The Effect of Three Mediterranean Diets on Remnant Cholesterol and Non-Alcoholic Fatty Liver Disease: A Secondary Analysis

Predictive utility of remnant cholesterol in atherosclerotic cardiovascular disease

PURPOSE OF REVIEW

Remnant cholesterol (RC) is the cholesterol carried in lipoproteins derived from the catabolism of chylomicrons and very low-density lipoproteins. Evidence supporting the causal relationship of RC with atherosclerotic cardiovascular disease (ASVD) is accumulating rapidly. The number of impactful contributions to this field are increasing and provide a pathophysiological insight into the current residual cardiovascular risk beyond low-density cholesterol (LDL)-cholesterol (LDL-C). They also raise the question of whether RC should be used in prediction models and become the target of new therapeutic interventions. The intent of this review is to highlight the recent advances on the role of RC in atherogenesis and the validation of RC as a predictor of ASVD.

RECENT FINDINGS

Numerous prospective and retrospective cohorts helped validate a significant causal relationship of RC with various forms of ASVD, independent of LDL-C. A recent large Mendelian randomization study reinforced the existence of this relationship and showed that the risk of atherosclerotic events was driven nearly entirely by a direct effect of RC.

SUMMARY

Both available and accumulating evidence suggest that a lifelong reduction in RC could translate into a substantial reduction in ASVD risk. The data support a revision of current guidelines to incorporate RC as an independent risk factor for ASVD. We propose that early screening of RC should be implemented and that RC lowering should become the target of future drug developments.

Remnant cholesterol as a new lipid-lowering target to reduce cardiovascular events

PURPOSE OF REVIEW

Remnant cholesterol has become increasingly recognized as a direct contributor to the development of atherosclerosis and as an additional marker of cardiovascular risk. This review aims to summarize the pathophysiological mechanisms, and the current evidence base from epidemiological investigations and genetic studies that support a causal link between remnant cholesterol and atherosclerotic cardiovascular disease. Current and novel therapeutic approaches to target remnant cholesterol are discussed.

RECENT FINDINGS

A recent Mendelian randomization study of over 12 000 000 single-nucleotide polymorphisms associated with high levels of remnant cholesterol, demonstrated a genetic association between remnant cholesterol and adverse cardiovascular events among 958 434 participants.

SUMMARY

In this light, the emerging role of remnant cholesterol as an independent lipid risk marker warrants a reevaluation of lipid management guidelines and underscores the potential for novel therapeutic targets in cardiovascular disease prevention.

Serum remnant cholesterol is a potential predictor of liver stiffness in patients with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is associated with dyslipidemia, and the connection between dyslipidemia and remnant cholesterol (RC), a component of triglyceride-rich lipoproteins, remains enigmatic.

METHODS

In this cross-sectional study, our primary aim was to investigate the role of RC in the progression of NAFLD and to provide robust evidence of RC's involvement in the pathogenesis of NAFLD. We enrolled 2800 NAFLD patients from the National Health and Nutrition Examination Survey (NHANES). Logistic regression was employed to examine the relationship between serum RC levels and liver stiffness, while receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic capability of RC.

RESULTS

RC exhibited an independent correlation with the extent of liver stiffness, with odds ratios (OR) of 1.02 for liver steatosis (p = 0.014) and 1.02 for liver fibrosis (p = 0.014). To predict NAFLD, the optimal RC thresholds were 17.25 mg/dL for males and 15.25 mg/dL for females in the case of liver steatosis. For advanced liver fibrosis, the best thresholds were 17.25 mg/dL for males and 16.25 mg/dL for females.

CONCLUSIONS

RC demonstrated a positive correlation with the degree of liver stiffness and exhibited superior diagnostic efficacy for liver steatosis and fibrosis compared to other cholesterol indicators.

Specific Increase in Small Dense Low-Density Lipoprotein-Cholesterol Levels beyond Triglycerides in Patients with Diabetes: Implications for Cardiovascular Risk of MAFLD

AIMS

Small dense (sd) low-density lipoprotein (LDL)-cholesterol (C) is the most powerful predictor of cardiovascular (CV) disease among lipid biomarkers and is generated by hypertriglyceridemia and insulin resistance. Metabolic dysfunction-associated fatty liver disease (MAFLD) is a newly proposed liver disease with a high CV risk. We investigated the specific association of sdLDL-C with MAFLD beyond triglycerides (TG) and obesityMethods: Participants were 839 non-alcoholic drinkers with type 2 diabetes enrolled in a regional diabetes cohort. Fatty liver (FL) and visceral fat area (VFA) was detected by computed tomography scan. sdLDL-C and LDL-TG were measured by our established homogeneous assay. TG rich lipoprotein (TRL) was calculated by subtracting LDL-C plus HDL-C from total-C. Grade of sdLDL-C (≤ 24, 25-34, 35-44, and ≥ 45 mg/dL) was classified according to the Hisayama study.

RESULTS

Compared to non-FL counterparts, FL subjects were younger, predominantly male and smokers; and had higher body mass index (BMI), VFA, hemoglobin A1c, C-peptide, TG, and sdLDL-C, while had similar levels of LDL-C, LDL-TG, and TRL-C. Multivariate logistic analysis revealed that sdLDL-C was the most powerful lipid parameter for identifying FL, independent of TG, HDL-C, BMI, and VFA. The independent association between TG and FL was lost when sdLDL-C was added to the analysis. These results remained the same when lipid-lowering drug users were excluded. After adjustment for confounders, the odds ratio for FL was 2.4-2.7 at sdLDL ≥ 35 mg/dL based on sdLDL ≤ 24 mg/dL.

CONCLUSIONS

sdLDL-C levels are specifically elevated in patients with diabetes and MAFLD, independent of TG and VFA, suggesting liver-centered metabolic abnormalities.

Pomegranate (Punica granatum L.) peel extract ameliorates metabolic syndrome risk factors in patients with non-alcoholic fatty liver disease: a randomized double-blind clinical trial

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) is a metabolic syndrome (MS)-related liver disorder that has an increasing prevalence. Thus, the aim of our study is to evaluate the effects of pomegranate peel extract (PP) supplementation on hepatic status and metabolic syndrome risk factors.

METHODS

In phase one, the hydro-alcoholic extraction of the peel of 750 kg of pomegranate (Punica granatum L.) was performed by the soaking method. Then, in phase two, NAFLD patients received 1500 mg of placebo (n = 37) or pomegranate peel capsules (n = 39) with a 500-kcal deficit diet for 8 weeks. Gastrointestinal intolerance, dietary intake, lipid and glycemic profiles, systolic and diastolic blood pressure, body composition, insulin resistance indexes, and elastography-evaluated NAFLD changes were followed.

RESULTS

The mean age of participants was 43.1 ± 8.6 years (51.3% female). Following the intervention, the mean body weight (mean changes: -5.10 ± 2.30 kg), waist circumference (-7.57 ± 2.97 cm), body mass index (-1.82 ± 0.85 kg/m2), body fat index (-1.49 ± 0.86), and trunk fat (- 3.93 ± 3.07%), systolic (-0.63 ± 0.29 cmHg) and diastolic (-0.39 ± 0.19 cmHg) blood pressure, total cholesterol (-10.51 ± 0.77 mg/dl), triglyceride (-16.02 ± 1.7 mg/dl), low-density lipoprotein cholesterol (-9.33 ± 6.66 mg/dl; all P < 0.001), fat free mass (- 0.92 ± 0.90 kg; P < 0.003), and fasting blood sugar (-5.28 ± 1.36 mg/dl; P = 0.02) decreased significantly in PP in contrast to the placebo group in the raw model and when adjusted for confounders. Also, high-density lipoprotein cholesterol (5.10 ± 0.36 mg/dl), liver steatosis and stiffness (- 0.30 ± 0.17 and - 0.72 ± 0.35 kPa, respectively, all P < 0.001) improved in the PP group. However, fasting insulin (P = 0.81) and homeostatic model assessment for insulin resistance (HOMA-IR) (P = 0.93) were not significantly different when comparing two groups during the study in the raw and even adjusted models.

CONCLUSION

In conclusion, 1500 mg pomegranate peel extract along with a weight-loss diet improved metabolic syndrome risk factors and reduced hepatic steatosis in patients with NAFLD after 8 weeks.

Effects of various interventions on non-alcoholic fatty liver disease (NAFLD): A systematic review and network meta-analysis

Background: With the increasing prevalence of obesity and metabolic syndrome, the incidence of non-alcoholic fatty liver disease (NAFLD) is also increasing. In the next decade, NAFLD may become the main cause of liver transplantation. Therefore, the choice of treatment plan is particularly important. The purpose of this study was to compare several interventions in the treatment of NAFLD to provide some reference for clinicians in selecting treatment methods.

Methods: We searched Public Medicine (PubMed), Medline, Excerpta Medica Database (Embase), and Cochrane Library from January 2013 to January 2023 to identify randomized controlled trials (RCTs) published in English. The network meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Forty-three studies accounting for a total of 2,969 patients were included, and alanine aminotransferase (ALT), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL) were selected as outcome measures for analysis and comparison.

Results: We evaluated the results of drug, diet, and lifestyle interventions between the intervention and control groups. Curcumin (CUN) and probiotics (PTC) were selected for medication, the Mediterranean diet (MDED) was selected for special diet (SPD), and various kinds of exercise and lifestyle advice were selected for lifestyle interventions (LFT). The SUCRA was used to rank interventions according to the effect on ALT indicators (SUCRA: PTC 80.3%, SPD 65.2%, LFT 61.4%, PLB 32.8%, CUN 10.2%), TC indicators (SUCRA: PTC 89.4%, SPD 64%, CUN 34%, LFT 36.6%, PLB 17%), and LDL indicators (SUCRA: PTC 84.2%, CUN 69.5%, LFT 51.7%, PLB 30.1%, SPD 14.5%). The pairwise meta-analysis results showed that MDED was significantly better than NT in improving ALT [SMD 1.99, 95% CI (0.38, 3.60)]. In terms of improving TC and LDL, ATS was significantly better than NT [SMD 0.19, 95% CI (0.03, 0.36)] [SMD 0.18, 95% CI (0.01, 0.35)].

Conclusion: Our study showed that PTC is most likely to be the most effective treatment for improving NAFLD indicators. Professional advice on diet or exercise was more effective in treating NAFLD than no intervention.

What's New in the Treatment of Non-Alcoholic Fatty Liver Disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is a serious health problem due to its high incidence and consequences. In view of the existing controversies, new therapeutic options for NAFLD are still being sought. Therefore, the aim of our review was to evaluate the recently published studies on the treatment of NAFLD patients. We searched for articles in the PubMed database using appropriate terms, including "non-alcoholic fatty liver disease", "nonalcoholic fatty liver disease", "NAFLD", "diet", "treatment", "physical activity", "supplementation", "surgery", "overture" and "guidelines". One hundred forty-eight randomized clinical trials published from January 2020 to November 2022 were used for the final analysis. The results show significant benefits of NAFLD therapy associated with the use of not only the Mediterranean but also other types of diet (including low-calorie ketogenic, high-protein, anti-inflammatory and whole-grain diets), as well as enrichment with selected food products or supplements. Significant benefits in this group of patients are also associated with moderate aerobic physical training. The available therapeutic options indicate, above all, the usefulness of drugs related to weight reduction, as well as the reduction in insulin resistance or lipids level and drugs with anti-inflammatory or antioxidant properties. The usefulness of therapy with dulaglutide and the combination of tofogliflozin with pioglitazone should be emphasized. Based on the results of the latest research, the authors of this article suggest a revision of the therapeutic recommendations for NAFLD patients.

Association between Cardiovascular Disease and Liver Disease, from a Clinically Pragmatic Perspective as a Cardiologist

Cardiovascular diseases and liver diseases are closely related. Non-alcoholic fatty liver disease has the same risk factors as those for atherosclerotic cardiovascular disease and may also be a risk factor for atherosclerotic cardiovascular disease on its own. Heart failure causes liver fibrosis, and liver fibrosis results in worsened cardiac preload and congestion. Although some previous reports regard the association between cardiovascular diseases and liver disease, the management strategy for liver disease in patients with cardiovascular diseases is not still established. This review summarized the association between cardiovascular diseases and liver disease. In patients with non-alcoholic fatty liver disease, the degree of liver fibrosis progresses with worsening cardiovascular prognosis. In patients with heart failure, liver fibrosis could be a prognostic marker. Liver stiffness assessed with shear wave elastography, the fibrosis-4 index, and non-alcoholic fatty liver disease fibrosis score is associated with both liver fibrosis in patients with liver diseases and worse prognosis in patients with heart failure. With the current population ageing, the importance of management for cardiovascular diseases and liver disease has been increasing. However, whether management and interventions for liver disease improve the prognosis of cardiovascular diseases has not been fully understood. Future investigations are needed.

The Association of Remnant Cholesterol with Endothelial Dysfunction and Subclinical Atherosclerosis in a Check-Up Population in China

AIM

Vascular endothelial function and atherosclerosis are known to be important risk factors for cardiovascular disease. However, it remains unknown whether remnant cholesterol (RC) correlates with vascular endothelial function and atherosclerosis as represented by flow-mediated vasodilation (FMD) and brachial-ankle pulse wave velocity (baPWV). Therefore, in this study, we aimed to investigate this in the general population.

METHODS

In this study, we examined 13,237 subjects who have undergone blood lipid, FMD, and baPWV measurements. Participants were divided into four groups based on RC quartiles. Multivariable linear regression models were used to calculate odds ratios for FMD and baPWV according to the RC levels.

RESULTS

A significant negative relationship was found between RC and FMD (β=-0.14, p=0.014), whereas RC was positively associated with baPWV (β=21.42, p＜0.001), especially in the male and without chronic disease medication populations. The population was divided into three groups according to their lipids: dyslipidemia group, nondyslipidemia but RC increased group (RC ＞0.78 mmol/L), and nondyslipidemia and RC normal group (RC ≤ 0.78 mmol/L). The FMD of the three groups was 7.09%±3.36%, 7.39%±3.38%, and 7.57%±3.54%, respectively. The baPWV of the three groups was 1445.26±261.56 cm/s, 1425.04±265.24 cm/s, and 1382.73±267.75 cm/s. Significant differences were noted between the groups.

CONCLUSIONS

The findings indicated that a higher RC was an independent predictive factor for participants with endothelial function and atherosclerosis. It is important to use RC as a risk management indicator of vascular function, especially for those with normal conventional lipid parameters but increased RC.

The Effect of Low Glycemic Index Mediterranean Diet and Combined Exercise Program on Metabolic-Associated Fatty Liver Disease: A Joint Modeling Approach

Background: Excessive caloric intake and reduced energy expenditure are associated with the onset of metabolic-associated fatty liver disease (MAFLD). The aim of this study was to probe the benefits of a low glycemic index Mediterranean diet (LGIMD) and a combined exercise program (CEP) on MAFLD by monitoring the clinical process through anthropometric measurement, body mass index (BMI), and specific biomarkers, such as the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR). Methods: The study was conducted at the National Institute of Gastroenterology, ‘S. de Bellis’, Italy. Subjects were invited to join the study for 12 months. Results: 54 participants were enrolled. Joint modeling of longitudinal and time-to-event data was applied. Overall, a statistically significant direct effect of LGIMD/CEP adherence on ln (BMI), a statistically significant direct effect of LGIMD/CEP adherence on time-to-event and a strong statistically significant direct effect of log (BMI) on time-to-event were observed. In addition, a statistically significant direct effect of LGIMD/CEP adherence on ln(HOMA-IR), a statistically significant direct effect of LGIMD/CEP adherence on time-to-event and a statistically significant direct effect of ln(HOMA-IR) on time-to-event were observed. Conclusions: LGIMD/CEP significantly improved MAFLD status; in addition, longitudinal BMI and HOMA-IR were good predictors of the disappearance of diagnostic criteria for MAFLD.

Exosomal FZD-7 Expression Is Modulated by Different Lifestyle Interventions in Patients with NAFLD

Non-alcoholic fatty liver disease (NAFLD) is a multifactorial condition characterized from hypertriglyceridemia and hepatic fat accumulation, in the absence of alcohol intake. NAFLD starts as steatosis (NAFL), and the continued injury relative to the toxic fat induces inflammation, steatohepatitis (NASH), and HCC. One of the factors determining liver degeneration during the evolution of NAFLD is a modification of Wnt/Frizzled (FZD) signaling. In particular, an inhibition of Wnt signaling and an overexpression of a specific FZD receptor protein, namely, the FZD7, have been observed in NAFLD. Actually, the prognosis and the follow-up of NAFLD is not easy, and the liver biopsy is the gold standard for an accurate detection of liver fibrosis. In this study, the modulation of the FZD7 expression levels in plasma-derived exosomes of NAFLD-affected patients, before and after specific lifestyle interventions, were experimentally evaluated by Western blotting analysis. The experimental data were analyzed by an accurate statistical study that indicated, in the exosomes derived from plasma of NAFLD patients with moderate or severe steatosis, an average expression level of FZD7 that was significantly higher than healthy subjects at baseline; conversely, the values were normalized after 90 days of specific lifestyle interventions. The overall results suggested that the FZD7 delivered by exosomes represents a good candidate as a new and effective biomarker for diagnosis and prognosis of NAFLD.

Fasting, Nutrition and Weight Loss: An Approach to Refine Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is considered as one of the most common causes of chronic liver disease. It includes a group of conditions associated with fat deposition in liver cells. Also, NAFLD is strongly associated with obesity and insulin resistance (IR). Until now, there is no pharmacological treatment validated for this disease. Fasting, nutritional intervention, and weight loss can be considered the first line in treating hepatic steatosis. This review is based on the scientific evidence showing the results of these interventions in the past years. The results include fasting and nutritional support for NAFLD treatment in humans. In clinical trials and cohort studies, an increase in hepatic fat content was correlated with a weight loss of at least 7% and a diet resembling the Mediterranean diet (MD) improving hepatic biomarkers and histological regression of NAFLD. Fasting is a dietary approach known to improve the lipid profile in healthy and obese populations by decreasing overall cholesterol, triglycerides, LDL, and increasing HDL. Bariatric surgery helps improve liver fat content in patients with serious health problems due to overweight.

Effect of a 1-Year Controlled Lifestyle Intervention on Body Weight and Other Risk Markers (the Healthy Lifestyle Community Programme, Cohort 2)

INTRODUCTION

The prevalence of obesity is high and increasing worldwide. Obesity is generally associated with an increased risk of chronic disease and mortality. The objective of the study was to test the effect of a lifestyle intervention on body weight and other chronic disease risk markers.

METHODS

A non-randomized controlled trial was conducted, including mostly middle-aged and elderly participants recruited from the general population in rural northwest Germany (intervention: n = 114; control: n = 87). The intervention consisted of a 1-year lifestyle programme, focussing on four key areas: a largely plant-based diet (strongest emphasis), physical activity, stress management, and community support. Parameters were assessed at baseline, 10 weeks, 6 months, and 1 year. The control group received no intervention.

RESULTS

Compared to the control, in the intervention group, significantly lower 1-year trajectories were observed for body weight, body mass index (BMI), waist circumference (WC), total cholesterol, calculated LDL cholesterol, non-HDL cholesterol, remnant cholesterol (REM-C), glucose, HbA1c, and resting heart rate (RHR). However, between-group differences at 1 year were small for glucose, HbA1c, and cholesterol (apart from REM-C). No significant between-group differences were found for 1-year trajectories of measured LDL cholesterol, HDL cholesterol, triglycerides, insulin, blood pressure, and pulse pressure.

CONCLUSION

The intervention successfully reduced body weight, BMI, WC, REM-C, and RHR. However, at 1 year, effectiveness of the intervention regarding other risk markers was either very modest or could not be shown.

NAFLD Nutritional Management: Results from a Multidisciplinary Approach

Introduction

Lifestyle changes are the mainstay treatment of nonalcoholic fatty liver disease (NAFLD). We aimed to assess the magnitude of weight loss in a group of NAFLD patients followed on a combined lifestyle intervention by a multidisciplinary team.

Methods

Patients were assessed before and after a 12-month dietary intervention (Mediterranean diet aiming at weight loss). Patients who received a structured dietary plan along with general lifestyle recommendations were designated as the multidisciplinary treatment (MdT) group. Patients who declined follow-up still received general lifestyle recommendations and were designated as the conventional treatment group, being used as a control group.

Results

From the 77 patients with documented NAFLD, 31.2% of patients were overweight and 55.8% obese; 66 patients constituted the MdT group and 11 the conventional treatment group. After 3 months, 89% of patients lost weight; at 6 months, 75.4% maintained the weight lost. At 12 months, 65% of patients still decreased their weight, with 92.2% of patients in the MdT group still maintaining a lower weight than baseline versus just 50% in the conventional group (p = 0.008). Only patients in the MdT group presented a weight loss higher than 10% (9.6%; n = 6). At 12 months patients in the MdT group presented an average reduction of 4.2 kg versus a reduction of just 0.6 kg in the conventional treatment group (p = 0.016). The MdT group, but not the conventional group, presented significant differences in liver enzymes at 12 months compared to baseline.

Conclusion

Adherence to a multidisciplinary approach, compared to management solely by a hepatologist, in NAFLD patients, is effective with greater weight loss after a 12-month follow-up and a lower rate of weight gain recurrence.

Association between remnant cholesterol and arterial stiffness: A secondary analysis based on a cross-sectional study

The relationship between conventional lipid parameters and arterial stiffness (AS) has been verified by previous studies. However, it remains unknown whether non‐conventional lipid parameters have certain predictive effect on AS represented by brachial‐ankle pulse wave velocity (baPWV). Therefore, the study was to explore the relationship between remnant cholesterol (RC) and other non‐conventional lipid parameters and AS in the general population free from cardiovascular disease. The study included 912 participants aged 24–84 years from a medical health checkup center of Murakami Memorial Hospital. Logistic regression analysis and receiver operating characteristic (ROC) curves were used to examine the association between non‐conventional lipid parameters and AS. The results showed that compared with non‐AS group, the AS group had higher RC, non‐high‐density lipoprotein cholesterol (Non‐HDL‐C), atherogenic index of plasma (AIP), lipoprotein combine index (LCI), atherosclerosis index (AI), triglycerides/HDL‐C (TG/HDL‐C), Castelli's risk index I (CRI‐I) and Castelli's risk index II (CRI‐II). Then, the authors divided participants into two groups by the optimal cutoff point of 23.6 of RC determined by Youden index. The baPWV was significantly higher in higher RC group compared with lower RC group, and RC was positively correlated with baPWV. Multivariate Logistic regression analysis showed that, regarding lower RC as reference, higher RC was independently associated with higher risk of AS, independent of other risk factors (OR = 1.794, 95% CI: 1.267‐2.539, p = .001). The area under the curve of AS predicted by RC was higher than that of other non‐conventional lipid parameters (almost all p < .05). The findings indicated that increased RC was a significant predictor of AS.

Association of remnant cholesterol with nonalcoholic fatty liver disease: a general population-based study

BACKGROUND

Remnant cholesterol (RC) mediates the progression of coronary artery disease, diabetic complications, hypertension, and chronic kidney disease. Limited information is available on the association of RC with nonalcoholic fatty liver disease (NAFLD). This study aimed to explore whether RC can be used to independently evaluate the risk of NAFLD in the general population and to analyze the predictive value of RC for NAFLD.

METHODS

The study included 14,251 subjects enrolled in a health screening program. NAFLD was diagnosed by ultrasound, and the association of RC with NAFLD was assessed using the receiver operating characteristic (ROC) curve and logistic regression equation.

RESULTS

Subjects with elevated RC had a significantly higher risk of developing NAFLD after fully adjusting for potential confounding factors (OR 1.77 per SD increase, 95% CI 1.64-1.91, P trend< 0.001). There were significant differences in this association among sex, BMI and age stratification. Compared with men, women were facing a higher risk of RC-related NAFLD. Compared with people with normal BMI, overweight and obesity, the risk of RC-related NAFLD was higher in thin people. In different age stratifications, when RC increased, young people had a higher risk of developing NAFLD than other age groups. Additionally, ROC analysis results showed that among all lipid parameters, the AUC of RC was the largest (women: 0.81; men: 0.74), and the best threshold for predicting NAFLD was 0.54 in women and 0.63 in men.

CONCLUSIONS

The results obtained from this study indicate that (1) in the general population, RC is independently associated with NAFLD but not with other risk factors. (2) Compared with traditional lipid parameters, RC has a better predictive ability for NAFLD in men.

The Significance of the Mediterranean Diet in the Management of Non-Alcoholic Fatty Liver Disease: A Systematic Review

Non-alcoholic fatty liver disease (NAFLD) is the accumulation of intrahepatic fat occurring in the absence of alcohol abuse. The fatty changes in the liver are often the beginning of sequelae of complications, potentially causing steatohepatitis, liver cirrhosis, and hepatocellular carcinoma. The Mediterranean diet is not only a way of eating but is considered a lifestyle and primarily consists of a plant-based diet, with olive oil as the primary lipid. In this study, we reviewed the effectiveness of the Mediterranean diet on NAFLD and its efficacy in disease management. This systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) 2009 guidelines. The PubMed database was used to gather articles, using the following terms individually and in combination, "Mediterranean diet," "non-alcoholic fatty liver disease," "insulin resistance," "metabolic syndrome," "omega-3-fatty acids." A quality appraisal was completed to include 14 articles in this systematic review. The studies discuss the correlation between the Mediterranean diet and its role in preventing and treating NAFLD. Olive oil is the major monounsaturated fatty acid, whereas nuts, seeds, and fish consist largely of polyunsaturated fatty acids, both of which are essential components of the Mediterranean diet. The plant-based diet, having sufficient amounts of vegetables, legumes, and fruits, provides its anti-oxidant and anti-inflammatory effects, playing a fundamental role in preventing oxidative stress damage. Olive oil polyphenols increase apoptosis and cell cycle arrest. They also decrease proliferation and angiogenesis, all of which prevent neoplasia. Adapting the Mediterranean lifestyle has shown promising effects in NAFLD, reducing overall mortality and morbidity.

Dietary Interventions in Liver Diseases: Focus on MAFLD and Cirrhosis

Purpose of Review

Dietary interventions (DI) aimed at improving overweight and metabolic abnormalities in metabolic dysfunction-associated fatty liver disease (MAFLD) and at reducing malnutrition and sarcopenia in cirrhosis should become part of routine care in hepatology. This review focuses on recent advances in this field.

Recent Findings

In patients with MAFLD, a gradual reduction, respectively, of 7–10% of body weight if overweight or of 3–5% if lean, obtained by moderately reducing caloric intake, is effective to improve liver disease. Intermittent energy restriction might be an alternative to continuous energy restriction with higher adherence. Qualitative dietary adjustments should include increased intake of unprocessed foods including fruits and vegetables, whole grains, fiber, and unsaturated fatty acids (FAs), for example, through a Mediterranean diet. Refined carbohydrates (CHOs), saturated FA (SFAs), red meat, and processed meat should be limited. DI studies in HIV-infected subjects with MAFLD are very limited, and this is a field for future research. In patients with cirrhosis, DI should aim at correcting malnutrition and improving skeletal muscle mass. Daily diet contents should aim at achieving 30–35 kcal/kg of body weight, including 1.2–1.5 g/kg proteins, and oral or enteral supplementation might be used in patients unable to achieve these targets. In some studies, branched-chain amino acids (BCAAs) proved to be effective in improving muscle mass and were associated with a lower risk of hepatic encephalopathy. Obesity requires adjustment of the above-mentioned targets, and its management is challenging. Studies looking at the efficacy of DI recommended by the existing guidelines on clinical endpoints are a field for future research.

Summary

Dietary interventions are able to improve MAFLD and show potential to reduce complications in liver disease. Despite its key importance, there are many barriers limiting the implementation of DI in patients with chronic liver disease. Patients’ empowerment is crucial and should be the focus of specific educational programs. In addition, liver clinics would benefit from multidisciplinary teams involving experts in nutrition, physical exercise, primary care physicians, and psychologists when needed.

Decreased levels of physical activity: results from a cross-sectional study in southern Italy during the COVID-19 lockdown

BACKGROUND

During the COVID-19 pandemic, the Italian government took security measures to try to limit infections. Restrictive measures included social distancing, home confinement and the closure of all public structures like gyms and swimming pools. The impact of these limitations on health and lifestyle was inevitably negative. The purpose of this study was to establish the level of physical activity (PA), expressed as energy expenditure (MET-minute/week) in a Southern Italian population before and during the COVID-19 lockdown.

METHODS

An adapted version of the International Physical Activity Questionnaire-short form (IPAQ-SF) was published on the official website of the National Institute of Gastroenterology IRCCS S. de Bellis, Castellana Grotte, Bari, Italy and on several social media in May 2020.

RESULTS

Three hundred ten replies (72% women) from Apulia (60%), Calabria (28%), Campania (11%) and Sicily (1%) were included in the study. The COVID-19 lockdown had a negative effect on the vigorous PA intensity level and on walking, but not on the moderate PA intensity level. Additionally, daily time spent sitting down increased by more than 12% during the COVID-19 lockdown.

CONCLUSIONS

Isolation changed PA behaviors. The decreased energy expenditure (MET-minute/week) during the lockdown had a negative impact in both genders, especially on the young adults and adults' groups.