Gamma-glutamyltransferase, fatty liver index and hepatic insulin resistance are associated with incident hypertension in two longitudinal studies

Temporal relationship between hepatic steatosis and blood pressure elevation and the mediation effect in the development of cardiovascular disease

The temporal relationship between non-alcoholic fatty liver disease (NAFLD) and hypertension remains highly controversial, with ongoing debates on whether NAFLD induces hypertension or vice versa. We employed cross-lagged panel models to investigate the temporal relationship between hepatic steatosis (assessed by Fatty Liver Index [FLI] in the main analysis, and by Proton Density Fat Fraction [PDFF] in the validation study) and blood pressure (systolic and diastolic blood pressure [SBP/ DBP]). Subsequently, we employed causal mediation models to explore the mediation effect in CVD development, including ischemic heart disease and stroke. The main analysis incorporated repeated measurement data of 5,047 participants from the China Multi-Ethnic Cohort (CMEC) and 5,685 participants from the UK Biobank (UKB). In both cohorts, the path coefficients from FLI to blood pressure were significant and greater than the path from blood pressure to FLI, with βFLI→SBP = 0.081, P < 0.001 versus βSBP→FLI = 0.020, P = 0.031; βFLI→DBP = 0.082, P < 0.001 versus βDBP→FLI = -0.006, P = 0.480 for CEMC, and βFLI→SBP = 0.057, P < 0.001 versus βSBP→FLI = -0.001, P = 0.727; βFLI→DBP = 0.061, P < 0.001, versus βDBP→FLI = -0.006, P = 0.263 for UKB. The validation study with 962 UKB participants using PDFF consistently supported these findings. In the mediation analyses encompassing 11,108 UKB participants, SBP and DBP mediated 12.2% and 5.2% of the hepatic steatosis-CVD association, respectively. The proportions were lower for ischemic heart disease (SBP: 6.1%, DBP: non-statistically significant -6.8%), and relatively stronger for stroke (SBP: 19.4%, DBP: 26.1%). In conclusion, hepatic steatosis more strongly contributes to elevated blood pressure than vice versa. Blood pressure elevation positively mediates the hepatic steatosis-CVD association, particularly in stroke compared to ischemic heart disease.

Liver indicators affecting the relationship between BMI and hypertension in type 2 diabetes: a mediation analysis

BACKGROUND

Body mass index (BMI) is an important risk factor for hypertension in diabetic patients. However, the underlying mechanisms remain poorly understood. Although liver-derived biological intermediates may play irreplaceable roles in the pathophysiology of diabetes, few studies have explored them in the association between BMI and hypertension in diabetes.

OBJECTIVE

To investigate the role of liver enzymes in mediating the relationship between BIM exposure and hypertension in type 2 diabetes mellitus (T2DM).

METHODS

We included a total of 1765 participants from the China National Diabetic Chronic Complications Study Cohort. Associations between liver enzymes and hypertension were estimated using multivariable regression models. The function of liver indicators in the relationship between BMI and hypertension was assessed using mediation analysis. Mediation analysis was conducted, taking into account age, diabetes duration, current smoking, fasting plasma glucose level, glycated hemoglobin, anti-diabetic therapy, and family history of diseases, including diabetes, hypertension, obesity, and hyperlipidemia.

RESULTS

For men, the association of BMI with hypertension was partially mediated by alanine aminotransferase (ALT), with a proportion of mediation was 68.67%, by aspartate aminotransferase (AST) was 27.02%, and by γ-glutamyltransferase (GGT) was 38.58%, by AST/ALT was 63.35%; for women, the proportion mediated by ALT was 36.93%, and by AST was 37.47%, and GGT was 44.60%, and AST/ALT was 43.73% for BMI (all P < 0.05).

CONCLUSION

The effect of BMI on hypertension is partly mediated by liver indicators (ALT, AST, GGT, and AST/ALT) in diabetic patients. Our results may provide opportunities to identify new targets for hypertension interventions.

Association between serum gamma-glutamyltransferase and early-onset coronary artery disease: a retrospective case-control study

BACKGROUND

Serum gamma-glutamyltransferase (GGT) activity has been proposed as a promising predictor of atherosclerosis-related complications and a prognostic marker for cardiovascular diseases. The objective of this study was to investigate the potential correlation between serum levels of GGT and early-onset coronary artery disease (EOCAD).

METHODS

A retrospective, hospital-based case-control study was conducted, which included 860 patients with EOCAD and gender- and age-matched controls. Serum levels of GGT were measured using the reference measurement procedure on an automatic biochemistry analyser.

RESULTS

The serum GGT levels of patients with EOCAD (34.90 ± 31.44 U/L) were significantly higher than those of the control group (21.57 ± 16.44 U/L, p < .001). Elevated serum levels of GGT were found to be an independent risk factor for EOCAD, with an odds ratio (OR) of 1.021 (95% confidence interval (CI): 1.014-1.029). Additionally, for every quartile increase in serum GGT levels, the risk of developing EOCAD increased by 1.6-fold. Moreover, serum GGT levels were significantly associated with disease severity, with lower GGT levels observed in patients without significant vascular disease (31.74 ± 24.06 U/L) compared to those with two-vessel disease (33.06 ± 25.00 U/L, p = .002) and three-vessel disease (37.75 ± 36.76 U/L, p = .001).

CONCLUSIONS

The results of this study suggest that elevated serum GGT levels are associated with the development of EOCAD, and GGT may be implicated in the pathogenesis of the disease. Further large-scale prospective studies are needed to explore the potential relationship between serum GGT levels and the dynamic development of EOCAD.

The causal associations of non-alcoholic fatty liver disease with blood pressure and the mediating effects of cardiometabolic risk factors: A Mendelian randomization study

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is prevalent in hypertensive people, but the causal effect remains unclear. We employed Mendelian randomization (MR) approach to assess the causality between NAFLD and different blood pressure (BP) parameters.

METHOD AND RESULTS

Instrumental variables for genetically predicted NAFLD, including chronically elevated serum alanine aminotransferase levels (cALT) and imaging and biopsy-confirmed NAFLD, were obtained from a genome-wide association study (N = 164,197). Multiple MR methods were implemented, including Inverse variance weighted, MR-Egger, Maximum likelihood, Weighted median, Simple median, Penalised weighted median, MR-RAPS, and cML-MA. Outliers were detected using MR-PRESSO, and pleiotropy was assessed using MR-Egger intercept and Phenoscanner. Heterogeneity was quantified using Cochran's Q and Rucker's Q' tests. Potential shared risk factors were analyzed to reveal the mediating effect. A higher genetic predisposition to cALT was causally associated with an increased risk of elevated BP levels, resulting in 0.65 mmHg (95% CI, 0.42-0.87), 0.38 mmHg (95% CI, 0.25-0.50) and 0.33 mmHg (95% CI, 0.22-0.44) higher for systolic BP, diastolic BP and pulse pressure, respectively. When more stringent criteria were used, imaging and biopsy-confirmed NAFLD showed a 1.12 mmHg (95% CI, 0.94-1.30) increase in SBP and a 0.55 mmHg (95% CI, 0.39-0.70) increase in DBP. Risk factor and mediation analyses suggested type 2 diabetes and fasting insulin levels might mediate the causal relationship between NAFLD and BP.

CONCLUSION

The two-sample MR analyses showed robust causal effects of genetically predicted NAFLD on 3 different BP indices. The shared genetic profile between NAFLD and BP may suggest important therapeutic targets and early interventions for cardiometabolic risk factors.

Which Comes First, Nonalcoholic Fatty Liver Disease or Arterial Hypertension?

Non-alcoholic fatty liver disease (NAFLD) and arterial hypertension (AH) are widespread noncommunicable diseases in the global population. Since hypertension and NAFLD are diseases associated with metabolic syndrome, they are often comorbid. In fact, many contemporary published studies confirm the association of these diseases with each other, regardless of whether other metabolic factors, such as obesity, dyslipidemia, and type 2 diabetes mellites, are present. This narrative review considers the features of the association between NAFLD and AH, as well as possible pathophysiological mechanisms.

Nonalcoholic fatty liver disease and cognitive impairment: A prospective cohort study

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is prevalent and may affect cognitive function. We studied associations of NAFLD with risk of cognitive impairment. Secondarily we evaluated liver biomarkers (alanine aminotransferase (ALT), aspartate aminotransferase (AST), their ratio, and gamma-glutamyl transpeptidase).

METHODS

In a prospective cohort study, the REasons for Geographic and Racial Differences in Stroke, among 30,239 black and white adults aged ≥45,495 cases of incident cognitive impairment were identified over 3.4 years follow up. Cognitive impairment was identified as new impairment in two of three cognitive tests administered every two years during follow up; word list learning and recall, and verbal fluency. 587 controls were selected from an age, race, sex-stratified sample of the cohort. The fatty liver index was used to define baseline NAFLD. Liver biomarkers were measured using baseline blood samples.

RESULTS

NAFLD at baseline was associated with a 2.01-fold increased risk of incident cognitive impairment in a minimally adjusted model (95% CI 1.42, 2.85). The association was largest in those aged 45-65 (p interaction by age = 0.03), with the risk 2.95-fold increased (95% CI 1.05, 8.34) adjusting for cardiovascular, stroke and metabolic risk factors. Liver biomarkers were not associated with cognitive impairment, except AST/ALT >2, with an adjusted OR 1.86 (95% CI 0.81, 4.25) that did not differ by age.

CONCLUSIONS

A laboratory-based estimate of NAFLD was associated with development of cognitive impairment, particularly in mid-life, with a tripling in risk. Given its high prevalence, NAFLD may be a major reversible determinant of cognitive health.

Severity of non-alcoholic fatty liver disease is a risk factor for developing hypertension from prehypertension

BACKGROUND

There is little published evidence about the role of non-alcoholic fatty liver disease (NAFLD) in the progression from prehypertension to hypertension. This study was conducted to investigate the association of NAFLD and its severity with the risk of hypertension developing from prehypertension.

METHODS

The study cohort comprised 25, 433 participants from the Kailuan study with prehypertension at baseline; those with excessive alcohol consumption and other liver diseases were excluded. NAFLD was diagnosed by ultrasonography and stratified as mild, moderate, or severe. Univariable and multivariable Cox proportional hazard regression was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) of incident hypertension according to the presence and 3 categories of severity of NAFLD.

RESULTS

During a median of 12.6 years of follow-up, 10,638 participants progressed to hypertension from prehypertension. After adjusting for multiple risk factors, patients with prehypertension and NAFLD had a 15% higher risk of incident hypertension than those without NAFLD (HR = 1.15, 95% CI 1.10-1.21). Moreover, the severity of NAFLD was associated with the incidence of hypertension, which was higher in patients with more severe NAFLD (HR = 1.15 [95% CI 1.10-1.21] in the mild NAFLD group; HR = 1.15 [95% CI 1.07-1.24] in the moderate NAFLD group; and HR = 1.20 [95% CI 1.03-1.41] in the severe NAFLD group). Subgroup analysis indicated that age and baseline systolic blood pressure may modify this association.

CONCLUSIONS

NAFLD is an independent risk factor for hypertension in patients with prehypertension. The risk of incident hypertension increases with the severity of NAFLD.

Risk Scores for Prediction of Major Cardiovascular Events in Non-Alcoholic Fatty Liver Disease: A No Man's Land?

Over the past 100 years, cardiovascular disease (CVD) has become a leading cause of mortality and morbidity in developed countries, and similar trends have occurred for chronic liver disease. Subsequent research also indicated that people with non-alcoholic fatty liver disease (NAFLD) had a twofold increased risk of CV events and that this risk was doubled in those with liver fibrosis. However, no validated CVD risk score specific for NAFLD patients has yet been validated, as traditional risk scores tend to underestimate the CV risk in NAFLD patients. From a practical perspective, identifying NAFLD patients and assessing severity of liver fibrosis when concurrent atherosclerotic risk factors are already established may serve as an important criterion in new CV risk scores. The current review aims to assess current risk scores and their utility for the prediction of CV events among patients with NAFLD.

Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is a global public health problem. NAFLD is bidirectionally correlated with metabolic syndrome, which includes obesity, type 2 diabetes, hypertension, and dyslipidemia as major components. The presence of metabolic syndrome is associated with a higher prevalence of NAFLD, and vice versa. Also, the presence of metabolic syndrome in patients with NAFLD has been linked to a higher risk of cardiovascular diseases, liver-related complications, extrahepatic malignancies, and mortality, and possibly vice versa. Multidisciplinary care pathways including lifestyle modifications, control of metabolic risk, and potentially beneficial treatments are important to improve the clinical outcomes of patients with NAFLD.

Fatty liver index and cardiovascular outcomes in never-treated hypertensive patients: a prospective cohort

The prevalence of nonalcoholic fatty liver disease (NAFLD) has been increasing rapidly worldwide, affecting 25-30% of the population. Fatty liver index (FLI) is a validated marker of NAFLD and can be used as a screening tool for hepatic steatosis. The purpose of the study was to evaluate the relationship between FLI and the risk of major cardiovascular events in never treated hypertensive patients. We included 903 hypertensive patients without a history of cardiovascular disease (mean age 52.7 ± 11.4 years; men 55%; baseline clinic BP 149.8 ± 15.2/95.5 ± 10.1 mmHg). Participants were prospectively evaluated for a mean follow-up period of 5.2 ± 3.2 years with at least one annual visit. Patients were also categorized into two groups using an FLI of 60 units. The incidence of cardiovascular events during follow-up was 8.5% (n = 77). Patients with FLI < 60 (n = 625) had a better BP control compared to their counterparts with FLI ≥ 60 (n = 278) during follow up (43% vs 33%, p = 0.02). Cox-regression analysis indicated that FLI (Hazard Ratio [HR], 1.05; 95% Confidence Interval [CI], 1.03-1.07, p < 0.001), FLI z-scores (HR, 3.66; 95% CI, 2.22-6.04) and high-risk FLI (HR, 7.5; 95% CI, 3.12-18.04) were independent determinants of the outcome after adjustment for baseline and follow-up variables. Stratification by diabetes mellitus indicated that FLI predicted the outcome to a greater extent in those with than those without diabetes (P-interaction < 0.001). In conclusion, FLI has an independent prognostic value for the incidence of cardiovascular events in newly diagnosed, never-treated hypertensive patients. Therefore, FLI might identify higher-risk patients in the primary prevention of hypertension.

Antitumor Effects and Mechanisms of Metabolic Syndrome Medications on Hepatocellular Carcinoma

Liver cancer has a high incidence and mortality rate worldwide, with hepatocellular carcinoma (HCC) being the most common histological type. With the decrease in the number of newly infected patients and the spread of antiviral therapy, hepatitis virus-negative chronic liver diseases including steatohepatitis are increasingly accounting for a large proportion of HCC, and an important clinical characteristic is the high prevalence of metabolic syndrome including hypertension, type 2 diabetes (T2D), dyslipidemia, and obesity. Since patients with steatohepatitis are less likely to undergo surveillance for early detection of HCC, they may be diagnosed at an advanced stage and have worse prognosis. Therefore, treatment strategies for patients with HCC caused by steatohepatitis, especially in advanced stages, become increasingly important. Further, hypertension, T2D, and dyslipidemia may occur as side effects during systemic treatment, and there will be increasing opportunities to prescribe metabolic syndrome medications, not only for originally comorbid diseases, but also for adverse events during HCC treatment. Interestingly, epidemiological studies have shown that patients taking some metabolic syndrome medications are less likely to develop various types of cancers, including HCC. Basic studies have also shown that these drugs have direct antitumor effects on HCC. In particular, angiotensin II receptor blockers (a drug group for treating hypertension), biguanides (a drug group for treating T2D), and statins (a drug group for treating dyslipidemia) have shown to elucidate antitumor effects against HCC. In this review, we focus on the antitumor effects of metabolic syndrome medications on HCC and their mechanisms based on recent literature. New therapeutic agents are also increasingly being reported. Analysis of the antitumor effects of metabolic syndrome medications on HCC and their mechanisms will be doubly beneficial for HCC patients with metabolic syndrome, and the use of these medications may be a potential strategy against HCC.

Association between serum liver enzymes and hypertension using propensity score matching analysis: evidence from a large kurdish prospective cohort study

Background

The association between liver enzymes and hypertension (HTN) has been reported in some studies and the findings are inconsistent. This study was conducted to evaluate the association of liver enzymes with HTN among the Iranian Kurdish population.

Methods

This prospective cohort study was a part of the 5-years (2017–2021) follow-up phase of the Ravansar Non-Communicable Disease (RaNCD) cohort study in Kermanshah province, western Iran.The association between alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glut amyl transferase (GGT), and alkaline phosphatase (ALP) and HTN was investigated by Cox proportional-hazard model (CPHM). We used one-to-one Propensity score matching (PSM) analysis to minimize the effects of confounding factors on the relationship between liver enzymes and HTN .

Results

The full population included a total of 8267 participants. According to PSM, for liver enzyme GGT a total of 3664 participants were analyzed. The results of multivariate CPHM showed there is a relationship between participants with high level of GGT and had a higher risk of HTN (HR 1.34; 95% CI: 1.11–1.63). After PSM analysis, the effect of GGT on HTN remained positive and significant (HR 1.48; 95% CI: 1.22–1.78). The 5-years incidence rate of HTN in men and women were 1.27 and 0.81 (person-year), respectively.GGT had the greatest accuracy, which demonstrated an AUROC of 0.7837.

Conclusion

Results of this study showed GGT could be a potential biomarker among liver enzymes for early detection of HTN. Therefore, monitoring GGT levels is helpful in the early detection of HTN.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02884-3.

Liver-function parameters are associated with incident hypertension in a large Taiwanese population follow-up study

Previous studies demonstrated inconsistent results regarding the association between liver function and hypertension. In addition, large cohort follow-up studies are lacking. Therefore, this longitudinal study aimed to investigate the association between liver function and incident hypertension using data from the Taiwan Biobank (TWB). We evaluated liver biomarkers, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, alpha-fetoprotein (AFP), total bilirubin, and gamma-glutamyl transferase (GGT) in this study. A total of 21,293 participants without hypertension at baseline were analyzed. During the mean 3.9-year follow-up, 3002 participants developed hypertension (defined as incident hypertension). Multivariable analysis revealed that high AST (odds ratio [OR], 1.004; 95% confidence interval [CI], 1.001-1.007; p = 0.014), high ALT (OR, 1.004; 95% CI, 1.002-1.006; p < 0.001), high albumin (OR, 1.897; 95% CI, 1.573-2.286; p < 0.001), and high GGT (OR, 1.004; 95% CI, 1.003-1.005; p < 0.001) were significantly associated with incident hypertension in all study participants. In subgroup analysis of the participants with an ALT level ≤2 times the normal limit (80 u/l) (n = 20,983), multivariable analysis demonstrated that high ALT (OR, 1.009; 95% CI, 1.005-1.012; p < 0.001) and high GGT (OR, 1.005; 95% CI, 1.003-1.006; p < 0.001) were significantly associated with incident hypertension. In conclusion, we found that elevated AST, ALT, albumin, and GGT were associated with incident hypertension in a large Taiwanese cohort. A greater understanding of potential risk factors for hypertension may help to reduce the burden of hypertension in this Taiwanese population.

Malaysian Society of Gastroenterology and Hepatology consensus statement on metabolic dysfunction-associated fatty liver disease

The Malaysian Society of Gastroenterology and Hepatology saw the need for a consensus statement on metabolic dysfunction-associated fatty liver disease (MAFLD). The consensus panel consisted of experts in the field of gastroenterology/hepatology, endocrinology, bariatric surgery, family medicine, and public health. A modified Delphi process was used to prepare the consensus statements. The panel recognized the high and increasing prevalence of the disease and the consequent anticipated increase in liver-related complications and mortality. Cardiovascular disease is the leading cause of mortality in MAFLD patients; therefore, cardiovascular disease risk assessment and management is important. A simple and clear liver assessment and referral pathway was agreed upon, so that patients with more severe MAFLD can be linked to gastroenterology/hepatology care, while patients with less severe MAFLD can remain in primary care or endocrinology, where they are best managed. Lifestyle intervention is the cornerstone in the management of MAFLD. The panel provided a consensus on the use of statin, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, sodium-glucose cotransporter-2 inhibitor, glucagon-like peptide-1 agonist, pioglitazone, vitamin E, and metformin, as well as recommendations on bariatric surgery, screening for gastroesophageal varices and hepatocellular carcinoma, and liver transplantation in MAFLD patients. Increasing the awareness and knowledge of the various stakeholders on MAFLD and incorporating MAFLD into existing noncommunicable disease-related programs and activities are important steps to tackle the disease. These consensus statements will serve as a guide on MAFLD for clinicians and other stakeholders.

Evaluation of Relationship between Serum Liver Enzymes and Hypertension: A Cross-Sectional Study Based on Data from Rafsanjan Cohort Study

Background. Hypertension as a major risk factor for cardiovascular diseases is among the leading causes of death worldwide. The relationship between elevated serum levels of liver enzymes and hypertension has been reported in limited studies, and to the best of our knowledge, there are no previous reports in the literature on this issue in the southeast of Iran. Our investigation aimed at evaluating the relation between ALT, AST, GGT, and ALP with hypertension in the Rafsanjan Cohort Study, a city in Kerman Province, Iran. Methods. In this cross-sectional study, we used data obtained from the Rafsanjan Cohort Study (RCS), as a part of the prospective epidemiological research studies in Iran (PERSIAN). The association of the liver enzymes levels with hypertension was investigated using the multivariable logistic regression models. Results. Among 9930 participants, the mean age (±SD) was 49.94 (±9.56) years, and 46.56% were men. The odds of abnormal blood pressure significantly increased along with the higher levels of ALT, GGT, and ALP which remained significant only for ALP after adjustment for all confounding variables in both males and females (OR in males: 1.36, 95% CI = 1.09–1.69, OR in females: 1.25, 95% CI = 1.01–1.54). In subjects with normal levels of ALT, AST, GGT, and ALP, dose-response increases were observed for abnormal blood pressure in both genders. Finally, we found that, among liver enzymes, only elevated ALP was significantly correlated with the odds of stage 1 hypertension and stage 2 hypertension for both genders. Conclusions. In subjects with normal levels of ALT, AST, GGT, and ALP, dose-response increases were observed for abnormal blood pressure in both genders. Increased serum ALP activity was positively associated with increased odds of hypertension in males and females. Therefore, increased ALP could be an early indicator of hypertension.

Nonalcoholic fatty liver disease and risk of incident hypertension: a systematic review and meta-analysis

Several studies reported an association between nonalcoholic fatty liver disease (NAFLD) and the risk of incident hypertension. The objective of this systematic review and meta-analysis was to obtain a precise and reliable estimate of the nature and magnitude of this association. We systematically searched Ovid-MEDLINE up to March 2021 for observational studies in which NAFLD was diagnosed in adults using blood-based panels, imaging techniques or liver biopsy and with a follow-up ≥1 year. Measures of association from individual studies were meta-analyzed using random-effects models. Of the 1108 titles initially scrutinized, we included 11 cohort studies with data on 390 348 participants (52% male) and a mean follow-up of 5.7 years. In the overall analysis, NAFLD was associated with a moderately increased risk of incident hypertension (hazard ratio 1.66; 95% confidence interval (CI), 1.38-2.01; test for overall effect z = 5.266; P < 0.001). There was significant heterogeneity among the studies (P < 0.001). Sensitivity analyses showed that estimates were not affected by geographical location, duration of follow-up and adjustment for baseline blood pressure values. On the other hand, the magnitude of the association was lower in studies that adjusted for baseline adiposity compared with those that did not, explaining part of the observed heterogeneity. No significant publication bias was detected by funnel plot analysis and Egger's and Begg's tests. This large meta-analysis indicates that NAFLD is associated with a ~1.6-fold increased risk of developing hypertension. Further studies are needed to investigate the role of NAFLD severity in terms of inflammation and fibrosis on incident hypertension.

The National Consensus statement on the management of adult patients with non-alcoholic fatty liver disease and main comorbidities

The National Consensus was prepared with the participation of the National Medical Association for the Study of the Multimorbidity, Russian Scientific Liver Society, Russian Association of Endocrinologists, Russian Association of Gerontologists and Geriatricians, National Society for Preventive Cardiology, Professional Foundation for the Promotion of Medicine Fund PROFMEDFORUM. The aim of the multidisciplinary consensus is a detailed analysis of the course of non-alcoholic fatty liver disease (NAFLD) and the main associated conditions. The definition of NAFLD is given, its prevalence is described, methods for diagnosing its components such as steatosis, inflammation and fibrosis are described. The association of NAFLD with a number of cardio-metabolic diseases (arterial hypertension, atherosclerosis, thrombotic complications, type 2 diabetes mellitus (T2DM), obesity, dyslipidemia, etc.), chronic kidney disease (CKD) and the risk of developing hepatocellular cancer (HCC) were analyzed. The review of non-drug methods of treatment of NAFLD and modern opportunities of pharmacotherapy are presented. The possibilities of new molecules in the treatment of NAFLD are considered: agonists of nuclear receptors, antagonists of pro-inflammatory molecules, etc. The positive properties and disadvantages of currently used drugs (vitamin E, thiazolidinediones, etc.) are described. Special attention is paid to the multi-target ursodeoxycholic acid (UDCA) molecule in the complex treatment of NAFLD as a multifactorial disease. Its anti-inflammatory, anti-oxidant and cytoprotective properties, the ability to reduce steatosis an independent risk factor for the development of cardiovascular pathology, reduce inflammation and hepatic fibrosis through the modulation of autophagy are considered. The ability of UDCA to influence glucose and lipid homeostasis and to have an anticarcinogenic effect has been demonstrated. The Consensus statement has advanced provisions for practitioners to optimize the diagnosis and treatment of NAFLD and related common pathogenetic links of cardio-metabolic diseases.

MAFLD/NAFLD Biopsy-Free Scoring Systems for Hepatic Steatosis, NASH, and Fibrosis Diagnosis

Metabolic dysfunction-associated fatty liver disease (MAFLD), formerly known as nonalcoholic fatty liver disease, is the most prevalent liver disorder worldwide. Historically, its diagnosis required biopsy, even though the procedure has a variable degree of error. Therefore, new non-invasive strategies are needed. Consequently, this article presents a thorough review of biopsy-free scoring systems proposed for the diagnosis of MAFLD. Similarly, it compares the severity of the disease, ranging from hepatic steatosis (HS) and nonalcoholic steatohepatitis (NASH) to fibrosis, by contrasting the corresponding serum markers, clinical associations, and performance metrics of these biopsy-free scoring systems. In this regard, defining MAFLD in conjunction with non-invasive tests can accurately identify patients with fatty liver at risk of fibrosis and its complications. Nonetheless, several biopsy-free scoring systems have been assessed only in certain cohorts; thus, further validation studies in different populations are required, with adjustment for variables, such as body mass index (BMI), clinical settings, concomitant diseases, and ethnic backgrounds. Hence, comprehensive studies on the effects of age, morbid obesity, and prevalence of MAFLD and advanced fibrosis in the target population are required. Nevertheless, the current clinical practice is urged to incorporate biopsy-free scoring systems that demonstrate adequate performance metrics for the accurate detection of patients with MAFLD and underlying conditions or those with contraindications of biopsy.

Fibroblast growth factor 21 levels and liver inflammatory biomarkers in obese subjects after weight loss

INTRODUCTION

Previous studies have hypothesized fibroblast growth factor 21 (FGF-21) as a potential biomarker of the inflammation associated with liver diseases, which is also receiving considerable attention for its potential application concerning the management of obesity and co-morbidities. This study aimed to analyze the response of FGF-21 after a weight loss intervention and the relationships with other putative inflammatory liver biomarkers.

MATERIAL AND METHODS

Sixty-six obese participants from the RESMENA study were evaluated at baseline and following a 6-month energy restriction treatment. Anthropometric, body composition by DXA, routine laboratory measurements, which included transaminases and γ-glutamyl transferase (GGT) were analyzed by standardized methods. Moreover, FGF-21, M30 fragment (M30) and plasminogen activator inhibitor-1 (PAI-I) were analyzed as recognized liver inflammatory related biomarkers with specific ELISA kits.

RESULTS

Most measurements related to hepatic damage, inflammation and adiposity status improved at the end of the 6-month nutritional intervention. In addition, ΔFGF-21 shifts showed statistical relationships with changes in ΔM30, ΔGGT and ΔPAI. The reduction of M30 showed significant associations with changes in transaminases. Furthermore, PAI-I changes were associated with ΔM30 and ΔGGT regardless of weight loss. A linear regression model was set up to assess the influence of ΔPAI-I and ΔM30 on the variability of ΔFGF-21 (23.8%) adjusted by weight loss.

CONCLUSIONS

These results demonstrated interactions of some liver inflammatory mediators, specifically M30 and PAI-I with FGF-21. Thus, more investigation about FGF-21 is required given that this protein could be a biomarker of the obesity-inflammation-liver process.

Bidirectional Association between Hypertension and NAFLD: A Systematic Review and Meta-Analysis of Observational Studies

An increasing body of evidence connects non-alcoholic fatty liver disease (NAFLD) to hypertension. The objective of this systematic review and meta-analysis was to estimate the nature and magnitude of the association between NAFLD and hypertension. We systematically searched PubMed, Embase, Cochrane Library, and Web of Science for observational studies published up to May 1, 2021. Cohort studies that reported data on the association between NAFLD and incident hypertension or between hypertension and incident NAFLD were included. We used random-effects models to conduct meta-analysis on the measures of association from individual studies. A total of 11 studies were eligible for inclusion, among which 4 studies including 25,260 participants reported the association between hypertension and new-onset NAFLD. The presence of hypertension was significantly associated with an increased risk of incident NAFLD (HR 1.63, 95% CI: 1.41-1.88; I ² = 37.6%). On the other hand, 9 studies with data on 46,487 participants analyzed the effects of NAFLD on incident hypertension. Pooled analysis showed that the presence of NAFLD was significantly associated with an increased incidence of hypertension (HR 1.55, 95% CI: 1.29-1.87; I ² = 80.5%). There was significant heterogeneity among the studies in this analysis (p < 0.01). Sensitivity analyses showed that the magnitude of the association was significantly different in subgroups stratified by a mean age of participants and geographical location, which explains part of the heterogeneity. In conclusion, this meta-analysis indicates the existence of a bidirectional relationship between NAFLD and hypertension independent of traditional cardiometabolic risk factors.

In utero exposure to parabens and early childhood BMI z-scores - Associations between placental ethyl paraben, longitudinal BMI trajectories and cord blood metabolic biomarkers

BACKGROUND

Parabens are used as antimicrobial preservatives in personal care products. Few studies have dealt with adverse health outcomes, transplacental transfer, and obesogenic effects of prenatal exposure to parabens. We examined the association between placental paraben levels and cord blood metabolic biomarkers, considering modulating effects of maternal pre-pregnancy BMI and underlying epigenetic mechanisms, and investigated longitudinal effects of in utero paraben exposure on early childhood trajectories of BMI z-scores.

METHODS

Placental concentrations of four parabens [methyl (MeP), ethyl (EtP), propyl (PrP), and butyl (BuP)] were measured by ultra-performance liquid chromatography/tandem mass spectrometry in 229 placentas of the ENVIRONAGE birth cohort. The association with cord blood metabolic biomarkers [glucose, insulin, γ-glutamyltransferase (GGT), high-density and low-density lipoprotein (HDL and LDL)] was analyzed in multiple regression models with two different sets of, a priori selected potential confounders, additionally stratified for different maternal BMI groups and assessed by causal mediation analysis. The association between placental paraben concentration and differential DNA methylation of CpGs annotated to GGT and longitudinal measurements of BMI z-scores were investigated with adjusted linear mixed models.

RESULTS

The geometric means of placental MeP, EtP, PrP, and BuP levels above the limit of detection (LOD) were 4.42, 1.32, 1.51, and 0.35 ng/g respectively, with only EtP showing sufficient (88%) measurements above LOD for further analyses. An interquartile ratio (IQR) increase in placental EtP was associated with an increase of 12.61 % (95% CI: 1.80 24.57) in the geometric mean of cord GGT activity, and with a decrease of -3.64 % (95% CI: -6.80 to -0.39) in the geometric mean of cord glucose. Placental EtP levels were significantly associated with hypermethylation of cg08612779 annotated to GGT7 after correcting for multiple testing (ß = 0.0017, p = 0.049). An interquartile ratio (IQR) increment in placental EtP was associated with a decrease in longitudinal BMI z-score of 0.27 points (95% CI: -0.46 to -0.088).

CONCLUSION

Prenatal EtP exposure may affect early childhood BMI. The association of placental EtP with cord blood GGT and glucose levels provides a starting point for further research on mechanisms of paraben-related metabolic processes in utero.

Impact of Helicobacter pylori-Related Metabolic Syndrome Parameters on Arterial Hypertension

Arterial hypertension is a risk factor for several pathologies, mainly including cardio-cerebrovascular diseases, which rank as leading causes of morbidity and mortality worldwide. Arterial hypertension also constitutes a fundamental component of the metabolic syndrome. Helicobacter pylori infection is one of the most common types of chronic infection globally and displays a plethora of both gastric and extragastric effects. Among other entities, Helicobacter pylori has been implicated in the pathogenesis of the metabolic syndrome. Within this review, we illustrate the current state-of-the-art evidence, which may link several components of the Helicobacter pylori-related metabolic syndrome, including non-alcoholic fatty liver disease and arterial hypertension. In particular, current knowledge of how Helicobacter pylori exerts its virulence through dietary, inflammatory and metabolic pathways will be discussed. Although there is still no causative link between these entities, the emerging evidence from both basic and clinical research supports the proposal that several components of the Helicobacter pylori infection-related metabolic syndrome present an important risk factor in the development of arterial hypertension. The triad of Helicobacter pylori infection, the metabolic syndrome, and hypertension represents a crucial worldwide health problem on a pandemic scale with high morbidity and mortality, like COVID-19, thereby requiring awareness and appropriate management on a global scale.

Blood Plasma's Protective Ability against the Degradation of S-Nitrosoglutathione under the Influence of Air-Pollution-Derived Metal Ions in Patients with Exacerbation of Heart Failure and Coronary Artery Disease

One of the consequences of long-term exposure to air pollutants is increased mortality and deterioration of life parameters, especially among people diagnosed with cardiovascular diseases (CVD) or impaired respiratory system. Aqueous soluble inorganic components of airborne particulate matter containing redox-active transition metal ions affect the stability of S-nitrosothiols and disrupt the balance in the homeostasis of nitric oxide. Blood plasma’s protective ability against the decomposition of S-nitrosoglutathione (GSNO) under the influence of aqueous PM extract among patients with exacerbation of heart failure and coronary artery disease was studied and compared with a group of healthy volunteers. In the environment of CVD patients’ plasma, NO release from GSNO was facilitated compared to the plasma of healthy controls, and the addition of ascorbic acid boosted this process. Model studies with albumin revealed that the amount of free thiol groups is one of the crucial factors in GSNO decomposition. The correlation between the concentration of NO released and -SH level in blood plasma supports this conclusion. Complementary studies on gamma-glutamyltranspeptidase activity and ICP-MS multielement analysis of CVD patients’ plasma samples in comparison to a healthy control group provide broader insights into the mechanism of cardiovascular risk development induced by air pollution.

Circulating PCSK7 Level is Independently Associated with Obesity, Triglycerides Level and Fatty Liver Index in a General Population without Medication

AIM

Dyslipidemia and altered iron metabolism are typical features of non-alcoholic fatty liver disease (NAFLD). Proprotein convertase subtilisin/kexin type 7 (PCSK7), a transmembrane-anchored endonuclease, is associated with triglycerides level and processing of transferrin receptor 1. However, the significance of circulating PCSK7 has not been fully addressed, though prosegment PCSK7 is secreted from cells. We investigated the associations of plasma PCSK7 level with several parameters.

METHODS

Plasma PCSK7 concentration was measured in 282 subjects (male/female: 126/156) without medication of the Tanno-Sobetsu Study, a population-based cohort study.

RESULTS

There was no significant sex difference in PCSK7 level. Current smoking habit, but not alcohol drinking habit, was associated with increased PCSK7 level. PCSK7 concentration was negatively correlated with age and blood urea nitrogen and was positively correlated with body mass index (BMI) and levels of γ-glutamyl transpeptidase (γGTP), triglycerides and fatty liver index (FLI), which is calculated by BMI, waist circumference and levels of γGTP and triglycerides, as a noninvasive and simple predictor of NAFLD. There were no significant correlations of PCSK7 level with levels of iron and plasma PCSK9, a secreted PCSK family member and a regulator of low-density lipoprotein cholesterol level. Multivariable regression analyses after adjustment of age, sex and current smoking habit showed that PCSK7 concentration was independently associated with BMI (β=0.130, P=0.035), triglycerides (β=0.141, P=0.027) or FLI (β=0.139, P=0.030).

CONCLUSIONS

Plasma PCSK7 concentration is independently associated with chronic liver disease including obesity and elevated triglycerides level in a general population of individuals who had not regularly taken any medications.

Independent association of plasma xanthine oxidoreductase activity with hypertension in nondiabetic subjects not using medication

Xanthine oxidoreductase (XOR), a rate-limiting and catalyzing enzyme of uric acid formation in purine metabolism, is involved in reactive oxygen species generation. Plasma XOR activity has been shown to be a novel metabolic biomarker related to obesity, liver dysfunction, hyperuricemia, dyslipidemia, and insulin resistance. However, the association between plasma XOR activity and hypertension has not been fully elucidated. We investigated the association of hypertension with plasma XOR activity in 271 nondiabetic subjects (male/female: 119/152) who had not taken any medications in the Tanno-Sobetsu Study, a population-based cohort. Males had higher plasma XOR activity than females. Plasma XOR activity was positively correlated with mean arterial pressure (r = 0.128, P = 0.036). When the subjects were divided by the presence and absence of hypertension into an HT group (male/female: 34/40) and a non-HT group (male/female: 85/112), plasma XOR activity in the HT group was significantly higher than that in the non-HT group (median: 39 vs. 28 pmol/h/mL, P = 0.028). There was no significant difference in uric acid levels between the two groups. Multivariable logistic regression analysis showed that plasma XOR activity (odds ratio: 1.091 [95% confidence interval: 1.023-1.177] per 10 pmol/h/mL, P = 0.007) was an independent determinant of the risk for hypertension after adjustment for age, sex, current smoking and alcohol consumption, estimated glomerular filtration rate, brain natriuretic peptide, and insulin resistance index. The interaction of sex with plasma XOR activity was not significant for the risk of hypertension. In conclusion, plasma XOR activity is independently associated with hypertension in nondiabetic individuals who are not taking any medications.

Association between FTO (rs17817449) genetic variant, gamma-glutamyl transferase, and hypertension in Slovak midlife women

OBJECTIVES

This cross-sectional study investigates associations between the FTO rs 17817449 genetic variant, liver enzymes, and hypertension in Slovak midlife women.

METHODS

We assessed 576 Slovak women aged 39 to 65 years. The women were interviewed and examined during their medical examination at local Health Centers and then divided into subgroups according to their blood pressure status; 255 women with hypertension and 321 normotensive. The FTO genetic variant was detected by polymerase chain reaction-restriction fragment length polymorphism. Resultant data was analyzed by linear regression analysis and general linear models to adjust for risk factors associated with gamma-glutamyl transferase levels (GGT), including waist to hip ratio (WHR) and uric acid (UA).

RESULTS

A significant association between the FTO variant and GGT levels was observed in the hypertensive group after control for confounding covariates, including WHR and UA (p = .004). The predicted GGT level for GT/TT hypertensive carriers is 0.158 μkat/L higher than for GG carriers. Moreover, the two-way analysis of covariance revealed significant interaction between FTO effects and hypertension on logGGT levels (p = .042). Finally, hypertensive women with the T-allele had the highest estimated marginal mean value of logGGT at -0.39 μkat/L while the GG-genotype in both hypertensive and normotensive women had the lowest value at -0.54 μkat/L.

CONCLUSIONS

This study suggests that the FTO (rs17817449) variant is associated with higher serum GGT levels in hypertensive midlife women.

Elevated Fatty Liver Index Is Independently Associated With New Onset of Hypertension During a 10-Year Period in Both Male and Female Subjects

Background

Fatty liver index (FLI), a predictor of nonalcoholic fatty liver disease, has been reported to be associated with several metabolic disorders. Because of a sex difference in FLI level, we hypothesized that FLI is associated with development of hypertension to a greater extent in men or women.

Methods and Results

We investigated the relationship between FLI and development of hypertension during a 10‐year period in a general population of subjects who received annual health examinations (n=28 990). After exclusion (44.9%) of subjects with missing data and those with hypertension at baseline, a total of 15 965 subjects (men/women: 9466/6499) were included. FLI level was significantly higher in men than in women. During the 10‐year period, 2304 men (24.3%) and 745 women (11.5%) had new onset of hypertension. Multivariable Cox proportional hazard models with a restricted cubic spline showed that the hazard ratios (HRs) for development of hypertension after adjustment of age, systolic blood pressure, estimated glomerular filtration rate, habits of smoking and alcohol drinking, family history of hypertension, and diagnosis of diabetes mellitus and dyslipidemia increased gradually with increase in FLI in men and increased rapidly and then slowly with increase in FLI in women. There was a significant interaction between FLI and sex for the risk of hypertension in all of the subjects (P=0.049). The addition of FLI to traditional risk factors significantly improved the discriminatory capability.

Conclusions

A high level of FLI predicts the development of hypertension in both men and women, although distribution patterns of HRs were different between sexes.

Enhanced Susceptibility to Breast Cancer in Korean Women With Elevated Serum Gamma-Glutamyltransferase Levels: A Nationwide Population-Based Cohort Study

Background

The incidence of breast cancer has been gradually increasing in Korea. Recently, the elevated level of serum gamma-glutamyltransferase (GGT) has emerged to be associated with the development and progression of some malignancies. This study aimed to determine the effect of serum GGT levels on the risk of developing breast cancer in Korean women.

Methods

We used National Health Insurance Service Health Checkup data to examine the association between serum GGT levels and breast cancer development in Korean women. Women aged 40 years or older who participated in the Korean National Health Screening Examination between January 2009 and December 2009 and who did not develop any cancer within 1-year post examination were included in this analysis (n = 3,109,506). Cox proportional hazard regression analysis was conducted to calculate hazard ratios (HRs) with 95% confidence intervals (CIs).

Results

Overall, an elevated serum GGT level was associated with the increased risk of developing breast cancer; compared to the Q1 group, the Q4 group showed a significantly increased breast cancer risk (HR: 1.120,95% CI: 1.08-1.162). Such a relationship was stronger in post-menopausal women than pre-menopausal women (HR: 1.173, 95% CI: 1.107-1.243; HR: 1.070, 95% CI:1.019-1.124). Women with a high GGT level (Q4) were also at an increased risk of developing carcinoma in situ (CIS) (HR: 1.114, 95% CI: 1.04-1.192). In post-menopausal women, the Q4 group also exhibited higher CIS risk (HR: 1.266, 95% CI: 1.132-1.416). However, no significant difference in the risk of developing CIS was observed between the Q1 and Q4 groups in pre-menopausal women. Further analysis revealed that obese, post-menopausal women with a high GGT level (Q4) were associated with an increased risk of developing breast cancer (HR: 1.214, 95% CI: 1.125-1.31) and CIS (HR: 1.348, 95% CI: 1.159-1.569).

Conclusions

Our study results demonstrate that increased serum GGT level is a risk factor for developing breast cancer. The post-menopausal women group with obesity and elevated serum GGT level showed the highest incidence of breast cancer. Thus, serum GGT concentration could be a novel and potential risk factor for breast cancer. Further validation in different ethnic groups would be warranted.

Nonalcoholic fatty liver disease and cardiovascular concerns: The time for hepatologist and cardiologist close collaboration

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver cell damage worldwide. It is strongly associated with an increased risk of cardiovascular disease (CVD). There are not enough recommendations for screening subjects with nonalcoholic steatohepatitis cirrhosis, who are not candidates for liver transplantation, nor who are asymptomatic with NAFLD without cirrhosis. In the current comprehensive narrative review, we aimed to evaluate the associations between CVD and NAFLD. Distinguishing the mechanisms linking these two disorders offers the opportunity to develop targeted therapies. Moreover, we will discuss screening approaches (whom and how-to) and treatment modalities proposed to reduce cardiovascular risk in patients with NAFLD.

Association Between Sex-Specific Serum Gamma-Glutamyltransferase and Incidence of Hypertension in a Chinese Population Without Metabolic Syndrome: A Prospective Observational Study

Background: Higher serum gamma-glutamyltransferase (GGT) is associated with high risk of hypertension. We aimed to examine the association between sex-specific serum GGT levels and incident of hypertension in a Chinese population without metabolic syndrome. Methods: Participants who were free of hypertension and metabolic syndrome from the First Affiliated Hospital of Wenzhou Medical University between 2009 and 2014 were included. Participants were grouped into sex-specific quartiles of GGT levels (Q1-Q4) defined as: ≤19, 20-26, 27-38, and ≥39 U/L for male; ≤12, 13-15, 16-19, and ≥20 U/L for female. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incidence of hypertension according to sex-specific quartiles of GGT levels. Kaplan-Meier analysis and interaction analysis were conducted. Results: Among 38,806 participants included (average age 36.0 years, 54.0% men), 4,505 of them developed hypertension. In the overall study population, using Q1 as the reference group, participants in Q2, Q3, and Q4 showed a higher risk of developing hypertension, with HRs (95% CIs) of 1.126 (1.029-1.232), 1.187 (1.083-1.302), and 1.300 (1.182-1.431), respectively (P < 0.001), after adjusting for known confounders. Sex-specific analysis showed that the adjusted HRs for participants in Q4 (reference: Q1) were greater in females [1.321 (1.100-1.586, P < 0.001)] than in males [1.268 (1.133-1.420, P < 0.001)] (P for interaction = 0.047). Moreover, interaction analysis showed that this association was consistently observed when the participants were stratified by age, body mass index, and fatty liver status. Conclusion: Among Chinese adults without metabolic syndrome, serum GGT level was positively associated with incidence of hypertension, and the association was stronger in females than in males.

Gamma-glutamyltransferase, arterial remodeling and prehypertension in a healthy population at low cardiometabolic risk

Plasma gamma-glutamyltransferase (GGT) was suggested to reflect the level of systemic oxidative stress. Oxidative stress induces changes in arterial structure and function and contributes to the development of hypertension. Therefore, GGT may be associated with arterial remodeling and blood pressure (BP) increment, even in absence of disease. To test this hypothesis, we evaluated, in 825 healthy subjects at low cardiometabolic risk, the associations of plasma GGT with carotid artery intima-media thickness (IMT), luminal diameter and prehypertension; in 154 subjects was evaluated also the association with aortic stiffness (cfPWV). Associations were controlled for insulin sensitivity, C-reactive protein, and life-style habits. In the main population, BP was remeasured after 3 years. Carotid diameter and cfPWV, but not IMT, were directly and independently related to plasma GGT. Subjects with prehypertension (N = 330) had higher GGT as compared with subjects with normal BP (22 [14] vs 17 [11] IU/L; adjusted P = 0.001), and within prehypertensive subjects, those who developed hypertension during 3 years had higher GGT than those without incident hypertension (27 [16] vs 21 [14] IU/L; adjusted P < 0.05). Within subjects with arterial stiffness measurement, those with prehypertension (N = 79) had higher both GGT and arterial stiffness (25 [14] vs 16 [20] IU/L and 9.11 ± 1.24 vs 7.90 ± 0.94 m/s; adjusted P < 0.01 and <0.05). In the view of previous evidence linking plasma GGT concentration to the level of systemic oxidative stress, our findings suggest a role of oxidative stress in subclinical arterial damage and in prehypertension, even in healthy subjects free of cardiometabolic risk. Arterial organ damage may represent the link between GGT and hypertension.

Nonalcoholic Fatty Liver Disease and Cardiovascular Diseases: The Heart of the Matter

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most frequent cause of liver disease worldwide, comprising a plethora of conditions, ranging from steatosis to end-stage liver disease. Cardiovascular disease (CVD) has been associated with NAFLD and CVD-related events represent the main cause of death in patients with NAFLD, surpassing liver-related mortality. This association is not surprising as NAFLD has been considered a part of the metabolic syndrome and has been related to numerous CVD risk factors, namely, insulin resistance, abdominal obesity, dyslipidemia, hyperuricemia, chronic kidney disease, and type 2 diabetes. Moreover, both NAFLD and CVD present similar pathophysiological mechanisms, such as increased visceral adiposity, altered lipid metabolism, increased oxidative stress, and systemic inflammation that could explain their association. Whether NAFLD increases the risk for CVD or these diagnostic entities represent distinct manifestations of the metabolic syndrome has not yet been clarified. This review focuses on the relation between NAFLD and the spectrum of CVD, considering the pathophysiological mechanisms, risk factors, current evidence, and future directions.

NAFLD and cardiovascular diseases: a clinical review

Non-alcoholic fatty liver DISEASE (NAFLD) is the most common chronic liver disease in Western countries and affects approximately 25% of the adult population. Since NAFLD is frequently associated with further metabolic comorbidities such as obesity, type 2 diabetes mellitus, or dyslipidemia, it is generally considered as the hepatic manifestation of the metabolic syndrome. In addition to its potential to cause liver-related morbidity and mortality, NAFLD is also associated with subclinical and clinical cardiovascular disease (CVD). Growing evidence indicates that patients with NAFLD are at substantial risk for the development of hypertension, coronary heart disease, cardiomyopathy, and cardiac arrhythmias, which clinically result in increased cardiovascular morbidity and mortality. The natural history of NAFLD is variable and the vast majority of patients will not progress from simple steatosis to fibrosis and end stage liver disease. However, patients with progressive forms of NAFLD, including non-alcoholic steatohepatitis (NASH) and/or advanced fibrosis, as well as NAFLD patients with concomitant types 2 diabetes are at highest risk for CVD. This review describes the underlying pathophysiological mechanisms linking NAFLD and CVD, discusses the role of NAFLD as a metabolic dysfunction associated cardiovascular risk factor, and focuses on common cardiovascular manifestations in NAFLD patients.

Associations of Coffee Consumption with the Circulating Level of Alanine Aminotransferase and Aspartate Aminotransferase. A Meta-Analysis of Observational Studies

Background: The associations of coffee consumption with the circulating level of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) remains controversial. We conducted a meta-analysis of observational studies to sum up the existing evidence about this matter.Methods: A comprehensive literature-search up to January 2020, using PubMed, Embase and Web of Science databases, was conducted to identify the relevant observational studies that examined the associations of coffee consumption with the circulating level of ALT and AST. The standard mean difference (SMD) for the level of ALT and AST, odds ratio (OR) for the elevated ALT and AST and their corresponding 95% CIs for the highest versus lowest categories of coffee intake were determined.Results: A total of 19 observational studies, which involved 222,067 individuals, were included in this meta-analysis. The combined SMD suggested that coffee consumption was associated with a lower level of ALT (SMD = -0.14, 95% CI: -0.22 to -0.06; p = 0.001) and AST (SMD = -0.17, 95% CI: -0.20 to -0.13; p < 0.001), respectively. Meanwhile, the overall multivariable adjusted OR showed that coffee consumption was inversely associated with the elevated ALT (OR = 0.69, 95% CI: 0.60 to 0.79; p < 0.001) and AST (OR = 0.62, 95% CI: 0.48 to 0.81; p < 0.001), respectively.Conclusion: The results of this meta-analysis suggest that coffee consumption is inversely associated with the circulating level of ALT and AST, and elevated ALT and AST. More randomized controlled trials are needed to elaborate the concerned issues.

Association between serum liver enzymes and hypertension: a cross-sectional study in Bangladeshi adults

BACKGROUND

Hypertension is a major contributing factor to cardiovascular disease and is a leading cause of death in the world. The association between hepatic enzymes and hypertension has been reported in limited studies and the findings are inconsistent; data from Bangladeshi adults are not available yet. This study was conducted to estimate the prevalence of elevated liver enzymes and evaluate the association of elevated liver enzymes with hypertension in Bangladeshi adults.

METHODS

In this cross-sectional study, 302 blood samples were collected from adult participants and analyzed the serum concentrations of alanine and aspartate aminotransferase (ALT, AST), alkaline phosphatase (ALP), and γ-glutamyltransferase (GGT) and other markers related to hypertension. Hypertension was defined as resting SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg. Associations between elevated liver enzymes and hypertension were evaluated by multinomial logistic regression.

RESULTS

The mean concentrations of serum ALT, AST and GGT were significantly higher in the hypertensive group compared to the normotensive group (p < 0.01, p < 0.01 and p < 0.001, respectively). Overall, 49.2% of subjects in the hypertensive group and 38.1% of individuals in the normotensive group had at least one or more elevated liver enzymes. The prevalence of elevated ALT, AST, and GGT was significantly higher among participants in the hypertensive group compared to the normotensive group (p < 0.01, p < 0.01 and p < 0.001, respectively). An increasing trend for elevated liver enzymes was observed with increasing blood pressure. Serum ALT and GGT showed an independent relationship with hypertension.

CONCLUSIONS

The prevalence of elevated liver enzymes was higher in hypertensive individuals. Increased serum ALT and GGT activities were positively associated with hypertension in Bangladeshi adults.

Nonalcoholic Fatty Liver Disease

Hypertension, a multifactorial disorder resulting from the interplay between genetic predisposition and environmental risk factors, affects ≈30% of adults. Emerging evidence has shown that nonalcoholic fatty liver disease (NAFLD), as an underestimated metabolic abnormality, is strongly associated with an increased risk of incident prehypertension and hypertension. However, the role of NAFLD in the development of hypertension is still obscure and is highly overlooked by the general public. Herein, we highlight the epidemiological evidence and putative mechanisms focusing on the emerging roles of NAFLD in hypertension, with the purpose of reinforcing the notion that NAFLD may serve as an independent risk factor and an important driving force in the development and progression of hypertension. Finally, we also briefly summarize the current potential treatments for NAFLD that might also be beneficial approaches against hypertension.

Insulin resistance, but not insulin response, during oral glucose tolerance test (OGTT) is associated to worse histological outcome in obese NAFLD

BACKGROUND AND AIM

Obese subjects are at high risk of nonalcoholic fatty liver disease (NAFLD) and diabetes (T2D) due to insulin resistance (IR). Since high glucose levels are as toxic as lipids for hepatic metabolism, we hypothesize that altered response to oral glucose tolerance test (OGTT) is associated to more severe NAFLD with significant/advanced liver damage.

METHODS AND RESULTS

We studied 90 subjects with morbid obesity (73F/17M, BMI = 43.2 ± 5,9 kg/m²) undergoing bariatric surgery and intraoperative liver biopsy, and measured HbA1c, HOMA-IR (fasting Glucose x Insulin/22.5), OGTT glucose and insulin profile, and calculated OGIS (muscle insulin sensitivity), hepatic-IR (glucose [AUC_0-30] x insulin [AUC_0-30]) during OGTT, insulin response as (insulin [dAUC_0-120]/glucose [dAUC_0-120] or Insulinogenic Index (IGI = (I₃₀-I₀)/(G₃₀-G₀)). Patients were divided in 3 groups according to liver biopsy: A (no-NAFLD, 23%), B (simple steatosis (SS), 53%) and C (NASH, 24%) with similar age, gender and BMI. Diabetes was 0% in no-NAFLD, 13% in SS, 35% in NASH. During OGTT, OGIS decreased from A to C (422 vs 360 vs 338, p < 0.01). Increased insulin concentrations, HbA1c, HOMA-IR and OGIS, not Hep-IR, were strongly associated to hepatic steatosis (p = 0.03, p = 0.0001 and p = 0.01 respectively). Hepatic fibrosis stage was mild as most of the patients had fibrosis grade-1 (69% vs. 8% no fibrosis) and associated to fasting insulin, HbA1c and HOMA-IR. dAUC-I/dAUC-G was similar in the 3 groups, while only AUC-I was strongly associated to steatosis (r = 0.35, p = 0.005), but not to fibrosis.

CONCLUSIONS

In morbid obesity indexes of IR, and not of insulin response, are markers of histological severity of liver disease.

The Intricate Relationship between Type 2 Diabetes Mellitus (T2DM), Insulin Resistance (IR), and Nonalcoholic Fatty Liver Disease (NAFLD)

Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) remain as one of the most global problematic metabolic diseases with rapidly increasing prevalence and incidence. Epidemiological studies noted that T2DM patients have by two-fold increase to develop NAFLD, and vice versa. This complex and intricate association is supported and mediated by insulin resistance (IR). In this review, we discuss the NAFLD immunopathogenesis, connection with IR and T2DM, the role of screening and noninvasive tools, and mostly the impact of the current antidiabetic drugs on steatosis liver and new potential therapeutic targets.

Nonalcoholic fatty liver disease is an early predictor of metabolic diseases in a metabolically healthy population

Aims

The relationship between nonalcoholic fatty liver disease and incident metabolic syndrome in metabolically healthy subjects is unknown. We aimed to investigate whether nonalcoholic fatty liver disease is a predictor of future metabolic syndrome in metabolically healthy subjects.

Materials and methods

Subjects who underwent health evaluation at least twice between 2009 and 2015 from the National Health Insurance Service-National Sample Cohort in South Korea were included. Patients without obesity who had no metabolic syndrome components were finally analyzed (n = 28,880). The definition of nonalcoholic fatty liver disease was based on both the hepatic steatosis and fatty liver indices. The incidence of metabolic syndrome, prediabetes/type 2 diabetes, hypertension, and dyslipidemia was compared between the subjects with and without nonalcoholic fatty liver disease.

Results

The presence of nonalcoholic fatty liver disease was associated with a higher risk of incident metabolic syndrome, prediabetes/type 2 diabetes, hypertension, and dyslipidemia in the entire cohort (metabolic syndrome: adjusted hazard ratio, 2.10; 95% confidence interval, 1.18–3.71; prediabetes/type 2 diabetes: adjusted hazard ratio, 1.42; 95% confidence interval, 1.06–1.90; hypertension: adjusted hazard ratio, 2.36; 95% confidence interval, 1.35–4.12; dyslipidemia: adjusted hazard ratio, 1.49; 95% confidence interval, 1.07–2.06). A similar finding was observed in the age-, sex-, smoking status-, and body mass index-based 1:5 propensity score-matched cohort of 1,092 subjects (metabolic syndrome: adjusted hazard ratio, 3.56; 95% confidence interval, 1.79–7.07; prediabetes/type 2 diabetes: adjusted hazard ratio, 1.97; 95% confidence interval, 1.04–3.73; hypertension: adjusted hazard ratio, 2.57; 95% confidence interval, 1.35–4.88; dyslipidemia: adjusted hazard ratio, 1.61; 95% confidence interval, 1.12–2.32).

Conclusions

Nonalcoholic fatty liver disease is an early predictor of metabolic dysfunction even in metabolically healthy populations.

Fatty liver index (FLI) and prediction of new cases of non-alcoholic fatty liver disease: A population-based study of northern Iran

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease is considered a major public health concern. The prediction of individuals who can acquire this disease would be valuable. The fatty liver index (FLI) is a non-invasive approach that has shown a good capability for discriminating individuals with non-alcoholic fatty liver disease (NAFLD) from those without it. Thus, this study evaluated the ability of the FLI to predict new cases of NAFLD following a 7-year follow up.

MATERIALS AND METHODS

This study was based on the results of follow-up on individuals who did not have NAFLD in 2009-2010, but acquired the disease by 2016-2017. A total of 2241 people who did not have NAFLD in 2009-2010 were evaluated 7 years later by ultrasound so as to diagnose new cases of NAFLD. The FLI was calculated based on data from phase 1 (performed in 2009-2010) of the cohort study. ROC analyses were performed to estimate the predictive ability of the FLI in the diagnosis of new cases of NAFLD. Logistic regression analysis was performed, in which the FLI was considered the predictor and new cases of NAFLD was the outcome.

RESULTS

The related AUCs for the FLI in men and women were 0.712 (95% CI = 0.675-0.749) and 0.721 (95% CI = 0.683-0.759), respectively. Based on the current findings, the FLI showed a significant association with NAFLD in multiple logistic regression analyses in both men and women (OR (95% CI) = 1.038 (1.029-1.047), p-value <0.001 in men and OR (95% CI) = 1.032 (1.023-1.041), p-value <0.001 in women in multiple logistic analyses).

CONCLUSION

In this study, the FLI was shown to have an acceptable capability of predicting the occurrence of new cases of NAFLD.

Non-alcoholic fatty liver disease: Prevalence and all-cause mortality according to sedentary behaviour and cardiorespiratory fitness. The HUNT Study

PURPOSE

Sedentary behaviour (SB) and low physical activity (PA) are independently associated with non-alcoholic fatty liver disease (NAFLD). Compared to PA, high cardiorespiratory fitness (CRF) has been associated with a higher protection against all-cause mortality and a number of specific diseases. However, this relationship has not been investigated in NAFLD. This study examined the roles of SB and CRF on: i) the likelihood of having NAFLD in the general population, and ii) the risk of mortality over 9 years within individuals having NAFLD.

METHODS

A cross-sectional analysis of 15,781 adults (52% female; age range 19-95 years) was conducted. Self-reported SB was divided into tertiles. CRF was estimated using validated non-exercise models, and the presence of NAFLD from the Fatty Liver Index. Adjusted Odds Ratios and 95% Confidence Intervals for NAFLD were estimated using logistic regression analyses. Hazard Ratios for all-cause mortality were estimated using Cox proportional hazard regression in individuals with NAFLD.

RESULTS

For each additional 1 h/d of SB, the likelihood of having NAFLD was significantly increased by 4% (CI, 3-6%). In combined analyses, compared with the reference group [high CRF and low (≤4 h/d) SB], individuals with low CRF had a markedly higher likelihood of having NAFLD (OR, 16.9; CI 12.9-22.3), even if they had SB ≤ 4 h/d. High CRF attenuated the negative role of SB up to 7 h/d on NAFLD. Over 9.4 ± 1.3 years of follow-up, individuals with NAFLD and low CRF had the risk of mortality increased by 52% (CI, 10-106%) compared to those with high CRF, regardless of SB or meeting PA guidelines.

CONCLUSIONS

Low CRF increases the risk of premature death in individuals with NAFLD, and is strongly associated with higher likelihood of having NAFLD, outweighing the influence of SB.

Effects of Olive Leaf Extract on Metabolic Response, Liver and Kidney Functions and Inflammatory Biomarkers in Hypertensive Patients

BACKGROUND AND OBJECTIVE

Hypertension is a long-term medical condition in which the blood pressure is gradually elevated. In this project, the effects of olive leaf extract (OLE) were evaluated on metabolic response, liver and kidney functions and also biomarkers of inflammation in hypertensive patients.

MATERIALS AND METHODS

In this randomized double-blind placebo controlled clinical trial, 60 hypertensive patients, aged 30-60 years old had participated. Patients were randomly assigned into two groups to receive either OLE or placebo tablets for 12 weeks. At the beginning and end of the intervention, metabolic parameters and biomarkers of liver, kidney and inflammation were measured in sera of the participants using available laboratory methods.

RESULTS

Compared with the placebo, changes in parameters associated with glucose metabolism were not statistically significant (p>0.05). The OLE tablets did not have significant effect on liver enzymes, total protein, albumin, urea and creatinine (p>0.05), but significantly decreased interleukin-6, interleukin-8 and tumor necrosis factor alpha as inflammatory biomarkers (p<0.05) in OLE group compared to the placebo group.

CONCLUSION

The results concluded that inflammation as a major cause of hypertension was significantly decreased in patients using OLE tablets.

Serum Gamma-Glutamyltransferase Levels are Associated with Cardiovascular Risk Factors in China: A Nationwide Population-Based Study

Serum gamma-glutamyltransferase (GGT), which is mainly derived from the liver, is a sensitive marker of liver cell damage and oxidative stress. More recently, it has been found that increased GGT plasma activity is also associated with cardiovascular disease (CVD). However, data on the relationship between GGT and cardiovascular risk factors (CRFs) are lacking in nationally representative samples of the Chinese population. Here, we aim to investigate both the association between GGT and CRFs and CRF clustering. A cross-sectional survey was conducted in a representative sample of 22897 adults aged 18 years and older from 2007 to 2011 nationally, which included a plurality of ethnic minorities. The participants were then divided into quartiles of sex-specific serum GGT. From the low to high GGT quartiles, the incidence of each CRF and clustered risk factors increased after adjusting for age, uric acid (UA), ethnicity, drinking, and all other risk factors. Individuals in the upper stratum (>75^th percentile) had higher prevalence rates of CRFs than did those in the lower stratum (all P < 0.05). Furthermore, the subjects with clustering of 1, 2, or ≥3 CRFs were still more likely to belong to the upper GGT quartiles (75th percentiles) than were those without risk factors (all P < 0.05). In conclusion, our data highlight that there is an association between higher serum GGT levels and prevalence of CRFs, which tend to cluster with the increase in GGT activity in Chinese adults.

Developmental origins of nonalcoholic fatty liver disease as a risk factor for exaggerated metabolic and cardiovascular-renal disease

Intrauterine growth restriction (IUGR) is linked to increased risk for chronic disease. Placental ischemia and insufficiency in the mother are implicated in predisposing IUGR offspring to metabolic dysfunction, including hypertension, insulin resistance, abnormalities in glucose homeostasis, and nonalcoholic fatty liver disease (NAFLD). It is unclear whether these metabolic disturbances contribute to the developmental origins of exaggerated cardiovascular-renal disease (CVRD) risk accompanying IUGR. IUGR impacts the pancreas, adipose tissue, and liver, which are hypothesized to program for hepatic insulin resistance and subsequent NAFLD. NAFLD is projected to become the major cause of chronic liver disease and contributor to uncontrolled type 2 diabetes mellitus, which is a leading cause of chronic kidney disease. While NAFLD is increased in experimental models of IUGR, lacking is a full comprehension of the mechanisms responsible for programming of NAFLD and whether this potentiates susceptibility to liver injury. The use of well-established and clinically relevant rodent models, which mimic the clinical characteristics of IUGR, metabolic disturbances, and increased blood pressure in the offspring, will permit investigation into mechanisms linking adverse influences during early life and later chronic health. The purpose of this review is to propose mechanisms, including those proinflammatory in nature, whereby IUGR exacerbates the pathogenesis of NAFLD and how these adverse programmed outcomes contribute to exaggerated CVRD risk. Understanding the etiology of the developmental origins of chronic disease will allow investigators to uncover treatment strategies to intervene in the mother and her offspring to halt the increasing prevalence of metabolic dysfunction and CVRD.

Changes in lysophospholipids and liver status after weight loss: the RESMENA study

Background

Obesity and comorbidities such as non-alcoholic fatty liver disease (NAFLD) are major public health burdens. Alterations in lipid metabolism are involved in hepatic diseases. The objective of this study was to assess the influence of weight loss on lysophospholipid (LP) metabolism and liver status in obese subjects as well as to provide new evidence regarding the interaction of LP metabolism as a key factor in the onset and management of obesity-related diseases such as liver damage.

Methods

Thirty-three subjects from the RESMENA (Reduction of Metabolic Syndrome in Navarra, NCT01087086) study were selected based on their Fatty Liver Index (FLI). Plasma lipid species (lysophosphatidilcholine: LPC, lysophosphatidilethanolamines: LPE and lysophosphatidylinositols: LPI specifically) were determined by LC-MS, while waist circumference (WC) and other non-invasive liver markers such as, FLI and BAAT scores as well as dietary records, anthropometrical measurements, body composition by DXA and other metabolic determinants were analyzed before and after a six-month hypocaloric nutritional intervention.

Results

Computed Z-scores of total LP (LPC, LPE, and LPI) were significantly decreased after 6-months of following a hypocaloric diet. Specifically, LPC14:0, LPC15:0, LPC16:1, LPC18:4, LPC20:4, showed clear relationships with weight loss. Changes in FLI score, WC and BAAT score revealed associations with general changes in LPC score. Interestingly the BAAT score was statistically associated with the LPC score after adjustment for weight loss.

Conclusion

The lipidomic LPC profile analysis revealed a generalized decrease in circulating lysophospholipids after weight loss. The involvement of particular LP in liver metabolism and obesity merit further attention, as some of these specific non-invasive liver markers were reduced independently of weight loss.

Trial registration

NCT01087086. Registered 15 March 2010, retrospectively registry.

Fatty liver index is a predictor of incident diabetes in patients with prediabetes: The PREDAPS study

OBJECTIVES

We evaluated the ability of the Fatty Liver Index (FLI), a surrogate marker of hepatic steatosis, to predict the development of type 2 diabetes (T2D) at 3 years follow-up in a Spanish cohort with prediabetes from a prospective observational study in primary care (PREDAPS).

METHODS

FLI was calculated at baseline for 1,142 adult subjects with prediabetes attending primary care centers, and classified into three categories: FLI <30 (no steatosis), FLI 30-60 (intermediate) and FLI ≥60 (hepatic steatosis). We estimated the incidence rate of T2D in each FLI category at 3 years of follow-up. The association between FLI and incident T2D was calculated using Cox regression models adjusted for age, sex, educational level, family history of diabetes, lifestyles, hypertension, lipid profile and transaminases.

RESULTS

The proportion of subjects with prediabetes and hepatic steatosis (FLI ≥60) at baseline was 55.7%. The incidence rate of T2D at 3 years follow-up was 1.3, 2.9 and 6.0 per 100 person-years for FLI<30, FLI 30->60 and FLI ≥60, respectively. The most significant variables increasing the risk of developing T2D were metabolic syndrome (hazard ratio [HR] = 3.02; 95% confidence interval [CI] = 2.14-4.26) and FLI ≥60 (HR = 4.52; 95%CI = 2.10-9.72). Moreover, FLI ≥60 was independently associated with T2D incidence: the HR was 4.97 (95% CI: 2.28-10.80) in the base regression model adjusted by sex, age and educational level, and 3.21 (95%CI: 1.45-7.09) in the fully adjusted model.

CONCLUSIONS

FLI may be considered an easy and valuable early indicator of high risk of incident T2D in patients with prediabetes attended in primary care, which could allow the adoption of effective measures needed to prevent and reduce the progression of the disease.

Non-alcoholic fatty liver disease, liver biomarkers and stroke risk: The Reasons for Geographic and Racial Differences in Stroke cohort. PLoS One. 2018;13:e0194153. [PMID: 29529073 PMCID: PMC5847237 DOI: 10.1371/journal.pone.0194153]

Background and purpose

Liver disease, particularly non-alcoholic fatty liver disease (NAFLD), is a risk factor for cardiovascular disease, but little is known about its relationship with ischemic stroke.

Methods

In the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort of 30,239 American black and white adults, we assessed baseline NAFLD as fatty liver index (FLI) >60, and assessed liver biomarkers aspartate aminotransferase (AST), alanine aminotransferase (ALT), γ-glutamyl transpeptidase (GGT), and the AST/ALT ratio and risk of incident ischemic stroke over 5.8 years using a case-cohort study design.

Results

Considering 572 strokes and a 1,017-person cohort sample, NAFLD was inversely associated with stroke risk in men (HR: 0.50; 95% CI: 0.26, 0.96), as was being in the highest ALT quintile versus the lowest (HR: 0.39; 95% CI: 0.19, 0.78) and the highest versus lowest GGT quintile (HR: 0.45, 95% CI: 0.24, 0.85), but not in women. Conversely, FLI score above the 90^th percentile was associated with increased stroke risk among women (HR: 2.26; 95% CI: 1.14–4.47), but not men. AST was not associated with stroke risk in either sex. AST/ALT ratio >2 was strongly associated with increased stroke risk in whites, but not blacks (HRs: 3.64; 95% CI: 1.42–9.35 and 0.97; 95% CI: 0.45–1.99, respectively; p for interaction = 0.03).

Conclusions

The relationships between NAFLD, liver biomarkers, and ischemic stroke are complex, and sex and race differences we observed require further study and confirmation.