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

Mediterranean diet and atrial fibrillation: a case-control study from China

Objective

The aim of this study was to assess the association between adherence to Mediterranean diet and the presence of atrial fibrillation (AF) in a Northern Chinese population.

Methods

This study was a single center, case-control study. A total of 952 low risk participants in Beijing Anzhen Hospital from 2016 to 2021 were collected, including 476 patients with first diagnosed of atrial fibrillation and 476 age and sex matched controls. According to the food frequency questionnaire (FFQ), the alternate Mediterranean diet score (AMED) was calculated, which was 0-9 points, indicating the adherence to the Mediterranean diet from low to high.

Results

The average age of the participants was 57.6 ± 9.1 years old, and 70.2% were men. After analyzing every component of AMED, vegetable consumption shows a negative correlation with the risk of AF, whereas alcohol consumption demonstrates a positive correlation with it (OR = 0.61, 95% CI 0.44-0.80, p < 0.001; OR = 1.99, 95% CI 1.48-2.58, p < 0.001). All patients were grouped according to AMED score. A significant inverse association between AMED and the risk of AF was observed. Compared with participants with AMED<4, the multivariable-adjusted ORs of AF were 0.75 (95% CI 0.55-1.06) for AMED 4-5 and 0.61 (95% CI 0.43-0.89) for AMED ≥6, with a trend in risk (p = 0.008). Results were consistent in stratified analyses of gender, age, BMI and smoking.

Conclusion

The Mediterranean diet was inversely associated with the risk of AF in this Northern Chinese population.

Folic Acid Ameliorates Anxiety- and Depressive-Like Behavior Induced by Nicotine Withdrawal Through Restoration of Behavioral and Biochemical Alterations in Adolescent Male Rats

BACKGROUND

The present study aimed to assess the efficacy of folic acid (FA) on withdrawal following nicotine (Nic) administration in adolescent male rats.

AIMS AND METHODS

Adolescent male rats were divided into two groups: (1) vehicle and (2) Nic (Nic-2 mg/kg), and were under treatment from 21 to 42 days of age. After that, they continued the experiment without treatment and returned to a regular diet, except for one of those who received Nic. The rats were divided into four groups where they were treated with different doses of FA (5, 10, and 15 mg/kg) and bupropion (Bup) by oral gavage, and the final group included normal rats that received only FA (15 mg/kg) from 42 days of age for three weeks during which withdrawal occurred.

RESULTS

Results showed that adolescent Nic exposure exacerbated the behavioral indices of anxiety- and depression-like behaviors, while FA attenuated the effects of Nic withdrawal on anxiety and depression as well as Bup. In support, the biochemical results demonstrated a balance between oxidant and antioxidant mediators in addition to the increase and decrease of serotonin and monoamine oxidase (MAO) activity in cortical tissue. TNF-α as an inflammatory agent was decreased, whereas IL-10 as an anti-inflammatory parameter was increased.

CONCLUSIONS

The present findings suggest anxiety and depression caused by Nic withdrawal were attenuated by FA more likely through the reduction activity of MAO, the important enzyme responsible for serotonin metabolism along with balance between oxidant/antioxidant and pro-inflammatory/anti-inflammatory mediators. However, various mechanisms might be involved, which requires further investigation.

IMPLICATIONS

Nic withdrawal-induced depression and anxiety like behavior in rats followed by neuro-oxidative damage and neuro-inflammation. FA supplementation as well as Bup improved cognitive disorders induced by Nic withdrawal by increasing neuro-inflammation and neuro-oxidative damage.

Inhibition of the acetylcholine-regulated potassium current prevents transient apnea-related atrial arrhythmogenic changes in a porcine model

BACKGROUND

More than 50% of patients with atrial fibrillation (AF) suffer from sleep disordered breathing (SDB). Obstructive respiratory events contribute to a transient, vagally mediated atrial arrhythmogenic substrate, which is resistant to most available antiarrhythmic drugs.

OBJECTIVE

The purpose of this study was to investigate the effect of pharmacologic inhibition of the G-protein-gated acetylcholine-regulated potassium current (IK,ACh) with and without acute autonomic nervous system activation by nicotine in a pig model for obstructive respiratory events.

METHODS

In 21 pigs, SDB was simulated by applying an intermittent negative upper airway pressure (INAP). AF inducibility and atrial effective refractory periods (aERPs) were determined before and during INAP by an S1S2 atrial pacing-protocol. Pigs were randomized into 3 groups-group 1: vehicle (n = 4); group 2: XAF-1407 (IK,ACh inhibitor) (n = 7); and group 3: nicotine followed by XAF-1407 (n = 10).

RESULTS

In group 1, INAP shortened aERP (ΔaERP -42.6 ms; P = .004) and transiently increased AF inducibility from 0% to 31%. In group 2, XAF-1407 prolonged aERP by 25.2 ms (P = .005) during normal breathing and prevented INAP-induced aERP shortening (ΔaERP -3.6 ms; P = .3) and AF inducibility. In group 3, INAP transiently shortened aERP during nicotine perfusion (ΔaERP -33.6 ms; P = .004) and increased AF inducibility up to 61%, which both were prevented by XAF-1407.

CONCLUSION

Simulated obstructive respiratory events transiently shorten aERP and increase AF inducibility, which can be prevented by the IK,ACh-inhibitor XAF-1407. XAF-1407 also prevents these arrhythmogenic changes induced by obstructive respiratory events during nicotine perfusion. Whether IK,ACh channels represent a target for SDB-related AF in humans warrants further study.

Pathophysiology and clinical relevance of atrial myopathy

Atrial myopathy is a condition that consists of electrical, structural, contractile, and autonomic remodeling of the atria and is the substrate for development of atrial fibrillation, the most common arrhythmia. Pathophysiologic mechanisms driving atrial myopathy are inflammation, oxidative stress, atrial stretch, and neurohormonal signals, e.g., angiotensin-II and aldosterone. These mechanisms initiate the structural and functional remodeling of the atrial myocardium. Novel therapeutic strategies are being developed that target the pathophysiologic mechanisms of atrial myopathy. In this review, we will discuss the pathophysiology of atrial myopathy, as well as diagnostic and therapeutic strategies.

Global burden of stroke attributable to secondhand smoke in 204 countries and territories from 1990 to 2019: analysis of the global burden of disease study

BACKGROUND

Secondhand smoke (SHS) continues a significant public health concern globally. This study aimed to assess the global burden of stroke attributable to SHS exposure during 1990-2019.

METHODS

This analysis utilized data on stroke morbidity and mortality from the Global Burden of Disease (GBD) 2019 study covering 204 countries and territories. We estimated stroke burden indicators attributable to SHS exposure, including age-standardized mortality rate (ASMR) and age-standardized disability-adjusted life-year rate (ASDR), stratified by age, sex, region, and stroke subtype.

RESULTS

In 2019, global SHS exposure accounted for 2.01 [95% uncertainty interval (UI): 1.49-2.58] million stroke mortality. The ASMR and ASDR were 2.5 (95% UI: 1.9-3.2) and 61.5 (95% UI: 46-78.8) per 100,000 population, respectively. The disease burden was higher among women than men and higher among the elderly than younger populations. Intracerebral hemorrhage and ischemic stroke had a more significant burden than subarachnoid hemorrhage. From 1990 to 2019, the ASMR and ASDR declined [estimated annual percentage change: -2.08 (95% CI: -2.21% to -1.95%) and -2.08% (95% CI: -2.19% to -1.97%) for each], but the absolute number of mortalities increased along with population growth. Substantial disparities existed across regions and sociodemographic groups.

CONCLUSION

Despite declining ASMR and ASDR over time, the absolute number of stroke deaths attributable to SHS continued to rise globally, imposing a considerable stroke burden worldwide. These findings can inform targeted interventions and policies aimed at SHS control.

Appraisal and characterization of candida load isolated from the oral cavity of smokers

Cigarette smoking is regarded as a major global health risk, therefore the aim of this work was to investigate the association of oral Candida spp. as one of the etiological agents of denture stomatitis with smokers of cigarette, hookah (shisha), and electronic smoking, also a dose-response relationship between the duration of smoking and the probability of denture stomatitis between volunteers. Oral rinse samples were collected from 47 male volunteers including 34 smokers and 13 non-smokers, also data of volunteers were collected via a questionnaire forum. Patterns of smoking were shown that smokers using tobacco cigarettes 17 (36.2 %), electronic cigarettes 16 (34.04 %), and hookah smokers 8 (17.02 %). A comparison of smokers and non-smokers regarding effects on oral health showed significantly finding (P < 0.05) indicating that smoking affects oral health in all evaluated parameters (an oral mucosal abnormality, mouth ulcers, bad breath, and feeling of dry mouth). Out of 19 Candida isolates, 18 (94.7 %) were identified as Candida albicans and 1 (5.3 %) as Candida tropicalis. Among the volunteers who presented with oral Candida (19 volunteers), 17 (89.5%) were smokers, while non-smoker volunteers were 2 (10.5 %), so it can be concluded that smoking was a significant positive correlation to the presence of Candida in the oral cavity. Five volunteers suffered from chronic diseases; 4 (8.5%) diabetes mellitus and 1 (2.1%) anemia as a systemic predisposing factor for oropharyngeal infection. Amphotericin and Nystatin had varying degrees of activity against isolated Candida isolates.

Vascular smooth muscle cell dysfunction in neurodegeneration

Vascular smooth muscle cells (VSMCs) are the key moderators of cerebrovascular dynamics in response to the brain's oxygen and nutrient demands. Crucially, VSMCs may provide a sensitive biomarker for neurodegenerative pathologies where vasculature is compromised. An increasing body of research suggests that VSMCs have remarkable plasticity and their pathophysiology may play a key role in the complex process of neurodegeneration. Furthermore, extrinsic risk factors, including environmental conditions and traumatic events can impact vascular function through changes in VSMC morphology. VSMC dysfunction can be characterised at the molecular level both preclinically, and clinically ex vivo. However the identification of VSMC dysfunction in living individuals is important to understand changes in vascular function at the onset and progression of neurological disorders such as dementia, Alzheimer's disease, and Parkinson's disease. A promising technique to identify changes in the state of cerebral smooth muscle is cerebrovascular reactivity (CVR) which reflects the intrinsic dynamic response of blood vessels in the brain to vasoactive stimuli in order to modulate regional cerebral blood flow (CBF). In this work, we review the role of VSMCs in the most common neurodegenerative disorders and identify physiological systems that may contribute to VSMC dysfunction. The evidence collected here identifies VSMC dysfunction as a strong candidate for novel therapeutics to combat the development and progression of neurodegeneration, and highlights the need for more research on the role of VSMCs and cerebrovascular dynamics in healthy and diseased states.