Association of low skeletal muscle mass with advanced liver fibrosis in patients with non-alcoholic fatty liver disease

Impact of segmental body composition on metabolic dysfunction-associated fatty liver disease in Chinese children

Purpose

This study aimed to assess the relationship between regional body composition and metabolic dysfunction-associated fatty liver disease (MAFLD) in Chinese children.

Methods

In this study, 1399 children aged 7-14 years were included. Liver steatosis was assessed using the controlled attenuation parameter (CAP) measured through Fibroscan. MAFLD is defined as the presence of liver steatosis along with either overweight/obesity, prediabetes/diabetes, or at least two metabolic index abnormalities. Regression analyses were applied to assess the relationship between regional body composition and MAFLD in children. Subgroup analyses were performed based on sex and weight.

Results

The participants had a mean age of 9 years, with 52.11% being boys. Among them, 134 (9.57%) were diagnosed with MAFLD, and 17 (1.22%) had severe fatty liver disease. We found an inverse correlation between the muscle percentage in each region and MAFLD, with the extremities demonstrating the most significant negative correlation (OR: 0.732; 95% CI: 0.634-0.844). Conversely, regional fat was positively associated with MAFLD, with the strongest correlation found in the upper limbs (OR: 3.104; 95% CI: 2.023-4.764). Subgroup analyses showed similar results.

Conclusion

The decrease in regional muscle percentage, particularly in the limbs, along with the increase in regional fat percentage, especially in the upper limbs, is associated with a higher probability of developing MAFLD in prepubertal children. Additional prospective studies are needed to strengthen and validate these findings.

Correlation of sarcopenia with progression of liver fibrosis in patients with metabolic dysfunction-associated steatotic liver disease: a study from two cohorts in China and the United States

OBJECTIVE

The objective of this study was to investigate the association between sarcopenia and liver fibrosis in patients aged 18-59 years with metabolic dysfunction-associated steatotic liver disease (MASLD) and to assess the potential of sarcopenia as a risk factor for the progression of liver fibrosis.

METHODS

The study included 821 patients with MASLD in the US cohort and 3,405 patients with MASLD in the Chinese cohort. Liver controlled attenuation parameters (CAP) and liver stiffness measurements (LSM) were assessed by vibration-controlled transient elastography (VCTE) to evaluate the extent of hepatic steatosis and fibrosis. Sarcopenia was assessed by measuring appendicular skeletal muscle mass (ASM) and calculating ASMI. To analyze the relationship between sarcopenia, ASMI, and liver fibrosis, logistic regression models, multivariate-adjusted models, and restricted cubic spline (RCS) models were employed, with stratification and interaction analyses.

RESULTS

The results demonstrated that patients with sarcopenia exhibited a markedly elevated risk of significant liver fibrosis, advanced liver fibrosis, and cirrhosis compared to those without sarcopenia in both cohorts. After adjusting for confounding variables, sarcopenia was identified as an independent risk factor for the progression of liver fibrosis in patients with MASLD. A significant negative correlation was observed between ASMI and the severity of liver fibrosis, with a progressive reduction in the risk of liver fibrosis associated with increasing ASMI. Additionally, a non-linear feature was evident in some liver fibrosis indicators. Subgroup analysis further corroborated the finding that the harmful effect of sarcopenia on liver fibrosis was consistent across all identified subgroups.

CONCLUSION

Sarcopenia may be associated with the progression of liver fibrosis in patients with MASLD. Monitoring ASMI may assist in identifying individuals at an elevated risk of liver fibrosis in MASLD patients.

Relationship between sarcopenia and metabolic dysfunction-associated steatotic liver disease (MASLD): A systematic review and meta-analysis

INTRODUCTION AND OBJECTIVES

Metabolic dysfunction-associated steatotic liver disease (MASLD) formerly known as Nonalcoholic fatty liver disease (NAFLD) is a common chronic disease. Identifying MASLD risk factors could help early intervention and reduce the burden of the disease. Previous studies investigated the association between sarcopenia and NAFLD. Several trials were published after the last meta-analysis with indecisive results. This is an updated meta-analysis which aims to assess the association between sarcopenia, MASLD, and MASLD-related fibrosis.

MATERIALS AND METHODS

Relevant trials published on PubMed, Web of Science, Scopus, and Cochrane Library databases until October 2022 were included. We included studies in which skeletal mass index (SMI) or sarcopenia was compared between patients with and without NAFLD now MASLD. Also, studies comparing fibrosis between MASLD patients with and without sarcopenia were included. Data were pooled as odds ratios (ORs) and 95 % confidence intervals (CIs) using Review Manager Software.

RESULTS

A total of 25 studies were included. The incidence of sarcopenia was significantly higher in MASLD than controls (OR, 1.25; 95 % CI, 1.08-1.44; P = 0.003). SMI odds showed no significant difference between MASLD patients and controls (OR, 1.02; 95 % CI, 0.91-1.15; P = 0.7). MASLD patients with sarcopenia had higher odds of fibrosis than MASLD patients without sarcopenia (OR, 1.49; 95 % CI, 1.03-2.14; P = 0.03).

CONCLUSIONS

Sarcopenia increased MASLD's probability and was associated with a higher probability of liver fibrosis in MASLD patients. However, SMI had no predictive value of MASLD occurrence.

Visceral Obesity and Its Association with Severe Coronary Artery Calcification in Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease

Background/Objectives: The role of body composition parameters in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) with presence and severity of coronary artery calcification (CAC) is still not fully elucidated. We aimed to evaluate the impact of computed tomography (CT)-based body composition parameters in patients with MASLD with CAC severity. Methods: In this multicenter study, 1870 individuals underwent cardiac CT for the detection of CAC as well as ultrasonography for the diagnosis of hepatic steatosis. The presence of CAC was defined by a CAC score threshold of >0, while severe CAC was defined by a threshold of >300. Using the abdominal cross-sectional CT images at the L3 vertebra level, we analyzed the skeletal muscle index, visceral to subcutaneous adipose tissue ratio, and muscle density using the Hounsfield unit. Results: Of 648 patients with MASLD, the proportions of presence of CAC and severe CAC were 45.2% and 9.9%, respectively. Visceral obesity was not associated with the presence of CAC after adjustment for age, sex, smoking, statin therapy, type 2 diabetes, and advanced fibrosis (adjusted odds ratio (aOR), 1.38; 95% confidence interval (CI), 0.86-2.23; p = 0.180). However, visceral obesity was independently associated with severe CAC after adjustment for several metabolic risk factors (aOR, 3.54; 95% CI, 1.25-14.90; p = 0.039), and adjustment for atherosclerotic cardiovascular disease risk scores (aOR, 3.74; 95% CI, 1.31-15.79; p = 0.032). Conclusions: Visceral obesity may serve as a novel prognostic CT-based radiological biomarker for patients with MASLD with severe CAC.

Prevalence and outcome of sarcopenia in non-alcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) includes a spectrum of conditions, progressing from mild steatosis to advanced fibrosis. Sarcopenia, characterized by decreased muscle strength and mass, shares common pathophysiological traits with NAFLD. An association exists between sarcopenia and increased NAFLD prevalence. However, data on the prevalence of sarcopenia in NAFLD and its impact on the outcomes of NAFLD remain inconsistent.

AIM

To analyze the prevalence and outcomes of sarcopenia in patients with NAFLD.

METHODS

We conducted a comprehensive search for relevant studies in MEDLINE, Embase, and Scopus from their inception to June 2023. We included studies that focused on patients with NAFLD, reported the prevalence of sarcopenia as the primary outcome, and examined secondary outcomes, such as liver fibrosis and other adverse events. We also used the Newcastle-Ottawa scale for quality assessment.

RESULTS

Of the 29 studies included, the prevalence of sarcopenia in NAFLD varied widely (1.6% to 63.0%), with 20 studies reporting a prevalence of more than 10.0%. Substantial heterogeneity was noted in the measurement modalities for sarcopenia. Sarcopenia was associated with a higher risk of advanced fibrosis (odd ratio: 1.97, 95% confidence interval: 1.44-2.70). Increased odds were consistently observed in fibrosis assessment through biopsy, NAFLD fibrosis score/body mass index, aspartate aminotransferase to alanine aminotransferase ratio, diabetes (BARD) score, and transient elastography, whereas the fibrosis-4 score showed no such association. Sarcopenia in NAFLD was associated with a higher risk of steatohepatitis, insulin resistance, cardiovascular risks, and mortality.

CONCLUSION

This systematic review highlights the critical need for standardized diagnostic criteria and measurement methods for sarcopenia in NAFLD patients. The variability in study designs and assessment methods for sarcopenia and liver fibrosis may account for the inconsistent findings. This review demonstrates the multidimensional impact of sarcopenia on NAFLD, indicating its importance beyond liver-related events to include cardiovascular risks, mortality, and metabolic complications.

Advanced liver fibrosis is associated with decreased gait speed in older patients with chronic liver disease

This study investigated whether the progression of liver fibrosis affects the prevalence of sarcopenia and incidence of decreased gait speed in older patients with chronic liver disease (CLD). Patients with CLD aged ≥ 60 years were classified into low, intermediate, and high fibrosis 4 (FIB-4) index groups according to the degree of liver fibrosis. The prevalence of sarcopenia and incidence of decreased gait speed (< 1.0 m/s) were compared among the three groups. Logistic regression analysis was performed to investigate factors affecting the risk of decreased gait speed. No significant difference was observed in the prevalence of sarcopenia among the three groups, but the incidence of decreased gait speed significantly differed (p = 0.029). When analyzed individually, a significant difference in decreased gait speed incidence was observed between the high and low FIB-4 index groups (p = 0.014). In logistic regression analysis, the progression of liver fibrosis (odds ratio: 1.32, 95% confidence interval: 1.13-1.55) and lower extremity muscle strength (LEMS) (odds ratio: 0.92, 95% confidence interval: 0.88-0.97) were significantly associated with decreased gait speed. As liver fibrosis progresses in older patients with CLD, it becomes important to focus on not only skeletal muscle mass and grip strength, but also gait speed and LEMS.

Sarcopenia, sarcopenic obesity and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), sarcopenia and sarcopenic obesity (SO) are highly prevalent conditions that may coexist, especially in the aging population, without any approved pharmacologic treatment for all of them. There are multiple pathophysiologic mechanisms suggested to explain an association between NAFLD and sarcopenia or SO, including alterations in the adipokines, cytokines, hepatokines and myokines, which may interplay with other factors, such as aging, diet and physical inactivity. In clinical terms, most observational studies support an association between NAFLD and sarcopenia or SO; importantly, there are few cohort studies indicating higher mortality in patients with NAFLD and sarcopenia. Their association also bears some treatment considerations: for example, pioglitazone or vitamin E, suggested as off label treatment for selected patients with nonalcoholic steatohepatitis, may be recommended in the coexistence of sarcopenia or SO, since limited evidence did not show adverse effects of them on sarcopenia and abdominal obesity. In this review, evidence linking sarcopenia and SO with NAFLD is summarized, with a special focus on clinical data. A synopsis of the major pathophysiological links between NAFLD and sarcopenia/SO is initially presented, followed by selected clinical studies and, finally, treatment considerations in patients with NAFLD and sarcopenia or SO are discussed.

Associations between muscle mass, strength, and performance and non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a rising global health issue. The influence of muscle in its pathophysiology has recently gained attention. Our aim was to investigate the association of low muscle mass, strength, and performance with the presence and severity of NAFLD.

METHODS

Patients with metabolic syndrome followed in an outpatient clinic, were consecutively included, between April 1st and December 31st, 2019. Abdominal ultrasound for the diagnosis of NAFLD, NAFLD fibrosis score (NFS) and Fibrosis-4 Index (FIB-4) for determination of significant fibrosis, dual-energy X-ray absorptiometry for calculation of skeletal muscle index (SMI = appendicular skeletal mass / weight x100) and sarcopenic index (SI = appendicular skeletal mass / Body Mass Index), and the Short Physical Performance Battery for muscle strength and performance assessment were performed. Sarcopenia was defined as low muscle strength and low SMI or SI.

RESULTS

A total of 157 patients were included, of which 68.8% had NAFLD, 66.2% low SMI, 50.3% low SI, 16.6% low performance and 11.5% low strength. In patients with NAFLD, prevalence of significant fibrosis by NFS was 15.7%. Low SMI was associated with presence of NAFLD when adjusted for age, sex, type 2 diabetes mellitus, hypertension, and dyslipidemia, but not for body mass index and waist circumference. Low SMI, low SI, and sarcopenia were associated with significant fibrosis in univariate analysis; the small number of events precluded a multivariable analysis.

CONCLUSIONS

Low SMI was associated with NAFLD independently of demographics and comorbidities but not of other parameters of body composition. This contrasts with most studies published on this matter.

Different effects of low muscle mass on the risk of non-alcoholic fatty liver disease and hepatic fibrosis in a prospective cohort

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and sarcopenia share insulin resistance as a common pathophysiology and have overlapping clinical manifestation of metabolic derangement; hence, it is difficult to differentiate the independent effect of sarcopenia on the development of NAFLD from concomitant metabolic disorders. Using a community-based prospective cohort study, the contributions of low muscle mass and genetic risk factors to the development of NAFLD and NAFLD-related hepatic fibrosis were investigated in the Korean population.

METHODS

This prospective community-based cohort study included 40-70-year-old adults, followed up biennially from 2001-2002 to 2017-2018. NAFLD was defined as a hepatic steatosis index of ≥36, and hepatic fibrosis was defined based on the fibrosis-4 index. Sex-specific quartiles of body mass index (BMI)-adjusted muscle mass were calculated (muscle mass/BMI), and low muscle mass was defined as the lowest quartile (Q1). Cox proportional hazard models for incident NAFLD or hepatic fibrosis incorporating age, sex, BMI of ≥25 kg/m² , metabolic syndrome and PNPLA3 and TM6SF2 risk alleles were used to assess the independent determinants for incident NAFLD and hepatic fibrosis among individuals with NAFLD at baseline.

RESULTS

Among the 4038 participants without NAFLD at baseline (mean age, 51.5 ± 8.8 years), 920 (22.8%) developed NAFLD during the 12-year follow-up period. As muscle mass decreased, the risk of NAFLD increased even after adjustment for age, sex, obesity, metabolic syndrome and PNPLA3 and TM6SF2 risk alleles [hazard ratio (HR) per quartile, 1.18, 95% confidence interval (CI), 1.11-1.27, P < 0.001]. TM6SF2 also affected the risk of NAFLD development [HR 1.19, (95% CI, 1.00-1.40), P = 0.044]. Of the 1176 patients with NAFLD but without hepatic fibrosis at baseline, the incident of hepatic fibrosis was found in 51.8%, 44.7%, 42.6% and 41.0% in Q1, Q2, Q3 and Q4 of BMI-adjusted muscle mass, respectively, during the follow-up period (P for trend = 0.006). However, this trend lost its statistical significance when adjusted for confounders. The PNPLA3 risk variant, but not the TM6SF2 genotype, was an independent risk factor for developing hepatic fibrosis among patients with NAFLD (HR 1.17, 95% CI 1.04-1.32, P = 0.010).

CONCLUSIONS

Both lower muscle mass index and genetic risk variants are important contributors to the development of NAFLD. In patients already diagnosed with NAFLD, however, PNPLA3 confers a greater risk for hepatic fibrosis progression than lower muscle mass.

Interaction between sarcopenia and nonalcoholic fatty liver disease

Sarcopenia and nonalcoholic fatty liver disease (NAFLD) are common health problems related to aging. Despite the differences in their diagnostic methods, several cross-sectional and longitudinal studies have revealed the close link between sarcopenia and NAFLD. Sarcopenia and NAFLD are linked by several shared pathogenetic mechanisms, including insulin resistance, hormonal imbalance, systemic inflammation, myostatin and adiponectin dysregulation, nutritional deficiencies, and physical inactivity, thus implicating a bidirectional relationship between sarcopenia and NAFLD. However, there is not sufficient data to support a direct causal relationship between sarcopenia and NAFLD. Moreover, it is currently difficult to conclude whether sarcopenia is a risk factor for nonalcoholic steatohepatitis (NASH) or is a consequence of NASH. Therefore, this review intends to touch on the shared common mechanisms and the bidirectional relationship between sarcopenia and NAFLD.

Muscle Fat Content Is Associated with Nonalcoholic Fatty Liver Disease and Liver Fibrosis in Chinese Adults

OBJECTIVES

Several studies have linked myosteatosis with nonalcoholic fatty liver disease (NAFLD) in individuals with obesity. The clinical significance of myosteatosis in individuals with NAFLD in the general population has not been well investigated. Here, we wanted to explore and compare the associations of NAFLD and liver fibrosis with muscle fat content and skeletal muscle mass (SMM) in a relatively large general population in China.

METHODS

We retrospectively included all participants who underwent abdominal CT scans in our health promotion center between April 2021 and October 2021. Muscle fat content was assessed by abdomen quantitative computed tomography (QCT) scans, and SMM was evaluated by bioelectrical impedance. NAFLD was assessed by ultrasonography. The NAFLD fibrosis score (NFS) and Fibrosis-4 Index (FIB-4) score were calculated to assess liver fibrosis.

RESULTS

Compared with participants without NAFLD, patients with NAFLD showed significantly increased intermuscular adipose tissue (IMAT%) (7.40±3.37% vs. 6.76±2.66%, P <0.01). According to a multiple logistic regression model, IMAT% (OR=1.091, 95% CI 1.030-1.155, P=0.003) was only independently correlated with NAFLD in obese participants. Mediation analysis showed that BMI mediated the association between IMAT% and NAFLD. In participants with NAFLD, increased IMAT% was independently associated with an increased intermediate to high risk of advanced fibrosis assessed by the NFS or FIB-4 score after adjusting for multiple potential confounders. However, SMM was only independently correlated with an intermediate to high risk for advanced fibrosis evaluated by the NFS and not by the FIB-4 score.

CONCLUSION

Increased muscle fat content is positively correlated with NAFLD and intermediate to high risk for advanced fibrosis in the general Chinese population.

Non-alcoholic fatty liver disease-related fibrosis and sarcopenia: An altered liver-muscle crosstalk leading to increased mortality risk

In the last few decades, the loss of skeletal muscle mass and function, known as sarcopenia, has significantly increased in prevalence, becoming a major global public health concern. On the other hand, the prevalence of non-alcoholic fatty liver disease (NAFLD) has also reached pandemic proportions, constituting the leading cause of hepatic fibrosis worldwide. Remarkably, while sarcopenia and NAFLD-related fibrosis are independently associated with all-cause mortality, the combination of both conditions entails a greater risk for all-cause and cardiac-specific mortality. Interestingly, both sarcopenia and NAFLD-related fibrosis share common pathophysiological pathways, including insulin resistance, chronic inflammation, hyperammonemia, alterations in the regulation of myokines, sex hormones and growth hormone/insulin-like growth factor-1 signaling, which may explain reciprocal connections between these two disorders. Additional contributing factors, such as the gut microbiome, may also play a role in this relationship. In skeletal muscle, phosphatidylinositol 3-kinase/Akt and myostatin signaling are the central anabolic and catabolic pathways, respectively, and the imbalance between them can lead to muscle wasting in patients with NAFLD-related fibrosis. In this review, we summarize the bidirectional influence between NAFLD-related fibrosis and sarcopenia, highlighting the main potential mechanisms involved in this complex crosstalk, and we discuss the synergistic effects of both conditions in overall and cardiovascular mortality.

Association Between Skeletal Muscle Mass and Severity of Steatosis and Fibrosis in Non-alcoholic Fatty Liver Disease

Background

Sarcopenia is known to be the risk factor of non-alcoholic fatty liver disease (NAFLD). However, studies evaluating the association of skeletal muscle mass (SMM) with liver fibrosis by transient elastography are limited. Here, we investigated the association of SMM with hepatic steatosis and fibrosis assessed in Chinese adults.

Methods

Patients who underwent liver ultrasonography at the Health Promotion Center of the First Affiliated Hospital of Nanjing Medical University between January 2020 to June 2021 were enrolled. We used transient elastography to evaluate the degree of hepatic fat and liver stiffness. Appendicular skeletal muscle mass was determined by bioelectrical impedance and was adjusted for body weight to derive the skeletal muscle mass index (SMI).

Results

Of 3,602 finally enrolled individuals, 1,830 had NAFLD and 1,772 did not have NAFLD. SMI gradually decreased as the severity of hepatic steatosis increased (40.47 ± 3.94% vs. 39.89 ± 3.57% vs. 39.22 ± 3.46% vs. 37.81 ± 2.84%, P < 0.001). Individuals with F3-F4 and F2 liver fibrosis groups had significantly lower SMI than individuals with F0-F1 stages (37.51 ± 3.19% vs. 38.06 ± 3.51% vs. 39.36 ± 3.38%, P < 0.001). As the SMI increased, the percentages of subjects with mild and severe NAFLD, and the percentages of subjects in F2 and F3-F4 stage were gradually decreased. SMI was independently associated with the severity of hepatic steatosis and fibrosis by logistic regression analysis. Moreover, decreased SMI was an independent risk factor for NAFLD and fibrosis.

Conclusion

SMI is closely associated with liver fat content and liver fibrosis in Chinese adults with NAFLD.

Association of Low Skeletal Muscle Mass with the Phenotype of Lean Non-Alcoholic Fatty Liver Disease

Low skeletal muscle mass (LSMM) has emerged as a potential risk factor for non-alcoholic fatty liver disease (NAFLD). However, its clinical implications in patients with lean NAFLD have not yet been elucidated. We investigated the role of LSMM in patients with lean NAFLD. Lean NAFLD was defined as a body mass index of ≤23 kg/m2. Using bioelectrical impedance analysis, the appendicular skeletal muscle mass (ASM) was adjusted by height squared. The LSMM was based on 1 SD below the sex-specific mean for young, healthy Asian adults. Of the 8905 ultrasound-confirmed NAFLD patients, 3670 (41.2%) were diagnosed with lean NAFLD. The lean NAFLD group was younger (45.0 vs. 49.0 years, p < 0.001), and had a lower waist circumference (74.0 vs. 85.0 cm, p < 0.001), lower prevalence of diabetes (3.1 vs. 7.4%, p < 0.001) and hypertension (4.2 vs. 15.2%, p < 0.001), and a higher proportion of LSMM (28.0 vs. 2.2%, p < 0.001) than the non-lean NAFLD group. Stepwise adjusted models suggested that LSMM was associated with lean individuals with NAFLD (odds ratio = 7.02, p < 0.001). LSMM may be a novel risk factor for lean NAFLD patients more than non-lean NAFLD patients, independent of classic metabolic factors.

Low skeletal muscle mass is associated with liver fibrosis in individuals with type 2 diabetes and nonalcoholic fatty liver disease

BACKGROUND AND AIM

Type 2 diabetes (T2D) and low skeletal muscle mass (SMM) are associated with increased risk of nonalcoholic fatty liver disease (NAFLD). However, data regarding the association between low SMM and NAFLD-related liver fibrosis in individuals with T2D are scarce. Therefore, we aimed to investigate the association between low SMM and liver fibrosis in individuals with T2D and NAFLD.

METHODS

Controlled attenuation parameter (CAP) of ≥ 248 dB/m was taken as cutoff suggesting NAFLD. Clinically relevant liver fibrosis and advanced liver fibrosis were defined as liver stiffness measurement (LSM) by transient elastography (TE) of ≥ 8.0 and ≥ 9.6 kPa, respectively. SMM was measured using dual energy X-ray absorptiometry (DEXA). Low SMM was defined as appendicular SMM index of < 7.0 kg/m² for men and < 5.4 kg/m² for women.

RESULTS

Of the 487 consecutive patients with T2D, 366 (75.1%) had NAFLD. Among individuals with NAFLD, 118 (32.2%) and 64 (17.5%) had clinically relevant liver fibrosis and advanced liver fibrosis, respectively. Low SMM was diagnosed in 78 (21.3%) individuals with NAFLD. Patients with low SMM were older (56.1 vs 52.8 years) and had longer duration of diabetes (10.3 vs 8.1 years). Low SMM was an independent risk factor associated with clinically relevant liver fibrosis (P = 0.002) and advanced liver fibrosis (P ≤ 0.0001). Associations between low SMM and clinically relevant- and advanced liver fibrosis were maintained even after sequential adjustment for confounding variables through the multivariate regression analysis.

CONCLUSIONS

Low SMM is independently associated with liver fibrosis in individuals with T2D and NAFLD.

"Bioelectrical impedance analysis in managing sarcopenic obesity in NAFLD"

INTRODUCTION

Sarcopenic obesity and its association with nonalcoholic fatty liver disease (NAFLD) is under-recognized by many healthcare providers in Western medicine due to the lack of awareness and diagnostic guidelines. The result is delayed recognition and treatment, which leads to further health deterioration and increased healthcare costs. Sarcopenic obesity is characterized by the presence of increased fat mass in combination with muscle catabolism related to chronic inflammation and/or inactivity. Previous research has recommended evaluating body composition and physical function performance to adequately diagnose sarcopenic obesity. Body composition analysis can be performed by imaging applications through magnetic resonance imaging, computed tomography, and dual-energy x-ray absorptiometry. Due to the cost of each device and radiation exposure for patients as evidenced in all three modalities, bioelectrical impedance analysis offers a noninvasive approach capable of providing quick and reliable estimates of lean body and fat mass.

METHODS AND RESULTS

This review analyzes the current evidence-based literature, indicating a lower skeletal muscle mass and increased visceral adipose tissue correlation to the advancement of fibrosis in fatty liver disease.

CONCLUSION

Given the substantial promising research conducted in predominantly Asian populations regarding body tissue distribution and NAFLD, additional prospective research is needed to extend these findings in Western populations.

Association between Fasting Ketonuria and Advanced Liver Fibrosis in Non-Alcoholic Fatty Liver Disease Patients without Prediabetes and Diabetes Mellitus

Ketone body production, an alternative fuel upon low glucose availability, reduces hepatic fat accumulation. However, its clinical implications have not been established in patients with nonalcoholic fatty liver disease (NAFLD). We investigated the association between spontaneous fasting ketonuria and liver fibrosis in patients with NAFLD without prediabetes and diabetes mellitus (DM). A total of 6202 patients with ultrasound confirmed NAFLD without prediabetes and DM were enrolled in the study. Using low cut off values of NAFLD fibrosis score (NFS) and fibrosis-4, liver fibrosis was defined as an intermediate-high probability of advanced liver fibrosis. Of the 6202 NAFLD patients, 360 (5.8%) had ketonuria. Compared to the patients without ketonuria, patients with ketonuria were younger (41.1 vs. 44.6 years, p < 0.001), had lower levels of glucose (87.2 vs. 91.0 mg/dL, p < 0.001), and homeostatic model assessment for insulin resistance (1.0 vs. 1.5, p < 0.001). The presence of ketonuria had an inverse association with liver fibrosis, assessed using both NFS (final adjusted odds ratio [aOR], 0.67; 95% confidence interval [CI], 0.45-1.01) and fibrosis-4 (aOR, 0.58; 95% CI, 0.40-0.84). The presence of ketonuria in NAFLD patients without prediabetes and DM may have favorable metabolic effects compared to the absence of ketonuria, independent of traditional metabolic factors.

Muscle mass and cellular membrane integrity assessment in patients with nonalcoholic fatty liver disease

OBJECTIVE

To evaluate the association between muscle mass depletion and compromising of the cell membrane integrity and clinical-anthropometric characteristics in patients with nonalcoholic fatty liver disease.

METHODS

This observational study evaluated waist circumference, body mass index, and waist-to-height ratio in patients with nonalcoholic fatty liver disease. Skeletal mass index corrected by weight and impairment of cell membrane integrity were assessed using bioelectrical impedance analysis.

RESULTS

In 56 patients, muscle mass depletion was observed in 62.5% and cell membrane impairment in 28.6%. The metabolic syndrome and elevated aspartate aminotransferase were the only clinical factors associated with mass depletion (p<0.05). The linear regression analysis showed association between skeletal mass index and waist-to-height ratio and waist circumference, after adjustments (p<0.05). The phase angle value was not different between those with and without mass depletion, and also it did not have correlation with skeletal mass index and clinical parameters (p>0.05).

CONCLUSIONS

The prevalence of mass depletion and cell membrane impairment was higher in patients with nonalcoholic fatty liver disease. The muscle mass depletion was associated with central obesity, aspartate aminotransferase elevated, and metabolic syndrome; however, the phase angle is not associated with clinical and anthropometric data.

The Association between Low Muscle Mass and Hepatic Steatosis in Asymptomatic Population in Korea

Background: An association between low muscle mass and nonalcoholic fatty liver disease (NAFLD) has been suggested. We investigated this relationship using controlled attenuation parameter (CAP). Methods: A retrospective cohort of subjects had liver FibroScan^® (Echosens, Paris, France) and bioelectrical impedance analyses during health screening exams. Low muscle mass was defined based on appendicular skeletal muscle mass/body weight ratios of one (class I) or two (class II) standard deviations below the sex-specific mean for healthy young adults. Results: Among 960 subjects (58.1 years; 67.4% male), 344 (45.8%, class I) and 110 (11.5%, class II) had low muscle mass. After adjusting for traditional metabolic risk factors, hepatic steatosis, defined as a CAP ≥ 248 dB/m, was associated with low muscle mass (class I, odds ratio (OR): 1.96, 95% confidence interval (CI): 1.38–2.78; class II, OR: 3.33, 95% CI: 1.77–6.26). A dose-dependent association between the grade of steatosis and low muscle mass was also found (class I, OR: 1.88, for CAP ≥ 248, <302; OR: 2.19, in CAP ≥ 302; class II, OR: 2.33, for CAP ≥ 248, <302; OR: 6.17, in CAP ≥ 302). High liver stiffness was also significantly associated with an increased risk of low muscle mass (class I, OR: 1.97, 95% CI: 1.31–2.95; class II, OR: 2.96, 95% CI: 1.51–5.78). Conclusion: Hepatic steatosis is independently associated with low muscle mass in a dose-dependent manner. The association between hepatic steatosis and low muscle mass suggests that particular attention should be given to subjects with NAFLD for an adequate assessment of muscle mass.

Association of Body Composition and Sarcopenia with NASH in Obese Patients

Obese patients often suffer from sarcopenia or sarcopenic obesity (SO) that can trigger inflammatory diseases including non-alcoholic steatohepatitis (NASH). Sarcopenia and SO can be diagnosed through measuring parameters of body composition such as skeletal muscle mass (SMM), skeletal muscle index (SMI) and fat mass (FM) obtained by bioelectrical impedance analysis (BIA). The aim of this study was to assess the relationship of body composition and NASH in patients with obesity. A total of 138 patients with obesity that underwent bariatric surgery were included in this study. BIA was used to estimate body composition. A liver biopsy was taken intraoperatively and histological assessment of NASH was performed. A total of 23 patients (17%) were classified as NASH and 65 patients (47%) met the criteria for borderline NASH. Body mass index (BMI) was significantly higher in patients with NASH compared to borderline NASH and no NASH (56.3 kg/m² vs. 51.6 kg/m² vs. 48.6 kg/m², p = 0.004). Concerning body composition, FM, but also SMM and SMI were significantly higher in patients with NASH (p-values 0.011, 0.005 and 0.006, resp.). Fat mass index (FMI) and weight-adjusted skeletal muscle index (SMI_weight) failed to reach statistical significance (p-values 0.067 and 0.661). In patients with obesity, higher FM were associated with NASH. Contrary to expectations, SMM and SMI were also higher in patients with NASH. Therefore, higher body fat, rather than sarcopenia and SO, might be decisive for development of NASH in patients with obesity.

Association of Skeletal Muscle and Adipose Tissue Distribution with Histologic Severity of Non-Alcoholic Fatty Liver

Adipose tissue and skeletal muscle is associated with non-alcoholic fatty liver disease (NAFLD). This study evaluates the association between body composition and histologic severity in patients with NAFLD. Using the cross-sectional CT images at the level of L3 vertebra and the histologic findings of 178 patients with biopsy-proven NAFLD, we analyzed the correlation of the histologic findings to the skeletal muscle index (SMI), subcutaneous adipose tissue index (SATI), and visceral adipose tissue index (VATI), which is defined as the body composition area (cm²) by height squared (m²). The clinical and laboratory features with body composition were analyzed to determine the risk factors for advanced fibrosis. The VATI significantly increased in severe non-alcoholic steatohepatitis (NASH) or advanced fibrosis. In addition, the VATI was correlated with the NAFLD activity score (NAS) and the fibrosis stage. In multivariate analyses, age (odds ratio (OR), 1.09; 95% confidence interval (CI), 1.02–1.19; p = 0.025), severe NASH (OR, 8.66; 95% CI, 2.13–46.40; p = 0.005), and visceral adiposity (OR, 6.77; 95% CI, 1.81–29.90; p = 0.007) were independently associated with advanced fibrosis in patients with NAFLD. Visceral adiposity is correlated with the histologic severity of NAFLD, which is independently associated with advanced fibrosis.

Low Skeletal Muscle Mass Is a Risk Factor for Subclinical Atherosclerosis in Patients with Nonalcoholic Fatty Liver Disease

Sarcopenia and nonalcoholic fatty liver disease (NAFLD) are associated with subclinical atherosclerosis. We aimed to investigate the association between low skeletal muscle mass (LSMM) and subclinical atherosclerosis in patients with NAFLD. A total of 683 patients with ultrasound-confirmed NAFLD who underwent carotid ultrasonography were enrolled retrospectively. The appendicular skeletal muscle mass divided by the body mass index was used to define LSMM. Using carotid ultrasound, increased carotid intima–media thickness (cIMT, >1 mm) and the presence of carotid plaques were measured. Of the 683 patients, 75 (11.0%) had LSMM. In multivariate analyses, LSMM was associated with increased cIMT (odds ratios (ORs) = 2.26 to 2.95, all p < 0.05) and carotid plaques (ORs = 2.05 to 2.90, all p < 0.05). The proportion of increased cIMT and carotid plaques was significantly higher in obese NAFLD patients with LSMM than in those without LSMM (33.3% vs. 17.6% for cIMT and 12.7% vs. 5.7% for carotid plaques, respectively; p < 0.001). Furthermore, LSMM was independently associated with increased cIMT (ORs = 2.44 to 3.30, all p < 0.05) and carotid plaques (ORs = 2.56 to 3.54, all p < 0.05) in obese NAFLD patients. LSMM is associated with subclinical atherosclerosis in patients with NAFLD.

Association between Atrial Fibrillation and Advanced Liver Fibrosis in Patients with Non-Alcoholic Fatty Liver Disease

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) is independently associated with the development of atrial fibrillation (AF). However, the association of AF with advanced liver fibrosis, which is related to all-cause, cardiovascular, and liver-related mortality, has not been established in NAFLD patients. We aimed to investigate the association between AF and advanced liver fibrosis in NAFLD patients.

MATERIALS AND METHODS

Out of 53704 adults who participated in the health check-up program, 6293 subjects aged 35 years and older were diagnosed as NAFLD using ultrasound. The stage of liver fibrosis was assessed based on the newly adjusted NAFLD fibrosis score (NFS) and Fibrosis-4 (Fib-4) Index, which were used to determine the low and high cut-off values (COVs).

RESULTS

Of 6293 patients with NAFLD, 59 (0.9%) were diagnosed with AF. Patients with AF were older (52.0 vs. 64.6 years, p<0.001), had higher body mass index (25.2 vs. 26.6 kg/m², p<0.001), and had bigger waist circumference (84.0 vs. 89.9 cm, p<0.001) than those without AF. In NAFLD patients, AF was independently associated with advanced liver fibrosis, assessed using both COVs of NFS [low-COV group: final adjusted odds ratios (aORs)=2.85, p=0.004; high-COV group: ORs=12.29, p<0.001). AF was independently associated with advanced liver fibrosis, assessed using both COVs of Fib-4 (low-COV group: aORs=2.49, p<0.001; high-COV group: aORs=3.84, p=0.016).

CONCLUSION

AF is independently associated with advanced liver fibrosis in patients with NAFLD.

Sarcopenia and fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease which may progress to non-alcoholic steatohepatitis. The prevalence of sarcopenia, which is the loss of muscle mass and strength, is increasing in the aging society. Recent studies reported the relationship between NAFLD and sarcopenia. The skeletal muscle is the primary organ for glucose disposal. Loss of muscle mass can cause insulin resistance, which is an important risk factor for NAFLD. Moreover, obesity, chronic low-grade inflammation, vitamin D deficiency, physical inactivity, hepatokines, and myokines might be involved in the pathophysiologic mechanism of sarcopenia and NAFLD. Although most of the previous studies have demonstrated the positive correlation between sarcopenia and NAFLD, the difference in diagnostic methods of sarcopenia and NAFLD leads to difficulties in interpretation and application. This review discusses the concept and diagnosis of sarcopenia and NAFLD, common pathophysiology, and clinical studies linking sarcopenia to NAFLD. The presentation of the association between sarcopenia and NAFLD may provide an opportunity to prevent the deterioration of fatty liver disease.