Dietary sodium intake is associated with long-term risk of new-onset atrial fibrillation

Excessive dietary sodium intake augments long-term risk of atrial fibrillation in older adults with hyperglycemia: A community-based prospective cohort study

AIM

Studies investigating the association between sodium intake and new-onset atrial fibrillation (AF) have come to controversial results. This study aimed to assess the effect of excessive sodium intake on new-onset AF in individuals with hyperglycemia.

METHODS

Between April 2007 and November 2011, 2841 community-dwelling individuals aged 60 years and older were recruited from the Shandong area, China. Dietary sodium intake was estimated using 24-hour urine collection within seven consecutive days. Fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) were assessed. New-onset AF was diagnosed using ICD-10 with codes I48 (I48.0 - I48.9) during follow-up.

RESULTS

The findings were that excessive sodium intake significantly and independently increased the risk of new-onset AF in older adults with hyperglycemia: hazard ratio (HR) 1.525 [95% confidence interval 1.147;2.029] adjusted P = 0.004. The risk of new-onset AF increased by 29.3% (HR 1.293 [1.108;1.509] adjusted P = 0.001) with a one-standard deviation increase in sodium intake. Excessive sodium intake synergistically interacted with hyperglycemia on the increased risk of new-onset AF (HR 1.599 [1.342;1.905] adjusted P < 0.001 for FPG and HR 1.516 [1.271;1.808] adjusted P < 0.001 for HbA1c).

CONCLUSION

Our findings indicate that excessive sodium intake independently enhances the risk of new-onset AF among patients with hyperglycemia. A sodium-restricted diet may perhaps result in a multiplier effect on reducing the risk of new-onset AF.

The Complex but Fascinating Relationship between Sport and Atrial Fibrillation: From Pathophysiology to the Clinical Scenario

Atrial fibrillation (AF) is the most common cause of hospital admission among all arrhythmias in the general population. Moreover, AF represents the most common arrhythmia in the athletic population as well. The complex but fascinating relationship between sport and atrial fibrillation has not yet been fully clarified. Although the benefits of moderate physical activity in controlling cardiovascular risk factors and in reducing the risk of atrial fibrillation have been widely demonstrated, some concerns have been raised about the potential adverse effects of physical activity. Endurance activity in middle-aged men athletes appears to increase the risk of AF. Several different physiopathological mechanisms may explain the increased risk of AF in endurance athletes, including the imbalance of the autonomic nervous system, changes in left atrial size and function and presence of atrial fibrosis. The goal of this article is to review the epidemiology, pathophysiology and clinical management for AF in athletes, including pharmacological and electrophysiological strategies.

Evaluating the association between dietary salt intake and the risk of atrial fibrillation using Mendelian randomization

Background

Previous studies have suggested that dietary salt intake affects atrial fibrillation (AF); however, the causal association between them still remains unclear. Thus, we conducted this Mendelian randomization (MR) study to explore the correlation between them.

Methods

Genetic instruments for dietary salt intake were from a genome-wide association study (GWAS), which included 462,630 European individuals. Summary-level data for AF were obtained from another published GWAS (22,068 cases and 116,926 controls). The inverse-variance weighting (IVW) method was performed as the primary MR analysis. Multiple MR methods, including Robust Adjusted Profile Score (MR-RAPS), maximum likelihood estimation, and Mendelian randomization pleiotropy residual sum and outlier test (MR-PRESSO) were conducted as complementary analyses. The MR-Egger regression intercept and MR-PRESSO global test were conducted to test potential horizontal pleiotropy. The IVW (Q) method and MR-Egger were performed to detect heterogeneity.

Results

Our results suggested that high dietary salt intake was significantly correlated with increased risk of AF [IVW: odds ratio (OR), 1.36; 95% confidence interval (CI), 1.04–1.77; p = 2.25E-02]. The maximum likelihood estimation (OR, 1.37; 95% CI, 1.05–1.78; p = 2.09E-02), MR-RAPS (OR, 1.37; 95% CI, 1.03–1.81; p = 2.79E-02), and MR-PRESSO method (OR, 1.36; 95% CI, 1.05–1.76; p = 2.37E-02) also showed that dietary salt intake was significantly correlated with the risk of AF.

Conclusion

The findings of this study provide robust evidence supporting the correlation between dietary salt intake and the risk of AF. Future studies are required to further clarify this relationship and translate the findings into clinical and public health practice.

Burden of atrial fibrillation and its attributable risk factors from 1990 to 2019: An analysis of the Global Burden of Disease study 2019

BACKGROUND

Understanding the pattern and trend of the atrial fibrillation (AF) burden are essential for developing effective preventive strategies. The purpose of this study was to estimate AF burdens and risk factors in 204 countries and territories between 1990 and 2019.

MATERIALS AND METHODS

Data were extracted from the Global Burden of Disease 2019, including incidence, death, disability-adjusted life-years (DALYs), and the attributable risk factors. In order to quantify changes in the age-standardized incidence rate (ASIR), age-standardized death rate (ASDR), and age-standardized DALY rate between 1990 and 2019, the estimated annual percentage change (EAPC) was used. Also, AF burden was assessed in relation to the Socio-demographic Index (SDI).

RESULTS

Globally, there were 4,720,324 incident cases, 117,038 deaths and 8,393,635 DALYs in 2019. There were no significant changes in ASIR, ASDR, or age-standardized DALY rates from 1990 to 2019. Although the burden and trend of AF varied in different regions and countries, the ASIR, ASDR and age-standardized DALY rate were positively correlated with SDI. Furthermore, the burden of AF was higher in males and elderly. The age-standardized DALY rate worldwide was primarily attributable to high systolic blood pressure, followed by high body-mass index, alcohol use, smoking, diet high in sodium and lead exposure.

CONCLUSION

AF remained a major public health challenge worldwide, with substantial variation at regional and national levels. There is an urgent need to increase public awareness about AF risk factors and to bring about cost-effective interventions for AF in order to reduce its future burden.

Electrolyte’s imbalance role in atrial fibrillation: Pharmacological management

The contribution of the perpetuation of atrial fibrillation is caused by electrical remodeling in which calcium, sodium and potassium channels could refer to changes in the ion channel protein expression, development of fibrosis, gene transcription and ion channel redistribution. Calcium and magnesium could influence the risk of atrial fibrillation which is the leading cause of cardiac death, heart failure and ischemic stroke. The elevated serum concentration of calcium had a higher range of in-patient’s mortality, increased total cost of hospitalization and increased length of hospital stay as compared to those without hypercalcemia in atrial fibrillation patients. Moreover, chloride channels could affect homeostasis, atrial myocardial metabolism which may participate in the development of atrial fibrillation. Up to a 50% risk of incidence of AF are higher in which left ventricular hypertrophy, sudden cardiovascular death and overall mortality relate to a low serum magnesium level. Additionally, magnesium prevents the occurrence of AF after cardiac surgery, whereas greater levels of serum phosphorus in the large population-based study and the related calcium–phosphorus products were linked with a greater incidence of AF. Numerous clinical studies had shown the high preoperative risk of AF that is linked with lower serum potassium levels. The conventional risk factor of increased risk of new onset of AF events could independently link with high dietary sodium intake which enhances the fibrosis and inflammation in the atrium but the mechanism remains unknown. Many drugs were used to maintain the electrolyte imbalance in AF patients.

Prevention and Treatment of Atrial Fibrillation via Risk Factor Modification

Atrial fibrillation (AF) is the most common clinically significant arrhythmia, and it increases stroke risk. A preventive approach to AF is needed because virtually all treatments such as cardioversion, antiarrhythmic drugs, ablation, and anticoagulation are associated with high cost and carry significant risk. A systematic review was performed to identify effective lifestyle-based strategies for reducing primary and secondary AF. A PubMed search was performed using articles up to March 1, 2021. Search terms included atrial fibrillation, atrial flutter, exercise, diet, metabolic syndrome, type 2 diabetes mellitus, obesity, hypertension, stress, tobacco smoking, alcohol, Mediterranean diet, sodium, and omega-3 fatty acids. Additional articles were identified from the bibliographies of retrieved articles. The control of hypertension, ideally with a renin-angiotensin-aldosterone system inhibitor, is effective for preventing primary AF and recurrence. Obstructive sleep apnea is a common cause of AF, and treating it effectively reduces AF episodes. Alcohol increases the risk of AF in a dose-dependent manner, and abstinence reduces risk of recurrence. Sedentary behavior and chronic high-intensity endurance exercise are both risk factors for AF; however, moderate physical activity is associated with lower risk of AF. Recently, sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1 agonists have been associated with reduced risk of AF. Among overweight/obese patients, weight loss of ≥10% is associated with reduced AF risk. Lifestyle changes and risk factor modification are highly effective for preventing AF.

Sodium Toxicity in the Nutritional Epidemiology and Nutritional Immunology of COVID-19

Dietary factors in the etiology of COVID-19 are understudied. High dietary sodium intake leading to sodium toxicity is associated with comorbid conditions of COVID-19 such as hypertension, kidney disease, stroke, pneumonia, obesity, diabetes, hepatic disease, cardiac arrhythmias, thrombosis, migraine, tinnitus, Bell's palsy, multiple sclerosis, systemic sclerosis, and polycystic ovary syndrome. This article synthesizes evidence from epidemiology, pathophysiology, immunology, and virology literature linking sodium toxicological mechanisms to COVID-19 and SARS-CoV-2 infection. Sodium toxicity is a modifiable disease determinant that impairs the mucociliary clearance of virion aggregates in nasal sinuses of the mucosal immune system, which may lead to SARS-CoV-2 infection and viral sepsis. In addition, sodium toxicity causes pulmonary edema associated with severe acute respiratory syndrome, as well as inflammatory immune responses and other symptoms of COVID-19 such as fever and nasal sinus congestion. Consequently, sodium toxicity potentially mediates the association of COVID-19 pathophysiology with SARS-CoV-2 infection. Sodium dietary intake also increases in the winter, when sodium losses through sweating are reduced, correlating with influenza-like illness outbreaks. Increased SARS-CoV-2 infections in lower socioeconomic classes and among people in government institutions are linked to the consumption of foods highly processed with sodium. Interventions to reduce COVID-19 morbidity and mortality through reduced-sodium diets should be explored further.

Estimated salt intake and risk of atrial fibrillation in a prospective community-based cohort

INTRODUCTION

Hypertension predisposes to atrial fibrillation (AF) - a major risk factor for ischaemic stroke. Since a high dietary salt consumption is associated with hypertension, we investigated the association between urinary sodium excretion as a marker for dietary sodium intake and risk of new-onset AF in community-dwelling adults.

METHOD

The UK Biobank includes 40- to 69-year-old British residents recruited 2006-2010. Participants were divided into sex-specific quintiles according to 24-hour sodium excretion estimated based on spot samples with the Kawasaki equation. We excluded participants with AF at baseline. Cox regression adjusted for cardiovascular risk factors was used to assess associations with risk of AF, using the third quintile as reference.

RESULTS

A total of 257 545 women and 215 535 men were included. During up to 10 years' follow-up, 2221 women and 3751 men were diagnosed with AF. There was a tendency for an increased risk of AF in the lowest and highest quintiles of estimated daily salt intake in both women and men. In the fully adjusted model, significant associations were seen amongst men in the lowest and highest quintiles of sodium excretion (hazard ratio, HR_Qv1 , 1.20; 95% CI, 1.08-1.32, P < 0.001, and HR_Qv5 1.15, 95% CI, 1.03-1.27, P = 0.011).

CONCLUSION

We found evidence for a U-shaped association between estimated daily salt intake and AF risk amongst men. A suggestive J-shaped association in women was not statistically confirmed, but analyses were likely underpowered. Our results suggest that above a certain physiological minimum level progressively higher salt intake is associated with increasing risk of AF.

Sodium Intake and Target Organ Damage in Hypertension-An Update about the Role of a Real Villain

Salt intake is too high for safety nowadays. The main active ion in salt is sodium. The vast majority of scientific evidence points out the importance of sodium restriction for decreasing cardiovascular risk. International Guidelines recommend a large reduction in sodium consumption to help reduce blood pressure, organ damage, and cardiovascular risk. Regulatory authorities across the globe suggest a general restriction of sodium intake to prevent cardiovascular diseases. In spite of this seemingly unanimous consensus, some researchers claim to have evidence of the unhealthy effects of a reduction of sodium intake, and have data to support their claims. Evidence is against dissenting scientists, because prospective, observational, and basic research studies indicate that sodium is the real villain: actual sodium consumption around the globe is far higher than the safe range. Sodium intake is directly related to increased blood pressure, and independently to the enlargement of cardiac mass, with a possible independent role in inducing left ventricular hypertrophy. This may represent the basis of myocardial ischemia, congestive heart failure, and cardiac mortality. Although debated, a high sodium intake may induce initial renal damage and progression in both hypertensive and normotensive subjects. Conversely, there is general agreement about the adverse role of sodium in cerebrovascular disease. These factors point to the possible main role of sodium intake in target organ damage and cardiovascular events including mortality. This review will endeavor to outline the existing evidence.

Temporal trend analysis of stroke and salt intake: a 15-year population-based study

Objectives: The aim of this study was to evaluate temporal trends of salt intake with stroke incidence, stroke subtypes, and blood pressure in an adult population.Methods: Data were extracted from Isfahan Salt Study. The stroke incidence rate, average salt intake, systolic and diastolic blood pressure in adults, aged over 18 years were considered from 2000 to 2014. The Average Annual Percent Changes (AAPC), parallelism, and the coincidence of trends were estimated, using a permutation test.Results: The trend of salt intake was increased from 2010 to 2014 (AAPC = +1.59, P-value = 0.004). The trend of the stroke incidence rate was nonlinear with two change points in 2003 and 2009. The overall stroke incidence rate increased by 6.65% per year (95% CI: 1.66, 11.8, P-value = 0.015). The temporal trend changes of stroke incidence rate were steeper in patients who aged 40-45 and over 50 years (+6 to +11.5%) than in patients who aged 19-40 and 45-50 (range: -3.3% to 0). The parallelism hypothesis of longitudinal changes between salt intake and ischemic stroke was accepted in patients, aged <50 years (P-value = 0.871).Conclusions: The average salt intake and its cone-shaped variance over 15 years of the study, indicated that salt intake reduction programs and policies were effective to stop associating intake increase until 2007, however, associated intake was increased since that time, which necessitates performing preventive programs. More importantly, the trend of salt intake and ischemic stroke was similar in patients who aged <50 years, regardless of considering their blood pressure.