Secondhand smoke and atrial fibrillation: Data from the Health eHeart Study

Smoking Cessation and Incident Atrial Fibrillation in a Longitudinal Cohort

BACKGROUND

Although smoking heightens the risk of AF, it remains unknown if that risk is amenable to modification after smoking cessation.

OBJECTIVES

This study sought to evaluate the association between smoking cessation and atrial fibrillation (AF) risk in a large longitudinal cohort.

METHODS

After excluding those with prevalent AF and no history of smoking at baseline, we evaluated 146,772 UK Biobank participants with serial smoking assessments. We compared AF risk between former smokers at baseline and those who quit smoking during the study to current smokers. Incident AF was ascertained from outpatient and inpatient encounters and identified using International Classification of Diseases codes. Cox models were used to compare the risk of incident AF among current and former smokers as well as those who quit smoking during the study while controlling for age, sex, race, body mass index, education, cardiovascular comorbidities, alcohol use, and pack-years.

RESULTS

Among the 146,772 participants (48.3% female; age: 57.3 ± 7.9 years), 37,377 (25.5%) currently smoked; 105,429 (72.0%) were former smokers; and 3,966 (2.7%) quit smoking during the study. Over a mean 12.7 ± 2.0 years of follow-up, 11,214 (7.6%) participants developed AF. Compared to current smokers, the adjusted risk of AF was 13% lower in former smokers (HR: 0.87; 95% CI: 0.83-0.91) and 18% lower in those who quit smoking during the study (HR: 0.82; 95% CI: 0.70-0.95).

CONCLUSIONS

Compared to those who continue to smoke, smoking cessation was associated with a lower risk of AF.

Associations of Dietary and Lifestyle Components with Atrial Fibrillation

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia that still remains a significant health concern, especially due to its consequences, including stroke and heart failure. This review explores the intricate interplay between AF, lifestyle choices, and dietary habits. It is particularly focused on findings from diverse studies about non-pharmacological methods of managing AF. Moreover, its purpose is to elucidate the implementation of lifestyle changes such as physical activity or proper diet choices in the integrated treatment strategy of patients with AF.

Aging and atrial fibrillation: A vicious circle

Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia observed in clinical practice. Its prevalence increases dramatically with advancing age. This review article discusses the recent advances in studies investigating the relationship between aging and AF and the possible underlying mechanisms.

Secondhand Smoking and the Fetus: A Bibliometric Analysis

Background

Bibliometric analysis may indicate the most active specialist, authors, and journals in a given research field. To the authors' knowledge, there is no bibliometric analysis to provide a macroscopic overview in the field of secondhand smoke that harms non-smoker.

Methods

Using the bibliometric method, 644 articles that were present in the Scopus database between 1973-2020 on the subject were considered. The data were analyzed by two visualization and science-mapping software called Bibliometrix and VoS Viewer. Also, reference publication year stereoscopy and Co-Citation historiography were used. In the qualitative analysis, 52 articles were selected that had the most citation and were analyzed.

Results

In this paper, the findings show that the documents were published in 364 sources with an average citation per document of 25.14 and more than 3 authors or nearly 4 authors per document. The peak reference publication year stereoscopy happened in the year 199 with 974 references. The countries with the highest number of MCP were the USA, China, and Spain. The "International Journal of Environmental Research" and "Public Health", has raised their publications in the field of secondhand smoke and pregnancy rapidly since 2003. Among the titles, "passive smoking" was the most used.

Conclusion

The study highlights the importance of understanding the harmful effects of secondhand smoke on the developing fetus. The findings also shed light on key research trends, influential authors, and active research areas, which can guide future studies and support evidence-based decision-making in the field of maternal and child health.

Interindividual Variability in Self-Monitoring of Blood Pressure Using Consumer-Purchased Wireless Devices

BACKGROUND

Engagement with self-monitoring of blood pressure (BP) declines, on average, over time but may vary substantially by individual.

OBJECTIVES

We aimed to describe different 1-year patterns (groups) of self-monitoring of BP behaviors, identify predictors of those groups, and examine the association of self-monitoring of BP groups with BP levels over time.

METHODS

We analyzed device-recorded BP measurements collected by the Health eHeart Study-an ongoing prospective eCohort study-from participants with a wireless consumer-purchased device that transmitted date- and time-stamped BP data to the study through a full 12 months of observation starting from the first day they used the device. Participants received no instruction on device use. We applied clustering analysis to identify 1-year self-monitoring, of BP patterns.

RESULTS

Participants had a mean age of 52 years and were male and White. Using clustering algorithms, we found that a model with three groups fit the data well: persistent daily use (9.1% of participants), persistent weekly use (21.2%), and sporadic use only (69.7%). Persistent daily use was more common among older participants who had higher Week 1 self-monitoring of BP frequency and was associated with lower BP levels than the persistent weekly use or sporadic use groups throughout the year.

CONCLUSION

We identified three distinct self-monitoring of BP groups, with nearly 10% sustaining a daily use pattern associated with lower BP levels.

Air Pollution, Built Environment, and Early Cardiovascular Disease

As the world's population becomes increasingly urbanized, there is growing concern about the impact of urban environments on cardiovascular health. Urban residents are exposed to a variety of adverse environmental exposures throughout their lives, including air pollution, built environment, and lack of green space, which may contribute to the development of early cardiovascular disease and related risk factors. While epidemiological studies have examined the role of a few environmental factors with early cardiovascular disease, the relationship with the broader environment remains poorly defined. In this article, we provide a brief overview of studies that have examined the impact of the environment including the built physical environment, discuss current challenges in the field, and suggest potential directions for future research. Additionally, we highlight the clinical implications of these findings and propose multilevel interventions to promote cardiovascular health among children and young adults.

Cannabis, cocaine, methamphetamine, and opiates increase the risk of incident atrial fibrillation

AIMS

Atrial fibrillation (AF) is now regarded as a preventable disease, requiring a search for modifiable risk factors. With legalization of cannabis and more lenient laws regarding the use of other illicit substances, investigation into the potential effects of methamphetamine, cocaine, opiate, and cannabis exposure on incident AF is needed.

METHODS AND RESULTS

Using Office of Statewide Health Planning and Development databases, a longitudinal analysis was performed of adult Californians ≥18 years of age who received care in an emergency department, outpatient surgery facility, or hospital from 1 January 2005 to 31 December 2015. Associations between healthcare coding for the use of each substance and a new AF diagnosis were assessed. Among 23,561,884 patients, 98 271 used methamphetamine, 48 701 used cocaine, 10 032 used opiates, and 132 834 used cannabis. Of the total population, 998 747 patients (4.2%) developed incident AF during the study period. After adjusting for potential confounders and mediators, use of methamphetamines, cocaine, opiates, and cannabis was each associated with increased incidence of AF: hazard ratios 1.86 [95% confidence interval (CI) 1.81-1.92], 1.61 (95% CI 1.55-1.68), 1.74 (95% CI 1.62-1.87), and 1.35 (95% CI 1.30-1.40), respectively. Negative control analyses in the same cohort failed to reveal similarly consistent positive relationships.

CONCLUSION

Methamphetamine, cocaine, opiate, and cannabis uses were each associated with increased risk of developing incident AF. Efforts to mitigate the use of these substances may represent a novel approach to AF prevention.

Passive Smoking Exposure Modifies Cardiovascular Structure and Function: Beijing Child Growth and Health Cohort (PROC) Study

Passive smoking exposure in children is prevalent worldwide and exposes children to respiratory and systemic toxins. In this study, we enrolled 568 children to study how secondhand smoke (SHS) might affect children's cardiovascular health in China. The measurement of nicotine and its metabolites in urine showed that 78.9% of children were exposed to SHS. Children exposed to SHS had greater interventricular septum thickness (p = 0.005) and left ventricular mass index (p = 0.008) than nonexposed children. Urinary norcotinine levels were associated with increased ascending aorta diameter (β = 0.10, 95%CI 0.02-0.17) and decreased left ventricular end systolic diameter (β = -0.10, 95%CI -0.19 to -0.01). The effects of SHS exposure on cardiovascular function: norcotinine levels associated with lower left ventricular mass index (β = -0.32, 95%CI -0.59 to -0.05), left ventricular end diastolic volume index (β = -0.43, 95%CI -0.85 to -0.02), and left ventricular end systolic volume index (β = -0.20, 95%CI -0.37 to -0.03). Moreover, there no no significant associations of nicotine, cotinine, and trans-3'-hydroxycotinine with cardiovascular health. Overall, SHS exposure in children remains prevalent in Beijing and may affect children's cardiovascular development, in both structure and function. It suggests that stricter and practical measures are needed toward the elimination of tobacco use in children's environments.

The underlying mechanism of PM2.5-induced ischemic stroke

Under the background of global industrialization, PM_2.5 has become the fourth-leading risk factor for ischemic stroke worldwide, according to the 2019 GBD estimates. This highlights the hazards of PM_2.5 for ischemic stroke, but unfortunately, PM_2.5 has not received the attention that matches its harmfulness. This article is the first to systematically describe the molecular biological mechanism of PM_2.5-induced ischemic stroke, and also propose potential therapeutic and intervention strategies. We highlight the effect of PM_2.5 on traditional cerebrovascular risk factors (hypertension, hyperglycemia, dyslipidemia, atrial fibrillation), which were easily overlooked in previous studies. Additionally, the effects of PM_2.5 on platelet parameters, megakaryocytes activation, platelet methylation, and PM_2.5-induced oxidative stress, local RAS activation, and miRNA alterations in endothelial cells have also been described. Finally, PM_2.5-induced ischemic brain pathological injury and microglia-dominated neuroinflammation are discussed. Our ultimate goal is to raise the public awareness of the harm of PM_2.5 to ischemic stroke, and to provide a certain level of health guidance for stroke-susceptible populations, as well as point out some interesting ideas and directions for future clinical and basic research.

Secondhand tobacco smoke exposure, urine cotinine, and risk of incident atrial fibrillation: The multi-ethnic study of atherosclerosis

BACKGROUND

Secondhand tobacco smoke (SHS) exposure may reduce heart rate variability and lead to atrial fibrillation (AF); however prior study findings have not been confirmed using objective measures for both SHS and AF events.

METHODS

We prospectively examined the association between SHS exposure and incident AF in 5731 participants, ages of 45-84 years and free of known AF and other cardiovascular diseases (CVD) at baseline (2000-2002), who were followed through 2015 in the Multi-Ethnic Study of Atherosclerosis (MESA). SHS weekly exposure time was identified by self-report. Urine cotinine was collected in a cohort subset of 3237 current non-smoking cohort participants. AF events were identified using Medicare claims, hospital records, and 12‑lead electrocardiographic findings. A multivariable Cox proportional hazards regression analysis was used with simultaneous adjustment for demographic factors, educational level, health insurance status, active smoking status, tobacco pack-years, traditional CVD risk factors, depressive symptoms and medications.

RESULTS

During a median follow-up of 14.0 years, 856 and 452 AF events were identified in the overall and the cohort subset, respectively. No association of SHS exposure time or urine cotinine with incident AF was observed. However, a higher AF risk with greater urine cotinine (8.53-442.0 ng/mL) compared with lower urine cotinine (≤7.07 ng/mL) was observed in never smokers [hazard ratios (HR) and 95% confidence intervals: 1.60 (1.16, 2.19)], but not in former smokers [HR: 0.88 (0.63, 1.23)] (p-value for multiplicative interaction: 0.009 and for additive interaction: 0.017, respectively).

CONCLUSION

Objectively measured greater SHS exposure expressed by urine cotinine might be associated with 1.6-fold higher risk of incident AF in never smokers.

Harmful Impact of Tobacco Smoking and Alcohol Consumption on the Atrial Myocardium

Tobacco smoking and alcohol consumption are widespread exposures that are legal and socially accepted in many societies. Both have been widely recognized as important risk factors for diseases in all vital organ systems including cardiovascular diseases, and with clinical manifestations that are associated with atrial dysfunction, so-called atrial cardiomyopathy, especially atrial fibrillation and stroke. The pathogenesis of atrial cardiomyopathy, atrial fibrillation, and stroke in context with smoking and alcohol consumption is complex and multifactorial, involving pathophysiological mechanisms, environmental, and societal aspects. This narrative review summarizes the current literature regarding alterations in the atrial myocardium that is associated with smoking and alcohol.

Secondhand smoke exposure is associated with abnormal P-wave axis

OBJECTIVES

Secondhand smoke exposure (SHSE) is associated with increased risk of cerebrovascular accident (CVA). Abnormal P-wave axis (aPWA) is a marker for atriopathy that is also associated with CVA risk. We hypothesized that SHSE is associated with aPWA.

METHODS

This analysis included 5986 non-smokers (age 61.7 ± 13.8 years, 45.8% men, 77.4% Whites) from the Third National Health and Nutrition Examination Survey. SHSE was defined as serum cotinine ≥1 ng/ml aPWA was defined as any P-wave axis outside of 0-75°. Multivariable logistic regression was used to examine the association between SHSE and aPWA, overall and among subgroups stratified by demographics and comorbidities.

RESULTS

About 18.5% (n = 1109) of the participants had SHSE. aPWA was more prevalent among those with SHSE than those without (23.9% versus 19.8%, respectively, P-value = 0.003). In a model adjusted for sociodemographic and potential confounders, presence (versus absence) of SHSE was associated with increased odds of aPWA (odds ratio [95% confidence interval]: 1.28 [1.09, 1.50]; P-value = 0.003). This association was stronger among Whites vs non-Whites (interaction P-value = 0.04) and non-obese versus obese (interaction P-value = 0.04). Higher levels of serum cotinine were associated with increased odds of aPWA. Compared with serum cotinine level <1 ng/ml, serum cotinine ≥3 ng/ml and ≥6 ng/ml were associated with 35% (P-value = 0.002) and 38% (P-value = 0.002) increased odds of aPWA, respectively.

CONCLUSIONS

SHSE is associated with abnormal atrial conduction, measured as aPWA, with possible effect modification by ethnicity and obesity. These findings underscore the harmful effects of SHSE on cardiovascular health which merits a personalized risk assessment when counseling patients on SHSE.

Remote Assessment of Cardiovascular Risk Factors and Cognition in Middle-Aged and Older Adults: Proof-of-Concept Study

Background

Adults with cardiovascular disease risk factors (CVRFs) are also at increased risk of developing cognitive decline and dementia. However, it is often difficult to study the relationships between CVRFs and cognitive function because cognitive assessment typically requires time-consuming in-person neuropsychological evaluations that may not be feasible for real-world situations.

Objective

We conducted a proof-of-concept study to determine if the association between CVRFs and cognitive function could be detected using web-based, self-administered cognitive tasks and CVRF assessment.

Methods

We recruited 239 participants aged ≥50 years (mean age 62.7 years, SD 8.8; 42.7% [n=102] female, 88.7% [n=212] White) who were enrolled in the Health eHeart Study, a web-based platform focused on cardiac disease. The participants self-reported CVRFs (hypertension, high cholesterol, diabetes, and atrial fibrillation) using web-based health surveys between August 2016 and July 2018. After an average of 3 years of follow-up, we remotely evaluated episodic memory, working memory, and executive function via the web-based Posit Science platform, BrainHQ. Raw data were normalized and averaged into 3 domain scores. We used linear regression models to examine the association between CVRFs and cognitive function.

Results

CVRF prevalence was 62.8% (n=150) for high cholesterol, 45.2% (n=108) for hypertension, 10.9% (n=26) for atrial fibrillation, and 7.5% (n=18) for diabetes. In multivariable models, atrial fibrillation was associated with worse working memory (β=-.51, 95% CI -0.91 to -0.11) and worse episodic memory (β=-.31, 95% CI -0.59 to -0.04); hypertension was associated with worse episodic memory (β=-.27, 95% CI -0.44 to -0.11). Diabetes and high cholesterol were not associated with cognitive performance.

Conclusions

Self-administered web-based tools can be used to detect both CVRFs and cognitive health. We observed that atrial fibrillation and hypertension were associated with worse cognitive function even in those in their 60s and 70s. The potential of mobile assessments to detect risk factors for cognitive aging merits further investigation.

Predictors of incident SARS-CoV-2 infections in an international prospective cohort study

OBJECTIVE

Until effective treatments and vaccines are made readily and widely available, preventative behavioural health measures will be central to the SARS-CoV-2 public health response. While current recommendations are grounded in general infectious disease prevention practices, it is still not entirely understood which particular behaviours or exposures meaningfully affect one's own risk of incident SARS-CoV-2 infection. Our objective is to identify individual-level factors associated with one's personal risk of contracting SARS-CoV-2.

DESIGN

Prospective cohort study of adult participants from 26 March 2020 to 8 October 2020.

SETTING

The COVID-19 Citizen Science Study, an international, community and mobile-based study collecting daily, weekly and monthly surveys in a prospective and time-updated manner.

PARTICIPANTS

All adult participants over the age of 18 years were eligible for enrolment.

PRIMARY OUTCOME MEASURE

The primary outcome was incident SARS-CoV-2 infection confirmed via PCR or antigen testing.

RESULTS

28 575 unique participants contributed 2 479 149 participant-days of data across 99 different countries. Of these participants without a history of SARS-CoV-2 infection at the time of enrolment, 112 developed an incident infection. Pooled logistic regression models showed that increased age was associated with lower risk (OR 0.98 per year, 95% CI 0.97 to 1.00, p=0.019), whereas increased number of non-household contacts (OR 1.10 per 10 contacts, 95% CI 1.01 to 1.20, p=0.024), attending events of at least 10 people (OR 1.26 per 10 events, 95% CI 1.07 to 1.50, p=0.007) and restaurant visits (OR 1.95 per 10 visits, 95% CI 1.42 to 2.68, p<0.001) were associated with significantly higher risk of incident SARS-CoV-2 infection.

CONCLUSIONS

Our study identified three modifiable health behaviours, namely the number of non-household contacts, attending large gatherings and restaurant visits, which may meaningfully influence individual-level risk of contracting SARS-CoV-2.

Physical activity and atrial fibrillation: Data from wearable fitness trackers

BACKGROUND

Regular physical activity is an important determinant of cardiovascular health and quality of life. Previous investigations examining the association between exercise and atrial fibrillation (AF) have been limited by self-reported, retrospectively collected activity data.

OBJECTIVE

The purpose of this study was to objectively quantify differences in daily physical activity among individuals with and those without AF using electronic wearable activity trackers.

METHODS

Daily exercise data were directly obtained from wrist-worn activity trackers (Fitbit, San Francisco, CA) among participants in the Health eHeart (HeH) study. Average daily step count was compared between individuals with and those without AF both before and after adjusting for comorbidities. AF severity was quantified using the Atrial Fibrillation Effect on QualiTy of Life (AFEQT) survey.

RESULTS

Among 171,284 HeH study participants, 3333 individuals (234 with AF [7%]) submitted activity data. In unadjusted analysis, AF participants ambulated an average of 723 fewer steps per day (95% confidence interval [CI] 292-1154; P = .001) compared to individuals without AF. After adjustment for demographics and comorbid diseases, participants with AF demonstrated 591 fewer steps per day (95% CI 149-1033; P = .009). Among AF patients, AF severity was associated with less physical activity. For each single point decrease in AFEQT score (corresponding to more symptomatic AF), physical activity decreased by a mean 24 steps per day (95% CI 1-46; P = .04).

CONCLUSION

Objective, automatically collected step count data demonstrate that individuals with AF engage in significantly less average daily physical activity. In addition, worsening AF symptom severity is associated with reduced daily exercise.

Thirdhand Smoke Contamination and Infant Nicotine Exposure in a Neonatal Intensive Care Unit: An Observational Study

INTRODUCTION

Thirdhand smoke (THS) is ultrafine particulate matter and residue resulting from tobacco combustion, with implications for health-related harm (eg, impaired wound healing), particularly among hospitalized infants. Project aims were to characterize nicotine (THS proxy) transported on neonatal intensive care unit (NICU) visitors and deposited on bedside furniture, as well as infant exposure.

METHODS

Cross-sectional data were collected from participants in a metropolitan NICU. Participants completed a survey and carbon monoxide breath sample, and 41.9% (n = 88) of participants (n = 210) were randomly selected for finger-nicotine wipes during a study phase when all bedside visitors were screened for nicotine use and finger-nicotine levels. During an overlapping study phase, 80 mother-infant dyads consented to bedside furniture-nicotine wipes and an infant urine sample (for cotinine analyses).

RESULTS

Most nonstaff visitors' fingers had nicotine above the limit of quantification (>LOQ; 61.9%). Almost all bedside furniture surfaces (93.8%) and infant cotinine measures (93.6%) had values >LOQ, regardless of household nicotine use. Participants who reported using (or lived with others who used) nicotine had greater furniture-nicotine contamination (Mdn = 0.6 [interquartile range, IQR = 0.2-1.6] µg/m2) and higher infant cotinine (Mdn = 0.09 [IQR = 0.04-0.25] ng/mL) compared to participants who reported no household-member nicotine use (Mdn = 0.5 [IQR = 0.2-0.7] µg/m2; Mdn = 0.04 [IQR = 0.03-0.07] ng/mL, respectively). Bayesian univariate regressions supported hypotheses that increased nicotine use/exposure correlated with greater nicotine contamination (on fingers/furniture) and infant THS exposure.

CONCLUSIONS

Potential furniture-contamination pathways and infant-exposure routes (eg, dermal) during NICU hospitalization were identified, despite hospital prohibitions on tobacco/nicotine use. This work highlights the surreptitious spread of nicotine and potential THS-related health risks to vulnerable infants during critical stages of development.

IMPLICATIONS

THS contamination is underexplored in medical settings. Infants who were cared for in the NICU are vulnerable to health risks from THS exposure. This study demonstrated that 62% of nonstaff NICU visitors transport nicotine on their fingers to the NICU. Over 90% of NICU (bedside) furniture was contaminated with nicotine, regardless of visitors' reported household-member nicotine use or nonuse. Over 90% of infants had detectable levels of urinary cotinine during NICU hospitalizations. Results justify further research to better protect infants from unintended THS exposure while hospitalized.

Social Risk Factors and Atrial Fibrillation

Modifiable risk factor management is becoming one of the 3 treatment pillars in atrial fibrillation management along with anticoagulation as well as conventional rate and rhythm control strategies. Preventive therapies, such as reducing blood pressure and treating obstructive sleep apnea, are paramount in the strategy of preventing atrial fibrillation. Identification of new modifiable risk factors and triggers also could help in the global strategy to reduce atrial fibrillation. This article covers alcohol intake, tobacco smoking, caffeine, chocolate, cannabis use, and air pollution as social risk factors related to lifestyle habits that potentially could contribute to atrial fibrillation development.

A digital biomarker of diabetes from smartphone-based vascular signals

The global burden of diabetes is rapidly increasing, from 451 million people in 2019 to 693 million by 20451. The insidious onset of type 2 diabetes delays diagnosis and increases morbidity2. Given the multifactorial vascular effects of diabetes, we hypothesized that smartphone-based photoplethysmography could provide a widely accessible digital biomarker for diabetes. Here we developed a deep neural network (DNN) to detect prevalent diabetes using smartphone-based photoplethysmography from an initial cohort of 53,870 individuals (the 'primary cohort'), which we then validated in a separate cohort of 7,806 individuals (the 'contemporary cohort') and a cohort of 181 prospectively enrolled individuals from three clinics (the 'clinic cohort'). The DNN achieved an area under the curve for prevalent diabetes of 0.766 in the primary cohort (95% confidence interval: 0.750-0.782; sensitivity 75%, specificity 65%) and 0.740 in the contemporary cohort (95% confidence interval: 0.723-0.758; sensitivity 81%, specificity 54%). When the output of the DNN, called the DNN score, was included in a regression analysis alongside age, gender, race/ethnicity and body mass index, the area under the curve was 0.830 and the DNN score remained independently predictive of diabetes. The performance of the DNN in the clinic cohort was similar to that in other validation datasets. There was a significant and positive association between the continuous DNN score and hemoglobin A1c (P ≤ 0.001) among those with hemoglobin A1c data. These findings demonstrate that smartphone-based photoplethysmography provides a readily attainable, non-invasive digital biomarker of prevalent diabetes.

Association between secondhand smoke exposure and hypertension: nearly as large as smoking

: Active smoking is a widely accepted risk factor for cardiovascular disease and is recognized as a major public health problem. Passive smoking, also known as secondhand smoke exposure (SHSE), is thought to have similar cardiovascular consequences and the risk has been postulated to be equivalent to that of active smoking. A major component of this risk involves the connection with chronic hypertension. There are several population-based observational studies investigating the relationship between SHSE and chronic hypertension, all of which demonstrate a positive association. Given that SHSE appears to be a risk factor for chronic hypertension, SHSE should also be a risk factor for hypertensive end-organ disease. Many studies have sought to investigate this relationship, but this has yet to be fully elucidated. In this review, we focus on the current evidence regarding the association between SHSE and hypertension as well as exploration of the links between SHSE and hypertensive end-organ damage.

Role for risk factor treatment in the management of atrial fibrillation

Atrial fibrillation is the most common arrhythmia in the world with continued rising prevalence, significant morbidity and mortality, and a substantial financial burden. It has been associated with numerous modifiable risk factors and chronic medical conditions. Treatment of these modifiable risk factors has improved rhythm control of atrial fibrillation as well as demonstrated cost-effectiveness. Primary prevention of underlying chronic disease should be incorporated into the treatment paradigm for AF. Comprehensive management with integrated care including the patient, allied health professionals, primary care physicians, and specialists will be needed to reverse the epidemiological trends, improve quality of life, and mortality.

Air pollutants disrupt iron homeostasis to impact oxidant generation, biological effects, and tissue injury

Air pollutants cause changes in iron homeostasis through: 1) a capacity of the pollutant, or a metabolite(s), to complex/chelate iron from pivotal sites in the cell or 2) an ability of the pollutant to displace iron from pivotal sites in the cell. Through either pathway of disruption in iron homeostasis, metal previously employed in essential cell processes is sequestered after air pollutant exposure. An absolute or functional cell iron deficiency results. If enough iron is lost or is otherwise not available within the cell, cell death ensues. However, prior to death, exposed cells will attempt to reverse the loss of requisite metal. This response of the cell includes increased expression of metal importers (e.g. divalent metal transporter 1). Oxidant generation after exposure to air pollutants includes superoxide production which functions in ferrireduction necessary for cell iron import. Activation of kinases and phosphatases and transcription factors and increased release of pro-inflammatory mediators also result from a cell iron deficiency, absolute or functional, after exposure to air pollutants. Finally, air pollutant exposure culminates in the development of inflammation and fibrosis which is a tissue response to the iron deficiency challenging cell survival. Following the response of increased expression of importers and ferrireduction, activation of kinases and phosphatases and transcription factors, release of pro-inflammatory mediators, and inflammation and fibrosis, cell iron is altered, and a new metal homeostasis is established. This new metal homeostasis includes increased total iron concentrations in cells with metal now at levels sufficient to meet requirements for continued function.

Early life tobacco exposure and children's telomere length: The HELIX project

Telomere length and mitochondrial DNA content are considered biomarkers of cellular aging, oxidative stress, and inflammation, but there is almost no information on their association with tobacco smoke exposure in fetal and early life. The aim of this study was to assess whether prenatal and childhood tobacco exposure were associated with leukocyte telomere length (LTL) and mitochondrial DNA (mtDNA) content in children. As part of a multi-centre European birth cohort study HELIX (Human Early-Life Exposome) (n = 1396) we assessed maternal smoking status during pregnancy through questionnaires, and through urinary cotinine levels that were then used to classify women as not exposed to smoking (<10 µg/L), exposed to secondhand smoke (SHS) (10-50 µg/L) and active smokers (>50 µg/L). When the children were around 8 years of age (range: 5.4-12.0 years), childhood SHS tobacco smoke exposure was assessed through an extensive questionnaire and through measurements of urinary cotinine (<3.03 µg/L non-detected, >3.03 µg/L detected). Leukocyte mtDNA content and LTL were measured in the children at 8 years employing real time polymerase chain reaction (qPCR). Effect estimates were calculated using multivariate linear regression models for prenatal and childhood exposures adjusted for potential confounders. Maternal cotinine levels indicative of SHS exposure during pregnancy were associated with a decrease of 3.90% in LTL in children (95% CI: -6.68, -0.91), compared with non-smoking, whereas the association for maternal cotinine levels indicative of active smoking did not reach statistical significance (-3.24%; 95% CI: -6.59, 0.21). Childhood SHS tobacco exposure was not associated with LTL in children. Global SHS exposure during childhood was associated with an increase of 3.51% (95% CI: 0.78, 6.27) in mtDNA content. Our findings suggest that tobacco smoke exposure during pregnancy, even at SHS levels, may accelerate telomere shortening in children and thus induce biological aging from an early age.

Is second hand smoking associated with atrial fibrillation risk among women in Israel? A case-control study

BACKGROUND

The first complete ban on indoor smoking in all public spaces (including bars and restaurants) occurred in 1994 in Israel, because of clear scientific evidence that SHS (Second Hand Smoking) is dangerous to non-smokers. Despite the smoking-ban law warning about the dangers of smoking, SHS remains in houses. The role of cigarette smoking on cardiac arrhythmia is less clearly defined and secondhand smoke (SHS) impact on the risk of atrial fibrillation (AF) remains unknown. The aim of this study was to evaluate the relationship between SHS and AF risk in Israeli women.

METHODS

This was a population-based case-control study consisting of never-smoking women aged 30-80 from Israel: 102 cases (diagnosed) of AF and 109 population- based controls. All participants were interviewed using a socio-demographic questionnaire that also related to past and current exposure to SHS.

RESULTS

SHS was associated with AF risk with adjusted odds ratio (OR) of 3.81 (95% confidence interval, CI 2.02-7.18). Higher exposure to SHS was associated with higher risk of AF compared to never-exposed women. Those exposed to SHS during one, two, or three life-periods (childhood, adolescence or adulthood) had an OR of 1.71 (95% CI 0.76-3.86), 2.87 (95% CI 1.25-6.56), and 9.14 (95% CI 4.09-20.44), respectively. Moreover, exposure to one pack/day increased the risk of AF by 2.89 times compared to 'never exposed' (95% CI 2.05-4.09).

CONCLUSIONS

SHS exposure in women who never smoked is associated with increased risk for AF.

Cumulative Lifetime Burden of Cardiovascular Disease From Early Exposure to Air Pollution

The disease burden associated with air pollution continues to grow. The World Health Organization (WHO) estimates ≈7 million people worldwide die yearly from exposure to polluted air, half of which-3.3 million-are attributable to cardiovascular disease (CVD), greater than from major modifiable CVD risks including smoking, hypertension, hyperlipidemia, and diabetes mellitus. This serious and growing health threat is attributed to increasing urbanization of the world's populations with consequent exposure to polluted air. Especially vulnerable are the elderly, patients with pre-existing CVD, and children. The cumulative lifetime burden in children is particularly of concern because their rapidly developing cardiopulmonary systems are more susceptible to damage and they spend more time outdoors and therefore inhale more pollutants. World Health Organization estimates that 93% of the world's children aged <15 years-1.8 billion children-breathe air that puts their health and development at risk. Here, we present growing scientific evidence, including from our own group, that chronic exposure to air pollution early in life is directly linked to development of major CVD risks, including obesity, hypertension, and metabolic disorders. In this review, we surveyed the literature for current knowledge of how pollution exposure early in life adversely impacts cardiovascular phenotypes, and lay the foundation for early intervention and other strategies that can help prevent this damage. We also discuss the need for better guidelines and additional research to validate exposure metrics and interventions that will ultimately help healthcare providers reduce the growing burden of CVD from pollution.

Health advocacy for reducing smoking rates in Hamamatsu, Japan

Efforts to reduce smoking at the Olympics that will be hosted in Tokyo in 2020 are spreading across the country, but they are not enough. In general, it is said that (1) smoke prevention education for minors, (2) smoking cessation support for smokers, and (3) smoking restriction in the social environment are necessary to reduce the smoking rate. Healthy Japan 21 called for achieving a numerical target for the reduction of youth smoking by 2010. The author is a principal school doctor at Hamamatsu Municipal Yuto Elementary School and has been teaching antismoking classes to elementary school students since 1999. In this area (Yuto District, Hamamatsu City in Shizuoka Prefecture, Japan), there is the Oki-jinja Shrine, which was built in 705, and a large event (Oki-jinja grand festival) is held there each autumn, attracting 2500 people. Since many people gather there, it is worthwhile to provide information about passive smoking prevention on shrine grounds. Since 1999, smoking prevention classes have been held at elementary schools, and in 2008, smoking was prohibited in the grounds of the Oki-jinja Shrine, making the festival there totally nonsmoking within the shrine grounds, among additional measures taken against smoking. In addition, measures against smoking at large events in Shizuoka Prefecture and Hamamatsu City have also been effective, and the smoking rate among Hamamatsu citizens has dropped to 10.2% (From Health Promotion Division, Hamamatsu City, 2016), which is expected to extend their healthy life expectancy. To reduce the smoking rate, it is important not only to provide administrative support but also to engage in steady civic activities.

The impact of anti-tobacco legislation on birth weight in Peru

Background

Tobacco exposure remains a significant issue for public health, especially for pregnant women. It increases the risk for premature labor, low birth weight and small for gestational age (SGA), among other effects. To reduce these risks, many countries have enacted public policies to curb tobacco exposure. Peru enacted anti-tobacco laws that forbid smoking in public places, require prevention text and images in products and publicity, along with restriction of sales to adults. We evaluated the effect of the implementation of this law on newborn outcomes: birth weight, prematurity and SGA.

Methods

This was a quasi-experimental study that utilized data from the Peruvian Live Birth Registry. Children born to mothers from urban areas were the intervention group, while children born to mothers from rural areas were considered the control group. Only singletons with information on birth weight and gestational age, born to mothers aged 12 to 49 years were included in the study. In addition, newborns with birth weights greater than + 4 standard deviations (SD) or less than - 4 SD from the gestational age-specific mean were excluded. To measure the effect of legislation on birth weight we performed a difference in differences analysis.

Results

A total of 2,029,975 births were included in the analysis. After adjusting for characteristics of the mother and the child, and contextual variables, the anti-tobacco law in Peru reduced the incidence of prematurity by 30 cases per 10,000 live births (95% CI: 19 to 42).

Conclusions

The reform had negligible effects on overall birth weights and on the incidence of SGA. This modest result suggests the need for a more aggressive fight against tobacco, prohibiting all types of advertising and promotion of tobacco products, among others measures.

Atrial fibrillation: A review of modifiable risk factors and preventive strategies

Atrial fibrillation (AF), as the most common cardiac arrhythmia worldwide, is associated with increased mortality and morbidity. Successful therapeutic strategies have been introduced so far, but they are associated with significant costs. Therefore, identification of modifiable risk factors of AF and the development of appropriate preventive strategies may play a substantial role in promoting community health and reducing health care system costs. Modifiable cardiovascular risk factors including obesity, hypertension, diabetes mellitus, obstructive sleep apnea, alcohol consumption, smoking, and sedentary lifestyles have been proposed as possible contributors to the development and progression of AF. In this review, we discuss the role of modifiable risk factors in the development and management of AF and the evidence for the underlying mechanism for each of the potential risk factor.

Setting and motivation in the decision to participate: An approach to the engagement of diverse samples in mobile research

Internet and mobile based research are powerful tools in the creation of large, cohort studies (eCohort). However, recent analysis indicates that an underrepresentation of minority and low income groups in these studies might exceed that found in traditional research [1-5]. In this report, we present findings from an experiment in research engagement using the Eureka Research Platform developed to enroll diverse populations in support of biomedical clinical research. This experiment involved the recruitment of African American and Latino participants in a smartphone based survey at a temporary, charitable, dental event sponsored, in part, by the research team, in order to explore the impact of setting and approach on recruitment outcomes. 211 participants enrolled including a significant representation of African Americans (51%) and Latinos (31%) and those with education levels at high school or less (37%). Interviews conducted after the study confirmed that our recruitment efforts within the context of a service event affected the decision to participate. While further research is necessary, this experiment holds promise for the engagement of underrepresented groups in research.

Characteristics of Atrial Fibrillation Patients with a Family History of Atrial Fibrillation

Background

Family history has been shown to be associated with increased risk of atrial fibrillation (AF). However, the specific AF characteristics that travel with a family history have not yet been elucidated. The purpose of this study was to determine whether a family history of AF is associated with specific patient characteristics in a worldwide, remote cohort.

Methods

From the Health eHeart Study, an internet-based prospective cohort, we performed a cross-sectional analysis of AF participants who reported their family history and completed questionnaires regarding their medical conditions and AF symptoms. We assessed demographics, cardiovascular comorbidities, and AF symptom characteristics in AF participants with and without a family history of AF.

Results

In multivariable analysis of 5,884 participants with AF (mean age 59.9 ± 14.5, 59% male, 92% white), female sex (odds ratio [OR]=1.35, 95% CI, 1.17-1.54, p<0.0001) and birth in the U.S. (OR=2.54, 95% CI, 2.12-3.05, p<0.0001) were independently associated with having a family history of AF. Having a family history of AF was also more commonly associated with symptoms of shortness of breath (OR=1.40, 95% CI, 1.07-1.82, p=0.014), chest pain, pressure, or discomfort (OR=1.95, 95% CI, 1.22-3.13, p=0.0052), and feeling generally "off" about oneself (OR=1.84, 95% CI, 1.27-2.67, p=0.0013).

Conclusions

Patients with a family history of AF are more likely to be female, be US-born, and experience symptoms of AF, suggesting underlying mechanistic differences between those with and without family history of AF.

Temporal patterns of self-weighing behavior and weight changes assessed by consumer purchased scales in the Health eHeart Study

Self-weighing may promote attainment and maintenance of healthy weight; however, the natural temporal patterns and factors associated with self-weighing behavior are unclear. The aims of this secondary analysis were to (1) identify distinct temporal patterns of self-weighing behaviors; (2) explore factors associated with temporal self-weighing patterns; and (3) examine differences in percent weight changes by patterns of self-weighing over time. We analyzed electronically collected self-weighing data from the Health eHeart Study, an ongoing longitudinal research study coordinated by the University of California, San Francisco. We selected participants with at least 12 months of data since the day of first use of a WiFi- or Bluetooth-enabled digital scale. The sample (N = 1041) was predominantly male (77.5%) and White (89.9%), with a mean age of 46.5 ± 12.3 years and a mean BMI of 28.3 ± 5.9 kg/m² at entry. Using group-based trajectory modeling, six distinct temporal patterns of self-weighing were identified: non-users (n = 120, 11.5%), weekly users (n = 189, 18.2%), rapid decliners (n = 109, 10.5%), increasing users (n = 160, 15.4%), slow decliners (n = 182, 17.5%), and persistent daily users (n = 281, 27.0%). Individuals who were older, female, or self-weighed 6-7 days/week at week 1 were more likely to follow the self-weighing pattern of persistent daily users. Predicted self-weighing trajectory group membership was significantly associated with weight change over time (p < .001). In conclusion, we identified six distinct patterns of self-weighing behavior over the 12-month period. Persistent daily users lost more weight compared with groups with less frequent patterns of scale use.

Childhood Tobacco Smoke Exposure and Risk of Atrial Fibrillation in Adulthood

BACKGROUND

Cigarette smoking is known to increase the risk of atrial fibrillation (AF), and a recent cross-sectional analysis suggested that parental smoking may be an AF risk factor.

OBJECTIVES

The purpose of this study was to assess if parental smoking predicts offspring AF in the Framingham Heart Study.

METHODS

This study analyzed Framingham Offspring cohort participants with parents in the Original cohort with known smoking status during the offspring's childhood. Framingham participants were evaluated every 2 to 8 years and were under routine surveillance for incident AF. The authors assessed AF incidence among Offspring participants exposed to parental smoking through age 18 years and performed a mediation analysis to determine the extent to which offspring smoking might explain observed associations.

RESULTS

Of 2,816 Offspring cohort participants with at least 1 parent in the Original cohort, 82% were exposed to parental smoking. For every pack/day increase in parental smoking, there was an 18% increase in offspring AF incidence (adjusted hazard ratio [HR]: 1.18; 95% confidence interval [CI]: 1.00 to 1.39; p = 0.04). Additionally, parental smoking was a risk factor for offspring smoking (adjusted odds ratio [OR]: 1.34; 95% CI: 1.17 to 1.54; p < 0.001). Offspring smoking mediated 17% (95% CI: 1.5% to 103.3%) of the relationship between parental smoking and offspring AF.

CONCLUSIONS

Childhood secondhand smoke exposure predicted increased risk for adulthood AF after adjustment for AF risk factors. Some of this relationship may be mediated by a greater propensity among offspring of smoking parents to smoke themselves. These findings highlight potential new pathways for AF risk that begin during childhood, offering new evidence to motivate smoking avoidance and cessation.

Correlation between HCN4 gene polymorphisms and lone atrial fibrillation risk

Background and objective: Atrial electrical remodelling (AER) was significantly associated with atrial fibrillation (AF) development. Polymorphisms in hyperpolarization activated cyclic nucleotide gated potassium channel 4 (HCN4) gene might be correlated with AER. In the present study, we explored the association of HCN4 polymorphisms (rs498005 and rs7164883) with lone AF risk in a Chinese Han population. Methods: In this case-control study, the Sanger sequencing method was utilized to genotype the HCN4 polymorphisms. Relative risk of AF was assessed by the χ² test, and presented by odds ratios (ORs) and corresponding 95% confidence intervals (CIs). Logistic regression analysis was performed for multivariate analysis. The effects of HCN4 polymorphisms on AF clinical features were analyzed by the Mann-Whitney U test and adjusted by the Bonferroni method. Results: C allele of rs498005 was significantly correlated with increased risk of AF (OR = 1.412, 95%CI = 1.012-1.970), and the association still exited after adjustment by age, gender, the status of smoking and drinking, histories of diabetes, hyperlipidaemia and myocardial infarction (adjusted OR = 1.473, 95%CI = 1.043-2.081). G allele of rs7164883 SNP was marginally associated with enhanced AF risk after adjustment by the above clinical parameters (adjusted OR = 1.742, 95%CI = 1.019-2.980). Atrial late potential (ALP), including TP (P wave duration after filtering) and LP₂₀ (the amplitude of superimposed potential in the final 20 ms of P wave) were significantly associated with rs498005 genotype (p < .001). Conclusion: HCN4 rs498005 and rs7164883 polymorphisms are significantly associated with AF risk.

The toxicology of air pollution predicts its epidemiology

The epidemiologic investigation has successively delineated associations of air pollution exposure with non-malignant and malignant lung disease, cardiovascular disease, cerebrovascular disease, pregnancy outcomes, perinatal effects and other extra-pulmonary disease including diabetes. Defining these relationships between air pollution exposure and human health closely parallels results of an earlier epidemiologic investigation into cigarette smoking and environmental tobacco smoke (ETS), two other particle-related exposures. Humic-like substances (HULIS) have been identified as a chemical component common to cigarette smoke and air pollution particles. Toxicology studies provide evidence that a disruption of iron homeostasis with sequestration of host metal by HULIS is a fundamental mechanistic pathway through which biological effects are initiated by cigarette smoke and air pollution particles. As a result of a common chemical component and a shared mechanistic pathway, it should be possible to extrapolate from the epidemiology of cigarette smoking and ETS to predict associations of air pollution exposure with human disease, which are currently unrecognized. Accordingly, it is anticipated that the forthcoming epidemiologic investigation will demonstrate relationships of air pollution with COPD causation, peripheral vascular disease, hypertension, renal disease, digestive disease, loss of bone mass/risk of fractures, dental disease, eye disease, fertility problems, and extrapulmonary malignancies.

Sleep characteristics that predict atrial fibrillation

BACKGROUND

The relationship between sleep disruption, independent of obstructive sleep apnea (OSA), and atrial fibrillation (AF) is unknown.

OBJECTIVE

The purpose of this study was to determine whether poor sleep itself is a risk factor for AF.

METHODS

We first performed an analysis of participants in the Health eHeart Study and validated those findings in the longitudinal Cardiovascular Health Study, including a subset of patients undergoing polysomnography. To determine whether the observed relationships readily translated to medical practice, we examined 2005-2009 data from the California Healthcare Cost and Utilization Project.

RESULTS

Among 4553 Health eHeart participants, the 526 with AF exhibited more frequent nighttime awakening (odd ratio [OR] 1.47; 95% confidence interval [CI] 1.14-1.89; P = .003). In 5703 Cardiovascular Health Study participants followed for a median 11.6 years, frequent nighttime awakening predicted a 33% greater risk of AF (hazard ratio [HR] 1.33; 95% CI 1.17-1.51; P <.001). In patients with polysomnography (N = 1127), every standard deviation percentage decrease in rapid eye movement (REM) sleep was associated with a 18% higher risk of developing AF (HR 1.18; 95% CI 1.00-1.38; P = .047). Among 14,330,651 California residents followed for a median 3.9 years, an insomnia diagnosis predicted a 36% increased risk of new AF (HR 1.36; 95% CI 1.30-1.42; P <.001).

CONCLUSION

Sleep disruption consistently predicted AF before and after adjustment for OSA and other potential confounders across several different populations. Sleep quality itself may be important in the pathogenesis of AF, potentially representing a novel target for prevention.

Association between serum cotinine levels and electrocardiographic left atrial abnormality

BACKGROUND

Although the harmful effect of tobacco exposure on cardiovascular disease (CVD) and its risk factors are well established, the constituents of cigarette-smoke and the pathophysiological mechanism involved are unknown. Recently, deep terminal negativity of P wave in V1 (DTNPV1) has emerged as a marker of left atrial abnormality that predicts atrial fibrillation, stroke, and death due to all-cause or CVD. Therefore, we examined the association between serum cotinine levels with abnormal DTNPV1 using the Third National Health and Nutrition Examination Survey.

METHODS

This analysis included 4,507 participants (mean age 58 ± 13 years, 53% women, 49% non-Hispanic white) of NHANES III, without history of CVD or major electrocardiographic abnormalities and not on heart rate modifying medications. Multivariable logistic regression analysis was used to examine the association between serum cotinine and abnormal DTNPV1-defined from automatically processed electrocardiograms as values of the amplitude of the terminal negative phase of P wave in lead V1 exceeding 100 μV.

RESULTS

Abnormal DTNPV1 was detected in 2.3% (n = 105) of the participants. In a model adjusted for demographics and CVD risk factors, each 10 ng/ml serum cotinine was associated with 2% increased odds of abnormal DTNPV1 (odds ratio 1.02, 95% confidence interval 1.01-1.03, p-value < 0.001). This association was consistent in subgroups stratified by age, sex, race, smoking status, hypertension, diabetes, dyslipidemia, and chronic obstructive pulmonary disease.

CONCLUSION

Elevated serum cotinine levels are associated with an abnormal DTNPV1. This suggests that nicotine exposure can lead to left atrial abnormalities, a possible mechanism for increased risk of CVD.

Socio-economic inequalities in secondhand smoke exposure at home in the context of mother-child pairs in Bangladesh

OBJECTIVES

This study aimed to examine socio-economic disparities in mother-child pairs' self-reported and cotinine-measured secondhand smoke (SHS) exposure at home.

STUDY DESIGN

This is a cross-sectional study.

METHODS

This study was conducted in the Rajshahi district of Bangladesh from May to July 2017. A total of 541 mother-child pairs were interviewed for self-reported measured SHS; cotinine-measured saliva test was performed on 263 mothers and 236 children. Mother-child pairs' SHS exposure at home was the outcome of interest.

RESULTS

Overall self-reported prevalence of SHS exposure at home was 49.0%. Self-reported SHS exposure among mothers (50.2%) and children (51.3%) were lower than the prevalence rate of cotinine-measured exposure for mothers (60.5%) and their children (58.9%). Maternal rich bands of wealth were found to be associated with lower likelihood of self-reported (adjusted odds ratio [AOR] = 0.59, 95% confidence interval [CI] = 0.35-0.99) and cotinine-measured SHS exposure among mothers (AOR = 0.17, 95% CI = 0.08-0.37). Maternal rich bands of wealth were also found to be associated with lower likelihood of cotinine-measured SHS exposure among children (AOR = 0.11, 95% CI = 0.07-0.26).

CONCLUSIONS

Socio-economic inequalities exist in exposure to SHS at home. Interventional approaches aimed at reducing SHS at home are urgently needed at public health and healthcare service level, with special focus given to the socioeconomically disadvantaged groups.

Smartphone-Based Geofencing to Ascertain Hospitalizations

BACKGROUND

Ascertainment of hospitalizations is critical to assess quality of care and the effectiveness and adverse effects of various therapies. Smartphones, mobile geolocators that are ubiquitous, have not been leveraged to ascertain hospitalizations. Therefore, we evaluated the use of smartphone-based geofencing to track hospitalizations.

METHODS AND RESULTS

Participants aged ≥18 years installed a mobile application programmed to geofence all hospitals using global positioning systems and cell phone tower triangulation and to trigger a smartphone-based questionnaire when located in a hospital for ≥4 hours. An in-person study included consecutive consenting patients scheduled for electrophysiology and cardiac catheterization procedures. A remote arm invited Health eHeart Study participants who consented and engaged with the study via the internet only. The accuracy of application-detected hospitalizations was confirmed by medical record review as the reference standard. Of 22 eligible in-person patients, 17 hospitalizations were detected (sensitivity 77%; 95% confidence interval, 55%-92%). The length of stay according to the application was positively correlated with the length of stay ascertained via the electronic medical record (r=0.53; P=0.03). In the remote arm, the application was downloaded by 3443 participants residing in all 50 US states; 243 hospital visits at 119 different hospitals were detected through the application. The positive predictive value for an application-reported hospitalization was 65% (95% confidence interval, 57%-72%).

CONCLUSIONS

Mobile application-based ascertainment of hospitalizations can be achieved with modest accuracy. This first proof of concept may ultimately be applicable to geofencing other types of prespecified locations to facilitate healthcare research and patient care.

Atrial Fibrillation: Epidemiology, Pathophysiology, and Clinical Outcomes

The past 3 decades have been characterized by an exponential growth in knowledge and advances in the clinical treatment of atrial fibrillation (AF). It is now known that AF genesis requires a vulnerable atrial substrate and that the formation and composition of this substrate may vary depending on comorbid conditions, genetics, sex, and other factors. Population-based studies have identified numerous factors that modify the atrial substrate and increase AF susceptibility. To date, genetic studies have reported 17 independent signals for AF at 14 genomic regions. Studies have established that advanced age, male sex, and European ancestry are prominent AF risk factors. Other modifiable risk factors include sedentary lifestyle, smoking, obesity, diabetes mellitus, obstructive sleep apnea, and elevated blood pressure predispose to AF, and each factor has been shown to induce structural and electric remodeling of the atria. Both heart failure and myocardial infarction increase risk of AF and vice versa creating a feed-forward loop that increases mortality. Other cardiovascular outcomes attributed to AF, including stroke and thromboembolism, are well established, and epidemiology studies have championed therapeutics that mitigate these adverse outcomes. However, the role of anticoagulation for preventing dementia attributed to AF is less established. Our review is a comprehensive examination of the epidemiological data associating unmodifiable and modifiable risk factors for AF and of the pathophysiological evidence supporting the mechanistic link between each risk factor and AF genesis. Our review also critically examines the epidemiological data on clinical outcomes attributed to AF and summarizes current evidence linking each outcome with AF.

Direct Measurements of Smartphone Screen-Time: Relationships with Demographics and Sleep

BACKGROUND

Smartphones are increasingly integrated into everyday life, but frequency of use has not yet been objectively measured and compared to demographics, health information, and in particular, sleep quality.

AIMS

The aim of this study was to characterize smartphone use by measuring screen-time directly, determine factors that are associated with increased screen-time, and to test the hypothesis that increased screen-time is associated with poor sleep.

METHODS

We performed a cross-sectional analysis in a subset of 653 participants enrolled in the Health eHeart Study, an internet-based longitudinal cohort study open to any interested adult (≥ 18 years). Smartphone screen-time (the number of minutes in each hour the screen was on) was measured continuously via smartphone application. For each participant, total and average screen-time were computed over 30-day windows. Average screen-time specifically during self-reported bedtime hours and sleeping period was also computed. Demographics, medical information, and sleep habits (Pittsburgh Sleep Quality Index-PSQI) were obtained by survey. Linear regression was used to obtain effect estimates.

RESULTS

Total screen-time over 30 days was a median 38.4 hours (IQR 21.4 to 61.3) and average screen-time over 30 days was a median 3.7 minutes per hour (IQR 2.2 to 5.5). Younger age, self-reported race/ethnicity of Black and "Other" were associated with longer average screen-time after adjustment for potential confounders. Longer average screen-time was associated with shorter sleep duration and worse sleep-efficiency. Longer average screen-times during bedtime and the sleeping period were associated with poor sleep quality, decreased sleep efficiency, and longer sleep onset latency.

CONCLUSIONS

These findings on actual smartphone screen-time build upon prior work based on self-report and confirm that adults spend a substantial amount of time using their smartphones. Screen-time differs across age and race, but is similar across socio-economic strata suggesting that cultural factors may drive smartphone use. Screen-time is associated with poor sleep. These findings cannot support conclusions on causation. Effect-cause remains a possibility: poor sleep may lead to increased screen-time. However, exposure to smartphone screens, particularly around bedtime, may negatively impact sleep.

Cardiovascular Consequences of Childhood Secondhand Tobacco Smoke Exposure: Prevailing Evidence, Burden, and Racial and Socioeconomic Disparities: A Scientific Statement From the American Heart Association

BACKGROUND

Although public health programs have led to a substantial decrease in the prevalence of tobacco smoking, the adverse health effects of tobacco smoke exposure are by no means a thing of the past. In the United States, 4 of 10 school-aged children and 1 of 3 adolescents are involuntarily exposed to secondhand tobacco smoke (SHS), with children of minority ethnic backgrounds and those living in low-socioeconomic-status households being disproportionately affected (68% and 43%, respectively). Children are particularly vulnerable, with little control over home and social environment, and lack the understanding, agency, and ability to avoid SHS exposure on their own volition; they also have physiological or behavioral characteristics that render them especially susceptible to effects of SHS. Side-stream smoke (the smoke emanating from the burning end of the cigarette), a major component of SHS, contains a higher concentration of some toxins than mainstream smoke (inhaled by the smoker directly), making SHS potentially as dangerous as or even more dangerous than direct smoking. Compelling animal and human evidence shows that SHS exposure during childhood is detrimental to arterial function and structure, resulting in premature atherosclerosis and its cardiovascular consequences. Childhood SHS exposure is also related to impaired cardiac autonomic function and changes in heart rate variability. In addition, childhood SHS exposure is associated with clustering of cardiometabolic risk factors such as obesity, dyslipidemia, and insulin resistance. Individualized interventions to reduce childhood exposure to SHS are shown to be at least modestly effective, as are broader-based policy initiatives such as community smoking bans and increased taxation.

PURPOSE

The purpose of this statement is to summarize the available evidence on the cardiovascular health consequences of childhood SHS exposure; this will support ongoing efforts to further reduce and eliminate SHS exposure in this vulnerable population. This statement reviews relevant data from epidemiological studies, laboratory-based experiments, and controlled behavioral trials concerning SHS and cardiovascular disease risk in children. Information on the effects of SHS exposure on the cardiovascular system in animal and pediatric studies, including vascular disruption and platelet activation, oxidation and inflammation, endothelial dysfunction, increased vascular stiffness, changes in vascular structure, and autonomic dysfunction, is examined.

CONCLUSIONS

The epidemiological, observational, and experimental evidence accumulated to date demonstrates the detrimental cardiovascular consequences of SHS exposure in children.

IMPLICATIONS

Increased awareness of the adverse, lifetime cardiovascular consequences of childhood SHS may facilitate the development of innovative individual, family-centered, and community health interventions to reduce and ideally eliminate SHS exposure in the vulnerable pediatric population. This evidence calls for a robust public health policy that embraces zero tolerance of childhood SHS exposure.

Association of smoking with the risk of incident atrial fibrillation: A meta-analysis of prospective studies

BACKGROUND

Several studies have investigated the role of smoking in incident atrial fibrillation (AF) but have reported contradictory results. Identifying the quantitative association between smoking and AF risk is important for AF management and prevention; therefore, we aimed to estimate the association of smoking with incident AF.

METHODS

We systematically retrieved relevant studies reporting on the association between smoking and AF using the Cochrane Library, PubMed, and Embase databases. The data were extracted from applicable articles, and we used a random effects model to pool the effect estimates.

RESULTS

Sixteen prospective studies with an overall number of 286,217 participants and 11,878 AF cases met the inclusion criteria. A higher prevalence of AF was confirmed among smokers (risk ratio [RR]=1.23, 95% confidence interval [CI] 1.08-1.39; P=0.001). These results were stable in the sensitivity analysis. The pooled RRs showed consistent positive associations in most subgroups. Specifically, 8 articles compared both current smokers (RR=1.39, 95% CI 1.11-1.75) and former smokers (RR=1.16, 95% CI: 1.00-1.36) with never smokers. Four articles compared ever smokers (pooled RR=1.21, 95% CI 0.93-1.57) with never smokers, and 7 articles compared current smokers (pooled RR=1.21, 95% CI 1.03-1.42) with non-current smokers. Additionally, we estimated that 6.7% of the total risk of AF in men and 1.4% of the risk in women were attributable to smoking worldwide.

CONCLUSIONS

Based on the published literature, smoking is associated with a modest increased risk of incident AF. Smoking cessation seemed to reduce but not entirely eliminate the excess risk of AF.

Association between secondhand smoking in the home and respiratory morbidity in preschool children

Abstract OBJECTIVE Identifying the prevalence of secondhand smoking in the home and its association with morbidity and hospitalization from respiratory causes in preschool children. METHOD This is a cross-sectional study conducted in five early childhood education centers at a public university in São Paulo. Sample size calculation was performed and the participants were randomly determined. Data were collected through questionnaires completed by family members or caregivers of 215 children. Chi-square and Student's t-test were used for the statistical analysis, using a 0.05 significance level. RESULTS The prevalence of secondhand smoke in the household was 15.3%. Bivariate analysis revealed that secondhand smoke in the household was associated with the occurrence of rapid breathing, subdiaphragmatic retractions in the past three months, and treated ear infections/otitis. CONCLUSION A low prevalence of secondhand smoking in the home was found. Secondhand smoke was associated with a higher prevalence of respiratory symptoms and morbidity.