Increased arterial stiffness and impaired endothelial function in nonalcoholic Fatty liver disease: a pilot study

Relation between non-alcoholic fatty liver disease and carotid artery intimal media thickness as a surrogate for atherosclerosis: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD), characterized by hepatic steatosis without heavy alcohol consumption or other chronic conditions, encompasses a spectrum from non-alcoholic fatty liver to non-alcoholic steatohepatitis leading to cirrhosis. This analysis aimed to investigate the correlation between NAFLD and carotid intimal media thickness (C-IMT), a non-invasive surrogate for atherosclerosis.

METHODOLOGY

Database searches, including PubMed, EMBASE and Cochrane Library, yielded studies up to April 2023. Included were studies exploring the NAFLD-C-IMT relationship in populations aged >18 years. Exclusions comprised non-English papers, those involving animals or pediatric populations and studies lacking control groups.

RESULTS

No statistical significance was noted between mild and moderate NAFLD compared to the control group regarding C-IMT [95% confidence intervals (CI): -0.03, 0.12] and (95% CI: -0.03, 0.21), respectively. There was a statistically significant difference only in the Severe NAFLD group ( P value 0.03). NAFLD with and without metabolic syndrome showed statistically significant differences compared to control regarding C-IMT (95% CI: 0.04, 0.12) and (95% CI: 0.01, 0.07), respectively. Fifty-nine studies were mentioned without classification of NAFLD severity and revealed a high statistically significant difference between NAFLD and controls regarding C-IMT with (95% CI: 0.09, 0.12, P < 0.00001). Stratified analysis according to sex was done in two studies and revealed statistical differences between NAFLD and control regarding C-IMT in both groups.

CONCLUSION

This meta-analysis underscores a significant association between NAFLD and increased C-IMT, emphasizing the importance of assessing C-IMT in NAFLD patients to identify cardiovascular risk and tailor therapeutic interventions for improved patient outcomes.

Influence of MAFLD and NAFLD on arterial stiffness: A longitudinal cohort study

BACKGROUND AND AIMS

This cohort study investigated associations of nonalcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD) with risk of increase in arterial stiffness (AS), measured as brachial-ankle pulse wave velocity (baPWV).

METHODS AND RESULTS

Participants who had health examinations between 2006 and 2019 were analyzed for fatty liver and increased baPWV using liver ultrasonography and automatic volume plethysmography device. Participants were classified based on presence of MAFLD or NAFLD and further divided into subgroups: no fatty liver disease (reference), NAFLD-only, MAFLD-only, and both NAFLD and MAFLD. Subgroups were additionally stratified by sex. Cox proportional hazard model was utilized to analyze the risk of developing baPWV ≥1400 cm/s in participants without baseline elevation of the baPWV. The NAFLD and MAFLD groups exhibited higher risks of increased baPWV (NAFLD: adjusted hazard ratio (aHR), 1.35 [95% CI, 1.29-1.42]; MAFLD: aHR, 1.37 [95% CI, 1.31-1.43]) compared to group without the conditions. Incidence of NAFLD or MAFLD were higher in men than in women but aHR of developing the increase in AS was higher in women. In subgroup analysis, the MAFLD-only group presented the strongest associations with increase in AS (aHR, 1.53 [95% CI, 1.43-1.64]), with the trend more pronounced in women than in men (Women, aHR, 1.63 [95% CI, 1.08-2.46]; Men, aHR 1.45 [95% CI, 1.35-1.56]).

CONCLUSIONS

Both NAFLD and MAFLD are significantly associated with elevated AS. These associations tended to be stronger in MAFLD than in NAFLD, in women than in men.

Association of nonalcoholic fatty liver disease and carotid media-intima thickness: A systematic review and a meta-analysis

Introduction

The relationship between cardiovascular disorders and nonalcoholic fatty liver disease (NAFLD) has been extensively studied. To better pool this data and make a more definite conclusion, we performed a meta-analysis to evaluate the association between NAFLD and the thickness of media and intima of carotid artery (CIMT) and cardiovascular disorders.

Methods

We searched PubMed, Ovid, Scopus, ProQuest, Web of Science, and the Cochrane Library, and analyzed the pooled data using R studio and the "metafor" package.

Results

The final analysis included a total of 59 studies with 16,179 cases and 26,120 control individuals. NAFLD was shown to be associated with an increase of 0.1231 mm (20.6%) in carotid artery intima-media thickness (CIMT) (p = 0.002, 95% confidence interval [CI]: 0.0462-0.2000) in individuals with NAFLD. The prevalence of atherosclerotic plaques in the carotid arteries and the occurrence of NAFLD are significantly correlated, according to a meta-analysis based on 17 distinct studies (p = 0.001, 1.28-1.43, 95% CI, odds ratio = 1.356).

Conclusion

Patients with increased CIMT are considerably more likely to have NAFLD. Large prospective investigations are required to corroborate these findings and their prognostic significance, along with the effectiveness of the available interventions.

Reactive Oxygen Species in the Aorta and Perivascular Adipose Tissue Precedes Endothelial Dysfunction in the Aorta of Mice with a High-Fat High-Sucrose Diet and Additional Factors

Metabolic syndrome (Mets) is the major contributor to the onset of metabolic complications, such as hypertension, type 2 diabetes mellitus (DM), dyslipidemia, and non-alcoholic fatty liver disease, resulting in cardiovascular diseases. C57BL/6 mice on a high-fat and high-sucrose diet (HFHSD) are a well-established model of Mets but have minor endothelial dysfunction in isolated aortas without perivascular adipose tissue (PVAT). The purpose of this study was to evaluate the effects of additional factors such as DM, dyslipidemia, and steatohepatitis on endothelial dysfunction in aortas without PVAT. Here, we employed eight-week-old male C57BL/6 mice fed with a normal diet (ND), HFHSD, steatohepatitis choline-deficient HFHSD (HFHSD-SH), and HFHSD containing 1% cholesterol and 0.1% deoxycholic acid (HFHSD-Chol) for 16 weeks. At week 20, some HFHSD-fed mice were treated with streptozocin to develop diabetes (HFHSD-DM). In PVAT-free aortas, the endothelial-dependent relaxation (EDR) did not differ between ND and HFHSD (p = 0.25), but in aortas with PVAT, the EDR of HFHSD-fed mice was impaired compared with ND-fed mice (p = 0.005). HFHSD-DM, HFHSD-SH, and HFHSD-Chol impaired the EDR in aortas without PVAT (p < 0.001, p = 0.019, and p = 0.009 vs. ND, respectively). Furthermore, tempol rescued the EDR in those models. In the Mets model, the EDR is compromised by PVAT, but with the addition of DM, dyslipidemia, and SH, the vessels themselves may result in impaired EDR.

Evaluating the Arterial Stiffness as a Useful Tool in the Management of Obese Children

Childhood obesity speeds up the development of arterial stiffness and progressively increases the values of arterial pressure. The purpose of this study is to investigate the value of using pulse wave analysis (PWA) to measure arterial stiffness as a sign of vascular wall impairment in obese children. The research was focused on 60 subjects: 33 obese and 27 normal-weight. Ages ranged from 6 to 18 years old. PWA includes parameters such as pulse wave velocity (PWV), augmentation index (AIx), peripheral and central blood pressure (SBP, DBP, cSBP, cDBP), heart rate, and central pulse pressure (cPP). The device used was a Mobil-O-Graph. Blood parameters were taken from the subject's medical history, not older than 6 months. A high BMI and a large waist circumference are linked to a high PWV. The levels of LDL-c, triglycerides (TG), non-HDL-c, TG/HDL-c ratio, and total cholesterol-HDL-c ratio significantly correlate to PWV, SBP, and cSBP. Alanine aminotransferase is a reliable predictor of PWV, AIx, SBP, DBP, and cDBP, while aspartate aminotransferase is a significant predictor of AIx, mean arterial pressure (MAP), cSBP, and cPP. 25-OH-Vitamin D negatively correlates with PWV, SBP, and MAP and significantly predicts the MAP. Cortisol and TSH levels are not significant to arterial stiffness in obese children without specific comorbidities and neither is fasting glucose in obese children without impaired glucose tolerance. We conclude that PWA contributes valuable data regarding patients' vascular health and should be considered a reliable tool in the management of obese children.

Endothelial Cell Dysfunction and Nonalcoholic Fatty Liver Disease (NAFLD): A Concise Review

Nonalcoholic fatty liver disease (NAFLD) is one of the most common liver diseases worldwide. It is strongly associated with obesity, type 2 diabetes (T2DM), and other metabolic syndrome features. Reflecting the underlying pathogenesis and the cardiometabolic disorders associated with NAFLD, the term metabolic (dysfunction)-associated fatty liver disease (MAFLD) has recently been proposed. Indeed, over the past few years, growing evidence supports a strong correlation between NAFLD and increased cardiovascular disease (CVD) risk, independent of the presence of diabetes, hypertension, and obesity. This implies that NAFLD may also be directly involved in the pathogenesis of CVD. Notably, liver sinusoidal endothelial cell (LSEC) dysfunction appears to be implicated in the progression of NAFLD via numerous mechanisms, including the regulation of the inflammatory process, hepatic stellate activation, augmented vascular resistance, and the distortion of microcirculation, resulting in the progression of NAFLD. Vice versa, the liver secretes inflammatory molecules that are considered pro-atherogenic and may contribute to vascular endothelial dysfunction, resulting in atherosclerosis and CVD. In this review, we provide current evidence supporting the role of endothelial cell dysfunction in the pathogenesis of NAFLD and NAFLD-associated atherosclerosis. Endothelial cells could thus represent a "golden target" for the development of new treatment strategies for NAFLD and its comorbid CVD.

Synergistic effects of liver fibrosis and sarcopenia on endothelial dysfunction and arterial stiffness in patients with type 2 diabetes

Aims

To investigate synergistic effects of liver fibrosis evaluated by FibroScan and sarcopenia on endothelial function and arterial stiffness in patients with type 2 diabetes.

Methods

This cross-sectional study evaluated liver fibrosis (LF) and sarcopenia in 115 patients with type 2 diabetes. LF was assessed as the liver stiffness measurement (LSM) in transient elastography (FibroScan) and was defined as an LSM greater than or equal to 8.0 kPa. Sarcopenia was defined as a ratio of appendicula skeletal muscle mass to body mass index of<0.789 in men and<0.512 in women. Endothelial function was measured by reactive hyperemia index (RHI) with tonometry, and arterial stiffness was evaluated by the cardio-ankle vascular index (CAVI). Endothelial dysfunction was defined an RHI value below 1.67, while arterial stiffness was defined a CAVI value above 9.0. Patients were divided into four groups: no LF and no sarcopenia; LF but no sarcopenia; no LF but sarcopenia; and LF and sarcopenia. The composite of endothelial dysfunction of arterial stiffness was defined as an outcome.

Results

In patients with LF, RHI was significantly lower and CAVI was significantly higher than in patients without LF. Furthermore, RHI was significantly lower in patients with sarcopenia than in those without it. Patients with both LF and sarcopenia had the lowest RHI and the highest CAVI and urinary albumin levels. Sarcopenia and HDL cholesterol were independent factor the composite of endothelial dysfunction and arterial stiffness.

Conclusion

LF and sarcopenia are independently associated with endothelial dysfunction and arterial stiffness in patients with type 2 diabetes. Coexistence of LF and sarcopenia may synergistically lead to vascular damage and thus contribute to the high risk of cardiovascular disease in people with type 2 diabetes.

Non-alcoholic fatty liver disease increases risk of carotid atherosclerosis and ischemic stroke: An updated meta-analysis with 135,602 individuals

BACKGROUND/AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with the development of cardiovascular disease. While existing studies have examined cardiac remodeling in NAFLD, there has been less emphasis on the development of carotid atherosclerosis and stroke. We sought to conduct a meta-analysis to quantify the prevalence, risk factors, and degree of risk increment of carotid atherosclerosis and stroke in NAFLD.

METHODS

Embase and Medline were searched for articles relating to NAFLD, carotid atherosclerosis, and stroke. Proportional data was analysed using a generalized linear mixed model. Pairwise meta-analysis was conducted to obtain odds ratio or weighted mean difference for comparison between patients with and without NAFLD.

RESULTS

From pooled analysis of 30 studies involving 7,951 patients with NAFLD, 35.02% (95% confidence interval [CI], 27.36-43.53%) had carotid atherosclerosis with an odds ratio of 3.20 (95% CI, 2.37-4.32; P<0.0001). Pooled analysis of 25,839 patients with NAFLD found the prevalence of stroke to be 5.04% (95% CI, 2.74-9.09%) with an odds ratio of 1.88 (95% CI, 1.23-2.88; P=0.02) compared to non-NAFLD. The degree of steatosis assessed by ultrasonography in NAFLD was closely associated with risk of carotid atherosclerosis and stroke. Older age significantly increased the risk of developing carotid atherosclerosis, but not stroke in NAFLD.

CONCLUSION

This meta-analysis shows that a stepwise increment of steatosis of NAFLD can significantly increase the risk of carotid atherosclerosis and stroke development in NAFLD. Patients more than a third sufferred from carotid atherosclerosis and routine assessment of carotid atherosclerosis is quintessential in NAFLD.

Endothelial Dysfunction in Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Individuals with nonalcoholic fatty liver disease (NAFLD) are characterized by increased cardiovascular risk. Endothelial dysfunction, a mechanism implicated in those processes, may constitute the missing link in this interaction. Therefore, this systematic review and meta-analysis aims to evaluate the association of endothelial dysfunction, assessed by flow-mediated dilation (FMD) of the brachial artery, with NAFLD. We conducted a systematic literature search for studies assessing the difference in FMD between patients with NAFLD and controls. Exclusion criteria consisted of preclinical studies, studies in children/adolescents, no FMD assessment, and the absence of an NAFLD/control group. The database search identified 96 studies. Following the application of the exclusion criteria, 22 studies were included in the meta-analysis (NAFLD: 2164 subjects; control: 3322 subjects). Compared with controls, patients with NAFLD had significantly lower FMD% values (SMD: −1.37, 95% CI −1.91 to −0.83, p < 0.001, I2: 98%). Results remained unaffected after exclusion of any single study. Subgroup analysis revealed significantly decreased FMD in NAFLD subjects diagnosed with liver ultrasound or liver biopsy compared with method combination or other methods, while no differences were observed according to the chosen cuff inflation threshold, the presence of a significant difference in obesity measures between the groups, or the type of the control group (age- and sex-matched vs. other). Funnel plot asymmetry was not observed. Finally, compared with patients with pure steatosis, individuals with nonalcoholic steatohepatitis had significantly lower FMD (SMD: −0.81, 95% CI −1.51 to −0.31, p = 0.003, I2: 81%). In conclusion, FMD of the brachial artery, indicative of endothelial dysfunction, was significantly reduced in subjects with nonalcoholic fatty liver disease. Patients with nonalcoholic steatohepatitis might be facing a more pronounced endothelial impairment.

Towards harnessing the value of organokine crosstalk to predict the risk for cardiovascular disease in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Importantly, NAFLD increases the risk for cardiovascular disease (CVD). A causal relationship has been substantiated. Given the pandemic proportions of NAFLD, a reliable scoring system for predicting the risk of NAFLD-associated CVD is an urgent medical need. We here review cumulative evidence suggesting that systemically released organokines - especially certain adipokines, hepatokines, and cardiokines - may serve this purpose. The underlying rationale is that these signalers directly communicate between white adipose tissue, liver, and heart as key players in the pathogenesis of NAFLD and resultant CVD events. Moreover, evidence suggests that these organ-specific cytokines are secreted in a biologically predetermined, cascade-like pattern. Consequently, upon pinpointing organokines of relevance, we sketch requirements to establish an algorithm predictive of the CVD risk in patients with NAFLD. Such an algorithm, as to be consolidated in the form of an applicable equation, may be improved continuously by machine learning. To the best of our knowledge, such an option has not yet been considered. Establishing and implementing a reliable algorithm for determining the NAFLD-associated CVD risk has the potential to save many NAFLD patients from life-threatening CVD events.

Coagulation and Endothelial Dysfunction Associated with NAFLD: Current Status and Therapeutic Implications

Non-alcoholic fatty liver disease (NAFLD) is closely related to insulin resistance, type 2 diabetes mellitus and obesity. It is considered a multisystem disease and there is a strong association with cardiovascular disease and arterial hypertension, which interfere with changes in the coagulation system. Coagulation disorders are common in patients with hepatic impairment and are dependent on the degree of liver damage. Through a review of the literature, we consider and discuss possible disorders in the coagulation cascade and fibrinolysis, endothelial dysfunction and platelet abnormalities in patients with NAFLD.

Association between non-alcoholic fatty liver disease and subclinical atherosclerosis in Western and Asian cohorts: an updated meta-analysis

Background

Non-alcoholic fatty liver disease (NAFLD) is a well-established risk factor for cardiovascular disease, with ethnic and regional differences noted. With the recent surge of research within this field, we re-examine the evidence associating NAFLD with subclinical atherosclerosis, and investigate potential regional differences.

Methods

This is a systematic review and meta-analysis. PubMed and EMBASE were systematically searched for publications from January 1967 to July 2020 using standardised criteria. Original, observational studies investigating the association between NAFLD and either carotid intima-media thickness (CIMT) and/or coronary artery calcification (CAC) were included. Key outcomes included differences in mean CIMT, the presence of increased CIMT, the presence of CAC and the development/progression of CAC. Pooled ORs and pooled standard differences in means were calculated using random-effects models. Between-study heterogeneity was quantified using the Q statistic and I². Subgroup analyses stratified by region of study (Asian vs Western) were also conducted.

Results

64 studies involving a total of 172 385 participants (67 404 with NAFLD) were included. 44 studies assessed the effect of NAFLD on CIMT, with the presence of NAFLD associated with increased CIMT (OR 2.00, 95% CI 1.56 to 2.56). 22 studies assessed the effects of NAFLD on CAC score, with the presence of NAFLD associated with the presence of any coronary calcification (OR 1.21, 95% CI 1.12 to 1.32), and the development/progression of CAC (OR 1.26, 95% CI 1.04 to 1.52). When stratified by region, these associations remained consistent across both Asian and Western populations (p>0.05). The majority (n=39) of studies were classified as ‘high quality’, with the remaining 25 of ‘moderate quality’.

Conclusions

There is a significant positive association between various measures of subclinical atherosclerosis and NAFLD, seen across both Western and Asian populations. These results re-emphasise the importance of early risk evaluation and prophylactic intervention measures to preclude progression to clinical cardiovascular disease in patients with NAFLD.

Fatty Liver Index is Positively Associated with Arterial Stiffness in a Chinese Cohort Undergoing Health Assessment

Objective

Nonalcoholic fatty fiver disease (NAFLD) is a metabolic liver injury closely related to insulin resistance. Fatty liver index (FLI) can be used as a surrogate marker and is a validated index for NAFLD. This study aimed to explore the relationship between FLI and arterial stiffness in a Chinese population.

Methods

From December 2017 to March 2019, 402 inpatients (mean age 51.12 ± 11.95 years) were recruited for cardiovascular disease screening at Ruijin Hospital North, Shanghai. Measurement of brachial systolic, diastolic, mean, and pulse pressure was done with cuff sphygmomanometry and carotid-femoral pulse wave velocity (cfPWV) was measured (SphygmoCor) to assess arterial stiffness.

Results

Subjects were divided into three groups according to their FLI < 30, normal; 30–59, intermediate fatty liver index; ≥ 60, NAFLD. The proportion of subjects with hepatic steatosis (FLI ≥ 60), intermediate FLI (30–59), and no steatosis (FLI < 30) was 34.4%, 31.8%, and 33.8%, respectively. The male population (53.9%) had significantly higher FLI levels (p < 0.05). Subjects with FLI ≥ 60 had higher cfPWV (8.41 ± 1.77 m/s) than those with FLI < 30 (7.81 ± 1.83 m/s; p = 0.006). cfPWV was positively correlated with logFLI (r = 0.168, p = 0.001). After adjusting for age, sex, body mass index, mean arterial blood pressure, glucose, cholesterol, heart rate, and glomerular filtration rate (eGFR), FLI remained positively associated with cfPWV (β = 0.097, p = 0.024).

Conclusion

cfPWV, as a measure of arterial stiffness, is higher in the NAFLD group when compared to that in normal groups. Fatty liver index is positively associated with arterial stiffness in a Chinese population.

Liver fibrosis is associated with carotid atherosclerosis in patients with liver biopsy-proven nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is related to subclinical atherosclerosis. However, whether the severity of the disease (or which histopathological component) is associated with subclinical atherosclerosis remains controversial. This study aimed to investigate the association between the histopathological severity of NAFLD and carotid intima-media thickness (CIMT) in Japanese patients with liver biopsy-proven NAFLD. Maximum-CIMT (max-CIMT) was measured as an index of carotid atherosclerosis in 195 biopsy-proven NAFLD patients. A significant association was observed between the severity of fibrosis (but not steatosis, inflammation, and ballooning) and max-CIMT. Older age, male gender, hypertension, and advanced fibrosis were independently linked to max-CIMT ≥ 1.2 mm. The prevalence of max-CIMT ≥ 1.2 mm was significantly higher in the advanced fibrosis group than in the non-advanced fibrosis group (75.4% versus 44.0%; p < 0.01). Non-invasive liver fibrosis markers and scoring systems, including fibrosis-4 index, NAFLD fibrosis score, hyaluronic acid, and Wisteria floribunda agglutinin positive Mac-2-binding protein, demonstrated that the diagnostic performance for max-CIMT ≥ 1.2 mm was similar to that of biopsy-based fibrosis staging. In conclusion, advanced fibrosis is significantly and independently associated with high-risk CIMT. Non-invasive fibrosis markers and scoring systems could help estimate the risk of atherosclerosis progression in patients with NAFLD.

Mutation of the 5'-untranslated region stem-loop mRNA structure reduces type I collagen deposition and arterial stiffness in male obese mice

Arterial stiffening, a characteristic feature of obesity and type 2 diabetes, contributes to the development and progression of cardiovascular diseases (CVD). Currently, no effective prophylaxis or therapeutics is available to prevent or treat arterial stiffening. A better understanding of the molecular mechanisms underlying arterial stiffening is vital to identify newer targets and strategies to reduce CVD burden. A major contributor to arterial stiffening is increased collagen deposition. In the 5'-untranslated regions of mRNAs encoding for type I collagen, an evolutionally conserved stem-loop (SL) structure plays an essential role in its stability and post-transcriptional regulation. Here, we show that feeding a high-fat/high-sucrose (HFHS) diet for 28 wk increases adiposity, insulin resistance, and blood pressure in male wild-type littermates. Moreover, arterial stiffness, assessed in vivo via aortic pulse wave velocity, and ex vivo using atomic force microscopy in aortic explants or pressure myography in isolated femoral and mesenteric arteries, was also increased in those mice. Notably, all these indices of arterial stiffness, along with collagen type I levels in the vasculature, were reduced in HFHS-fed mice harboring a mutation in the 5'SL structure, relative to wild-type littermates. This protective vascular phenotype in 5'SL-mutant mice did not associate with a reduction in insulin resistance or blood pressure. These findings implicate the 5'SL structure as a putative therapeutic target to prevent or reverse arterial stiffening and CVD associated with obesity and type 2 diabetes.NEW & NOTEWORTHY In the 5'-untranslated (UTR) regions of mRNAs encoding for type I collagen, an evolutionally conserved SL structure plays an essential role in its stability and posttranscriptional regulation. We demonstrate that a mutation of the SL mRNA structure in the 5'-UTR decreases collagen type I deposition and arterial stiffness in obese mice. Targeting this evolutionarily conserved SL structure may hold promise in the management of arterial stiffening and CVD associated with obesity and type 2 diabetes.

Endothelial Progenitor Cells Dysfunctions and Cardiometabolic Disorders: From Mechanisms to Therapeutic Approaches

Metabolic syndrome (MetS) is a cluster of several disorders, such as hypertension, central obesity, dyslipidemia, hyperglycemia, insulin resistance and non-alcoholic fatty liver disease. Despite health policies based on the promotion of physical exercise, the reduction of calorie intake and the consumption of healthy food, there is still a global rise in the incidence and prevalence of MetS in the world. This phenomenon can partly be explained by the fact that adverse events in the perinatal period can increase the susceptibility to develop cardiometabolic diseases in adulthood. Individuals born after intrauterine growth restriction (IUGR) are particularly at risk of developing cardiovascular diseases (CVD) and metabolic disorders later in life. It has been shown that alterations in the structural and functional integrity of the endothelium can lead to the development of cardiometabolic diseases. The endothelial progenitor cells (EPCs) are circulating components of the endothelium playing a major role in vascular homeostasis. An association has been found between the maintenance of endothelial structure and function by EPCs and their ability to differentiate and repair damaged endothelial tissue. In this narrative review, we explore the alterations of EPCs observed in individuals with cardiometabolic disorders, describe some mechanisms related to such dysfunction and propose some therapeutical approaches to reverse the EPCs dysfunction.

Non-Alcoholic Fatty Liver Disease and Cardiovascular Comorbidities: Pathophysiological Links, Diagnosis, and Therapeutic Management

Non-alcoholic fatty liver disease (NAFLD) has a growing prevalence in recent years. Its association with cardiovascular disease has been intensively studied, and certain correlations have been identified. The connection between these two entities has lately aroused interest regarding therapeutic management. In order to find the best therapeutic options, a detailed understanding of the pathophysiology that links (NAFLD) to cardiovascular comorbidities is needed. This review focuses on the pathogenic mechanisms that are behind these two diseases and on the therapeutic management available at this time.

Association of arterial stiffness with the histological severity of nonalcoholic fatty liver disease

BACKGROUND

Although arterial stiffness has been reported to be associated with nonalcoholic fatty liver disease (NAFLD), previous studies have relied only on noninvasive assessments for the diagnosis of NAFLD. This study attempted to investigate the association of arterial stiffness with the histological severity of NAFLD.

METHODS

We analyzed data from a biopsy-proven prospective NAFLD cohort. Augmentation index corrected for a heart rate of 75 bpm (AI@75) was obtained using applanation tonometry of the radial artery.

RESULTS

A total of 154 patients (mean age 55.2 years; females 55.8%) with biopsy-proven NAFLD were analyzed. Patients with higher AI@75 (≥ 76%) showed more severe grades of lobular and portal inflammation and hepatocellular ballooning, and more advanced stages of fibrosis compared to those with lower AI@75 (< 76%) (p < 0.05 for each). The presence of nonalcoholic steatohepatitis (NASH) (adjusted odds ratio [aOR] 2.48; 95% confidence interval [CI] 1.31-6.16; p = 0.008), lobular inflammation (aOR 2.03; 95% CI 1.09-3.78; p = 0.025) hepatocellular ballooning (aOR 2.82; 95% CI 1.23-6.43; p = 0.014), and significant fibrosis (≥ F2) (aOR 3.42; 95% CI 1.50-7.79; p = 0.003) were independently associated with higher AI@75 (≥ 76%) even after adjustment for confounders.

CONCLUSION

Arterial stiffness as indicated by higher AI@75 was associated with more severe NAFLD histology. This adds to the evidence for the association between increased arterial stiffness and NAFLD.

Association and Prediction of Subclinical Atherosclerosis by Nonalcoholic Fatty Liver Disease in Asymptomatic Patients

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NAFLD) has been increasing in the general population. This study evaluated the association between NAFLD and significant coronary stenosis in asymptomatic adults and evaluated sex-based differences.

METHODS

We performed a retrospective cross-sectional study in participants without previous cardiovascular diseases who visited the Seoul National University Hospital Health Promotion Center for a health checkup between January 1, 2010, and December 31, 2015. NAFLD was diagnosed on sonography, while coronary artery stenosis (CAS) was assessed on coronary computed tomography angiography (CCTA).

RESULTS

We obtained 3,693 participants who met the inclusion criteria, and 3,449 of them had no significant stenosis. Among the participants with significant stenosis, the prevalence of NAFLD was 59.4% (145 patients). The prevalence of NAFLD was 47.26% in male participants, which was higher than that in female participants. The association between NAFLD and significant CAS persisted after adjusting for age, body mass index, glycated hemoglobin, and Framingham risk factors. The correlation between NAFLD and significant coronary stenosis appeared to be stronger in women than in men, but the absolute risk was higher in men than in women.

CONCLUSION

NAFLD was strongly associated with CAS. We should be alert about an increased cardiovascular risk in patients with NAFLD and more intensively provide primary prevention by performing tests to detect subclinical atherosclerosis.

Gender-specific associations between apolipoprotein A1 and arterial stiffness in patients with nonalcoholic fatty liver disease

Background

Lipid metabolism factors may play an important role in the progression of nonalcoholic fatty liver disease (NAFLD) and its related cardiovascular dysfunctions. The study aims to assess whether Apolipoprotein A-1 (ApoA1) was associated with vascular stiffness in NAFLD patients.

Methods

From 2012 to 2013, we included 2,295 non-alcohol users with fatty liver disease (1,306 male patients) and completely excluded subjects who drank any alcohol ever to eliminate the effect of alcohol intake. The serum ApoA1 levels and the brachial-ankle pulse wave velocity (baPWV) were measured.

Results

The baPWV in men was much higher than in female patients (1,412.79 cm/s vs. 1,358.69 cm/s, P < 0.001). ApoA1 level was positively associated with baPWV odd ratio (OR), 4.18; 95% confidence interval (CI) [1.16-15.1], P < 0.05) in patients with AST/ALT < 1 and (OR, 4.70; 95% CI [1.36-16.23], P < 0.05) in patients with AST/ALT ≥ 1 respectively. Only arterial stiffness in men was associated with ApoA1 (OR, 3.96; 95% CI [1.29-12.30], P < 0.05) in logistics regression models adjusted for age, gender, body mass index, education attainment, physical activity, smoking, history of hypertension and high-density lipoprotein. The relationship between ApoA1 and baPWV in male NAFLD patients remained significant (confidence, 156.42; 95% CI [49.34-263.50], P < 0.05) in the fully adjusted linear regression model.

Conclusion

The serum ApoA1 was associated with arterial stiffness in male NAFLD patients. Increased ApoA1 level should be considered as an independent risk factor for arterial stiffness in male NAFLD patients, suggesting that NAFLD may alter arterial stiffness by "ApoA1-related" mechanism in men.

An Overview of Lipid Metabolism and Nonalcoholic Fatty Liver Disease. Biomed Res Int. 2020;2020:4020249. [PMID: 32733940 PMCID: PMC7383338 DOI: 10.1155/2020/4020249]

The occurrence of nonalcoholic fatty liver disease (NAFLD) is associated with major abnormalities of hepatic lipid metabolism. We propose that lipid abnormalities directly or indirectly contribute to NAFLD, especially fatty acid accumulation, arachidonic acid metabolic disturbance, and ceramide overload. The effects of lipid intake and accumulation on NAFLD and NAFLD treatment are explained with theoretical and experimental details. Overall, these findings provide further understanding of lipid metabolism in NAFLD and may lead to novel therapies.

The Role of Adipokines in the Development of Arterial Stiffness and Hypertension

The study aimed to assess the role and the relationship of adipokines as well as parameters of arterial stiffness in newly diagnosed hypertension. Forty-nine newly diagnosed hypertensive cases (median age 47 ± 6 years) and 48 normotensive patients (median age 47 ± 6 years) were enrolled to this study. Patients underwent echocardiography, noninvasive assessment of hemodynamic parameters using SphygmoCor tonometer (Atcor Med). The levels of the adipokines-leptin, adiponectin, and resistin-were investigated. The augmentation pressure, augmentation index, and pulse wave velocity (PWV) were higher in patients with hypertension compared with controls (Ps < .05). Patients with hypertension had higher E/E' ratio, higher diameter of left atrium, and lower tricuspid annular plane systolic excursion compared with the control group (Ps < .05). Patients with hypertension had significant higher levels of leptin (ng/mL) and lower levels of adiponectin (μg/mL) compared with normotensive patients. The multivariate analysis showed that PWV (odds ratio [OR] 1.95, 95% CI, 1.2-2.9; P = .002) and leptin level (OR 1.01, 95% CI, 1.004-1.031; P = .01) were significantly associated with hypertension. Arterial stiffness as determined by PWV and leptin are associated with newly diagnosed hypertension. Elevated serum leptin level may influence the potential mechanism leading to sympathetic activation.

Non-alcoholic fatty liver disease: A growing public health problem in Turkey

Non-alcoholic fatty liver disease (NAFLD) is histologically classified as either non-alcoholic fatty liver or non-alcoholic steatohepatitis (NASH). NASH is the progressive subtype of NAFLD. Individuals with NASH are at significant risk of developing hepatic fibrosis, cirrhosis, hepatocellular carcinoma, and liver-related and all-cause mortality. NAFLD is closely associated with obesity, type 2 diabetes mellitus (T2DM), metabolic syndrome, and cardiovascular events. Its prevalence is estimated to be above 30% in Turkey; and recent studies confirm this estimate. According to these studies, the prevalence of NAFLD in Turkey is between 48.3% and 60.1%. Currently, Turkey can be considered a risky region in terms of NAFLD burden as it is the most obese country in Europe with an obesity prevalence of 32.1% according to the 2016 World Health Organization data. Moreover, along with the increasing prevalence of obesity and T2DM in Turkey, the burden of NAFLD is estimated to increase in the upcoming decade. Despite the growing burden, we lack well-designed systemic studies that investigate NAFLD and its marked histological severity. In this review, we present studies on the burden of NAFLD and NASH, the natural history of NAFLD, and its association with other systemic diseases conducted with Turkish populations.

No association between aortic stiffness and liver steatosis in morbidly obese patients

BACKGROUND AND AIMS

Patients with non-alcoholic fatty liver disease are characterized by increased aortic stiffness, but it is unclear whether this is related to non-alcoholic fatty liver disease itself or concomitant metabolic syndrome components, including hypertension and diabetes. Previous studies were methodologically limited by ultrasound-based assessment of liver steatosis or performing liver biopsy in patients with more severe disease. Therefore, we prospectively measured aortic pulse wave velocity (aPWV) in non-selected obese subjects admitted for bariatric surgery with liver biopsy, allowing assessment of the association between aortic stiffness and biopsy-confirmed liver steatosis.

METHODS

We evaluated 120 consecutive severely obese patients (79 females; mean age 42 ± 10 years, mean body mass index 45.0 ± 5.3 kg/m²) without cardiac disease or alcohol-induced liver disease, who were admitted for bariatric surgery. The presence or absence of liver steatosis was defined by wedge liver biopsy. aPWV was measured with the Doppler method at the time of preoperative transthoracic echocardiography.

RESULTS

Based on liver biopsy results, 82 patients (68%) had liver steatosis and 38 (32%) had no steatosis. Univariate linear regression analysis showed that age, mean arterial pressure, liver steatosis, heart rate, female gender, and diabetes were significantly associated with aPWV. However, only age, mean arterial pressure, heart rate, and diabetes remained significant in the multivariate model (p ≤ 0.001).

CONCLUSIONS

We found no independent association between biopsy-confirmed liver steatosis and aortic stiffness measured by Doppler aPWV in morbidly obese individuals. Aortic stiffness in these subjects is related to comorbidities and not to non-alcoholic fatty liver disease itself.

Angiotensin II Type 1 Receptor rs5186 Gene Variant Predicts Incident NAFLD and Associated Hypertension: Role of Dietary Fat-Induced Pro-Inflammatory Cell Activation

OBJECTIVES

Hypertension has been linked to the presence and severity of nonalcoholic fatty liver disease (NAFLD) through unclear mechanisms. The gain-of-function rs5186 A1166C variant in angtiotensin receptor type 1 (AGTR1) gene has been linked to hypertension, cardiovascular disease and metabolic syndrome. We assessed the impact of AGTR1 A1166C variant on NAFLD incidence and severity and on glucose and lipid metabolism and explored the underlying mechanisms.

METHODS

We followed up 314 healthy nonobese, nondiabetic, nonhypertensive, insulin-sensitive participants in a population-based study, characterized for AGTR1 rs5186 A1166C variant, adipokine profile, inflammatory and endothelial dysfunction markers. An independent cohort of 78 biopsy-proven nondiabetic NAFLD patients and controls underwent an oral glucose tolerance test with Minimal Model analysis of glucose homeostasis, and an oral fat tolerance test with measurement of plasma lipoproteins, adipokines, MCP-1, calprotectin, and nuclear factor-κB activation in circulating mononuclear cells.

RESULTS

AGTR1 A1166C polymorphism predicted 9.8-year incident NAFLD (odds ratio: 1.67, 95% CI: 1.26-2.21) and hypertension (odds ratio: 1.49, 95% CI: 1.12-2.63) and 9-year increase in cardiovascular disease risk and endothelial dysfunction markers. In the cross-sectional cohort, AGTR1 C allele carriers had higher insulin resistance. Despite comparable fasting lipid profiles, AGTR1 C allele carriers showed postprandial triglyceride-rich and cholesterol-rich VLDL lipoprotein accumulation, higher resistin, MCP-1 and calprotectin responses and nuclear factor-κB activation in mononuclear cells, and a blunted postprandial adiponectin response to fat, which predicted liver histology, hepatocyte apoptosis activation, insulin resistance, and endothelial dysfunction.

DISCUSSION

AGTR1 A1166C variant affects liver disease, insulin resistance, and endothelial dysfunction in NAFLD, at least in part by modulating adipokine, chemokine, and pro-inflammatory cell activation in response to fat ingestion.

Non-alcoholic fatty liver disease presence and severity are associated with aortic stiffness beyond abdominal obesity: The ELSA-Brasil

BACKGROUND AND AIMS

It is uncertain whether non-alcoholic fatty liver disease (NAFLD) is associated with aortic stiffness in a racial/ethnically diverse and admixed society. We addressed whether NAFLD presence and severity were associated with carotid-femoral pulse wave velocity (cf-PWV) in individuals free of cardiovascular disease.

METHODS

In 7196 individuals free of cardiovascular disease at the baseline Brazilian longitudinal study of adult health, we classified NAFLD presence and severity (mild, moderate and severe) by ultrasound hepatic attenuation. We measured cf-PWV using a non-invasive validated device (Complior SP, Artech Medicale France). We compared cf-PWV of NAFLD individuals to those without by analysis of covariance adjusted for demographics, life style, waist circumference, and arterial pressure. We also analyzed the cf-PWV trend from no-NAFLD to severe NAFLD.

RESULTS

In unadjusted analysis, from no-NAFLD to severe NAFLD, there were slightly older individuals, lower frequency of smokers, more prevalent diabetes and hypertension. In adjusted analysis, there was slightly higher cf-PWV (m/s) (95%CI) in NAFLD vs. no-NAFLD, respectively 9.32 (9.22, 9.41) and 9.24 (9.15, 9.33) (p = 0.037). Across NAFLD severity spectrum, adjusted cf-PWV increased from 9.24 (9.15, 9.33) in no-NAFLD to 9.69 (9.46, 9.93) in severe NAFLD (p for trend association = 0.001). In sensitivity analysis, diabetes adjustment nullified the association of binary NAFLD with cf-PWV, but not that of increasingly severe NAFLD.

CONCLUSIONS

In racial/ethnically diverse individuals free of cardiovascular disease, NAFLD is associated with aortic stiffness beyond abdominal obesity. The specific NAFLD impact on CVD worldwide is potentially relevant.

Non-alcoholic fatty liver disease-From the cardiologist perspective

Non-alcoholic fatty liver disease (NAFLD) includes a range of disorders characterized by excess accumulation of triglycerides within the liver. While simple steatosis may be clinically stable, non-alcoholic steatohepatitis (NASH) can be progressive. Inflammation is believed to be the driving force behind NASH and the progression to fibrosis and subsequent cirrhosis. NAFLD is globally considered a significant health concern not only because of its incidence but also because of its economic impact. The fact that NAFLD is associated with cardiovascular disease is widely recognized, as well as the fact that NAFLD patient mortality rises when such an association is present. In particular, NAFLD is associated with coronary and carotid atherosclerosis, endothelial dysfunction and arterial rigidity, ventricles function, valves morphology, congestive heart failure, and arrhythmias (especially atrial fibrillation). Additionally, the hypercoagulability status in NAFLD patient may be suggested by the presence of inflammatory and coagulation markers. In order to differentiate between milder forms and the more severe ones that necessitate aggressive therapy, individualized risk scores may be used. This narrative review will analyze and interpret the papers published in PubMed in the last 16 years, in an attempt to expand our understanding of the NASH as a possible cardiovascular risk factor.

Usefulness of controlled attenuation parameter for detecting increased arterial stiffness in general population

BACKGROUND

Liver fibroscan has recently been suggested as an alternative method to measure liver steatosis noninvasively. In this study, we evaluated usefulness of controlled attenuation parameter (CAP) for detecting increased arterial stiffness in general population.

METHODS

A total of 515 asymptomatic patients without potential cause of liver disease who had liver fibroscan and cardio-ankle vascular index (CAVI) during their health check-up exams were included. A cut off of CAP ≥222 dB/m was used to define fatty liver and CAVI ≥ 8 for increased arterial stiffness.

RESULTS

Both unadjusted and adjusted regression analyses showed significant association between fatty liver and increased arterial stiffness [unadjusted Odds ratio (OR) 1.896, 95% CI 1.305-2.754, p = .001 for CAP ≥ 222 dB/m alone]. With all traditional cardiovascular risk factors such as age, gender, body mass index, hypertension, diabetes mellitus, hypercholesterolemia and smoking adjusted, CAP ≥ 222 dB/m still showed significant association with increased arterial stiffness (OR 2.309, 95% CI 1.419-3.756, p = .001). The correlation between CAP-defined fatty liver and arterial stiffness was especially strong in subjects without diabetes (OR 2.959, 95% CI 1.709-5.122, p < 0.001).

CONCLUSION

CAP ≥ 222 dB/m is independently associated with increased arterial stiffness. As increased arterial stiffness is a surrogate and prognosticator for cardiovascular disease, surveillance using liver fibroscan may help screen and further stratify risk of patients.

Assessment of Arterial Stiffness and Body Composition in Stable Liver Transplant Recipients

INTRODUCTION

Arterial stiffness and central arterial pressure are important factors in the diagnosis of cardiovascular diseases. The tendency of patients after liver transplantation to reach above-normal BMI values promotes the development of arterial stiffness and lipid disorders.

METHODS

The study was conducted on a group of 42 patients after liver transplantation at the Nephrology and Transplantology Outpatient Clinic, Medical University of Warsaw, the Infant Jesus Teaching Hospital, Warsaw 0.5-17 years after surgery. The body composition test was carried out with the Tanita Mc780 device, and the central pressure and pulse wave velocity (PWV) with the Schiller BR-102 PLUS PWA device, using the oscillometric method on the brachial artery. Medical documentation was analyzed and the laboratory parameters values routinely determined during follow-up visits were assessed.

RESULTS

There was a statistically significant correlation between central diastolic pressure and BMI (r = 0.46, P < .05), and a lack of correlation between patients' age and PWV value (r = 0.06, P < .05), which indicated the age of patients in this study was not associated the stiffness of their arteries. PWV level in patients after liver transplantation whose BMI value is within the normal range was 7.62 m/s, while overweight and obese patients had PVW values of 8.58 m/s (P < .05).

CONCLUSIONS

In conclusion, our data indicate that 1. the level of central arterial pressure increases with the development of stiffness in the arteries; 2. patients after liver transplantation tend to grow in terms of body weight and body fat content over time after surgery; and 3. the level of bilirubin in the blood is significantly increased among patients with fat content above the upper limit of the normal range.

Association between nonalcoholic fatty liver disease and subclinical atherosclerosis: a cross-sectional study on population over 40 years old

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) refers to fatty infiltration of liver in the absence of excessive alcohol abuse. However, the problem that whether NAFLD is correlated with subclinical atherosclerosis assessed by carotid intima-media thickness (CIMT) and brachial-ankle pulse wave velocity (ba-PWV) remains a source of controversy. This can be attributed to the differences in diagnosis methods, population ethnicity, sampling size and bias. This study aimed to further investigate the association of NAFLD with subclinical atherosclerosis.

METHODS

A cross-sectional study was carried out in the current study on population aged over 40 years derived from Kailuan community-based prospective study among Chinese adults from June 2010 to June 2011. NAFLD was evaluated through ultrasonography and histories of alcohol consumption. Clinical parameters and medical histories of patients were collected in the manner of interview performed by trained investigators using the standardized questionnaires. The biochemical parameters were analyzed at the central laboratory. CIMT and ba-PWV of each patient were measured. Multivariate logistic regression was used to analyze the associations of NAFLD with subclinical atherosclerosis assessed by CIMT or ba-PWV.

RESULTS

A total of 4112 participants aged over 40 years were enrolled from Kailuan cohort, including 2229 men and 1883 women. The overall prevalence of NAFLD was 38.2% in the total population. Statistically significant differences were found in CIMT (P < 0.0001) and ba-PWV (P = 0.0007) according to the presence of NAFLD. It is notably that the multivariate logistic regression revealed NAFLD was independently associated with elevated CIMT after adjusting the conventional cardiovascular and metabolic risk factors (OR = 1.663, 95% CI = 1.391-1.989, P < 0.0001). In addition, NAFLD was also found to be positively associated with elevated ba-PWV after adjusting age, gender, BMI, current smoking and regular exercising (OR = 1.319, 95% CI = 1.072-1.624, P = 0.0089).

CONCLUSIONS

Our findings suggest that NAFLD is remarkably correlated with subclinical atherosclerosis, which should be strongly advised to engage in the preventive strategies for cardiovascular diseases (CVDs).

Reactive hyperemia index (RHI) and cognitive performance indexes are associated with histologic markers of liver disease in subjects with non-alcoholic fatty liver disease (NAFLD): a case control study

Background

No study evaluated vascular health markers in subjects with non-alcoholic fatty liver disease (NAFLD) through a combined analysis of reactive hyperemia peripheral arterial tonometry (RH-PAT) and arterial stiffness indexes.

Aim of the study

We aimed to assess whether NAFLD and its histological severity are associated with impairment of arterial stiffness and RH-PAT indexes in a mixed cohort of patients with biopsy-proven NAFLD.

Materials and methods

The Kleiner classification was used to grade NAFLD grade. Pulse wave velocity (PWV) and augmentation index (Aix) were used as markers of arterial stiffness, whereas endothelial function was assessed using reactive hyperemia index (RHI). The mini-mental state examination (MMSE) was administered to test cognitive performance.

Results

80 consecutive patients with biopsy-proven NAFLD and 83 controls without fatty liver disease. NAFLD subjects showed significantly lower mean RHI, higher mean arterial stiffness indexes and lower mean MMSE score. Multivariable analysis after correction for BMI, dyslipidaemia, hypertension, sex, diabetes, age and cardiovascular disease showed that BMI, diastolic blood pressure and RHI are significantly associated to NAFLD. Simple linear regression analysis showed among non-alcoholic steatohepatitis (NASH) subjects a significant negative relationship between ballooning grade and MMSE and a significant positive association between Kleiner steatosis grade and augmentation index.

Conclusions

Future research will be addressed to evaluate the relationship between inflammatory markers and arterial stiffness and endothelial function indexes in NAFLD subjects. These study will evaluate association between cardiovascular event incidence and arterial stiffness, endothelial and cognitive markers, and they will address the beneficial effects of cardiovascular drugs such as statins and ACE inhibitors on these surrogate markers in NAFLD subjects.

Evaluation of endothelial dysfunction in patients with nonalcoholic fatty liver disease: Association of selenoprotein P with carotid intima-media thickness and endothelium-dependent vasodilation

BACKGROUND

In patients with NAFLD, there is an increased risk of cardiovascular disease (CVD). Selenoprotein P (SelP), a hepatokine, is associated with insulin resistance (IR) and serum SelP was found to be elevated in patients with NAFLD.

AIM

This study aimed to determine the risk of CVD in NAFLD patients and the association of serum SelP levels with this NAFLD related CVD risk.

METHODS

Ninety-three patients with NAFLD and 37 healthy controls were included in the study. Complete blood count, C-reactive protein (CRP), fasting glucose, serum lipid levels, and SelP levels were tested from fasting blood samples. Moreover, body mass index (BMI), HOMA-IR, carotid intima-media thickness (cIMT) and flow-mediated dilatation (FMD) were measured.

RESULTS

In patients with NAFLD, the FMD ratio was significantly lower than in controls (P=0.027). cIMT measurements were similar in both groups (P=0.996). Serum SelP levels were significantly higher than controls (P<0.001). SelP levels were significantly correlated with BMI, fasting glucose, LDL-cholesterol and HOMA-IR (r=0.395, P<0.001; r=0.322, P=0.002; r=0.353, P<0.001; r=0.521, P<0.001, respectively). Also, SelP levels were significantly lower and correlated with FMD (r=-0.674, P<0.001). SelP, ESR and CRP were significantly higher (P<0.05) and FMD ratios were significantly lower (P<0.05) in patients with nonalcoholic steatohepatitis (NASH) when compared to patients with simple steatosis.

CONCLUSION

These results suggest that in young NAFLD patients without additional comorbidities, there is an increased risk of CVD. FMD may be a better predictor for assessment of CVD risk when compared with cIMT. We assume that there could also be an important role of SelP in the pathogenesis of NASH.

Increased arterial stiffness in nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND

Arterial function is a marker of early atherosclerotic changes and cardiovascular disease. Several studies have suggested the possible association between nonalcoholic fatty liver disease (NAFLD) and increased arterial stiffness. Thus, we conducted a systematic review and meta-analysis to better characterize this association.

PATIENTS AND METHODS

A comprehensive search of the databases of the MEDLINE and EMBASE was carried out from inception through September 2016. All observational studies that compared arterial stiffness between NAFLD patients and healthy controls were included. Arterial stiffness was measured by pulse wave velocity (PWV) and augmentation index. We calculated pooled mean difference (MD) with 95% confidence intervals (CIs) using the random-effects model.

RESULTS

Data were extracted from 12 studies involving 9351 NAFLD patients and 17 684 controls. NAFLD is significantly associated with increased arterial stiffness as determined by carotid-femoral PWV (MD=0.75 m/s, 95% CI: 0.43-1.07, I=88%), brachial-ankle PWV (MD=0.82 m/s, 95% CI: 0.57-1.07, I=92%), and augmentation index (pooled MD=2.54%, 95% CI: 0.07-5.01, I=73%) compared with healthy controls.

CONCLUSION

In conclusion, our study demonstrated a higher degree of arterial stiffness in NAFLD patients compared with controls. However, this association might be related to the higher prevalence of cardiometabolic risk factors in NAFLD patients. Further studies are needed to determine an independent association between NAFLD and arterial stiffness adjusting to cardiometabolic risks.

Non-alcoholic fatty liver disease as a risk factor for female sexual dysfunction in premenopausal women

Objective

Non-alcoholic fatty liver disease (NAFLD) has become a common and important chronic liver disease worldwide. Previous studies have indicated that NAFLD has an adverse effect on the quality of life, but information is lacking about the impact of NAFLD on female sexual dysfunction. The aim of this study was to determine the association between NAFLD and female sexual dysfunction in premenopausal women.

Methods

This retrospective study consisted of premenopausal women who were sexually active and visited the outpatient clinic for a routine health check-up between January 2010 and December 2011. Based on the examination of the liver ultrasound scan, the study population was divided into 2 groups: cases with NAFLD and normal controls (cases without NAFLD). The female sexual function was compared between the two groups of cases. For the assessment of sexual function, a female sexual function index (FSFI) questionnaire was used.

Results

Four hundred seventy women were included, and the prevalence of NAFLD and female sexual dysfunction were 67/470 (14.3%) and 238/470 (50.6%), respectively. Cases with NAFLD had a lower total FSFI score and higher rate of female sexual dysfunction than the normal control [median score of total FSFI (interquartile range): 24.7 (21.9–27.8) in NAFLD vs. 26.7 (23.7–29.8) in normal control, p<0.005; the female sexual dysfunction: 64.2% in NAFLD vs. 48.4% in normal control, p<0.05]. This difference in female sexual dysfunction between the two groups remained significant after adjustment.

Conclusion

NAFLD is associated with female sexual dysfunction in premenopausal women.

Effects of chronic hepatitis C infection on arterial stiffness

Nonalcoholic fatty liver disease (NAFLD) is associated with increased arterial stiffness. Although chronic hepatitis C virus (HCV) infection was shown to be associated with metabolic disorder and chronic inflammation, the effects of chronic HCV infection on arterial stiffness remain unclear. This study recruited 221 patients including 32 normal controls, 72 NAFLD patients, and 117 subjects with HCV infection. Arterial stiffness was assessed by peripheral arterial stiffness index, Compliance Index (CI), and central arterial stiffness index, Stiffness Index derived from digital volume pulse by photoplethysmography. Levels of oxidative stress marker and inflammatory markers were also measured. The HCV group had significantly lower CI (4.8 ± 3.1 units vs. 3.9 ± 2.1 units vs. 3.0 ± 1.7 units; P for trend <.001) and higher Stiffness Index (7.0 ± 1.6 m/s vs. 8.3 ± 2.3 m/s vs. 8.4 ± 2.3 m/s; P for trend = .001) compared with the normal controls and NAFLD groups. Multivariate linear regression analysis showed that CI was independently correlated with systolic blood pressure (beta = -0.202, P = .013) and HCV infection (beta = -0.216, P = .036). Chronic HCV infection was independently associated with peripheral arterial stiffness. Peripheral arterial stiffness in chronic HCV infection was not associated with a marker of general inflammation (high-sensitivity C-reactive protein); however, a role for more specific markers of inflammation cannot be ruled out.

Soy Improves Cardiometabolic Health and Cecal Microbiota in Female Low-Fit Rats

Phytoestrogen-rich soy is known to ameliorate menopause-associated obesity and metabolic dysfunction for reasons that are unclear. The gut microbiota have been linked with the development of obesity and metabolic dysfunction. We aimed to determine the impact of soy on cardiometabolic health, adipose tissue inflammation, and the cecal microbiota in ovariectomized (OVX) rats bred for low-running capacity (LCR), a model that has been previously shown to mimic human menopause compared to sham-operated (SHM) intact control LCR rats. In this study, soy consumption, without affecting energy intake or physical activity, significantly improved insulin sensitivity and body composition of OVX rats bred for low-running capacity. Furthermore, soy significantly improved blood lipid profile, adipose tissue inflammation, and aortic stiffness of LCR rats. Compared to a soy-free control diet, soy significantly shifted the cecal microbial community of LCR rats, resulting in a lower Firmicutes:Bacteroidetes ratio. Correlations among metabolic parameters and cecal bacterial taxa identified in this study suggest that taxa Prevotella, Dorea, and Phascolarctobacterium may be taxa of interest. Our results suggest that dietary soy ameliorates adiposity, insulin sensitivity, adipose tissue inflammation, and arterial stiffness and exerts a beneficial shift in gut microbial communities in a rat model that mimics human menopause.

The use of statins alone, or in combination with pioglitazone and other drugs, for the treatment of non-alcoholic fatty liver disease/non-alcoholic steatohepatitis and related cardiovascular risk. An Expert Panel Statement

Non-alcoholic fatty liver disease (NAFLD), the most common liver disease, is characterized by accumulation of fat (>5% of the liver tissue), in the absence of alcohol abuse or other chronic liver diseases. It is closely related to the epidemic of obesity, metabolic syndrome or type 2 diabetes mellitus (T2DM). NAFLD can cause liver inflammation and progress to non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis or hepatocellular cancer (HCC). Nevertheless, cardiovascular disease (CVD) is the most common cause of death in NAFLD/NASH patients. Current guidelines suggest the use of pioglitazone both in patients with T2DM and in those without. The use of statins, though considered safe by the guidelines, have very limited use; only 10% in high CVD risk patients are on statins by tertiary centers in the US. There are data from several animal studies, 5 post hoc analyses of prospective long-term survival studies, and 5 rather small biopsy proven NASH studies, one at baseline and on at the end of the study. All these studies provide data for biochemical and histological improvement of NAFLD/NASH with statins and in the clinical studies large reductions in CVD events in comparison with those also on statins and normal liver. Ezetimibe was also reported to improve NAFLD. Drugs currently in clinical trials seem to have potential for slowing down the evolution of NAFLD and for reducing liver- and CVD-related morbidity and mortality, but it will take time before they are ready to be used in everyday clinical practice. The suggestion of this Expert Panel is that, pending forthcoming randomized clinical trials, physicians should consider using a PPARgamma agonist, such as pioglitazone, or, statin use in those with NAFLD/NASH at high CVD or HCC risk, alone and/or preferably in combination with each other or with ezetimibe, for the primary or secondary prevention of CVD, and the avoidance of cirrhosis, liver transplantation or HCC, bearing in mind that CVD is the main cause of death in NAFLD/NASH patients.

Nonalcoholic fatty liver disease - A multisystem disease?

Non-alcoholic fatty liver disease (NAFLD) is one of the most common comorbidities associated with overweight and metabolic syndrome (MetS). Importantly, NAFLD is one of its most dangerous complications because it can lead to severe liver pathologies, including fibrosis, cirrhosis and hepatic cellular carcinoma. Given the increasing worldwide prevalence of obesity, NAFLD has become the most common cause of chronic liver disease and therefore is a major global health problem. Currently, NAFLD is predominantly regarded as a hepatic manifestation of MetS. However, accumulating evidence indicates that the effects of NAFLD extend beyond the liver and are negatively associated with a range of chronic diseases, most notably cardiovascular disease (CVD), diabetes mellitus type 2 (T2DM) and chronic kidney disease (CKD). It is becoming increasingly clear that these diseases are the result of the same underlying pathophysiological processes associated with MetS, such as insulin resistance, chronic systemic inflammation and dyslipidemia. As a result, they have been shown to be independent reciprocal risk factors. In addition, recent data have shown that NAFLD actively contributes to aggravation of the pathophysiology of CVD, T2DM, and CKD, as well as several other pathologies. Thus, NAFLD is a direct cause of many chronic diseases associated with MetS, and better detection and treatment of fatty liver disease is therefore urgently needed. As non-invasive screening methods for liver disease become increasingly available, detection and treatment of NAFLD in patients with MetS should therefore be considered by both (sub-) specialists and primary care physicians.

Nonalcoholic fatty liver disease, association with cardiovascular disease and treatment. (I). Nonalcoholic fatty liver disease and its association with cardiovascular disease

Non-alcoholic fatty liver disease (NAFLD) comprises a series of histologically lesions similar to those induced by alcohol consumption in people with very little or no liver damage. The importance of NAFLD is its high prevalence in the Western world and, from the point of view of the liver, in its gradual progression from steatosis to steatohepatitis, cirrhosis, and liver cancer. During the last decade it has been observed that NAFLD leads to an increased cardiovascular risk with acceleration of arteriosclerosis and events related to it, being the main cause of its morbidity and mortality. This review, updated to January 2016, consists of two parts, with the first part analysing the association of NAFLD with cardiovascular disease.

Loss of Nlrp3 Does Not Protect Mice from Western Diet-Induced Adipose Tissue Inflammation and Glucose Intolerance

We tested the hypothesis that loss of Nlrp3 would protect mice from Western diet-induced adipose tissue (AT) inflammation and associated glucose intolerance and cardiovascular complications. Five-week old C57BL6J wild-type (WT) and Nlrp3 knockout (Nlrp3-/-) mice were randomized to either a control diet (10% kcal from fat) or Western diet (45% kcal from fat and 1% cholesterol) for 24 weeks (n = 8/group). Contrary to our hypothesis that obesity-mediated white AT inflammation is Nlrp3-dependent, we found that Western diet-induced expression of AT inflammatory markers (i.e., Cd68, Cd11c, Emr1, Itgam, Lgals, Il18, Mcp1, Tnf, Ccr2, Ccl5 mRNAs, and Mac-2 protein) were not accompanied by increased caspase-1 cleavage, a hallmark feature of NLRP3 inflammasome activation. Furthermore, Nlrp3 null mice were not protected from Western diet-induced white or brown AT inflammation. Although Western diet promoted glucose intolerance in both WT and Nlrp3-/- mice, Nlrp3-/- mice were protected from Western diet-induced aortic stiffening. Additionally, Nlrp3-/- mice exhibited smaller cardiomyocytes and reduced cardiac fibrosis, independent of diet. Collectively, these findings suggest that presence of the Nlrp3 gene is not required for Western diet-induced AT inflammation and/or glucose intolerance; yet Nlrp3 appears to play a role in potentiating arterial stiffening, cardiac hypertrophy and fibrosis.

Regular Exercise Reduces Endothelial Cortical Stiffness in Western Diet-Fed Female Mice

We recently showed that Western diet-induced obesity and insulin resistance promotes endothelial cortical stiffness in young female mice. Herein, we tested the hypothesis that regular aerobic exercise would attenuate the development of endothelial and whole artery stiffness in female Western diet-fed mice. Four-week-old C57BL/6 mice were randomized into sedentary (ie, caged confined, n=6) or regular exercise (ie, access to running wheels, n=7) conditions for 16 weeks. Exercise training improved glucose tolerance in the absence of changes in body weight and body composition. Compared with sedentary mice, exercise-trained mice exhibited reduced endothelial cortical stiffness in aortic explants (sedentary 11.9±1.7 kPa versus exercise 5.5±1.0 kPa; P<0.05), as assessed by atomic force microscopy. This effect of exercise was not accompanied by changes in aortic pulse wave velocity (P>0.05), an in vivo measure of aortic stiffness. In comparison, exercise reduced femoral artery stiffness in isolated pressurized arteries and led to an increase in femoral internal artery diameter and wall cross-sectional area (P<0.05), indicative of outward hypertrophic remodeling. These effects of exercise were associated with an increase in femoral artery elastin content and increased number of fenestrae in the internal elastic lamina (P<0.05). Collectively, these data demonstrate for the first time that the aortic endothelium is highly plastic and, thus, amenable to reductions in stiffness with regular aerobic exercise in the absence of changes in in vivo whole aortic stiffness. Comparatively, the same level of exercise caused destiffening effects in peripheral muscular arteries, such as the femoral artery, that perfuse the working limbs.

Increasing aortic stiffness is predictive of advanced liver fibrosis in patients with type 2 diabetes: the Rio-T2DM cohort study

BACKGROUND & AIMS

Type 2 diabetes mellitus (T2DM) is a risk factor for cardiovascular disease (CVD) and advanced stages of non-alcoholic fatty liver disease (NAFLD). The aim was to evaluate the association between aortic stiffness, a preclinical CVD marker, with advanced liver fibrosis identified by transient elastography (TE) in T2DM outpatients with NAFLD.

METHODS

This longitudinal study included 291 T2DM patients with NAFLD detected by ultrasonography, who had two carotid-femoral pulse wave velocity (cf-PWV) measurements and a TE examination (Fibroscan(®) ) performed over a median follow-up of 7 years. Advanced liver fibrosis (corresponding to ≥ F3 stage) was considered as median values >7.9 kPa (M probe) or >7.2 kPa (XL probe). Increased aortic stiffness was defined as cf-PWV >10 m/s.

RESULTS

Eighty patients (27.5%) had advanced liver fibrosis. Overall, there was an increase in cf-PWV of 0.1 m/s/year (1% per year). Both a high aortic stiffness at the 2nd cf-PWV examination [odds ratios (OR): 3.0; 95% CI: 1.3-7.2; P = 0.011] and a serial increase in aortic stiffness (OR: 2.1; 95% CI: 1.0-4.3; P = 0.046) were associated with increased odds of having advanced liver fibrosis. Patients who presented either an increase in aortic stiffness or persisted with high values had significantly higher mean liver stiffness than those who either decreased aortic stiffness or persisted with normal cf-PWV values (mean difference: 2.1 kPa, 95% CI: 0.5-3.7 kPa, P = 0.012), after adjustments for anthropometric-demographic and clinical laboratory covariates.

CONCLUSIONS

In T2DM patients with NAFLD, a high or increasing aortic stiffness predicted development of advanced liver fibrosis on TE.

Fatty liver is an independent predictor of early carotid atherosclerosis

BACKGROUND & AIMS

Whether steatosis is incidentally or causally associated with carotid atherosclerosis is debated, and long-term follow-up data are missing. This study aims to examine the impact of steatosis on the presence and progression of carotid intima-media thickness (C-IMT) and carotid plaques (CP) in a large cohort with longitudinal follow-up.

METHODS

A retrospective single-center study between 1995 and 2012. Transversal cohort: patients with ⩾2 cardiovascular risk factors without previous cardiovascular events. Longitudinal cohort: patients with two consecutive C-IMT measurements more than 2years apart. Steatosis was defined by a surrogate marker, the fatty liver index (FLI). CP and C-IMT were assessed by carotid ultrasound.

RESULTS

In the transversal cohort (n=5671) both C-IMT and the Framingham risk score (FRS) increased across FLI quartiles (0.58±0.12, 0.61±0.14, 0.63±0.14, 0.64±0.14mm, and 5±5%, 9±7%, 12±8%, 15±9%, p<0.001 for both). Steatosis predicted C-IMT better than diabetes or dyslipidemia. Steatosis independently predicted C-IMT (p=0.002) and FRS (p<0.001) after adjustment for metabolic syndrome and cardiovascular risk factors. In the longitudinal cohort (n=1872, mean follow-up 8±4years), steatosis occurred in 12% and CP in 23% of patients. C-IMT increased in patients with steatosis occurrence (from 0.60±0.13mm to 0.66±0.14mm, p=0.001) whereas it did not change in those that stayed free of steatosis. Steatosis at baseline predicted CP occurrence (OR=1.63, 95% CI 1.10-2.41, p=0.014), independent of age, sex, type-2 diabetes, tobacco use, hsCRP, hypertension and C-IMT.

CONCLUSIONS

In patients with metabolic syndrome at risk for cardiovascular events, steatosis contributes to early atherosclerosis and progression thereof, independent of traditional cardiovascular risk factors.

The Association between Non-Invasive Hepatic Fibrosis Markers and Cardiometabolic Risk Factors in the Framingham Heart Study

Background & Aims

Non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular related death, particularly in those with hepatic fibrosis. We determined the prevalence of predicted fibrosis based on non-invasive fibrosis markers and the association of hepatic fibrosis with cardiovascular risk factors.

Methods

Cross-sectional study of 575 Framingham Heart Study participants with NAFLD based on computed tomography. We determined the prevalence of predicted fibrosis based on the aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio, AST to platelet ratio index (APRI), the Fibrosis-4 score (FIB4), and the NAFLD Fibrosis Score (NFS). Using multivariable logistic regression models, we examined the association between low, indeterminate, or high risk for fibrosis according to the NFS and various cardiometabolic risk factors.

Results

The predicted risk of fibrosis was 12%, 4%, 5%, and 32% for the NFS, FIB4, APRI, and AST/ALT ratio, respectively. In multivariable models, participants with a high risk for advanced fibrosis by the NFS had a wider pulse pressure (adjusted mean difference = 6.87 mm Hg; p = 0.0002) and an increased odds of hypertension (OR 2.92; p = 0.007) compared to those with low risk of fibrosis. There were no statistically significant differences between other cardiovascular risk factors for those with a high versus low risk of fibrosis.

Conclusions

The AST/ALT ratio, APRI, and NFS give widely disparate predictions of liver fibrosis. Participants with a high risk for fibrosis based on NFS had wider pulse pressure and increased odds of hypertension. Whether modifying these risk factors impacts cardiovascular endpoints in NAFLD patients remains unknown.

Nonalcoholic fatty liver disease as a multi-systemic disease

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease. NAFLD includes a wide spectrum of liver conditions ranging from simple steatosis to nonalcoholic steatohepatitis and advanced hepatic fibrosis. NAFLD has been recognized as a hepatic manifestation of metabolic syndrome linked with insulin resistance. NAFLD should be considered not only a liver specific disease but also an early mediator of systemic diseases. Therefore, NAFLD is usually associated with cardiovascular disease, chronic kidney disease, type 2 diabetes, obesity, and dyslipidemia. NAFLD is highly prevalent in the general population and is associated with increased cardiovascular morbidity and mortality. The underlying mechanisms and pathogenesis of NAFLD with regard to other medical disorders are not yet fully understood. This review focuses on pathogenesis of NAFLD and its relation with other systemic diseases.