Sarcopenia is associated with severe liver fibrosis in patients with non-alcoholic fatty liver disease

Growth differentiation factor 15 predicts advanced fibrosis in biopsy-proven non-alcoholic fatty liver disease

BACKGROUND & AIMS

We explored whether growth differentiation factor 15 (GDF15) affects the histological severity of non-alcoholic fatty liver disease (NAFLD) independent of insulin resistance.

METHODS

In a biopsy-proven NAFLD cohort, we measured serum GDF15 levels using enzyme-linked immunosorbent assays.

RESULTS

Among 190 subjects (mean age, 53 ± 14 years; men, 52.1%), 72 (men, 65.3%) and 78 (men, 44.9%) were diagnosed with biopsy-proven non-alcoholic fatty liver (NAFL) and non-alcoholic steatohepatitis (NASH) respectively. GDF15 levels were significantly higher in NASH patients than in controls (P = .010) or NAFL patients (P = .001). Subjects with advanced fibrosis (≥F3) also showed higher GDF15 levels compared to the others (F0-2; P < .001). Among NAFLD patients, the highest quartile of GDF15 levels was significantly associated with a risk of advanced fibrosis even after adjustment for age, gender, body mass index, smoking status, hypertension, diabetes, aspartate aminotransferase, platelet, albumin, insulin resistance and low skeletal muscle mass (odds ratio, 4.27; 95% confidence interval, 1.04-17.63), but not with NASH risk. GDF15 levels showed a significant positive correlation with liver stiffness (Spearman's ρ, .525; P < .001). Palmitate treatment increased the GDF15 mRNA expression level significantly in Kupffer cells, but not in hepatocytes. In LX-2 cells, GDF15 treatment resulted in enhanced expression of α-smooth muscle actin and collagen I, as well as phosphorylation of SMAD2 and SMAD3.

CONCLUSIONS

Our findings suggest that GDF15 may serve as a novel biomarker of advanced fibrosis in NAFLD, thereby indicating the need for urgent anti-fibrotic pharmacotherapy.

Loop diuretics are associated with greater risk of sarcopenia in patients with non-dialysis-dependent chronic kidney disease

Introduction

Sarcopenia, the age-related loss of muscle mass and function, frequently accompanies chronic kidney disease. The aim of this study was to clarify the prevalence and the risk factors for sarcopenia among patients with non-dialysis-dependent chronic kidney disease (NDD-CKD), focusing on the use of drugs.

Methods

We conducted a cross-sectional analysis on a cohort of 260 patients with NDD-CKD in a university hospital, recruited between June 2016 and March 2017. We extracted data on patient gender, age, cause of chronic kidney disease, use of drugs, and comorbidities that could potentially affect the prevalence of sarcopenia. Sarcopenia was diagnosed using the criteria of the Asian Working Group for Sarcopenia. Logistic regression analysis was performed to analyze the association of each factor on the prevalence of sarcopenia.

Results

25.0% of our study subjects had sarcopenia. Multivariable analysis revealed that an increased risk of sarcopenia was significantly associated with age, male gender, body mass index, diabetes mellitus, and loop diuretic use (odds ratio, 4.59: 95% confidence interval, 1.81–11.61: P-value 0.001).

Conclusions

In our cohort, the prevalence of sarcopenia in patients with NDD-CKD was high, and diuretics use, particularly loop diuretic use, was suggested to be a risk factor of sarcopenia. Although loop diuretics are commonly used in patients with CKD, careful consideration of the risk of sarcopenia may be necessary.

Altered amino acid concentrations in NAFLD: Impact of obesity and insulin resistance

Plasma concentrations of amino acids (AAs), in particular, branched chain AAs (BCAAs), are often found increased in nonalcoholic fatty liver disease (NAFLD); however, if this is due to increased muscular protein catabolism, obesity, and/or increased insulin resistance (IR) or impaired tissue metabolism is unknown. Thus, we evaluated a) if subjects with NAFLD without obesity (NAFLD-NO) compared to those with obesity (NAFLD-Ob) display altered plasma AAs compared to controls (CTs); and b) if AA concentrations are associated with IR and liver histology. Glutamic acid, serine, and glycine concentrations are known to be altered in NAFLD. Because these AAs are involved in glutathione synthesis, we hypothesized they might be related to the severity of NAFLD. We therefore measured the AA profile of 44 subjects with NAFLD without diabetes and who had a liver biopsy (29 NAFLD-NO and 15 NAFLD-Ob) and 20 CTs without obesity, by gas chromatography-mass spectrometry, homeostasis model assessment of insulin resistance, hepatic IR (Hep-IR; Hep-IR = endogenous glucose production × insulin), and the new glutamate-serine-glycine (GSG) index (glutamate/[serine + glycine]) and tested for an association with liver histology. Most AAs were increased only in NAFLD-Ob subjects. Only alanine, glutamate, isoleucine, and valine, but not leucine, were increased in NAFLD-NO subjects compared to CTs. Glutamate, tyrosine, and the GSG-index were correlated with Hep-IR. The GSG-index correlated with liver enzymes, in particular, gamma-glutamyltransferase (R = 0.70), independent of body mass index. Ballooning and/or inflammation at liver biopsy were associated with increased plasma BCAAs and aromatic AAs and were mildly associated with the GSG-index, while only the new GSG-index was able to discriminate fibrosis F3-4 from F0-2 in this cohort.

CONCLUSION

Increased plasma AA concentrations were observed mainly in subjects with obesity and NAFLD, likely as a consequence of increased IR and protein catabolism. The GSG-index is a possible marker of severity of liver disease independent of body mass index. (Hepatology 2018;67:145-158).

Systematic review with meta-analysis: the significance of histological disease severity in lean patients with nonalcoholic fatty liver disease

BACKGROUND

Current evidence suggests that lean and obese patients with nonalcoholic fatty liver disease (NAFLD) share an altered metabolic and cardiovascular profile. However, there is an incomplete understanding of the natural history of "lean-NAFLD." Indeed, an unanswered question is whether lean (BMI ≤ 25 Kg/m² ) NAFLD-patients are protected from severe histological outcomes.

AIM

To perform a meta-analysis with the goal of providing a quantitative estimation of the magnitude of fibrosis, as well as histological features associated with the disease severity, in lean versus overweight/obese-NAFLD patients.

METHODS

Through a systematic search up to July 2017, we identified eight studies that compared histological outcomes in lean (n = 493) versus overweight/obese (n = 2209) patients.

RESULTS

Relative to lean-NAFLD, overweight/obese-NAFLD patients showed significantly (P = .032) higher fibrosis scores; the observed difference in means between the two groups, which is the absolute difference between the mean value of fibrosis score [0-4] ± standard error, was 0.28 ± 0.13. The risk of having nonalcoholic steatohepatitis-NASH (OR 0.58 95% CI 0.34-0.97) was significantly lower in lean-NAFLD (n = 322) than in overweight/obese-NAFLD (n = 1357), P = .04. Relative to lean-NAFLD, overweight/obese-NAFLD patients also have significantly greater NAFLD activity (difference in means ± SE: 0.58 ± 0.16, P = .0004) and steatosis (difference in means ± SE: 0.23 ± 0.07, P = .002) scores.

CONCLUSIONS

Lean-NAFLD patients tend to show less severe histological features as compared to overweight/obese-NAFLD patients. Subsequent longitudinal assessment is needed to understand the clinical impact of these findings; however, the significant ~ 25% increment of mean fibrosis score in overweight/obese patients suggests that obesity could predict a worse long-term prognosis.

Nonalcoholic fatty liver disease and sarcopenia in a Western population (NHANES III): The importance of sarcopenia definition

BACKGROUND

Recent epidemiological studies have shown that sarcopenia is associated with non-alcoholic fatty liver disease (NAFLD) and advanced fibrosis in an Asian population. We investigated whether NAFLD is associated with a higher risk of sarcopenia using a different definition in elderly patients.

METHODS

A population-based cross-sectional survey of US patients was conducted, involving 2551 participants aged 60-75 years. NAFLD was measured by ultrasound. Sarcopenia was defined by both a low muscle mass and poor muscle function. In addition, the skeletal muscle index (SMI) was calculated as the absolute muscle mass (kilograms) divided by height² (meters) or total body mass (kilograms). A multivariable logistic regression was conducted to estimate the relationship between sarcopenia and NAFLD in the elderly.

RESULTS

After adjusting for age, sex, and race/ethnicity, severe hepatic steatosis was associated with a decreased risk of sarcopenia as defined by the height-adjusted SMI (odds ratio (OR) 0.63; 95% confidence interval (CI) 0.46-0.87). In contrast, severe hepatic steatosis was associated with an increased risk of sarcopenia as defined by the weight-adjusted SMI (OR 1.73; 95% CI 1.31-2.28). These significant associations remained after further adjustments for other potential confounding variables.

CONCLUSIONS

NAFLD is associated with a lower risk of sarcopenia when using the height-adjusted SMI. In contrast, it showed the opposite result when using the weight-adjusted SMI. The definition of sarcopenia may be an important factor when examining its relationship with NAFLD.

Sarcopenia in hiding: The risk and consequence of underestimating muscle dysfunction in nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Up to one third of individuals with NAFLD will develop nonalcoholic steatohepatitis (NASH), which is associated with progression to cirrhosis and is rapidly becoming the leading indication for liver transplantation. Sarcopenia is defined as a progressive and generalized loss of skeletal muscle mass, strength, and function. It is observed in up to 60% of patients with end-stage liver disease and portends a poor prognosis. Recent studies have shown that sarcopenia is a novel risk factor for developing NAFLD. Pathophysiological mechanisms relating sarcopenia and NASH may include insulin resistance (IR) and increased inflammation. IR leads to accumulation of triglycerides in both muscle tissue and the liver. It also exacerbates proteolysis and leads to muscle depletion. Chronic inflammation leads to liver injury and progression of fibrosis. The inflammatory milieu also stimulates protein catabolism. Viewing skeletal muscle as an endocrine organ that secretes various salutary myokines may help us understand its role in the development of steatosis. A better understanding of the pathophysiology will aid in developing physical and pharmacological therapeutic interventions. In this review, we will explore the complex inter-relationships between sarcopenia and NASH. We will discuss the impact of sarcopenia in patients with NASH and therapeutic options for the management of sarcopenia. (Hepatology 2017;66:2055-2065).

Relationship between skeletal muscle mass and liver fibrosis markers for patients with hepatitis C virus related liver disease

We aimed to elucidate the relationship between serum liver fibrosis markers (Mac-2 binding protein glycosylation isomer (M2BPGi), FIB-4 index, aspartate aminotransferase to platelet ratio index and hyaluronic acid), and skeletal muscle mass and to investigate factors linked to skeletal muscle mass loss (SMML) in patients with chronic hepatitis C (CHC, n = 277, median age = 64 years). We defined patients with psoas muscle index [PMI, sum of bilateral psoas muscle mass calculated by manual trace method at the lumber 3 level on the computed tomography images divided by height squared (cm/m)] less than 6.36 cm/m for male and 3.92 cm/m for female as those with SMML based on the recommendations in current guidelines. Receiver operating curve (ROC) analysis was performed for predicting SMML in 4 liver fibrosis markers and parameters linked to SMML were also investigated in the univariate and multivariate analyses. In terms of liver fibrosis stages, F4 was observed in 115 patients, F3 in 67, F2 in 38, F1 in 53, and F0 in 4. The median (range) PMI for male and female were 6.198 (2.999-13.698) and 4.100 (1.691-7.052) cm/m, respectively. There were 72 male patients with SMML (55.4%) and 58 female patients with SMML (39.5%) (P = .0112). In both male and female, a significant inverse correlation between PMI and levels of liver fibrosis markers was observed in all liver fibrosis markers. ROC analyses for predicting SMML revealed that FIB-4 index had the highest area under the ROC (AUC = 0.712), followed by M2BPGi (AUC = 0.692). In the multivariate analysis of factors linked to SMML, gender (P = .0003), body mass index (P < .0001), FIB-4 index (P = .0039), and M2BPGi (P = .0121) were found to be significant predictors. In conclusion, liver fibrosis markers, especially FIB-4 index, can be helpful for predicting SMML in CHC patients.

Predictors Associated with Increase in Skeletal Muscle Mass after Sustained Virological Response in Chronic Hepatitis C Treated with Direct Acting Antivirals

Aims: We aimed to examine changes in skeletal muscle mass in chronic hepatitis C (CHC) patients undergoing interferon (IFN)-free direct acting antivirals (DAAs) therapy who achieved sustained virological response (SVR). Patients and methods: A total of 69 CHC patients treated with DAAs were analyzed. We compared the changes in skeletal muscle index (SMI) using bio-impedance analysis at baseline and SMI at SVR. SMI was calculated as the sum of skeletal muscle mass in upper and lower extremities divided by height squared (cm²/m²). Further, we identified pretreatment parameters contributing to the increased SMI at SVR. Results: SMI in males at baseline ranged from 6.73 to 9.08 cm²/m² (median, 7.65 cm²/m²), while that in females ranged from 4.45 to 7.27 cm²/m² (median, 5.81 cm²/m²). At SVR, 36 patients (52.2%) had increased SMI as compared with baseline. In the univariate analysis, age (p = 0.0392), hyaluronic acid (p = 0.0143), and branched-chain amino acid to tyrosine ratio (BTR) (p = 0.0024) were significant pretreatment factors linked to increased SMI at SVR. In the multivariate analysis, only BTR was an independent predictor linked to the increased SMI at SVR (p = 0.0488). Conclusion: Pretreatment BTR level can be helpful for predicting increased SMI after SVR in CHC patients undergoing IFN-free DAAs therapy.

New trends on obesity and NAFLD in Asia

Traditionally, obesity and its related diseases have been considered a problem in Western countries. However, in the past two decades, urbanisation in many Asian countries has led to a sedentary lifestyle and overnutrition, setting the stage for the epidemic of obesity. This article reviews the epidemiological trend of obesity in Asia, with special emphasis on the emerging condition of non-alcoholic fatty liver disease (NAFLD). Currently, the population prevalence of NAFLD in Asia is around 25%, like many Western countries. While hepatocellular carcinoma and end-stage liver disease secondary to NAFLD remain uncommon, a rising trend has emerged. Around 8-19% of Asians with body mass indexes less than 25kg/m² are also found to have NAFLD, a condition often described as "lean" or "non-obese" NAFLD. Although this condition is generally less severe than that in more obese patients, steatohepatitis and fibrotic disease are well recognized. Central adiposity, insulin resistance and weight gain are major risk factors, and genetic predisposition, such as the PNPLA3 polymorphism appears to be more important in the development of NAFLD in the non-obese population. Lifestyle modification remains the cornerstone of management for obesity and NAFLD, but few patients can achieve adequate weight reduction and even fewer can maintain the weight in the long run. While pharmacological agents have entered phase III development for steatohepatitis, Asian patients are under-represented in most drug trials. Future studies should define the optimal management of obesity and NAFLD in Asia.

Nonalcoholic fatty liver disease: Evolving paradigms

In the last years new evidence has accumulated on nonalcoholic fatty liver disease (NAFLD) challenging the paradigms that had been holding the scene over the previous 30 years. NAFLD has such an epidemic prevalence as to make it impossible to screen general population looking for NAFLD cases. Conversely, focusing on those cohorts of individuals exposed to the highest risk of NAFLD could be a more rational approach. NAFLD, which can be diagnosed with either non-invasive strategies or through liver biopsy, is a pathogenically complex and clinically heterogeneous disease. The existence of metabolic as opposed to genetic-associated disease, notably including ”lean NAFLD” has recently been recognized. Moreover, NAFLD is a systemic condition, featuring metabolic, cardiovascular and (hepatic/extra-hepatic) cancer risk. Among the clinico-laboratory features of NAFLD we discuss hyperuricemia, insulin resistance, atherosclerosis, gallstones, psoriasis and selected endocrine derangements. NAFLD is a precursor of type 2 diabetes (T2D) and metabolic syndrome and progressive liver disease develops in T2D patients in whom the course of disease is worsened by NAFLD. Finally, lifestyle changes and drug treatment options to be implemented in the individual patient are also critically discussed. In conclusion, this review emphasizes the new concepts on clinical and pathogenic heterogeneity of NAFLD, a systemic disorder with a multifactorial pathogenesis and protean clinical manifestations. It is highly prevalent in certain cohorts of individuals who are thus potentially amenable to selective screening strategies, intensive follow-up schedules for early identification of liver-related and extrahepatic complications and in whom earlier and more aggressive treatment schedules should be carried out whenever possible.

The Challenges of Nutritional Assessment in Cirrhosis

Purpose of Review

Nutritional status in patients with cirrhosis is very frequently associated with macro- and micronutrient deficiencies. Cirrhosis itself is the cause of malnutrition and nutritional deficiencies but these conditions have to be identified and addressed properly as they can worsen the prognosis of cirrhosis. The goals of this review are to 1) identify and describe the challenges associated with nutritional assessment in cirrhosis and 2) describe recent advancements when using clinical, laboratory, and instrumental tools in the evaluation of malnourished patients with liver diseases.

Recent Findings

The most promising tools for nutritional assessment in cirrhosis include the evaluation of body composition with phase angle obtained by bioelectrical impedance analysis, computed tomography transverse images at the level of third lumbar vertebra. The Royal-Free Hospital global assessment algorithm appears to be helpful but needs further validation.

Summary

Nutritional assessment in cirrhosis is challenging as several factors, including edema, can interfere with it and because of lack of a validated gold standard. Regardless, nutritional assessment methods have been developed in recent years and should gain relevance in the clinical practice.

Impact of Virtual Touch Quantification in Acoustic Radiation Force Impulse for Skeletal Muscle Mass Loss in Chronic Liver Diseases

Background and aims: We sought to clarify the relationship between virtual touch quantification (VTQ) in acoustic radiation force impulse and skeletal muscle mass as assessed by bio-electronic impedance analysis in patients with chronic liver diseases (CLDs, n = 468, 222 males and 246 females, median age = 62 years). Patients and methods: Decreased skeletal muscle index (D-SMI) was defined as skeletal muscle index (SMI) <7.0 kg/m² for males and as SMI <5.7 kg/m² for females, according to the recommendations in current Japanese guidelines. We examined the correlation between SMI and VTQ levels and investigated factors linked to D-SMI in the univariate and multivariate analyses. The area under the receiver operating curve (AUROC) for the presence of D-SMI was also calculated. Results: In patients with D-SMI, the median VTQ level was 1.64 meters/second (m/s) (range, 0.93–4.32 m/s), while in patients without D-SMI, the median VTQ level was 1.11 m/s (range, 0.67–4.09 m/s) (p < 0.0001). In the multivariate analysis, higher VTQ was found to be an independent predictor linked to the presence of D-SMI (p < 0.0001). In receiver operating characteristic analysis, body mass index had the highest AUROC (0.805), followed by age (0.721) and VTQ (0.706). Conclusion: VTQ levels can be useful for predicting D-SMI in patients with CLDs.

Changes in skeletal muscle mass after endoscopic treatment in patients with esophageal varices

To the best of our knowledge, no available data with regard to changes in skeletal muscle mass for liver cirrhosis (LC) patients with esophageal varices (EVs) undergoing endoscopic therapy as a primary prophylaxis could exist. As endoscopic therapies, such as endoscopic injection sclerotherapy or endoscopic band ligation for EVs, accompany invasive procedure and patients with EVs receiving endoscopic therapies mostly rest in bed during hospitalization, clarifying these issues are clinically of importance. The purposes of this study were therefore to examine changes in skeletal muscle mass for LC patients with EVs undergoing endoscopic therapy as a primary prophylaxis and to identify pretreatment predictors which are associated with the amelioration in skeletal muscle mass. This is a subgroup analysis in our previous randomized controlled trial. A total of 51 LC patients with EVs were analyzed. Skeletal muscle mass was assessed using bioimpedance analysis (BIA). Skeletal muscle index (SMI) was defined as sum of skeletal muscle mass in body trunk and upper and lower extremities divided by height squared (cm/m) using data for BIA. We compared the changes in SMI at baseline and SMI at Day 50 after endoscopic treatment for EVs. Our study cohort included 33 males and 18 females with median (range) age of 62 (29-81) years. There were 31 patients with Child-Pugh A and 20 with Child-Pugh B. The median SMI for the entire cohort at baseline was 8.96 cm/m (range, 5.87-13.11 cm/m), while the median SMI for the entire cohort at Day 50 was 8.83 cm/m (range, 5.59-12.29 cm/m) (P = .9995). In baseline characteristics, prealbumin (P = .0477), branched-chain amino acid to tyrosine ratio (BTR) (P = .0056), and retinol-binding protein (P = .0296) in the increased SMI group (n = 15) were significantly higher than those in the nonincreased SMI group (n = 36). Multivariate analysis for the above 3 significant factors showed that only BTR was a significant prognostic pretreatment factor linked to the presence of increased SMI (P = .0235). In conclusion, pretreatment BTR level can be helpful for predicting increased SMI after endoscopic therapy as a primary prophylaxis for LC patients with EVs.