Should we lower lipids in nonalcoholic fatty liver disease?

Lipid Metabolism in Metabolic-Associated Steatotic Liver Disease (MASLD)

Metabolic-associated steatotic liver disease (MASLD) is a cluster of pathological conditions primarily developed due to the accumulation of ectopic fat in the hepatocytes. During the severe form of the disease, i.e., metabolic-associated steatohepatitis (MASH), accumulated lipids promote lipotoxicity, resulting in cellular inflammation, oxidative stress, and hepatocellular ballooning. If left untreated, the advanced form of the disease progresses to fibrosis of the tissue, resulting in irreversible hepatic cirrhosis or the development of hepatocellular carcinoma. Although numerous mechanisms have been identified as significant contributors to the development and advancement of MASLD, altered lipid metabolism continues to stand out as a major factor contributing to the disease. This paper briefly discusses the dysregulation in lipid metabolism during various stages of MASLD.

Medications in type-2 diabetics and their association with liver fibrosis

BACKGROUND

The prevalence of nonalcoholic fatty liver disease (NAFLD) is significantly rising worldwide. Type-2 diabetes (T2D) is a major risk factor for NAFLD progression.

AIM

To assess the association of commonly used medications to advanced fibrosis (AF) in patients with biopsy-proven NAFLD and T2D.

METHODS

We used the International Classification of Disease 9^th Revision Clinical Modification coding system to identify patients with T2D and included patients who underwent liver biopsy for suspected NAFLD between January 1, 2000 to December 31, 2015. We compared demographics, clinical characteristics, and differences in pattern of medication use in patients who had biopsy-proven AF to those without it. A univariate and multivariate analysis was performed to assess the association of different classes of medication with the presence of AF.

RESULTS

A total of 1183 patients were included in the final analysis, out of which 32% (n = 381) had AF on liver biopsy. Mean age of entire cohort was 52 years and majority were females (65%) and Caucasians (85%). Among patients with AF, 51% were on oral hypoglycemics, 30% were on insulin, 66% were on antihypertensives and 27% were on lipid lowering agents for the median duration of 19 mo, 10 mo, 26 mo, and 24 mo respectively. Medications associated with decreased risk of AF included metformin, liraglutide, lisinopril, hydrochlorothiazide, atorvastatin and simvastatin while the use of furosemide and spironolactone were associated with higher prevalence of AF.

CONCLUSION

In our cohort of T2D with biopsy proven NAFLD, the patients who were receiving metformin, liraglutide, lisinopril, hydrochlorothiazide, atorvastatin and simvastatin were less likely to have AF on biopsy, while patients who were receiving furosemide and spironolactone had a higher likelihood of having AF when they underwent liver biopsy. Future studies are needed to confirm these findings and to establish measures for prevention of NAFLD progression in patients with T2D.

Nonalcoholic Fatty Liver Disease: An Important Consideration for Primary Care Providers in Hawai'i

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. NAFLD is a broad term for both non-alcoholic fatty liver (NAFL), which describes simple fatty liver without inflammation, and non-alcoholic steatohepatitis (NASH), the more severe phenotype with hepatocellular inflammation. The population of Hawai'i is particularly vulnerable to the NAFLD and obesity epidemics due to its large proportions of high-risk ethnic minorities exposed to varying degrees of westernization. Unfortunately, primary care providers (PCPs) often face a lack of awareness on the diagnosis and disease spectrum of NAFLD. Early initiation of treatment for NAFLD is crucial to slow its progression and prevent liver-related morbidity and mortality. This review aims to raise awareness for NAFLD among PCPs in Hawai'i by summarizing the disease's epidemiology, diagnosis, and treatment. The diagnostic workup of NAFLD in the primary care setting involves exclusion of other liver disease etiologies and staging assessment of fibrosis and steatosis through non-invasive means such as serum biomarkers or elastography. Patients with overt signs and symptoms of cirrhosis or a high likelihood of advanced hepatic fibrosis should be referred to liver disease specialists. The role of PCPs in NAFLD management involves facilitating weight loss through therapeutic lifestyle modifications and treatment of comorbid cardiovascular conditions. Evidence-based pharmacologic therapies for NAFLD are available, such as vitamin E and pioglitazone, with more currently in development.

Insulin resistance linked to subtle myocardial dysfunction in normotensive Turner syndrome young patients without structural heart diseases

Background Turner syndrome (TS) patients have increased cardiovascular risk. This cardiovascular risk is famously attributed to structural abnormalities of the left side of the heart such as aortic stenosis and aortic coarctation. However, due to insulin resistance and subsequent pathogenic mechanisms, normotensive TS patients without structural abnormalities may develop varying degrees of myocardial dysfunction. The aim of this research was to examine the role of speckle tracking echocardiography in early detection of Turner cardiomyopathy and to correlate this myocardial dysfunction with measures of insulin resistance. Methods This cross-sectional case control study included 30 children with TS and 30 age-matched healthy controls. TS patients were excluded if: hypertensive, with major structural abnormalities of the heart or other systemic diseases that may affect myocardial function. Conventional speckle tracking echocardiography and glucose-insulin ratio were performed for all study subjects. Results Routine echocardiographic parameters of left ventricular systolic function were similar in cases and controls while global longitudinal and circumferential strain (GLS and GCS) were lower in patients with TS than controls: (-13.2±1.1 vs. -18.3±2.4, p-value<0.000) and (-11.3±1.1 vs. -16.3±2.1, p-value<0.000), respectively. Fasting glucose:insulin ratio (FGIR) proved to be the best predictor of myocardial dysfunction in TS patients by multivariate analysis. Conclusions This study points towards the potential role of two-dimensional (2D) speckle tracking echocardiography in early detection of subtle systolic myocardial dysfunction in TS patients. It also points towards the implication of insulin resistance in precipitation of the observed dysfunction in TS patients.

The nonalcoholic fatty liver disease (NAFLD) fibrosis score, cardiovascular risk stratification and a strategy for secondary prevention with ezetimibe

OBJECTIVE

The nonalcoholic fatty liver disease fibrosis score (NFS) is comprised of unique metabolic risk indicators that may accurately predict residual cardiovascular (CV) risk in patients with established coronary disease and metabolic dysfunction.

METHODS

We applied the NFS prospectively to 14,819 post-ACS patients randomized to ezetimibe/simvastatin (E/S) or placebo/simvastatin (P/S), in the IMPROVE-IT trial, using validated NFS cutoffs. The primary endpoint included CV death, myocardial infarction, unstable angina, revascularization or stroke. Outcomes were compared between NFS categories and treatment arms using frequency of events, KM rates and adjusted Cox proportional hazard models. The ability of the NFS to predict recurrent CV events was independently validated in 5395 placebo-treated patients enrolled in the SOLID-TIMI 52 trial.

RESULTS

Among 14,819 patients enrolled in IMPROVE-IT, 14.2% (N = 2106) were high-risk (NFS > 0.67). The high-risk group had a 30% increased risk of recurrent major CV events, compared to the low-risk NFS group (HR 1.30 [1.19-1.43]; p < 0.001). Among high-risk patients, ezetimibe/simvastatin conferred a 3.7% absolute reduction in risk of recurrent CV events, compared to placebo/simvastatin (HR 0.85 [0.74-0.98]), translating to a number-needed-to-treat of 27. Similar benefit was not found in the low-risk group (HR ezetimibe/simvastatin vs. placebo/simvastatin, 1.01 [0.91-1.12]; p-interaction = 0.053). The relationship between NFS category and recurrent CV events was independently validated in patients enrolled in SOLID-TIMI 52 (HR for NFS > 0.67 vs. NFS < -1.455 = 1.55 [1.32-1.81]; p < 0.001).

CONCLUSION

Stratification of cardiovascular risk by NFS identifies an independent population of patients who are at highest risk of recurrent events, and most likely to benefit from dual lipid-lowering therapy. Clinical trials.gov: NCT00202878.

Managing non-alcoholic fatty liver disease

The prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing rapidly with the obesity and diabetes mellitus epidemics. It is rapidly becoming the most common cause of liver disease worldwide. NAFLD can progress to serious complications such as cirrhosis, hepatocellular carcinoma and death. Therefore, it is important to recognise this condition so that early intervention can be implemented. Lifestyle modifications and strict control of metabolic risk factors are the mainstay of treatment. As disease progression is slow in the majority of NAFLD patients, most can be managed well by primary care physicians. NAFLD patients with advanced liver fibrosis should be referred to specialist care for further assessment.

Pharmacological management of nonalcoholic fatty liver disease in type 2 diabetes

INTRODUCTION

The prevalence of nonalcoholic fatty liver disease (NAFLD) in patients with type 2 diabetes (T2D) is high and it is associated with poor prognosis. Hepatic steatosis results as a consequence of excessive hepatic lipid accumulation which correlates with insulin resistance and lipotoxicity, with subsequent oxidative stress, inflammation, apoptosis and fibrosis. Areas covered: This article presents the main pathophysiologic mechanisms and currently available drugs evaluated for their therapeutic effects on NAFLD/nonalcoholic steatohepatitis (NASH) and drugs under development that target relevant pathogenetic pathways. However, to date there is no particular drug approved for treatment of NAFLD in patients with T2D. Expert commentary: Early recognition and intervention are essential to ameliorate disease progression. Specific recommendations are still needed for NAFLD/NASH screening and diagnosis and therapeutic algorithm in patients with T2D. Lifestyle optimization with significant weight loss is a key intervention in patients with NAFLD and T2D. Pioglitazone, liraglutide, vitamin E, OCA and pentoxifylline have proven some histological improvements in NASH and omega 3-PUFAs were shown to decrease liver fat, but no specific recommendation can be made for treatment of NASH. Perhaps a combination of agents that target different pathogenic pathways are needed to better control disease progression, but more robust evidence for these agents is still needed.

Pathogenesis and novel treatment options for non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease affects 20-40% of the population. Its active form, non-alcoholic steatohepatitis (NASH), is characterised by hepatocyte injury, liver inflammation, and progression of fibrosis, and has emerged as one of the most important causes of liver failure and hepatocellular carcinoma. Weight reduction of 10% by dietary restriction and regular exercise is sufficient to reverse NASH in most patients, but in practice this reduction is often not achieved. Available drugs such as vitamin E, pioglitazone, and pentoxifylline have borderline efficacy, but are limited by potential side-effects and toxicities, and do not improve liver fibrosis. However, basic and translational research has improved our understanding of the pathophysiology of NASH, thereby identifying several promising new treatment targets. Several drugs are in phase 2 and 3 development and could enter clinical practice in the near future. In this Review, we discuss the pathogenesis, treatment evaluation, existing therapies, and potential new treatments for NASH.

Renin-angiotensin system and fibrosis in non-alcoholic fatty liver disease

BACKGROUND & AIMS

Therapeutic options are limited for patients with non-alcoholic fatty liver disease (NAFLD). One promising approach is the attenuation of necroinflammation and fibrosis by inhibition of the renin-angiotensin system (RAS). We explored whether the risk of fibrosis was associated with the use of commonly used medications in NAFLD patients with hypertension. Specifically, we sought to determine the association between RAS blocking agents and severity of hepatic fibrosis in NAFLD patients with hypertension.

METHODS

Cross-sectional study where clinical information including demographics, anthropometry, medical history, concomitant medication use, biochemical and histological features were ascertained in 290 hypertensive patients with biopsy proven NAFLD followed at two hepatology outpatient clinics. Stage of hepatic fibrosis was compared in patients with and without RAS blocker use. Other risk factors for fibrosis were evaluated from the electronic medical records and patient follow-up.

RESULTS

Baseline characteristics of hypertensive patients treated with and without RAS blockers were similar except for less ballooning (1.02 vs. 1.31, P = 0.001) and lower fibrosis stage (1.63 vs. 2.16, P = 0.002) in patients on RAS blockers On multivariate analysis, advancing age (OR: 1.04; 95%CI: 1.01-1.06, P = 0.012) and presence of diabetes (OR: 2.55; 95%CI: 1.28-5.09, P = 0.008) had an independent positive association, while use of RAS blockers (OR: 0.37; 95%CI: 0.21-0.65, P = 0.001) and statins (OR: 0.52; 95%CI: 0.29-0.93, P = 0.029) had a negative association with advanced fibrosis.

CONCLUSION

Hypertensive patients with NAFLD on baseline RAS blockers had less advanced hepatic fibrosis suggesting a beneficial effect of RAS blockers in NAFLD.

P2X7 receptor as a key player in oxidative stress-driven cell fate in nonalcoholic steatohepatitis

Incidences of nonalcoholic fatty liver disease parallels increase in the global obesity epidemic. NAFLD has been shown to be associated with risks of cardiometabolic disorders and kidney disturbances. It is accompanied by insulin and leptin resistance that complicate the diagnosis and treatment of this public health menace. Though significant research is underway for understanding the molecular mechanisms of NAFLD and its subsequent inflammatory and fibrotic manifestations like nonalcoholic steatohepatitis, the role of purinergic receptors has been unclear. It is increasingly being recognized that damage associated molecular patterns like NAD and ATP that are released from injured cells via hepatocellular injury either by oxidative stress or lipotoxicity from steatosis activate the purinergic receptor. Based on evidence from inflammatory responses in the airways and vasculature and autoimmune complications in humans and rodents, it is beyond doubt that hepatocellular inflammation such as that seen in NASH can result from the activation of purinergic receptors. This event can result in the formation of inflammasomes and can be an important pathway for the progression of NASH. The present review evaluates the current knowledge of the role of oxidative stress and its signaling via P2X7 receptors in hepatocellular injury that might contribute to the NASH pathophysiology.