the impact of regularly timed low-dose caffeine (0.3 mg per kg per h) and moderate illuminance blue-enriched white light (~90 lux, ~88 melEDI lux, 6300 K) as countermeasures, separately and combined, in a multi-night simulation of sleep-wake shifts experienced during spaceflight among 16 participants (7 F, ages 26-55). We find that chronic administration of low-dose caffeine improves subjective and objective correlates of alertness and performance during an overnight work schedule involving chronic sleep loss and circadian misalignment, although we also find that caffeine disrupts subsequent sleep. We further find that 90 lux of blue-enriched light moderately reduces electroencephalogram (EEG) power in the theta and delta regions, which are associated with sleepiness. These findings support the use of low-dose caffeine and potentially blue-enriched white light to enhance alertness and performance among astronauts and shiftworking populations.

Sleep and circadian hygiene practices association with sleep quality among Brazilian adults

Objective

To investigate the association of sleep and circadian hygiene practices (sleep-promoting and sleep-disturbing behaviors) with sleep quality indicators.

Methods

Participants (n = 2050; 18-65 y) were part of virtual population-based research. Logistic regression models were fitted to assess differences in the OR (95% CI) of poor quality with sleep-promoting/disturbing practices (time-of-day of exercise, pre-bedtime routine, naps, electronic devices with illuminated screens, caffeine and alcohol consumption, and smoking). Linear regression analyses evaluated differences in sleep duration, latency, and awakenings associated with the same variables. Restricted cubic splines were used to study the shape of the association of screen time before bed with sleep duration, latency, and awakenings. Analyses were adjusted for age, sex, region, marital status, educational level, evening diet quality, and BMI.

Results

Evening use of electronic devices with illuminated screens showed a negative effect on all sleep parameters. Reporting dinner as the largest meal and evening caffeine consumption was associated with shorter sleep duration and longer sleep latency. Smokers had higher odds of longer latency. A protective effect of morning exercises was demonstrated on sleep quality, latency, and awakenings. Alcohol consumers presented lower odds of poor quality and lower frequency of awakenings. Pre-bedtime practices showed no or negative effect on sleep outcomes.

Conclusions

Recommendations to promote sleep quality and prevent sleep-related problems, with corresponding circadian health benefits, should include engaging in regular exercise, preferably in the morning, and avoiding naps, heavy meals close to bedtime, caffeine, smoking, and evening screen exposure.

Interplay of sleep patterns and oxidative balance score on total cardiovascular disease risk: Insights from the National Health and Nutrition Examination Survey 2005-2018

Background

Unhealthy lifestyle and diet may contribute to the development of cardiovascular disease (CVD), but limited evidence exists regarding the association between sleep patterns, oxidative stress-related exposures to diet and lifestyle, and CVD risk.

Methods

We analysed data from 10 212 adults in the National Health and Nutrition Examination Survey (NHANES) database (2005-2018). Self-report questionnaires were used to collect data on sleep duration, sleepiness, and trouble sleeping, classified into three categories: healthy, intermediate, and poor sleep patterns. Healthy sleep was defined as sleeping seven to nine hours per night with no self-reported sleepiness or trouble sleeping, while intermediate and poor sleep patterns indicated one and two to three sleep problems, respectively. The oxidative balance score (OBS) was calculated based on twenty oxidative stress-related exposures to dietary and lifestyle factors, with a higher score indicating greater antioxidant exposure. Survey-based multivariable-adjusted regression analysis was conducted to examine the association of sleep patterns or OBS alone and combined with the total and specific CVD risk.

Results

Participants with poor sleep patterns had a higher likelihood of developing CVD (odds ratio (OR) = 1.76; 95% confidence interval (CI) = 1.26-2.45, P < 0.05), while an inverse association was found between OBS and CVD risk (quartile (Q) 4 vs Q1: OR = 0.67; 95% CI = 0.47-0.94, P = 0.02, P for trend <0.05). There was an interaction between sleep patterns and OBS (P for interaction = 0.03). Participants with unhealthy (intermediate and poor) sleep patterns and pro-oxidant OBS (Q1 and Q2) were significantly associated with increased risk of total CVD (OR = 2.31; 95% CI = 1.42-3.74, P < 0.05), as well as angina and congestive heart failure, but not coronary heart disease (CHD). Stratified analysis showed that among individuals without hyperlipidaemia, participants with both unhealthy sleep patterns and pro-oxidant OBS exhibited a higher risk of CHD compared to those with healthy sleep patterns and antioxidative OBS.

Conclusions

Unhealthy sleep patterns and reduced oxidative balance are positively associated with an increased risk of overall and specific CVD. Interventions that target healthy sleep habits and antioxidant-rich diets and lifestyles may be important for reducing the risk of CVD.

Genetic association between coffee/caffeine consumption and the risk of obstructive sleep apnea in the European population: a two-sample Mendelian randomization study

BACKGROUND

The association between coffee/caffeine consumption and obstructive sleep apnea (OSA) risk remains unclear.

PURPOSE

To determine the relationship between coffee/caffeine consumption and the risk of OSA, using the Mendelian randomization (MR) method in the European population.

METHODS

Two sets of coffee consumption-associated genetic variants were, respectively, extracted from the recent genome-wide meta-analysis (GWMA) and genome-wide association study (GWAS) of coffee consumption. Taking other caffeine sources into account, genetic variants associated with caffeine consumption from tea and plasma caffeine (reflecting total caffeine intake) were also obtained. The inverse variance weighted (IVW) technique was utilized as the primary analysis, supplemented by the MR-Egger, weighted-median, and MR-Pleiotropy RESidual Sum and Outlier (PRESSO) techniques. Leave-one-out (LOO) analysis was performed to assess whether the overall casual estimates were driven by a single SNP. Additional sensitivity analyses were performed using similar methods, while the genetic variants associated with confounders, e.g., body mass index and hypertension, were excluded.

RESULTS

The IVW method demonstrated that coffee consumption GWMA (OR: 1.065, 95% CI 0.927-1.224, p = 0.376), coffee consumption GWAS (OR: 1.665, 95% CI 0.932-2.977, p = 0.086), caffeine from tea (OR: 1.198, 95% CI 0.936-1.534, p = 0.151), and blood caffeine levels (OR: 1.054, 95% CI 0.902-1.231, p = 0.508) were unlikely to be associated with the risk of OSA. The other three methods presented similar results, where no significant associations were found. No single genetic variant was driving the overall estimates by the LOO analysis. These findings were also supported by the sensitivity analyses with no confounding genetic variants.

CONCLUSION

Our study found no association between coffee/caffeine consumption and the risk of OSA.

International society of sports nutrition position stand: coffee and sports performance

Based on review and critical analysis of the literature regarding the contents and physiological effects of coffee related to physical and cognitive performance conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society:(1) Coffee is a complex matrix of hundreds of compounds. These are consumed with broad variability based upon serving size, bean type (e.g. common Arabica vs. Robusta), and brew method (water temperature, roasting method, grind size, time, and equipment).(2) Coffee's constituents, including but not limited to caffeine, have neuromuscular, antioxidant, endocrine, cognitive, and metabolic (e.g. glucose disposal and vasodilation) effects that impact exercise performance and recovery.(3) Coffee's physiologic effects are influenced by dose, timing, habituation to a small degree (to coffee or caffeine), nutrigenetics, and potentially by gut microbiota differences, sex, and training status.(4) Coffee and/or its components improve performance across a temporal range of activities from reaction time, through brief power exercises, and into the aerobic time frame in most but not all studies. These broad and varied effects have been demonstrated in men (mostly) and in women, with effects that can differ from caffeine ingestion, per se. More research is needed.(5) Optimal dosing and timing are approximately two to four cups (approximately 473-946 ml or 16-32 oz.) of typical hot-brewed or reconstituted instant coffee (depending on individual sensitivity and body size), providing a caffeine equivalent of 3-6 mg/kg (among other components such as chlorogenic acids at approximately 100-400 mg per cup) 60 min prior to exercise.(6) Coffee has a history of controversy regarding side effects but is generally considered safe and beneficial for healthy, exercising individuals in the dose range above.(7) Coffee can serve as a vehicle for other dietary supplements, and it can interact with nutrients in other foods.(8) A dearth of literature exists examining coffee-specific ergogenic and recovery effects, as well as variability in the operational definition of "coffee," making conclusions more challenging than when examining caffeine in its many other forms of delivery (capsules, energy drinks, "pre-workout" powders, gum, etc.).

Current therapeutic targets and multifaceted physiological impacts of caffeine

Caffeine, which shares consubstantial structural similarity with purine adenosine, has been demonstrated as a nonselective adenosine receptor antagonist for eliciting most of the biological functions at physiologically relevant dosages. Accumulating evidence supports caffeine's beneficial effects against different disorders, such as total cardiovascular diseases and type 2 diabetes. Conversely, paradoxical effects are also linked to caffeine ingestion in humans including hypertension-hypotension and tachycardia-bradycardia. These observations suggest the association of caffeine action with its ingested concentration and/or concurrent interaction with preferential molecular targets to direct explicit events in the human body. Thus, a coherent analysis of the functional targets of caffeine, relevant to normal physiology, and disease pathophysiology, is required to understand the pharmacology of caffeine. This review provides a broad overview of the experimentally validated targets of caffeine, particularly those of therapeutic interest, and the impacts of caffeine on organ-specific physiology and pathophysiology. Overall, the available empirical and epidemiological evidence supports the dose-dependent functional activities of caffeine and advocates for further studies to get insights into the caffeine-induced changes under specific conditions, such as asthma, DNA repair, and cancer, in view of its therapeutic applications.

Association of tea and coffee consumption with the risk of all-cause and cause-specific mortality among individuals with metabolic syndrome: a prospective cohort study

BACKGROUND

The relationship between tea and coffee consumption and mortality among patients with metabolic syndrome (MetS) remains barely explored. Herein, this study aimed to examine the association between tea and coffee consumption and the likelihood of all-cause and cause-specific mortality in patients with MetS.

METHODS

A total of 118,872 participants with MetS at baseline from the UK Biobank cohort were included. Information on tea and coffee consumption was obtained during recruitment using a touchscreen questionnaire. Hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality were determined using Cox proportional hazards models.

RESULTS

During a median follow-up of 13.87 years, 13,666 deaths were recorded, with 5913, 3362, and 994 deaths from cancer, cardiovascular diseases (CVD), and respiratory disease (RD), respectively. This research showed a significant inverse association between tea intake and the risk of all-cause and cancer mortality, the respective HRs (95% CI) for consuming tea 2 vs. 0 cup/day were 0.89 (0.84-0.95), and 0.91 (0.83-0.99), and tea intake ≥ 4 cups/day could reduce CVD mortality by 11% (HR 0.89; 95% CI 0.81-0.98). The U-shaped nonlinear association between coffee intake and all-cause/CVD mortality was examined (all p-nonlinear < 0.001). The HRs (95% CI) for coffee consumption 1 vs. 0 cup/day were 0.93 (0.89-0.98) and 0.89 (0.80-0.99), and for ≥ 4 vs. 0 cup/day were 1.05 (1.01-1.11) and 1.13 (1.03-1.25), respectively. Notably, the combined intake of tea and coffee presented a protective effect against all-cause mortality (HR < 1).

CONCLUSIONS

The importance of daily tea and moderate coffee consumption in individuals with MetS to optimise health benefits are highlighted.

Coffee as a dietary strategy to prevent SARS-CoV-2 infection

BACKGROUND

To date, most countries lifted the restriction requirement and coexisted with SARS-CoV-2. Thus, dietary behavior for preventing SARS-CoV-2 infection becomes an interesting issue on a daily basis. Coffee consumption is connected with reduced COVID-19 risk and correlated to COVID-19 severity. However, the mechanisms of coffee for the reduction of COVID-19 risk are still unclear.

RESULTS

Here, we identified that coffee can inhibit multiple variants of the SARS-CoV-2 infection by restraining the binding of the SARS-CoV-2 spike protein to human angiotensin-converting enzyme 2 (ACE2), and reducing transmembrane serine protease 2 (TMPRSS2) and cathepsin L (CTSL) activity. Then, we used the method of "Here" (HRMS-exploring-recombination-examining) and found that isochlorogenic acid A, B, and C of coffee ingredients showed their potential to inhibit SARS-CoV-2 infection (inhibitory efficiency 43-54%). In addition, decaffeinated coffee still preserves inhibitory activity against SARS-CoV-2. Finally, in a human trial of 64 subjects, we identified that coffee consumption (approximately 1-2 cups/day) is sufficient to inhibit infection of multiple variants of SARS-CoV-2 entry, suggesting coffee could be a dietary strategy to prevent SARS-CoV2 infection.

CONCLUSIONS

This study verified moderate coffee consumption, including decaffeination, can provide a new guideline for the prevention of SARS-CoV-2. Based on the results, we also suggest a coffee-drinking plan for people to prevent infection in the post-COVID-19 era.

Stress and sleep quality in medical students: a cross-sectional study from Vietnam

Background

The COVID-19 pandemic has resulted in significant global social and economic disruptions, as well as changes in personal attitude and behavior. The purpose of this research is to assess the sleep quality and stress levels of medical students.

Method

Data was collected from medical students over the course of a month in 2021. A total of 4,677 students at the University of Medicine Pham Ngoc Thach were invited to complete an anonymous web-based survey, which included the Pittsburgh Sleep Quality Questionnaire Index (PSQI) for measuring sleep quality and the COVID-19 Student Stress Questionnaire (CSSQ) for evaluating stress.

Results

A total of 1,502 students participated in our survey. More than half of the participants exhibited poor quality of sleep as indicated by their PSQI score. Many students reported going to bed after midnight and spending time on their smartphones. Among the students surveyed, 21.84% experienced low levels of stress (CSSQ ≤6), 63.38% had mild stress (7 ≤ CSSQ score ≤ 14), 14.78% reported high levels of stress (CSSQ >14).

Conclusion

This study showed a high prevalence of poor sleep quality in the surveyed students, which could be attributed to changes in their behavior following the COVID-19 outbreak. Mild stress was also frequently observed, and it may be related to sleep disorders in this population. These important findings provide valuable insights for making recommendations, including lifestyle modifications to improve sleep quality.

Sleep, alcohol, and caffeine in financial traders

Alcohol and caffeine are two of the most commonly used substances for altering human consciousness. While their adverse effects on sleep have been separately examined in the laboratory and epidemiological levels, how they impact real-world night-to-night sleep, in isolation or together, remains unclear. This is especially true in occupations wherein the use of alcohol and caffeine is high (e.g., financial services sector). Using a six-week micro-longitudinal study, here we examined the real-world impact of alcohol, caffeine, and their combined consumption in a cohort of financial traders. We demonstrate that alcohol consumption significantly degrades the subjective quality of sleep (p < 0.001). Caffeine consumption led to a different phenotype of sleep impairment, resulting in a detrimental reduction in sleep quantity (p = 0.019), rather than a marked alteration in sleep quality. Contrary to our hypothesis, when consumed in combination, evening alcohol consumption interacted with ongoing caffeine consumption such that alcohol partially mitigated the impairments in sleep quantity associated with caffeine (p = 0.032). This finding suggests the sedating effects of alcohol and the psychoactive stimulant effects of caffeine obscure each other's impact on sleep quantity and sleep quality, respectively-potentially explaining their interdependent use in this cohort (i.e., "self-medication" of evening sedation with alcohol to combat the prior daytime ingestion of caffeine and vice versa). More generally, these results contribute to a unique understanding of the singular and combinatory impacts of two of the most commonly used substances for augmenting human consciousness under free-living, real-world conditions, the performance-impairing (and thus economic-cost) consequences of which may be important to the business sector and the society.

Sleep timing, workplace well-being and mental health in healthcare workers

INTRODUCTION

Healthcare workers face an elevated risk of burnout, sleep disorders, and mental health issues, potentially stemming from the misalignment of their circadian rhythm due to nonstandard work schedules. This cross-sectional survey aims to examine the connections between sleep timing, workplace well-being (including burnout and absenteeism), and mental health outcomes (specifically depression and poor sleep) in healthcare workers. Additionally, the survey takes into account individual and professional factors, as well as the interaction with work schedules.

METHODS

The study encompasses 4,971 healthcare workers from both public and private healthcare facilities in France, including nurses, nursing assistants, and physicians recruited during the third wave of the COVID-19 pandemic. The Maslach Burnout Inventory assesses burnout, the Center for Epidemiologic Studies Depression Scale measures depression, and the Pittsburgh Sleep Quality Index evaluates poor sleep. Sleep timing is categorized into morning, neutral, and evening timing, referred to as midsleep. Multivariate logistic regression analysis is conducted to explore the relationships between sleep timing and burnout, depression, and poor sleep, while adjusting for various factors.

RESULTS

The findings reveal that 56.5% of participants experience burnout, 29.8% report depression, and 64.5% report poor sleep. Nurses and nursing assistants exhibit a higher prevalence of poor sleep. Morning sleep timing is associated with burnout among those with fixed schedules and with depression among those with shift schedules. Among physicians, both morning and evening sleep timing are associated with depression, while morning sleep timing is linked to poor sleep across all subgroups.

INTERPRETATION

This study suggests that the misalignment between healthcare workers' internal circadian rhythm and their work schedules may contribute to an increased risk of burnout, depression, and poor sleep. Occupational health services and policymakers should recognize the potential for enhancing workplace well-being and mental health outcomes by enabling healthcare workers to maintain sleep schedules that accommodate their needs.

Caffeine Consumption in Polish Adults: Development and Validation of a Polish Questionnaire for Assessing Caffeine Intake

Objective: Caffeine is one of the oldest natural substances consumed by people. Its consumption in Poland has not been well described. The aim of this study was to design and validate an online food frequency questionnaire (FFQ) on caffeine intake and to use it to estimate caffeine consumption in Polish adults.Method: The FFQ was prepared and validated in a pilot study. The intake assessment was conducted in 2019-2020 on 372 respondents, aged 18 to 60 years. The FFQ included products such as coffee, tea, energy drinks, and carbonated drinks, as well as supplements and chocolate.Results: We showed good repeatability of the FFQ and it was considered a valid tool. The mean total caffeine intake among all participants was 426.7 mg ± 283.4 mg/day of all sources; in women, it was 446.4 mg ± 306.2 mg/day, while in men, it was 394.1 ± 236.4 mg/day. Forty-three percent of the respondents consumed more than 400 mg of caffeine/day. Coffee was the main source of caffeine and contributed to 65% of total caffeine consumption. Women consumed 90% more green tea than men (p < 0.01). Overweight and obese people have 20% greater total caffeine intake (p = 0.01) and consumed 20% more coffee (p = 0.02) and 30% more black tea (p = 0.01) than people of normal weight.Conclusions: Average caffeine consumption among Polish adults slightly exceeds the safe consumption dose established by the European Food Safety Authority. Body weight status can differentiate caffeine intake.

Sleep patterns before and after competition: A real-world examination of elite athletes

Good sleep before and after competitions is crucial to cognitive, physiological performance and recovery. Yet, elite athletes face a unique set of challenges when acquiring good sleep before and after competitions, and indeed commonly report sleep problems when it matters most. This study examined the sleep of elite athletes before and after competition compared to before and after free days. A total of 1808 unique nights of actigraphy (n = 1495) and sleep diary (n = 1335) data from elite Australian Football League and National Rugby League male athletes (N = 85, M-age = 24.4 ± 3.6) were collected and analysed using multi-level mixed models. On nights before competitions, athletes advanced sleep timings (p < .001, d = 0.63) and increased total sleep time (p < .001, d = 0.65) compared to nights before free days. On nights after competitions, athletes delayed sleep timings (p < .001, d = 1.64), reduced total sleep time (p < .001, d = 1.28), and had significantly worse quality sleep (p < .001, d = 0.71) compared to nights after free days. Sleep was especially worse following night competitions. While elite athletes and organisations may be implementing effective sleep strategies to optimise sleep the night before competitions, strategies to improve sleep after competitions may be lacking. We discuss potential factors contributing to this asymmetry and propose areas for research moving forward.

Does the timing of intake matter? Association between caffeine intake and depression: Evidence from the National Health and Nutrition Examination Survey

BACKGROUND

Recent research suggests that caffeine intake is associated with a reduced risk of depression. However, the relationship between caffeine intake during different periods of the day and depression is still unclear.

METHODS

This cross-sectional study analyzed noninstitutionalized adults from the National Health and Nutrition Examination Survey, with a weighted representation of approximately 218 million US adults. Covariate-adjusted sample-weighted regressions were used to examine associations between caffeine intake and depression in different periods.

RESULTS

Caffeine intake during non-early morning periods (outside of 5:00-8:00 AM) is associated with a high prevalence of depression (unadjusted OR: 1.08, 95%CI: 1.05-1.11; adjusted OR: 1.03, 95 % CI: 1.00-1.06). Participants who consumed caffeine in the early morning (5:00-8:00 AM) had a lower prevalence of depression compared to participants who did not consume caffeine in the early morning (unadjusted OR: 0.75, 95%CI: 0.67-0.85; adjusted OR: 0.86, 95 % CI: 0.75-0.99).

LIMITATIONS

Cross-sectional study could not determine the temporal association; patients with depression in this study were not clinically diagnosed with Major Depressive Disorder.

CONCLUSIONS

Among US adults, early morning caffeine consumers had a lower prevalence of depression than non-consumers; caffeine intake during non-early morning periods is associated with a high prevalence of depression. Our results may suggest the importance of caffeine intake time for depression.

Protocol of the Budapest sleep, experiences, and traits study: An accessible resource for understanding associations between daily experiences, individual differences, and objectively measured sleep

Sleep is both a neurophysiological state and a biologically necessary behavior that performs a variety of indispensable roles for human health, development, and cognitive functioning. Despite this, comparatively little is known about the relationships between daily experiences and sleep features. Importantly, these relationships are bidirectional in nature, may be differently associated with subjectively and objectively assessed sleep, and may also be modulated by individual differences To address this challenge, we created the Budapest Sleep, Experiences, and Traits Study (BSETS), a multidisciplinary observational sleep study utilizing novel remote EEG devices. BSETS was designed to establish a dataset for future use in investigating the relationships between sleep features and daily experiences. In this paper we describe the protocol of the currently ongoing BSETS, which examines a community-dwelling sample of over 250 healthy participants who are studied in a naturalistic setting using a large questionnaire assessing psychological, demographic, and anthropometric information, as well as evening/morning diaries of sleep and daily experiences, and mobile EEG recordings over a period of 7 days. This dataset will become an accessible resource to the wider scientific community and can be utilized to investigate the complex multidirectional relationships between objectively and subjectively measured sleep, daily experiences, and individual differences, bestowing it with significant value for sleep researchers as well as practitioners working in clinical settings with patients suffering from disordered sleep.

Prevalence and associated factors of poor sleep quality among industrial workers in Addis Ababa, Ethiopia: findings from a cross-sectional study

OBJECTIVE

This study aimed to investigate the prevalence and associated factors of poor sleep quality among Bole Lemi Industrial Park workers in Addis Ababa, the capital of Ethiopia.

DESIGN

An institution-based cross-sectional study was conducted from July to August 2022. The data were collected using a validated and standardised Pittsburgh Sleep Quality Index Questionnaire. The collected data were entered into EpiData V.4.6 and analysed using Stata V.14. A multivariable binary logistic regression analysis was conducted to identify factors associated with poor sleep quality. The association was determined using an adjusted OR (AOR) with a 95% CI at a p value of <0.05.

SETTING

The study was conducted in Bole Lemi Industrial Park in Addis Ababa.

PARTICIPANTS

A total of 370 workers participated in this study.

OUTCOME MEASURES

The primary outcome of the study was the prevalence of poor sleep quality.

RESULTS

The total response rate was 87.7%. The majority (260, 70.3%) of the participants were female. The mean (±SD) age of the participants was 30.5 (±10.6) years. The prevalence of poor sleep quality during the last months was found to be 75.4% (n=279) (95% CI: 70.7% to 79.7%). Undiversified dietary intake (AOR: 1.63; 95% CI (1.09 to 2.78)), caffeine consumption more than 250 mg per day (AOR: 2.57; 95% CI (1.12 to 6.05)) and night shift work (AOR: 2.36; 95% CI (1.27 to 4.41)) were risk factors for poor sleep quality among sampled workers.

CONCLUSION

This study detected that poor sleep quality is highly prevalent among garment and textile industry workers, indicating that it is a significant public health issue that requires immediate attention. Therefore, modifications of the work environment involving night shift work and the improvement of workers' personal lifestyles involving dietary diversification and caffeine consumption are needed to minimise the burden of poor sleep quality among workers.

Poor sleep is associated with work environment among 10,087 French healthcare workers: Results from a nationwide survey

Poor sleep is a prevalent issue among healthcare workers and can have detrimental effects on their health. Various individual and professional factors, including the work environment, may contribute to poor sleep. However, only a limited number of studies have examined the simultaneous influence of these factors. Hence, we conducted a nationwide survey among graduated healthcare workers in both public and private healthcare facilities in France. The aim was to analyze the association between poor sleep, assessed using the Pittsburgh Sleep Quality Index (>5), and the work environment, evaluated using the Job Content Questionnaire. The study encompassed 10,087 healthcare workers, among whom 6,540 (64.8%) reported experiencing poor sleep. Nurses, health executives, nursing assistants, and other allied healthcare professionals were more likely to experience poor sleep compared to physicians. Through multivariate regression analysis, we identified several aspects of the work environment associated with an increased likelihood of poor sleep. These factors included high speed and quantity of work, high complexity and intensity, high fragmentation and unpredictability, limited decision-making latitude, underutilization of skills, lack of emotional support from colleagues, and sustained workplace bullying. These findings highlight the significance of considering the work environment in addressing sleep issues among healthcare professionals.

Caffeine consumption and sleep in a submarine environment: An observational study

Submariners face many environmental and operational challenges to maintaining good sleep, including suboptimal lighting, shift work, and frequent interruptions. Anecdotally, many Sailors consume caffeine to alleviate the effects of poor sleep on alertness, mood, and performance; however, caffeine itself may also degrade sleep quantity and/or quality. This study provides the first exploration of the potential relationship between caffeine use and sleep onboard submarines. Objective measures (wrist actigraphy, available from 45 participants), self-report sleep metrics, and self-reported caffeine consumption were collected from 58 US Navy Sailors before and during a routine submarine underway at sea lasting 30 days. Contrary to expectations, less caffeine was reportedly consumed at sea (232.8 ± 241.1 mg) than on land prior to the underway (M = 284.4 ± 251.7 mg; X2 (1) = 7.43, p = 0.006), positive rather than negative relationships were observed between caffeine consumption and sleep efficiency (F = 6.11, p = 0.02), and negative relationships were observed between caffeine consumption and wake after sleep onset (F = 9.36, p = 0.004) and sleep fragmentation (F = 24.73, p < 0.0001). However, in contrast, higher caffeine consumption was also negatively related to self-reported sleep duration while at sea (F = 4.73, p = 0.03). This observational study is the first to measure relationships between caffeine consumption and sleep quantity and/or quality in a submarine environment. We propose that the unique submarine environment and the unique caffeine consumption patterns of submariners should be considered in the development of potential countermeasures for sleepiness.

Caffeine - Essentials for anaesthesiologists: A narrative review

Caffeine has a multitude of uses in anaesthesia, and numerous studies have evaluated its efficacy and usefulness in various aspects of anaesthesia and medical practice. Its various applications in anaesthesia include its role in awakening from anaesthesia, managing post-dural puncture headache, managing post-sedation paradoxical hyper-activity in children, post-operative bowel paralysis, and apnoea in paediatric populations, that is, apnoea in infancy, paediatric obstructive apnoea, and post-anaesthetic apnoea in pre-mature infants. Though the effects of caffeine on bronchial smooth muscle, neurological, and cardio-vascular systems are well known, the relatively little-known effects on the endocrine and gastro-intestinal (GI) system have been recently taking primacy for eliciting its therapeutic benefits. The literature shows encouraging evidence in favour of caffeine, but unambiguous evidence of caffeine benefits for patients is lacking and needs further investigation. In this narrative review of literature, we summarise the available literature to provide insights into the pharmacokinetics, pharmacodynamics, clinical application of caffeine in modern anaesthetic practice, and evidence available in this field to date. An awareness of the various physiological effects, adverse effects, reported applications, and their evidence will widen the horizon for anaesthesiologists to increase its rational use and advance research in this field. Well-designed randomised controlled trials regarding the various outcomes related to caffeine use in anaesthesia should be planned to generate sound evidence and formulate recommendations to guide clinicians.

Coffee consumption and abdominal aortic calcification among adults with and without hypertension, diabetes, and cardiovascular diseases

BACKGROUND AND AIMS

This study was performed to investigate the effect of coffee consumption on abdominal aortic calcification (AAC) among adults with and without hypertension, diabetes, and cardiovascular diseases (CVD).

METHODS AND RESULTS

A total of 2548 participants from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 were included. Coffee consumption was obtained from 24-h dietary recalls. Dual-energy X-ray absorptiometry (DXA) was used to measure the severity of AAC. In the fully adjusted model, compared with non-drinkers, high coffee consumption (≥390 g/d) was associated with higher AAC scores among participants with hypertension (β = 0.72, 95% CI: 0.21-1.22), diabetes (β = 1.20, 95% CI: 0.35-2.05), and CVD (β = 2.03, 95% CI: 0.71-3.36). We did not observe such an association among participants without hypertension, diabetes, and CVD. Furthermore, decaffeinated coffee was not associated with AAC.

CONCLUSION

In conclusion, patients with hypertension, diabetes, and CVD should focus on coffee consumption, especially caffeinated coffee, to reduce the burden of AAC.

Sleep and Perivascular Spaces

PURPOSE OF REVIEW

The glymphatic system is hypothesized to act as the brain's filtration system to remove toxic solutes that accumulate throughout the day. Perivascular spaces (PVSs) play a fundamental role in the ability of the glymphatic system to function, and sleep influences the effectiveness of this system. This article reviews the complexity of the interplay between sleep, the glymphatic system, and PVS.

RECENT FINDINGS

New imaging techniques have illuminated the structure of PVS and their associations with differing disease states. Research has shown that sleep may play a key role in the function of PVS and the influence of adenosine, astrocyte, and aquaporin-4 channel in the function of the glymphatic system. Emerging data suggest that differing pathological states such as neuroinflammatory conditions, neurodegenerative diseases, and cognitive dysfunction may be associated with underlying glymphatic system dysfunction, and sleep disorders could be a potential intervention target.

Sleep Health, Individual Characteristics, Lifestyle Factors, and Marathon Completion Time in Marathon Runners: A Retrospective Investigation of the 2016 London Marathon

Despite sleep health being critically important for athlete performance and well-being, sleep health in marathoners is understudied. This foundational study explored relations between sleep health, individual characteristics, lifestyle factors, and marathon completion time. Data were obtained from the 2016 London Marathon participants. Participants completed the Athlete Sleep Screening Questionnaire (ASSQ) along with a brief survey capturing individual characteristics and lifestyle factors. Sleep health focused on the ASSQ sleep difficulty score (SDS) and its components. Linear regression computed relations among sleep, individual, lifestyle, and marathon variables. The analytic sample (N = 943) was mostly male (64.5%) and young adults (66.5%). A total of 23.5% of the sample reported sleep difficulties (SDS ≥ 8) at a severity warranting follow-up with a trained sleep provider. Middle-aged adults generally reported significantly worse sleep health characteristics, relative to young adults, except young adults reported significantly longer sleep onset latency (SOL). Sleep tracker users reported worse sleep satisfaction. Pre-bedtime electronic device use was associated with longer SOL and longer marathon completion time, while increasing SOL was also associated with longer marathon completion. Our results suggest a deleterious influence of pre-bedtime electronic device use and sleep tracker use on sleep health in marathoners. Orthosomnia may be a relevant factor in the relationship between sleep tracking and sleep health for marathoners.

Evaluation of Sleep Behavior and the Use of Sleep Aids among Adults Living in Saudi Arabia: A Cross-Sectional Study

A negative attitude toward sleep has greatly affected sleep habits. In addition to contributing to physical and metabolic disorders, poor sleep quality may cause emotional disturbances. This study aimed to measure sleep behavior and factors contributing to poor sleep quality in the Madinah region, Saudi Arabia. We also assessed whether the use of sleeping aids improved peoples sleep. Three hundred and ninety-nine adults in the Madinah region of Saudi Arabia participated in this cross-sectional study. Three data domains were collected using an online questionnaire between 30 January and 26 April 2022. In the first domain, the characteristics of participants were discussed. In the second domain, questions about sleep behavior were asked. In the third domain, we examined the types, frequency, and impact of sleep aid use. Out of the 399 participants, 154 (38.59%) reported sleep problems. A total of 64.94% of the 154 participants blamed stress as the leading cause of their sleep disorders, and 74.68% of those with sleep problems reported reduced productivity. Among those who reported having sleep problems, 46.10% used sleep aids, with Panadol night (antihistamine) being the most used, 49.30%, followed by Melatonin at 39.44%. Sleep quality improved by 67.6% among those who used sleep aids. A total of 71.8% of the participants think it is not safe to use sleep aids in the long term. Our findings suggest that sleep problems are a prevalent concern in Madinah, Saudi Arabia, and even though the use of sleep aids improved sleep quality, it should be considered an emerging and important public health objective in Saudi Arabia. Further studies are needed to evaluate sleep quality and the level of sleep aid usage among other Saudi Arabian regions.

Potential Benefits of Coffee Consumption on Improving Biomarkers of Oxidative Stress and Inflammation in Healthy Individuals and Those at Increased Risk of Cardiovascular Disease

Cardiovascular diseases (CVDs) are considered the predominant cause of death globally. An abnormal increase in biomarkers of oxidative stress and inflammation are consistently linked with the development and even progression of metabolic diseases, including enhanced CVD risk. Coffee is considered one of the most consumed beverages in the world, while reviewed evidence regarding its capacity to modulate biomarkers of oxidative stress and inflammation remains limited. The current study made use of prominent electronic databases, including PubMed, Google Scholar, and Scopus to retrieve information from randomized controlled trials reporting on any association between coffee consumption and modulation of biomarkers of oxidative stress and inflammation in healthy individuals or those at increased risk of developing CVD. In fact, summarized evidence indicates that coffee consumption, mainly due to its abundant antioxidant properties, can reduce biomarkers of oxidative stress and inflammation, which can be essential in alleviating the CVD risk in healthy individuals. However, more evidence suggests that regular/prolonged use or long term (>4 weeks) consumption of coffee appeared to be more beneficial in comparison with short-term intake (<4 weeks). These positive effects are also observed in individuals already presenting with increased CVD risk, although such evidence is very limited. The current analysis of data highlights the importance of understanding how coffee consumption can be beneficial in strengthening intracellular antioxidants to alleviate pathological features of oxidative stress and inflammation to reduce CVD risk within the general population. Also covered within the review is essential information on the metabolism and bioavailability profile of coffee, especially caffeine as one of its major bioactive compounds.

Clinical Neurobiology of Sleep and Wakefulness

OBJECTIVE

This article focuses on novel neuronal mechanisms of sleep and wakefulness and relates basic science developments with potential translational implications in circadian neurobiology, pharmacology, behavioral factors, and the recently integrated potential pathways of sleep-related motor inhibition.

LATEST DEVELOPMENTS

During the past decade, remarkable advances in the molecular biology of sleep and wakefulness have taken place, opening a promising path for the understanding of clinical sleep disorders. Newly gained insights include the role of astrocytes in sleep brain homeostasis through the glymphatic system, the promotion of memory consolidation during states of reduced cholinergic activity during slow wave sleep, and the differential functions of melatonin receptors involving regulation of both circadian rhythm and sleep initiation. Ongoing investigations exploring sleep and circadian rhythm disruptions are beginning to unlock pathophysiologic aspects of neurologic, psychiatric, and medical disorders.

ESSENTIAL POINTS

An understanding of sleep and circadian neurobiology provides coherent and biologically credible approaches to treatments, including the identification of potential targets for neuromodulation.

Coffee bean processing: Emerging methods and their effects on chemical, biological and sensory properties

Emerging processing methods have been applied in coffee bean processing for improved sensory quality. The processes focus on optimizing the fermentation process of the coffee cherries and beans. This involves various pathways, including the formation of volatiles, flavor precursors and organic acids and the reduction in the concentrations of bioactive compounds. Comprehensive information regarding the effect of these emerging processes on the chemical, biological and sensory properties of the coffee beans is summarized. Emerging processes affected the coffee bean to various degrees depending on the raw material and the method used. The emerging methods promoted the reduction of bioactives such as caffeine and phenolics in coffee beans. Substantial improvement of these processes is needed to obtain coffee beans with improved biological activities. Effort to simplify the methods and optimize the post-fermentation process is crucial for the methods to be easily accessible by the producers and to produce defect-free coffee beans.