Association between Non-Alcoholic Fatty Liver Disease and Dietary Habits, Stress, and Health-Related Quality of Life in Korean Adults

Intermittent fasting and the liver: Focus on the Ramadan model

Intermittent fasting (IF) is an intervention that involves not only dietary modifications but also behavioral changes with the main core being a period of fasting alternating with a period of controlled feeding. The duration of fasting differs from one regimen to another. Ramadan fasting (RF) is a religious fasting for Muslims, it lasts for only one month every one lunar year. In this model of fasting, observers abstain from food and water for a period that extends from dawn to sunset. The period of daily fasting is variable (12-18 hours) as Ramadan rotates in all seasons of the year. Consequently, longer duration of daily fasting is observed during the summer. In fact, RF is a peculiar type of IF. It is a dry IF as no water is allowed during the fasting hours, also there are no calorie restrictions during feeding hours, and the mealtime is exclusively nighttime. These three variables of the RF model are believed to have a variable impact on different liver diseases. RF was evaluated by different observational and interventional studies among patients with non-alcoholic fatty liver disease and it was associated with improvements in anthropometric measures, metabolic profile, and liver biochemistry regardless of the calorie restriction among lean and obese patients. The situation is rather different for patients with liver cirrhosis. RF was associated with adverse events among patients with liver cirrhosis irrespective of the underlying etiology of cirrhosis. Cirrhotic patients developed new ascites, ascites were increased, had higher serum bilirubin levels after Ramadan, and frequently developed hepatic encephalopathy and acute upper gastrointestinal bleeding. These complications were higher among patients with Child class B and C cirrhosis, and some fatalities occurred due to fasting. Liver transplant recipients as a special group of patients, are vulnerable to dehydration, fluctuation in blood immunosuppressive levels, likelihood of deterioration and hence observing RF without special precautions could represent a real danger for them. Patients with Gilbert syndrome can safely observe RF despite the minor elevations in serum bilirubin reported during the early days of fasting.

Diagnostic indicators and lifestyle interventions of metabolic-associated fatty liver disease

MAFLD has become a major global health problem and is the leading cause of liver disease worldwide. The disease progresses from a simple fatty liver to gradual fibrosis, which progresses to cirrhosis and even hepatocellular liver cancer. However, the methods currently used for diagnosis are invasive and do not facilitate clinical assessment of the condition. As a result, research on markers for the diagnosis of MAFLD is increasing. In addition, there are no clinical medications for the treatment of MAFLD, and lifestyle interventions remain effective in the prevention and treatment of MAFLD. In this review, we attempt to make a summary of the emerging diagnostic indicators and effective lifestyle interventions for MAFLD and to provide new insights into the diagnosis and treatment of MAFLD.

Timing of energy intake and the therapeutic potential of intermittent fasting and time-restricted eating in NAFLD

Non-alcoholic fatty liver disease (NAFLD) represents a major public health concern and is associated with a substantial global burden of liver-related and cardiovascular-related morbidity and mortality. High total energy intake coupled with unhealthy consumption of ultra-processed foods and saturated fats have long been regarded as major dietary drivers of NAFLD. However, there is an accumulating body of evidence demonstrating that the timing of energy intake across a the day is also an important determinant of individual risk for NAFLD and associated metabolic conditions. This review summarises the available observational and epidemiological data describing associations between eating patterns and metabolic disease, including the negative effects of irregular meal patterns, skipping breakfast and night-time eating on liver health. We suggest that that these harmful behaviours deserve greater consideration in the risk stratification and management of patients with NAFLD particularly in a 24-hour society with continuous availability of food and with up to 20% of the population now engaged in shiftwork with mistimed eating patterns. We also draw on studies reporting the liver-specific impact of Ramadan, which represents a unique real-world opportunity to explore the physiological impact of fasting. By highlighting data from preclinical and pilot human studies, we present a further biological rationale for manipulating timing of energy intake to improve metabolic health and discuss how this may be mediated through restoration of natural circadian rhythms. Lastly, we comprehensively review the landscape of human trials of intermittent fasting and time-restricted eating in metabolic disease and offer a look to the future about how these dietary strategies may benefit patients with NAFLD and non-alcoholic steatohepatitis.

MCD Diet Modulates HuR and Oxidative Stress-Related HuR Targets in Rats

The endogenous antioxidant defense plays a big part in the pathogenesis of non-alcoholic fatty liver disease (NAFLD), a common metabolic disorder that can lead to serious complications such as cirrhosis and cancer. HuR, an RNA-binding protein of the ELAV family, controls, among others, the stability of MnSOD and HO-1 mRNA. These two enzymes protect the liver cells from oxidative damage caused by excessive fat accumulation. Our aim was to investigate the expression of HuR and its targets in a methionine-choline deficient (MCD) model of NAFLD. To this aim, we fed male Wistar rats with an MCD diet for 3 and 6 weeks to induce NAFLD; then, we evaluated the expression of HuR, MnSOD, and HO-1. The MCD diet induced fat accumulation, hepatic injury, oxidative stress, and mitochondrial dysfunction. A HuR downregulation was also observed in association with a reduced expression of MnSOD and HO-1. Moreover, the changes in the expression of HuR and its targets were significantly correlated with oxidative stress and mitochondrial injury. Since HuR plays a protective role against oxidative stress, targeting this protein could be a therapeutic strategy to both prevent and counteract NAFLD.

Sodium intake trend and current intake level by meal provision place among the citizens of Seoul

BACKGROUND/OBJECTIVES

The diversity of meal provision places has increased in recent years and sodium intake can vary depending on where meals are eaten, particularly in large cities. In this study, an analysis of the recent trends in sodium intake was performed and a comparison of sodium intake level according to meal provision place among citizens of Seoul was performed.

SUBJECTS/METHODS

Data from a 24-h recall dietary intake survey from the 2010-2019 Korea National Health and Nutrition Examination Survey (KNHANES) were used in order to determine the trends in sodium intake among citizens of Seoul, aged 3-74 years old. (n = 11,811). The trend of daily sodium intake was presented in absolute amount and proportion compared to the chronic disease risk reduction intake (CDRR) for each selected characteristic. A comparison of sodium intake level according to meal provision place by sex and age groups as a total amount per meal (mg), density per meal (mg/1,000 kcal), and proportion of the daily sodium intake was performed using the 2016-2019 KNHANES.

RESULTS

Sodium intake levels showed a downward trend from 2010-2019. The highest level of sodium intake was observed for subjects aged 30-49, and the level for males aged 30-49 was 202.8% higher than the CDRR. Results of the analysis of sodium intake per meal according to meal provision place showed that the highest sodium intake was in the order of restaurant meal (RM) > institutional foodservice (IF) > home meal (HM) > convenience food (CF). A higher sodium density (mg/1,000 kcal) was observed for IF compared with RM in most adults. Adults aged over 50 years old consumed more than half of the daily sodium in HM.

CONCLUSION

Significant variation in the level of sodium intake was observed according to sex and age groups, therefore, different approaches and nutrition policies based on meal provision place are needed.

The association between perceived stress, acculturation, and non-alcoholic fatty liver disease in Mexican-origin adults in Southern Arizona

Although available evidence indicates that Mexican-origin (MO) adults experience unique stressful life events, little is known about how stress may influence risk for developing non-alcoholic fatty liver disease (NAFLD) for this high-risk group. This study investigated the association between perceived stress and NAFLD and explored how this relationship varied by acculturation levels. In a cross-sectional study, a total of 307 MO adults from a community-based sample in the U.S-Mexico Southern Arizona border region completed self-reported measures of perceived stress and acculturation. NAFLD was identified as having a continuous attenuation parameter (CAP) score of ≥ 288 dB/m determined by FibroScan®. Logistic regression models were fitted to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) for NAFLD. The prevalence of NAFLD was 50 % (n = 155). Overall, perceived stress was high (Mean = 15.9) for the total sample. There were no differences by NAFLD status (No NAFLD: Mean = 16.6; NAFLD: Mean = 15.3; p = 0.11). Neither perceived stress nor acculturation were associated with NAFLD status. However, the association between perceived stress and NAFLD was moderated by acculturation levels. Specifically with each point increase in perceived stress, the odds of having NAFLD were 5.5 % higher for MO adults with an Anglo orientation and 1.2 % higher for bicultural MO adults. In contrast, the odds of NAFLD for MO adults with a Mexican cultural orientation were 9.3 % lower with each point increase in perceived stress. In conclusion, results highlight the need for additional efforts to fully understand the pathways through which stress and acculturation may influence the prevalence of NAFLD in MO adults.

MPEP Attenuates Intrahepatic Fat Accumulation in Obese Mice

The blockade of metabotropic glutamate receptor type 5 (mGluR5) was previously found to reduce fat accumulation in HEPG2 cells. Here, we evaluated the effects of mGluR5 blockade in a mouse model of steatosis. Male ob/ob mice fed a high-fat diet were treated with MPEP or vehicle. After 7 weeks, liver biopsies were collected, and nuclei were isolated from fresh tissue. Lipid droplet area and collagen deposition were evaluated on tissue slices; total lipids, lipid peroxidation, and ROS were evaluated on tissue homogenates; PPARα, SREBP-1, mTOR, and NF-κB were assayed on isolated nuclei by Western Blot. Target genes of the above-mentioned factors were assayed by RT-PCR. Reduced steatosis and hepatocyte ballooning were observed in the MPEP group with respect to the vehicle group. Concomitantly, increased nuclear PPARα and reduced nuclear SREBP-1 levels were observed in the MPEP group. Similar trends were obtained in target genes of PPARα and SREBP-1, Acox1 and Acc1, respectively. MPEP administration also reduced oxidative stress and NF-κB activation, probably via NF-κB inhibition. Levels of common markers of inflammation (Il-6, Il1β and Tnf-α) and oxidative stress (Nrf2) were significantly reduced. mTOR, as well as collagen deposition, were unchanged. Concluding, MPEP, a selective mGluR5 negative allosteric modulator, reduces both fat accumulation and oxidative stress in a 7-week murine model of steatosis. Although underlying mechanisms need to be further investigated, this is the first in vivo study showing the beneficial effects of MPEP in a murine model of steatosis.

Time-restricted feeding affects transcriptomic profiling of hypothalamus in pigs through regulating aromatic amino acids metabolism

BACKGROUND

Time-restricted feeding (TRF) is an effective means that can efficiently regulate the metabolism and health of animals and humans. However, the effect of TRF on hypothalamic function remains unclear.

RESULTS

Results showed that TRF significantly increased the activities of digestive enzymes lipase, maltase in the duodenum and lipase, trypsin in the pancreas whereas significantly decreased serum gastrointestinal hormones gastrin, glucagon-like peptide-1, cholecystokinin, peptide YY, and ghrelin. Metabolites related to amino acid metabolism, including citrulline, kynurenine, N-acetylleucine, l-tryptophan, and l-tyrosine, significantly increased in the TRF group. Differential metabolites were mainly enriched in phenylalanine, tyrosine, and tryptophan biosynthesis and tryptophan metabolism. Transcriptomic analysis of hypothalamus showed that a total of 462 differentially expressed genes (DEGs) were significantly changed by TRF. In particular, DEGs such as DDC, TH, GOT2, and DBH involved in aromatic amino acid metabolism pathways were significantly downregulated, whereas the expression of CYP1B1 was significantly upregulated. Moreover, DEGs (PDYN and PPP3CA) involved in amphetamine addiction and cocaine addiction were also downregulated in the TRF group.

CONCLUSION

Taken together, these results suggested that TRF improved the digestion and absorption of nutrients and thus increased the accessibilities of aromatic amino acids. The increasing of circulating aromatic amino acids might mediate the regulatory neuroendocrine effects of TRF regimes on the hypothalamus functions, especially on drug addictions. This study reveals a possible mechanism underlying the effects of regulating feeding patterns on the function of the hypothalamus by altering aromatic amino acids metabolism. © 2022 Society of Chemical Industry.

Support Needs and Coping Strategies in Non-Alcoholic Fatty Liver Disease (NAFLD): A Multidisciplinary Approach to Potential Unmet Challenges beyond Pharmacological Treatment

Non-alcoholic fatty liver disease (NAFLD) is the most frequently occurring chronic liver disease, affecting approximately 25–30% of the adult general population worldwide. NAFLD reflects excess hepatic accumulation of fat in the absence of increased alcohol intake, and, due to its close association with obesity, is frequently referred to as the ‘hepatic manifestation’ of metabolic syndrome. Indeed, a high percentage of individuals with NAFLD present with a combination of the cardio-metabolic comorbidities that are associated with the metabolic syndrome. In addition to its well-established link with the metabolic syndrome and increased risk for cardiovascular disease, NAFLD has also been associated with certain mental health issues (e.g., depression and stress). Although this link is now being increasingly recognized, there are still unmet needs regarding the holistic management of patients with NAFLD, which could further contribute to feelings of social isolation and loneliness. The latter conditions are also increasingly reported to pose a substantial risk to overall health and quality of life. To date, there is limited research that has explored these issues among patients with NAFLD, despite existing data which indicate that perceived loneliness and isolation may pose an additional health risk. Notably, many features associated with NAFLD have been related to these concepts, such as perceived stigma, fatigue, stress, and confusion regarding this diagnosis. As such, this review aimed to assess such potential problems faced by patients with NAFLD, and to explore the possibility of unmet support needs which could lead to perceived social isolation. Moreover, the importance of a compassionate approach towards such patients is discussed, together with potential coping strategies. Future research directions and the need for a multidisciplinary approach are also highlighted.

Non-Alcoholic Fatty Liver Disease (NAFLD) and Potential Links to Depression, Anxiety, and Chronic Stress

Non-alcoholic fatty liver disease (NAFLD) constitutes the most common liver disease worldwide, and is frequently linked to the metabolic syndrome. The latter represents a clustering of related cardio-metabolic components, which are often observed in patients with NAFLD and increase the risk of cardiovascular disease. Furthermore, growing evidence suggests a positive association between metabolic syndrome and certain mental health problems (e.g., depression, anxiety, and chronic stress). Given the strong overlap between metabolic syndrome and NAFLD, and the common underlying mechanisms that link the two conditions, it is probable that potentially bidirectional associations are also present between NAFLD and mental health comorbidity. The identification of such links is worthy of further investigation, as this can inform more targeted interventions for patients with NAFLD. Therefore, the present review discusses published evidence in relation to associations of depression, anxiety, stress, and impaired health-related quality of life with NAFLD and metabolic syndrome. Attention is also drawn to the complex nature of affective disorders and potential overlapping symptoms between such conditions and NAFLD, while a focus is also placed on the postulated mechanisms mediating associations between mental health and both NAFLD and metabolic syndrome. Relevant gaps/weaknesses of the available literature are also highlighted, together with future research directions that need to be further explored.

The effects of Ramadan intermittent fasting on liver function in healthy adults: A systematic review, meta-analysis, and meta-regression

INTRODUCTION

Growing evidence is suggestive that intermittent fasting likely to improve liver function; however, still the evidences are controversial to draw a definitive conclusion. Therefore, we conducted a systematic review and meta-analysis to estimate the effect size for changes in liver function tests (LFT) in healthy people practicing Ramadan diurnal intermittent fasting (RDIF), and to examine the impact of different covariates using subgroup analysis and meta-regression.

METHODS

Scientific databases were searched from date of inception in 1950 to the end of July 2020. The liver function tests searched and analyzed were aspartate transaminase (AST), alanine transaminase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), bilirubin (BLU), L-lactate dehydrogenase (LDH) and prothrombin time (PT).

RESULTS

Twenty studies (601 adult participants in total, aged 18-57 years) conducted in 10 countries between 1987 and 2020 were identified. RDIF-induced effect sizes for the LFT expressed as standardized mean difference (SMD) [95% confidence interval] were: AST (no. of studies K = 16, number of subjects N = 502, SMD = -0.257 [-0.381, -0.133], I² = 42%); ALT (K = 16, N = 502, SMD = -0.105 [-0.282, 0.07], I² = 71%); GGT (K = 2, N = 46, SMD = -0.533 [-0.842, -0.224], I² = 0%); ALP (K = 10, N = 312, SMD = -0.318 [-0.432, -0.204], I² = 0.0%); BLU (K = 10, N = 325, SMD = -0.264 [-0.520, -0.007], I² = 70.1%); LDH (K = 5, N = 145, SMD = -0.041 [-0.380, 0.298], I² = 72%); PT (K = 2, N = 74, SMD = -0.027 [-0.732, 0.678], I² = 87%).

CONCLUSION

RDIF induces significant but small (AST, ALP, BLU) to medium (GGT) positive changes on LFT, and may confer a transient, short-term protection against fatty liver disease in healthy subjects.

Retinoic Acid: A New Old Friend of IL-17A in the Immune Pathogeny of Liver Fibrosis

Despite all the medical advances mortality due to cirrhosis and hepatocellular carcinoma, the end stages of fibrosis, continuously increases. Recent data suggest that liver fibrosis is guided by type 3 inflammation with IL-17A at the top of the line. The storage of vitamin A and its active metabolites, as well as genetics, can influence the development and progression of liver fibrosis and inflammation. Retinoic acid (active metabolite of vitamin A) is able to regulate the differentiation of IL-17A⁺/IL-22–producing cells as well as the expression of profibrotic markers. IL-17A and its pro-fibrotic role in the liver is the most studied, while the interaction and communication between IL-17A, IL-22, and vitamin A–active metabolites has not been investigated. We aim to update what is known about IL-17A, IL-22, and retinoic acid in the pathobiology of liver diseases.

Beyond the Paradigm of Weight Loss in Non-Alcoholic Fatty Liver Disease: From Pathophysiology to Novel Dietary Approaches

Current treatment recommendations for non-alcoholic fatty liver disease (NAFLD) rely heavily on lifestyle interventions. The Mediterranean diet and physical activity, aiming at weight loss, have shown good results in achieving an improvement of this liver disease. However, concerns related to compliance and food accessibility limit the feasibility of this approach, and data on the long-term effects on liver-related outcomes are lacking. Insulin resistance is a central aspect in the pathophysiology of NAFLD; therefore, interventions aiming at the improvement of insulin sensitivity may be preferable. In this literature review, we provide a comprehensive summary of the available evidence on nutritional approaches in the management of NAFLD, involving low-calorie diets, isocaloric diets, and the novel schemes of intermittent fasting. In addition, we explore the harmful role of single nutrients on liver-specific key metabolic pathways, the role of gene susceptibility and microbiota, and behavioral aspects that may impact liver disease and are often underreported in clinical setting. At present, the high variability in terms of study populations and liver-specific outcomes within nutritional studies limits the generalizability of the results and highlights the urgent need of a tailored and standardized approach, as seen in regulatory trials in Non-Alcoholic Steatohepatitis (NASH).