Caffeine Use Research Articles

Caffeine consumption and onset of alcohol use among early adolescents

Preventing or delaying the onset of alcohol use among children and youth is an important public health goal. One possible factor in alcohol use onset among early adolescents is caffeine. The aim of this study was to assess the possible contribution of caffeine to the onset of alcohol use during early adolescence. We used data from the Young Mountaineer Health Study Cohort. Survey data were collected from 1349 (response rate: 80.7%) 6th grade students (mean age at baseline 11.5 years) in 20 middle schools in West Virginia during the fall of 2020, and again approximately 6 months later in spring of 2021. We limited our analyses to students reporting never having used any form of alcohol at baseline. Logistic regression was employed in multivariable analyses and both Odds Ratios and Relative Risks reported. At follow-up, almost 14% of participants reported having consumed alcohol at least once and 57% used caffeine of 100 mg + daily. In multivariable analyses we controlled for social and behavioral variables known to impact tobacco use. Caffeine use was operationalized as a three-level factor: no use, <100 mg per day, and 100 + mg per day, with the latter being the approximate equivalent of the minimum of a typical cup of coffee or can of energy drink. Caffeine use of 100 mg + per day was significantly related to alcohol use at 6-months follow-up (OR: 1.79, RR: 1.56, p = .037). We conclude that caffeine consumption among 11–12-year-old adolescents may be a factor in early onset of alcohol use.

The Impact of Dietary Factors on the Sleep of Athletically Trained Populations: A Systematic Review.

Many athletic populations report poor sleep, especially during intensive training and competition periods. Recently, diet has been shown to significantly affect sleep in general populations; however, little is known about the effect diet has on the sleep of athletically trained populations. With sleep critical for optimal recovery and sports performance, this systematic review aimed to evaluate the evidence demonstrating that dietary factors influence the sleep of athletically trained populations. Four electronic databases were searched from inception to May 2022, with primary research articles included if they contained a dietary factor(s), an outcome measure of sleep or sleepiness, and participants could be identified as ‘athletically trained’. Thirty-five studies were included, with 21 studies assessed as positive quality, 13 as neutral, and one as negative. Sleep or sleepiness was measured objectively in 46% of studies (n = 16). The review showed that evening (≥5 p.m.) caffeine intakes >2 mg·kg−1 body mass decreased sleep duration and sleep efficiency, and increased sleep latency and wake after sleep onset. Evening consumption of high glycaemic index carbohydrates and protein high in tryptophan may reduce sleep latency. Although promising, more research is required before the impact of probiotics, cherry juice, and beetroot juice on the sleep of athletes can be resolved. Athletic populations experiencing sleep difficulties should be screened for caffeine use and trial dietary strategies (e.g., evening consumption of high GI carbohydrates) to improve sleep.

Influence of caffeine and citrulline on magnetic properties when used as new fuels in the synthesis of CoFe2O4 nanoparticles by gel combustion

In this study, for the first time, caffeine and citrulline were used as fuels for the synthesis of the spinel ferrite CoFe2O4 by gel combustion. The influence of the oxidizer to fuel molar ratio (φ) on the synthesis of cobalt ferrite was studied. X-Ray Diffraction (XRD) showed that the spinel phase was obtained in all the combustions, but the use of caffeine as fuel allowed it to be obtained with high purity, while in the other combustions CoO appeared as a secondary phase due to changes in the reaction. Furthermore, the crystallite size was estimated using the Scherrer equation and considering the plane (311), finding it to be in the range of 32–40 nm, and increasing as the amount of fuel was increased. In addition, the adiabatic flame temperatures were estimated, finding that, in the synthesis with φ = 0.7, the flame temperatures were 1974 K and 1711 K, for the caffeine and citrulline respectively, which could be sufficient to obtain the phase in one stage. The ignition temperatures identified by DSC/TG thermal analysis for caffeine and citrulline samples with φ = 1.0 were 297 and 191 °C, respectively, which are in the range of traditional fuels. The morphology was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) which revealed that the particles were agglomerated as a result of high reaction temperatures. The magnetic properties identified by the vibrating sample magnetometer (VSM) for the sample with caffeine and ratio φ = 0.7 were saturation magnetization Ms = 95.16 emu g−1, coercivity field Hc = 710.76 Oe and remanent magnetization Mr = 44.86 emu g−1. Meanwhile, with citrulline and ratio φ = 0.7, the properties were saturation magnetization Ms = 59.14 emu g−1, coercivity field Hc 837.15 Oe and remanent magnetization Mr = 32.30 emu g−1. It should be pointed out that the high saturation magnetization values obtained with caffeine fuel exceed those reported with traditional fuels. The obtained results allow us to infer that these fuels could be used as alternatives in synthesizing inorganic oxides by combustion in one step.

Does caffeine use support suck/swallow/breathe coordination during breast and bottle, and lead to an earlier discharge?

Does caffeine use support suck/swallow/breathe coordination during breast and bottle, and lead to an earlier discharge?

Does smoking affect the prevalence of caffeine use in schizophrenia?

IntroductionCaffeine acts as a competing antagonist of adenosine receptors, increasing the release of norepinephrine and the activation of noradrenergic neurons. Long-standing schizophrenia patients frequently develop a comorbidly high daily caffeine intake. This could be explained by its relationship with smoking [1,2].ObjectivesTo determine caffeine consumption in schizophrenia and predisposing factors.MethodsCross-sectional study designed on a sample of 68 outpatients with a follow-up of at least 5 years at the Mental Health Unit, aged between 18 and 65 years, diagnosed with schizophrenia (ICD-10). Average daily caffeine intake was quantified by reference values for each beverage: coffee (66.7mg/100ml), tea (30mg/100ml), soft or energy drinks (11.5mg/100ml). High intake was defined as a consumption of ≥200mg of caffeine per day. Retrospective review of medical records revealed tobacco use and negative symptoms observed on the PANSS scale. Statistical analysis were performed using SPSS v21.0 (significance p&lt;0.05).Results88.2% of the subjects were daily caffeine consumers with a mean intake of 146.7mg/day (SD=5.8), and a mean consumption time of 6.2 years. Coffee was the predominant beverage in 66.7% of the cases, followed by soft or energy drinks (25%) and tea (0.1%). 45% of participants also had a high caffeine intake of ≥200 mg/day. Comorbid smoking was found in 93% of these patients. Negative symptomatology prevailed among caffeine consumers (PANSS-N= 41.3).ConclusionsXanthine abuse seems to be highly prevalent in people with schizophrenia, and there may be a relationship with smoking and negative psychotic symptoms.DisclosureNo significant relationships.

Caffeine ingestion by students at the Brazil faculty of medicine: a prospective observational cross-sectional study

Introduction: In higher education, the consumption of stimulant substances such as coffee is increasing intensely due to the high demand of concentration and disposition of individuals. This occurs mainly among medical students. Objective: It was to quantify and analyze caffeine intake and its effects on medical students at the Faculty of Medicine of Catanduva, Centro Universitário Padre Albino (UNIFIPA). Methods: This study followed a prospective observational cross-sectional model, following the rules of clinical research of the STROBE. Data collection took place from June 2019, through an objective questionnaire and self-application, which was answered by students from the first to the sixth year of FAMECA who were interested in answering and contributing to the research, which had as objective to quantify and analyze the use of caffeine, in addition to its motivations and side effects on the physiology of these students. This study was analyzed and approved by the Research Ethics Committee according to a substantiated opinion number 5,347,594, and obtaining the Informed Consent Form. For data analysis, a common descriptive analysis was performed, obtaining the values of total N, and statistical percentage (%) for all predictors. The One-Way test (ANOVA) was applied, adopting the α level lower than 0.05, with a statistically significant difference for the 95% CI. Results and Conclusion: The results of this study revealed that a very large number of university students ingest caffeine. Most of the students started consumption in the pre-college course and in college, with the aim of compensating for sleep, because they like the taste of energy drinks and improve academic performance, due to the intense routine due to the high workload requires greater attention, in order to to meet the demand for studies. Most students consume moderately caffeine, which is not harmful to health. However, a minority ingest excessive amounts of substances that contain caffeine and side effects are noted. Among these, the ones that stood out were stomach problems, anxiety and tachycardia. Thus, even representing the minority, it is of fundamental importance to carry out more studies on this topic. With this, it will be possible to provide more information to the population so that it is able to assess the impacts of the use of stimulants in clinical practice, in order to minimize possible adverse effects. Finally, the population will be able to use caffeine properly, according to the recommended dose, avoiding major health problems.

0410 Utility of the Urine Drug Screen in Maintenance of Wakefulness Testing Interpretation - A Single-Center, Retrospective Analysis in Pediatric Patients

Abstract Introduction Accurate assessment of hypersomnia depends upon consideration of several factors, including use of medications that affect alertness and sleep organization. Urine drug screens (UDS) are recommended when assessing hypersomnia, but there is little standardization with respect to screening methods, types of substances detected, and use in maintenance of wakefulness test (MWT) interpretation, in part because there is scant literature relating UDS results to patients’ characteristics, MWT findings and implications. Methods A retrospective analysis was performed in adolescents evaluated at Cincinnati Children's Sleep Center between 2008 and 2021 who underwent MWT with concurrent UDS to determine the adequacy of hypersomnia treatment. UDS in our laboratory were performed by Qualitative Immunoassay/Gas Chromatography-Mass Spectrometry/Liquid Chromatography-Tandem Mass Spectrometry. Results A total of 109 MWTs were accompanied by UDS in 79 patients. Patients were 17.7 [16.6, 18.6] years old (median, [IQ range]), 41.3% female, 68.8% White, 25.7% Black, 5.5% Other, with a BMI of 25.8 [22.1, 31.8] kg/m2. 85.3% had narcolepsy. In addition to prescribed medications, caffeine was positive in 54.1% of UDS, and diphenhydramine was positive in 58.7%. No patients reported use of caffeine or diphenhydramine on the day of MWT. There were no significant demographic differences between those who tested positive and negative for caffeine. The median sleep latency in those with caffeine-positive UDS was longer than those with caffeine-negative UDS, although it did not reach statistical significance (27.3 [14.7, 38.3] vs 19.1 [9.8, 36.1] minutes; P=0.15). Patients with a positive UDS for diphenhydramine all took modafinil/armodafinil. In addition, 80% of patients taking modafinil/armodafinil had diphenhydramine-positive results. Nicotine and cannabinoids were detected in 2 UDS. Conclusion Two unexpected substances (caffeine and diphenhydramine) were found on UDS during MWTs in a significant proportion of our cohort. Caffeine may influence the results of MWTs, although further investigations are warranted. The unexpected presence of diphenhydramine is a false positive for those patients on modafinil/armodafinil (supported by literature and confirmed by our laboratory director). Sleep clinicians should be aware of these findings and the implications of unexpected substances when interpreting MWTs. Support (If Any) Cincinnati Children's Hospital Research Fund

0676 Increased Depression Symptoms are Associated with Higher Nightmare Frequency within the Wisconsin Sleep Cohort

Abstract Introduction Nightmare frequency has been suggested as a strong clinical indicator of psychiatric disorders. Additionally, frequent nightmares are a possible underrepresented outcome of depression. As nightmares may increase the risk of negative health outcomes, such as suicide attempts, understanding possible sources of nightmare frequency is imperative. This study sought to examine the association between depression and anxiety on the incidence of high frequency of nightmares. Methods Using cross-sectional and longitudinal data from the Wisconsin Sleep Cohort, accessed through the National Sleep Research Resource, we conducted an analysis of demographics, co-occurring sleep disturbances, and mental health measures of participants experiencing ordinal frequencies of nightmares. The study sample included 758 Wisconsin state employees with a baseline and follow-up assessment (mean 4.46 years between visits; standard deviation 1.7). All participants were screened for depression and anxiety symptoms using the Zung Depression Scale (SDS), and the State-Trait Anxiety Inventory. Sleep disturbances, medication use, nightmares and insomnia were based on self-report. Nightmare frequency was categorized as high (≥2 per month) and low (&amp;lt;2 per month). Logistic regression was used to determine the association of baseline anxiety and depression scales (in the same model) with incidence of high nightmare frequency at follow-up, adjusted by age, sex, body mass index, hypertension medications, use of narcotics and caffeine. Results After adjusting for covariates, SDS scores at baseline were associated with an increased incidence of higher frequency of nightmares at follow-up (OR=1.05; 95%CI=1.01-1.10, p = 0.026), while anxiety at baseline was not (OR=1.03; 95%CI=0.99-1.07; p = 0.165). An increase in one unit of the SDS was associated with a 5% increase in the odds of presenting higher frequency nightmares at follow-up. Conclusion Participants with higher SDS scores had higher incidence of high frequency of nightmares upon follow up, however, those with anxiety did not. Further research should be targeted at gaining better understanding of the role of psychiatric conditions on the onset of nightmares. Support (If Any) NIH NHLBI (R01HL62252), NIA (R01AG036838, R01AG058680), and National Center for Research Resources (1UL1RR025011). The National Sleep Research Resource was supported by NIH-NHLBI (R24 HL114473, 75N92019R002).

How effectively does CBT-I address the traumatic and functional causes of insomnia and sleep disturbance in Veterans?

LAY SUMMARY Cognitive-behavioural therapy for insomnia (CBT-I) continues to be recommended as the first-line treatment for an increasing number of Veterans seeking help for insomnia. Unfortunately, these recommendations are made on the basis of evidence from the general public, who do not experience the same predisposing, activating, and maintaining causes of insomnia as Veterans. This review considers whether CBT-I really addresses the causes of insomnia among Veterans, which can be labelled as functional (e.g., caffeine use) and traumatic (e.g., nightmares). Nine randomized controlled trials of CBT-I delivered to Veterans having trouble falling or staying asleep were reviewed. Evidence was not consistent enough to support the continued recommendation of CBT-I as a first-line treatment for insomnia among Veterans. On a wider level, the authors question whether psychological causes of a mental health problem are always, or should be, fully considered in the process of creating clinical guidelines for treatment.

Temporal Associations between Substance Use and Somatic Symptoms in the Daily Lives of People with Fibromyalgia

Compared to the general population, a higher prevalence of substance use has been found among people with fibromyalgia (FM), but little is known about factors related to use of psychoactive stimulants and depressants. Somatic symptoms that are common to the condition could relate to the substance use, either in response to symptom occurrence or to prevent symptom onset. To address these unanswered questions, we examined the temporal associations between substance use (alcohol, nicotine, caffeine, and cannabis) and somatic symptoms (pain, mental fatigue, and physical fatigue) in the daily lives of adults with FM. Adults with FM (N=50; mean age=45±SD; 88% female, 86% white) completed ecological momentary assessments of substance use, pain intensity, and physical/mental fatigue via a smartphone app 5X/day for eight days. Linear-mixed effects models showed that use of nicotine and cannabis were positively associated with concurrent mental fatigue (respectively; B=12.08; p=0.003, B=6.93; p=0.02); in contrast caffeine consumption was negatively associated with concurrent mental fatigue B=-4.28; p=0.000. Of the substances examined, only caffeine use showed a significant contemporaneous association with physical fatigue (B= -4.85; p=0.000) and pain (B= -2.79; p=0.003). For temporal effects results, substance use was not related to later fatigue or pain ratings. However, higher level of pain intensity predicted higher odds of later cannabis use (B= 0.027; p<0.001). Findings indicated that only alcohol use showed no concurrent/temporal associations with somatic symptoms in FM. When participants reported caffeine use, they also reported lower mental fatigue, physical fatigue, and pain. Mental fatigue was higher when people reported use of nicotine or cannabis. In terms of symptoms predicting later substance use, only increased pain was related to later cannabis use. These findings may inform individualized interventions for symptom management and/or problems related to use of psychoactive substances. National Institute of Arthritis and Musculoskeletal and Skin Diseases of the NIH (grant K01-AR-064275).

The Association Between Quality of Diet, Frequency of Caffeine Consumption, Mental Distress, and Illicit ADHD Drug Use

The illicit use of Attention Deficit Hyperactivity Disorder (or ADHD) medications as study drugs is becoming common among undergraduate students. These “study drugs” are predominantly used to improve memory, focus, and attention with the end goal of boosting academic performance; however, studies on illicit drug use have hinted towards negative side effects that have the potential to compromise both mental and physical health. The relationship between lifestyle habits (i.e. diet and exercise) and illicit ADHD medication use is still unexplored; thus, the purpose of this study was to identify relationships between exercise patterns, caffeine consumption, dietary habits, and illicit ADHD medication use. An anonymous survey was sent to several universities via online platforms using Google Forms. A total of 1187 students completed the survey. The survey was comprised of the validated Food‐Mood Questionnaire, and included questions that addressed ADHD medication use frequency, academic performance, education on the effects of ADHD medication, and physical health. Our results reveal a statistically significant positive correlation between frequency of caffeine use and frequency of other drug use (including depressants and psychostimulants such as Adderall) (p &lt; 0.01). Additionally, a positive correlation was detected between frequency of caffeine consumption and various hallmarks of mental distress, including feelings of worthlessness, depression, and restlessness (p &lt; 0.01, 0.05, and 0.01 respectively). Additionally, there was a negative correlation between consumption of nutritious, healthy foods and illicit ADHD medication usage (p &lt; 0.05). Considering all, a potential vicious cycle may exist. Those who illicitly use psychostimulants develop poorer dietary habits negatively impacting brain function, which may trigger higher consumption of caffeine as a stimulant.

Licit Substance Use and Premenstrual Syndrome Symptom Severity in Female College Students.

Introduction:Premenstrual syndrome (PMS) affects the majority of women and is characterized by physical, behavioral, and mood symptoms, which can have a profound impact on quality of life. PMS symptoms have also been linked to licit substance use. This study examined the relationships between daily/problem use (DPU) of caffeine (Caf+), alcohol (Alc+), and tobacco (Cig+) and PMS symptomology in a sample of college women.Methods:Participants (N = 196) completed an anonymous one-time health survey. Demographic, PMS symptomatology, and DPU of licit substance variables were examined. Independent t-tests compared PMS symptom scores in women with and without Caf+, Cig+, and Alc+ use. One-way analysis of variances examined the associations between PMS symptom severity and number of DPU-positive substances.Results:PMS subscale severity (pain [F(2,190) = 4.47, p = 0.013], affective [F(2,192) = 8.21, p < 0.001], and water retention [F(2,191) = 13.37, p < 0.001]) and total PMS symptom severity [F(2,189) = 10.22, p < 0.001] showed a dose response effect, with the number of licit substances with DPU significantly associated with PMS symptom severity.Conclusions:This study findings provide important new information about the relationship between PMS symptoms and at-risk substance use. These are cross-sectional data, however, and affirm a need for longitudinal research to better understand the associations, with a focus on potential benefits of education and intervention.

Competitive Golf: How Longer Courses Are Changing Athletes and Their Approach to the Game.

Nutritional guidance for competitive golfers to improve performance is limited. Recommendations and study conclusions from older research used smaller golf courses compared to today and require a reevaluation of energy expenditure. This review identifies aerobic fitness, in addition to strength, as a key determinant of success. A novel nutritional approach that incorporates carbohydrate supplementation to support aerobic fitness without sacrificing the ability to build strength is presented since longer courses require more stamina. Strategies for training, competition, and recovery are outlined based on different skill levels. American College of Sports Medicine (ACSM) guidelines for carbohydrates, protein, and hydration intake are tailored specifically for competitive golf based on this approach. Putting requires precise movement and can be affected by fatigue. Nutritional studies in golf and similar sports that require focused movements are presented, exhibiting an improvement with adequate hydration and carbohydrate status and caffeine use. Competitive golf poses unique challenges to an athlete and commonly used ergogenic supplements that can improve performance in a variety of circumstances during training, competition, and while traveling are reviewed.

Sleep and Health-Related Characteristics among Adolescents during COVID-19: An Update.

Two opposing effects on adolescents’ health during COVID-19 lockdown have been described: A beneficial one due to longer sleep times during school closures and a detrimental one of psychological distress. This study investigated how sleep and health changed in the course of the pandemic when schools were open again. Overall, 12,238 adolescents in Switzerland participated in three cross-sectional online surveys: In 2017 under regular conditions (control group), during pandemic school closures in 2020 (closure group), and in 2021 still under pandemic conditions, but schools were open again (postclosure group). Sleep behavior and health-related characteristics (health-related quality of life; caffeine, alcohol, and nicotine use) in all three groups and depressive symptoms in the closure and postclosure groups were assessed. The sleep period on school days was longer in the closure group (median 9.00 h, interquartile range 8.25–9.75) and similar in the postclosure (7.92, 7.00–8.50) compared to the control group (7.75, 7.08–8.33). Health-related characteristics were better during school closures and similar to worse in the postclosure compared to the control group. Depressive symptom levels were higher in the postclosure than in the closure group. Therefore, beneficial effects were specific to school closures and adolescents’ psychological distress increased over the course of the pandemic.

Prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among active duty United States military personnel

BackgroundAlthough representative data on caffeine intake in Americans are available, these data do not include US service members (SMs). The few previous investigations in military personnel largely involve convenience samples. This cross-sectional study examined prevalence of caffeine consumers, daily caffeine consumption, and factors associated with caffeine use among United States active duty military service members (SMs).MethodsA stratified random sample of SMs were asked to complete an on-line questionnaire on their personal characteristics and consumption of caffeinated products (exclusive of dietary supplements). Eighteen percent (n = 26,680) of successfully contacted SMs (n = 146,365) completed the questionnaire.ResultsOverall, 87% reported consuming caffeinated products ≥1 time/week. Mean ± standard error per-capita consumption (all participants) was 218 ± 2 and 167 ± 3 mg/day for men and women, respectively. Caffeine consumers ingested 243 ± 2 mg/day (251 ± 2 mg/day men, 195 ± 3 mg/day women). On a body-weight basis, men and women consumed respectively similar caffeine amounts (2.93 vs 2.85 mg/day/kg; p = 0.12). Among individual caffeinated products, coffee had the highest use (68%), followed by sodas (42%), teas (29%), energy drinks (29%) and gums/candy/medications (4%). In multivariable logistic regression, characteristics independently associated with caffeine use (≥1 time/week) included female gender, older age, white race/ethnicity, higher body mass index, tobacco use or former use, greater alcohol intake, and higher enlisted or officer rank.ConclusionCompared to National Health and Nutrition Examination Survey data, daily caffeine consumption (mg/day) by SMs was higher, perhaps reflecting higher mental and physical occupational demands on SMs.

High time to study the relationship between marijuana use and economic behavior

With the increased acceptance of marijuana, it is important to understand the impacts of its use. While much attention has been paid to concerns such as health, relatively little attention has been paid to the relationship between marijuana use and basic economic behavior. This experimental study uses incentivized tasks to measure prosocial behavior, risk-taking, memory, cognitive ability, and responsiveness to incentives for 374 subjects, and examines how these behaviors vary with frequency of marijuana use. The general results provide little evidence that increased marijuana is associated with any change in these basic behaviors. Despite the fact that we observe males to be more frequent users of marijuana, more willing to take risks, and more selfish, the general lack off a relationship between economic behavior and frequency of marijuana use holds for both males and females. Relationships between caffeine, tobacco, and alcohol use and basic economic behavior are also analyzed.

Prenatal smoking, alcohol and caffeine exposure and offspring externalizing disorders: a systematic review and meta-analysis.

Several studies have indicated an association between maternal prenatal substance use and offspring externalizing disorders; however, it is uncertain whether this relationship is causal. We conducted a systematic review to determine: (1) if the literature supports a causal role of maternal prenatal substance use on offspring externalizing disorders diagnosis and (2) whether these associations differ across externalizing disorders. We searched Web of Science, Embase, PsycINFO and Medline databases. Risk of bias assessment was conducted using the Newcastle-Ottawa Scale (NOS), and where possible meta-analysis was conducted for studies classed as low risk of bias. We included studies of any design that examined prenatal smoking, alcohol or caffeine use. Studies in non-English language, fetal alcohol syndrome and comorbid autism spectrum disorders were excluded. Participants in the included studies were mothers and their offspring. Measurements included prenatal smoking, alcohol or caffeine use as an exposure, and diagnosis of attention-deficit hyperactivity disorder (ADHD), conduct disorder (CD) and oppositional defiant disorder (ODD) in offspring as an outcome. We included 63 studies, 46 of which investigated smoking and ADHD. All studies were narratively synthesized, and seven studies on smoking and ADHD were meta-analysed. The largest meta-analysis based on genetically sensitive design included 1 011 546 participants and did not find evidence for an association [odds ratio (OR)1-9 cigarettes = 0.90, 95% confidence interval (CI) = 0.83-1.11; OR> 10 cigarettes = 1.04, 95% CI = 0.79-1.36). Studies on alcohol exposure in all the outcomes reported inconsistent findings and no strong conclusions on causality can be made. Studies on caffeine exposure were mainly limited to ADHD and these studies do not support a causal effect. There appears to be no clear evidence to support a causal relationship between maternal prenatal smoking and offspring attention-deficit hyperactivity disorder. Findings with alcohol and caffeine exposures and conduct disorder and oppositional-defiant disorder need more research, using more genetically sensitive designs.

Caffeine Supplementation Strategies Among Endurance Athletes.

Caffeine is widely accepted as an endurance-performance enhancing supplement. Most scientific research studies use doses of 3–6 mg/kg of caffeine 60 min prior to exercise based on pharmacokinetics. It is not well understood whether endurance athletes employ similar supplementation strategies in practice. The purpose of this study was to investigate caffeine supplementation protocols among endurance athletes. A survey conducted on Qualtrics returned responses regarding caffeine supplementation from 254 endurance athletes (f = 134, m =120; age = 39.4 ± 13.9 y; pro = 11, current collegiate athlete = 37, recreational = 206; running = 98, triathlon = 83, cycling = 54, other = 19; training days per week = 5.4 ± 1.3). Most participants reported habitual caffeine consumption (85.0%; 41.2% multiple times daily). However, only 24.0% used caffeine supplements. A greater proportion of men (31.7%) used caffeine supplements compared with women (17.2%; p = 0.007). Caffeine use was also more prevalent among professional (45.5%) and recreational athletes (25.1%) than in collegiate athletes (9.4%). Type of sport (p = 0.641), household income (p = 0.263), education (p = 0.570) or working with a coach (p = 0.612) did not have an impact on caffeine supplementation prevalence. Of those reporting specific timing of caffeine supplementation, 49.1% and 34.9% reported consuming caffeine within 30 min of training and races respectively; 38.6 and 36.5% used caffeine 30–60 min before training and races. Recreational athletes reported consuming smaller amounts of caffeine before training (1.6 ± 1.0 mg/kg) and races (2.0 ± 1.2 mg/kg) compared with collegiate (TRG: 2.1 ± 1.2 mg/kg; RACE: 3.6 ± 0.2 mg/kg) and professional (TRG: 2.4 ± 1.1 mg/kg; RACE: 3.5 ± 0.6 mg/kg) athletes. Overall, participants reported minor to moderate perceived effectiveness of caffeine supplementation (2.31 ± 0.9 on a four-point Likert-type scale) with greatest effectiveness during longer sessions (2.8 ± 1.1). It appears that recreational athletes use lower caffeine amounts than what has been established as ergogenic in laboratory protocols; further, they consume caffeine closer to exercise compared with typical research protocols. Thus, better education of recreational athletes and additional research into alternative supplementation strategies are warranted.

Outcomes of noninvasive neurally adjusted ventilatory assist and nasal continuous positive airway pressure in preterm infants: a systematic review and meta-analysis.

The benefits of neurally adjusted ventilatory assist (NAVA) in preterm infants are unclear. This study aimed to explore if noninvasive NAVA is more beneficial for preterm infants than nasal continuous positive airway pressure (NCPAP). Meta-analysis was performed in three clinical trials comprising two randomized controlled trials and one crossover study. We compared NIV-NAVA and NCPAP and reported treatment failure, mortality, and adverse events as the primary outcomes. Three studies including 173 patients (89 of whom underwent NIV-NAVA) were eligible for this meta-analysis. This review found no difference in treatment failure between NIVNAVA and NCPAP (RR 1.09, 95% CI 0.65 to 1.84; RD 0.02, 95% CI -0.10-0.14; I2=33%, P=0.23). Similarly, there was no difference in mortality (RR 1.52, 95% CI 0.51-4.52, heterogeneity not applicable). Compared with NCPAP, NIVNAVA significantly reduced the use of caffeine (RR 0.85, 95% CI 0.74-0.98, I2=71%, P=0.03). Compared with NCPAP, there is insufficient evidence to conclude on the benefits or harm of NIV-NAVA therapy for preterm infants. The findings of this review should be confirmed using methodologically rigorous and adequately powered clinical trials.

The Impact of Caffeine Intake on Mental Health Symptoms in Postmenopausal Females with Overactive Bladder Symptoms: A Randomized, Double-Blind, Placebo-Controlled Trial.

Background: Caffeine has been associated with a dose-dependent variety of mental health changes, which have been found to precede or be a complication of overactive bladder (OAB) symptoms after menopause. The current study examines the effects of low and moderate caffeine intake on anxiety, depression, sleep, and stress in postmenopausal females with OAB. Materials and Methods: Eighty-one females were randomized in a prospective, double-blind, placebo-controlled study. Participants were allocated to 200 mg/day caffeine, 400 mg/day caffeine, and placebo capsules for 1 week each in a crossover design and evaluated using validated mental health questionnaires. Symptoms during each treatment phase were measured using Beck Anxiety and Depression Inventory, Insomnia Severity Index, and Perceived Stress Scale. Linear regression models were used to examine the impact of low (200 mg/day) and moderate (400 mg/day) dose of caffeine and placebo on mental health. Results: Fifty-six female participants finished the study. The mean age was 69.2 years (58.0-84.0 years). Two females dropped out during the treatment phase with 400 mg/day caffeine intake due to side effects associated with headaches and nausea. Moderate dose of caffeine showed a small positive effect on mental health, specifically a decrease in anxiety during 7 days of exposure (p < 0.05). Conclusions: Moderate caffeine use may decrease anxiety in postmenopausal patients with underlying OAB, whereas depression, insomnia, and perceived stress were not affected by low-to-moderate caffeine intake. Our results support that counseling efforts on moderate caffeine consumption in postmenopausal patients underline that low-to moderate caffeine intake may be appropriate and possibly beneficial unless contraindicated due to other underlying conditions. Clinical Trials Registration: clinicaltrials.gov (NCT02180048).