Association between non-alcoholic fatty liver disease and autonomic dysfunction in a Chinese population

Assessment of sympathovagal balance by HRV analysis in alcoholic and nonalcoholic fatty liver disease patients

BACKGROUND

Heart rate variability (HRV) is the variation in the time intervals between continuous heartbeats also called interbeat intervals to give information related to the heart, blood pressure, gaseous exchange, and sympathetic and parasympathetic balance. Abnormalities in the conduction of the cardiac system alter the measurements of heart rate variability and lead to alteration in autonomic function with a higher risk of mortality. So, our objective includes the assessment of sympathovagal balance in AFLD and NAFLD patients.

MATERIALS AND METHODS

The study included 78 alcoholic and 54 nonalcoholic fatty liver patients. A room temperature of 23°C with 25-35% humidity will be maintained in a recording room. Basal supine heart rate and BP will be recorded by the oscillometric method using an automated blood pressure monitor Omron MX3, India. Lead II ECG will be recorded for the next 5 minutes in total resting condition for short-term HRV analysis. Short-term HRV indices including time domain and frequency domain were recorded from each patient. Under time domain, SDNN, RMSSD, and average RR were noted. Under frequency domain, LF, HF, VLF, LF (nu), HF (nu), and LF/HF were calculated. The data were collected by using a 16-bit, power lab 8/30 data acquisition system (New South Wales, Australia) with acknowledge 3.8.2 software. Inferential analyses such as independent t-tests and Mann-Whitney tests were used to compare NAFLD and AFLD patient groups. Carl Pearson correlation analysis was performed to obtain a relationship between variables.

RESULTS

SDNN in (ms) which represents the overall HRV found to be decreased in both alcoholic (32.84 ± 79.08) and nonalcoholic fatty liver disease (22.04 ± 13.85) compared to the normal range (50 ± 16)) from 27 studies. The value of RMSSD in (ms) was decreased in both alcoholic (17.00 ± 12.48) and nonalcoholic fatty liver disease patients (14.00 ± 9.44) with the normal range of (42 ± 15) from 15 studies. Pearson correlation analysis showed the age of AFLD patients significantly and positively correlated with average RR. Pearson correlation analysis for the age of NAFLD patients was significantly and positively correlated with the average RR, HF, SDNN, RMSSD, and LF.

CONCLUSION

Altered autonomic activity was noted in both alcoholic and nonalcoholic fatty liver disease patients. An early prognosis of fatty liver is very necessary to prevent the disease progress into later fatal life-threatening stages.

A systematic review and meta-analysis of cohort studies on the potential association between NAFLD/MAFLD and risk of incident atrial fibrillation

Background and objective

The association between atrial fibrillation (AF) and non-alcoholic fatty liver disease (NAFLD) or metabolic-associated fatty liver disease (MAFLD) has been explored in recent cohort studies, however, the results have been controversial and inconclusive. This meta-analysis aimed to explore this potential association.

Methods

We systematically searched PubMed, Embase, and Web of Science databases to identify all relevant cohort studies investigating the association between NAFLD/MAFLD and AF published from database inception to October 30, 2022. Random-effects models were utilized to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for summary purposes. Additionally, subgroup and sensitivity analyses were performed.

Results

A total of 13 cohort studies with 14 272 735 participants were included. Among these, 12 cohort studies with 14 213 289 participants (median follow-up of 7.8 years) showed a significant association between NAFLD and an increased risk of incident AF (HR = 1.18, 95% CI: 1.12-1.23, P < 0.00001). Our subgroup analyses mostly yielded similar results, and the results of sensitivity analyses remained unchanged. However, meta-analysis of data from 2 cohort studies with 59 896 participants (median follow-up of 2.15 years) showed that MAFLD was not linked to incident AF (HR = 1.36, 95% CI: 0.63-2.92, P = 0.44).

Conclusion

Current evidence shows that NAFLD may be linked to a slightly higher risk of developing AF, particularly among Asian populations and those diagnosed with NAFLD using FLI criteria. Nevertheless, there is not enough evidence to support the proposed association between MAFLD and an increased risk of AF. To better understand this relationship, future studies should consider factors such as specific population, the severity of NAFLD/MAFLD, diagnostic methods of NAFLD and AF, and cardiometabolic risk factors.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero, identifier CRD42022371503.

2019 Global NAFLD Prevalence: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

The increasing rates of obesity and type 2 diabetes mellitus may lead to increased prevalence of nonalcoholic fatty liver disease (NAFLD). We aimed to determine the current and recent trends on the global and regional prevalence of NAFLD.

METHODS

Systematic search from inception to March 26, 2020 was performed without language restrictions. Two authors independently performed screening and data extraction. We performed meta-regression to determine trends in NAFLD prevalence.

RESULTS

We identified 17,244 articles from literature search and included 245 eligible studies involving 5,399,254 individuals. The pooled global prevalence of NAFLD was 29.8% (95% confidence interval [CI], 28.6%-31.1%); of these, 82.5% of included articles used ultrasound to diagnose NAFLD, with prevalence of 30.6% (95% CI, 29.2%-32.0%). South America (3 studies, 5716 individuals) and North America (4 studies, 18,236 individuals) had the highest NAFLD prevalence at 35.7% (95% CI, 34.0%-37.5%) and 35.3% (95% CI, 25.4%-45.9%), respectively. From 1991 to 2019, trend analysis showed NAFLD increased from 21.9% to 37.3% (yearly increase of 0.7%, P < .0001), with South America showing the most rapid change of 2.7% per year, followed by Europe at 1.1%.

CONCLUSIONS

Despite regional variation, the global prevalence of NAFLD is increasing overall. Policy makers must work toward reversing the current trends by increasing awareness of NAFLD and promoting healthy lifestyle environments.

Heart failure with preserved ejection fraction and non-alcoholic fatty liver disease: new insights from bioinformatics

AIMS

Heart failure with preserved ejection fraction (HFpEF) and non-alcoholic fatty liver disease (NAFLD) are related conditions with an increasing incidence. The mechanism of their relationship remains undefined. Here, we aimed to explore the potential mechanisms, diagnostic markers, and therapeutic options for HFpEF and NAFLD.

METHODS AND RESULTS

HFpEF and NAFLD datasets were downloaded from the Gene Expression Omnibus (GEO) database. Common differentially expressed genes (DEGs) were screened for functional annotation. A protein-protein interaction network was constructed based on the STRING database, and hub genes were analysed using GeneMANIA annotation. ImmuCellAI (Immune Cell Abundance Identifier) was employed for analysis of immune infiltration. We also used validation datasets to validate the expression levels of hub genes and the correlation of immune cells. To screen for diagnostic biomarkers, we employed the least absolute shrinkage and selection operator and support vector machine-recursive feature elimination. Drug signature database was used to predict potential therapeutic drugs. Our analyses identified a total of 33 DEGs. Inflammation and immune infiltration played important roles in the development of both diseases. The data showed a close relationship between chemokine signalling pathway, cytokine-cytokine receptor interaction, calcium signalling pathway, neuroactive ligand-receptor interaction, osteoclast differentiation, and cyclic guanosine monophosphate-protein kinase G signalling pathway. We demonstrated that PRF1 (perforin 1) and IL2RB (interleukin-2 receptor subunit beta) proteins were perturbed by the diseases and may be the hub genes. The analysis showed that miR-375 may be a potential diagnostic marker for both diseases. Our drug prediction analysis showed that bosentan, eldecalcitol, ramipril, and probucol could be potential therapeutic options for the diseases.

CONCLUSIONS

Our findings revealed common pathogenesis, diagnostic markers, and therapeutic agents for HFpEF and NAFLD. There is need for further experimental studies to validate our findings.

Metabolic Dysfunction-Associated Fatty Liver Disease Increases the Risk of Gastroesophageal Reflux Symptoms

OBJECTIVE

The present study aimed to explore the relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and gastroesophageal reflux symptoms (GERS).

METHODS

The present study was a cross-sectional observational study. The study population was 3002 subjects from a single hospital who underwent a health checkup from September 1, 2019, to December 31, 2020. The diagnosis of MAFLD was based on the diagnosis of fatty liver in the subject by ultrasound or computed tomography (CT) and the presence of one of the following conditions: overweight or obesity (body mass index [BMI] ≥ 23), type 2 diabetes mellitus, and metabolic abnormalities. The subjects were divided into the GERS group (n = 305) and the non-GERS group (n = 2697) based on the presence or absence of GERS, based on the GerdQ score.

RESULTS

The prevalence of MAFLD was significantly higher in the GERS group than in the non-GERS group (p = 0.001). In the univariate analysis of risk factors for GERS, MAFLD was identified as a risk factor for GERS (OR 1.5; 95% CI 1.176-1.913; p = 0.001). With adjustment of confounding factors such as BMI, waist circumference, lipid levels, and blood pressure, the correlation between MAFLD and GERS was attenuated but still significant (OR 1.408; 95% CI 1.085-1.826; p = 0.010).

CONCLUSION

MAFLD might be an independent risk factor for GERS.

Hepatic Nervous System in Development, Regeneration, and Disease

The liver is innervated by autonomic and sensory fibers of the sympathetic and parasympathetic nervous systems that regulate liver function, regeneration, and disease. Although the importance of the hepatic nervous system in maintaining and restoring liver homeostasis is increasingly appreciated, much remains unknown about the specific mechanisms by which hepatic nerves both influence and are influenced by liver diseases. While recent work has begun to illuminate the developmental mechanisms underlying recruitment of nerves to the liver, evolutionary differences contributing to species-specific patterns of hepatic innervation remain elusive. In this review, we summarize current knowledge on the development of the hepatic nervous system and its role in liver regeneration and disease. We also highlight areas in which further investigation would greatly enhance our understanding of the evolution and function of liver innervation.

Early cardiac electrical and structural changes in patients with non-obese non-alcoholic fatty liver disease

Background    Obese non-alcoholic fatty liver disease (NAFLD) was found to increase the risk of developing atrial fibrillation (AF) regardless of the metabolic syndrome subgroups that may accompany it. In this study, the effect of NAFLD on the structural and electrical functions of the heart was investigated using tissue Doppler echocardiography (TDE) in non-obese NAFLD patients without any known risk factors for AF.Material and methods    The study included 43 female patients (31.3±3.8 years), who had stage 2-3 hepatosteatosis detected by liver ultrasonography and diagnosed as non-obese NAFLD (patient group), and 31 healthy women (control group, 32.5±3.6 years). In addition to standard echocardiographic parameters, inter- and intra-atrial electromechanical delay (EMD) were evaluated by TDE.Results    Interatrial EMD (PA lateral - PA tricuspid) and intraatrial EMD (PA septum - PA tricuspid) were significantly longer in patient group (16.1±3.4 vs. 12.5±2.3 ms, p&lt;0.001, and 8.4±1.6 vs. 6.6±1.6 ms, p&lt;0.001, respectively). At the subclinical level. atrial size, left ventricular diastolic function, and left ventricular wall thickness measurements were greater in the patient group.Conclusion    Inter-atrial and intra-atrial EMD were detected in young women with non-obese NAFLD. In addition, at the subclinical level, structural and functional impairment was detected However, large-volume prospective studies are required to cobfirm these findings regarding the development of AF in non-obese NAFLD patients.

Autonomic Imbalance Increases the Risk for Non-alcoholic Fatty Liver Disease

BACKGROUND

Although autonomic imbalance is associated with an increased risk for metabolic disease, its effects on nonalcoholic fatty liver disease (NAFLD) remains unclear. We aimed to evaluate whether autonomic dysfunction predicts the risk for nonalcoholic fatty liver disease (NAFLD).

METHODS

A total of 33,899 participants without NAFLD who underwent health screening programs between 2011 and 2018 were enrolled. NAFLD was identified by ultrasonography. Autonomic activity was estimated using heart rate variability (HRV). Time domain [standard deviation of the normal-to-normal interval (SDNN) and root mean square difference (RMSSD)]; frequency domain [total power (TP), low frequency (LF), and high frequency (HF), and LF/HF ratio were analyzed.

FINDINGS

A total 6,466 participants developed NAFLD within a median of 5.7 years. Subjects with incident NAFLD showed decreased overall autonomic modulation and vagal activity with lowered SDNN, RMSSD, HF, normalized HF, compared to those without NAFLD. As the SDNN, RMSSD, TP, LF, and HF tertiles increased, the risk of NAFLD decreased with tertile 1 being the reference group [the hazard ratios (95% confidence intervals) of tertile 3 were 0.90 (0.85-0.96), 0.83 (0.78-0.88), 0.91 (0.86-0.97), 0.93 (0.87-0.99) and 0.89 (0.83-0.94), respectively] after adjusting for potential confounders. The risk for NAFLD was significantly higher in subjects in whom sustained elevated heart rate, normalized LF, and LF/HF ratio values than in those with sustained decrease in these parameters during follow-up.

CONCLUSIONS

Overall autonomic imbalance, decreased parasympathetic activity, and recently increased sympathetic activity might increase the risk of NAFLD.

Association of worsening of nonalcoholic fatty liver disease with cardiometabolic function and intestinal bacterial overgrowth: A cross-sectional study

Background & aims

Non-alcoholic fatty liver disease (NAFLD) has been associated with small bowel bacterial overgrowth (SIBO) and cardiometabolic dysfunction. This cross-sectional study aimed to evaluate the cardio-metabolic parameters and SIBO in patients with different degrees of hepatic fibrosis estimated by NAFLD fibrosis score (NFS).

Methods

Subjects (n = 78) were allocated to three groups: Healthy control (n = 30), NAFLD with low risk of advanced fibrosis (NAFLD-LRAF, n = 17) and NAFLD with a high risk of advanced fibrosis (NAFLD-HRAF, n = 31). Anthropometrics, blood pressure, electrocardiogram and heart rate variability (HRV) were evaluated. Only the NAFLD-LRAF and NAFLD-HRAF groups were submitted to blood biochemical analysis and glucose hydrogen breath tests.

Results

The NAFLD-HRAF group had higher age and body mass index when compared to the control and NAFLD-LRAF groups. The prevalence of SIBO in the NAFLD group was 8.33%. The low frequency/high-frequency ratio (LF/HF ratio) was augmented in NAFLD-LRAF (p < 0.05) when compared with control group. NAFLD-HRAF group had a wide QRS complex (p < 0.05) and reduced LF/HF ratio (p < 0.05) compared to the control and NAFLD-LRAF groups. Serum levels of albumin and platelets were more reduced in the NAFLD-HRAF subjects (p < 0.05) than in the NAFLD-LRAF.

Conclusions

NAFLD impairs cardiac autonomic function. Greater impairment was found in subjects with a worse degree of hepatic fibrosis estimated by NFS. Hypoalbuminemia and thrombocytopenia were higher in subjects with a worse degree of hepatic fibrosis, whereas prevalence of SIBO positive was similar between the groups.

Gastrointestinal and liver diseases and atrial fibrillation: a review of the literature

Atrial fibrillation (AF) is the most common arrhythmia worldwide and is associated with significant morbidity and mortality. A number of risk factors have been associated with AF, though few studies have explored the association between gastrointestinal and liver diseases and AF. Additionally, AF and treatment for AF may predispose to gastrointestinal and liver diseases. We review the current literature on the bidirectional associations between gastrointestinal and liver diseases and AF. We highlight the gaps in knowledge and areas requiring future investigation.

Does resistance training modulate cardiac autonomic control? A systematic review and meta-analysis

PURPOSE

To systematically evaluate the literature on the effects of resistance training (RT) on cardiac autonomic control in healthy and diseased individuals.

METHODS

Electronic databases Pubmed, PEDro, and Scopus were systematically searched from their inception up to June 2018. Randomized controlled trials, quasi-experimental trials, and cross-over controlled trials investigating the effect of RT (of at least 4 weeks duration) on cardiac autonomic control assessed either by linear or non-linear measures of heart rate variability (HRV), baroreflex sensitivity, or post-exercise heart rate recovery were included. Of the studies retrieved, 28 were included in the systematic review. Meta-analysis was performed on 21 studies of the total 28 studies.

RESULTS

Quality and characteristic assessment revealed fair quality evidence. The majority of literature on healthy humans suggested no change in cardiac autonomic control following RT. Standardized mean differences (SMD) showed a significant effect of RT on root mean square of successive differences between adjacent inter-beat (R-R) intervals (RMSSD) [SMD 0.96, 95% confidence interval (CI) 0.20-1.73; p = 0.01], ratio of low- to high-frequency power of HRV (LF/HF ratio; SMD -0.72, 95% CI -1.03 to -0.42; p < 0.00001), standard deviation of the instantaneous beat-to-beat variability (SD1; SMD 1.78, 95% CI 1.07-2.49, p < 0.00001), and sample entropy (SMD 1.17, 95% CI 0.36-1.97, p = 0.005) in diseased individuals.

CONCLUSION

This rigorous systematic analysis revealed that RT has no or minimal effects on cardiac autonomic control of healthy individuals, but RT leads to improvement in cardiac autonomic control of diseased individuals.

Nonalcoholic Fatty Liver Disease Is Associated with Increased Atrial Fibrillation Risk in an Elderly Chinese Population: A Cross-Sectional Study

Background

Atrial fibrillation and nonalcoholic fatty liver disease are two pathological conditions that are highly prevalent worldwide and share multiple CVD risk factors. There are rare researches performed among elderly adults.

Aims

We conducted this cross-sectional analysis of elderly adults (≥65 years) to investigate the association between atrial fibrillation and nonalcoholic fatty liver disease.

Methods

We analyzed clinical data of the elderly adults (≥ 65 years) who had health examination in Zhenhai Lianhua Hospital, Ningbo, China, in 2014.

Results

522 of the 1688 participants were diagnosed with nonalcoholic fatty liver disease, and 39 participants were diagnosed as having atrial fibrillation. Nonalcoholic fatty liver disease was associated with risk factors for AF in the elderly Chinese population (OR 1.95, 95% CI 1.03-3.69). Adjustments for age, gender, systolic blood pressure, fasting plasma glucose, γ-glutamyl transpeptidase, high-density lipoprotein, triglycerides, total cholesterol and albumin, nonalcoholic fatty liver disease, and prevalent atrial fibrillation remained statistically significant (OR 2.76, 95% CI 1.32-5.77).

Conclusions

Our results show that nonalcoholic fatty liver disease is associated with an increased risk of atrial fibrillation in an elderly Chinese population.

The Role of Nonalcoholic Fatty Liver Disease on Cardiovascular Manifestations and Outcomes

Cardiovascular disease has been postulated as the leading cause of mortality among patients with nonalcoholic fatty liver disease (NAFLD), rather than from sequalae of liver disease specifically. While there is ample evidence validating the association between NAFLD and increased cardiovascular comorbidities, events, and mortality, current data presents a challenge in attributing this effect solely due to NAFLD given the rampant presence of insulin resistance and type 2 diabetes mellitus (T2DM). Endpoints of increased cardiovascular risk remains tightly linked to the concomitant presence of insulin resistance and T2DM. Prospective studies accentuating early detection of NAFLD are imperative to institute early intervention and prevent future cardiovascular events.

The association between non-alcoholic fatty liver disease and atrial fibrillation: A meta-analysis

BACKGROUND/OBJECTIVES

The association between non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF) has been suggested by recent epidemiological studies although the results were inconsistent. This meta-analysis was conducted to summarize all available data.

METHODS

A comprehensive literature review was conducted using MEDLINE and EMBASE database through May 2017 to identify all studies that reported the risk of AF among patients with NAFLD versus those without NAFLD. Effect estimates from each study were extracted and combined together using the random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Of 1009 studies, 5 studies (two cross-sectional studies and three cohort studies) with 238,129 participants met the eligibility criteria and were included in the meta-analysis. The risk of AF in patients with NAFLD was significantly higher than subjects without NAFLD with the pooled risks ratio of 2.06 (95% confidence interval, 1.10-3.85). The statistical heterogeneity was high with an I² of 78%, which was the major limitation of this meta-analysis.

CONCLUSIONS

A significantly increased risk of AF among patients with NAFLD was demonstrated in this study.

Relations of Liver Fat With Prevalent and Incident Atrial Fibrillation in the Framingham Heart Study

Background

Obesity is an important risk factor for nonalcoholic fatty liver disease and atrial fibrillation (AF). Less is known about the relations between nonalcoholic fatty liver disease and AF. We sought to evaluate the association between fatty liver and prevalent and incident AF in the community.

Methods and Results

We examined Framingham Heart Study participants who underwent a study‐directed computed tomography scan, had hepatic steatosis (HS) evaluated, and did not report heavy alcohol use between 2002 and 2005. We evaluated cross‐sectional associations between liver fat and prevalent AF with logistic regression models. We assessed the relations between liver fat and incident AF during 12‐year follow‐up with Cox proportional hazards models. Of 2122 participants (53% women; mean age, 59.0±9.6 years), 20% had HS. AF prevalence (n=62) among individuals with HS was 4% compared to 3% among those without HS. There was no significant association between HS (measured as continuous or dichotomous variables) and prevalent AF in age‐ and sex‐adjusted or multivariable‐adjusted models. Incidence of AF (n=153) among participants with and without HS was 8.7 cases and 7.8 cases per 1000 person‐years, respectively. In age‐ and sex‐adjusted and multivariable‐adjusted models, there were no significant associations between continuous or dichotomous measures of HS and incident AF.

Conclusions

In our community‐based, longitudinal cohort study, liver fat by computed tomography scan was not significantly associated with increased prevalence or incidence of AF over 12 years of follow‐up.

Link Between Non-Alcoholic Fatty Liver Disease and Atrial Fibrillation: A Systematic Review and Meta-Analysis

Association between non-alcoholic fatty liver disease (NAFLD) and various cardiovascular diseases has been demonstrated previously. Recent clinical studies have shown that increased circulating levels of γ glutamyl transpeptidase and liver transaminase, markers which are elevated in NAFLD, increase the risk of new-onset atrial fibrillation. We conducted a systematic review and meta-analysis of the available evidence to establish the possible association of increased chances of atrial fibrillation in patients with NAFLD. We extensively searched the PubMed, EMBASE, Cochrane Library, ISI Web of Science and Scopus databases to identify all possible studies that investigated the possible association of NAFLD with atrial fibrillation. Random effect models were used to pool the data between NAFLD and non-NAFLD group. I² testing was done to assess the heterogeneity of the included studies. Our primary outcome was atrial fibrillation. A total of three studies including 1044 patients in the NAFLD arm and 1016 in the placebo arm were included. On pooled analysis, it was observed that patients with NAFLD had 2.5 times significantly higher chance (OR = 2.47, CI = 1.30-4.66, p = 0.005) of developing new-onset atrial fibrillation. Our meta-analysis identifies the paucity of high-quality evidence regarding the association between NAFLD and atrial fibrillation. More studies are needed to confirm the link between NAFLD and atrial fibrillation.

Association between gastroesophageal reflux disease and nonalcoholic fatty liver disease: A meta-analysis

BACKGROUND/AIM

The relationship between gastroesophageal reflux disease (GERD) and nonalcoholic fatty liver disease (NAFLD) has been demonstrated in recent epidemiologic studies although the results were inconsistent. This meta-analysis was conducted to summarize all available data and to estimate the risk of NAFLD among patients with GERD.

MATERIALS AND METHODS

Comprehensive literature review was conducted using MEDLINE and EMBASE database from inception through November 2016, to identify studies that compared the risk of NAFLD among patients with GERD versus those without GERD. Effect estimates from each study were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird.

RESULTS

Eight studies (four cross-sectional studies and four case-control studies) with 31,322 participants met the eligibility criteria and were included in the meta-analysis. The risk of NAFLD among patients with GERD was significantly higher than those without GERD with the pooled odds ratio of 2.07 (95% confidence interval, 1.54-2.79). The statistical heterogeneity was high with an I2 of 87%.

CONCLUSIONS

A significantly increased risk of NAFLD among patients with GERD was observed in this meta-analysis.

Cardiovascular Disease and Myocardial Abnormalities in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in many developed countries, affecting an estimated 30 % of the adult population. In this updated clinical review, we summarize the current knowledge regarding the strong association between NAFLD and the risk of coronary heart disease (CHD) and other functional, structural, and arrhythmic cardiac complications (e.g., left ventricular dysfunction, heart valve diseases and atrial fibrillation). We also briefly discuss the putative biological mechanisms linking NAFLD with these important extra-hepatic complications. To date, a large body of evidence has suggested that NAFLD is not simply a marker of CHD and other functional, structural, and arrhythmic cardiac complications, but also may play a part in the development and progression of these cardiac complications. The clinical implication of these findings is that patients with NAFLD may benefit from more intensive surveillance and early treatment interventions aimed at decreasing the risk of CHD and other cardiac and arrhythmic complications.

Association between Dietary Vitamin C Intake and Non-Alcoholic Fatty Liver Disease: A Cross-Sectional Study among Middle-Aged and Older Adults

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become one of the most prevalent chronic liver disease all over the world. The objective of this study was to evaluate the association between dietary vitamin C intake and NAFLD.

METHOD

Subjects were diagnosed with NAFLD by abdominal ultrasound examination and the consumption of alcohol was less than 40g/day for men or less than 20g/day for women. Vitamin C intake was classified into four categories according to the quartile distribution in the study population: ≤74.80 mg/day, 74.81-110.15 mg/day, 110.16-146.06 mg/day, and ≥146.07 mg/day. The energy and multi-variable adjusted odds ratio (OR), as well as their corresponding 95% confidence interval (CI), were used to determine the relationship between dietary vitamin C intake and NAFLD through logistic regression.

RESULT

The present cross-sectional study included 3471 subjects. A significant inverse association between dietary vitamin C intake and NAFLD was observed in the energy-adjusted and the multivariable model. The multivariable adjusted ORs (95%CI) for NAFLD were 0.69 (95%CI: 0.54-0.89), 0.93 (95%CI: 0.72-1.20), and 0.71 (95%CI: 0.53-0.95) in the second, third and fourth dietary vitamin C intake quartiles, respectively, compared with the lowest (first) quartile. The relative odds of NAFLD was decreased by 0.71 times in the fourth quartile of dietary vitamin C intake compared with the lowest quartile. After stratifying data by sex or the status of obesity, the inverse association remained valid in the male population or non-obesity population, but not in the female population or obesity population.

CONCLUSION

There might be a moderate inverse association between dietary vitamin C intake and NAFLD in middle-aged and older adults, especially for the male population and non-obesity population.

Cardiovascular Autonomic Dysfunction in Patients of Nonalcoholic Fatty Liver Disease

Aim. The present study was designed to evaluate the heart rate variability (HRV) in nonalcoholic fatty liver disease (NAFLD) and to assess the effect of grade of NAFLD and diabetic status on HRV. Methods. This cross-sectional study included 75 subjects (25 NAFLD without diabetes, 25 NAFLD with diabetes, and 25 controls). Measurements included anthropometry, body composition analysis, estimation of plasma glucose, serum lipids, hsCRP, and serum insulin. HRV analysis was performed in both time and frequency domains. Results. The time and frequency domain indices of overall variability (SDNN, total power) were significantly lower in NAFLD with diabetes as compared to the controls. However, the LF : HF ratio did not differ among the three groups. The variables related to obesity, lipid profile, and glucose metabolism were also higher in NAFLD with diabetes and those with Grade II NAFLD without diabetes, as compared to controls. Multivariate stepwise regression analysis showed a negative correlation between HRV and total cholesterol and fat percentage. Conclusion. The grade of NAFLD as well as diabetic status contributes to the decrease in the cardiovascular autonomic function, with diabetic status rather than grade of NAFLD playing a critical role. Serum lipids and adiposity may also contribute to cardiac autonomic dysfunction.

Non-Alcoholic Fatty Liver Disease as a Predictor of Atrial Fibrillation in Middle-Aged Population (OPERA Study)

Non-alcoholic fatty liver disease (NAFLD) and atrial fibrillation (AF) are widespread diseases and have multiple common risk factors and comorbidities. No studies of association between ultrasonography-diagnosed NAFLD and AF exist in other than diabetic population. The goal of this prospective study was to study the value of NAFLD as a predictor of atrial fibrillation. This study had 958 subjects from the OPERA (Oulu Project Elucidating Risk of Atherosclerosis) cohort, and the mean follow-up time was 16.3 years. NAFLD was diagnosed if the subject had fatty liver in ultrasonography and no excess alcohol intake. AF was followed in the National Registers. In this study 249 subjects (26.0%) had NAFLD and 37 (14.9%) of these had AF whereas only 56 (7.9%) of those without NAFLD experienced AF during the follow-up time (p = 0.001). In the multiple Cox regression analysis including potential confounders (age, sex, study group, diabetes, body mass index (BMI), waist circumference, alcohol consumption, smoking, serum alanine aminotransferase concentration (ALT), systolic blood pressure, quick index, left ventricular mass index, left atrial diameter, coronary artery disease (CAD), atrial natriuretic peptide (ANP) and high sensitive C-reactive protein (hs-CRP)), NAFLD remained as an independent predictor of AF (Adjusted OR, 1.88 (95% Confidence interval (CI) 1.03-3.45)). In conclusion, our data shows that NAFLD is independently associated with the risk of AF.

Non-alcoholic fatty liver disease as a consequence of autonomic imbalance and circadian desynchronization

The circadian system, headed by the suprachiasmatic nucleus, synchronizes behaviour and metabolism according to the external light-dark cycle through neuroendocrine and autonomic signals. Metabolic diseases, such as steatosis, obesity and glucose intolerance, have been associated with conditions of circadian misalignment wherein the feeding schedule has been moved to the resting phase. Here we describe the physiological processes involved in liver lipid accumulation and show how they follow a circadian pattern importantly regulated by both the autonomic nervous system and the feeding-fasting cycle. We propose that an unbalanced activity of the sympathetic-parasympathetic branches between organs induced by circadian misalignment provides the conditions for the development and progression of non-alcoholic fatty liver disease.