Clinical and pathological features of sarcopenia-related indices in patients with non-alcoholic fatty liver disease

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.

Prevalence of Sarcopenia and Its Defining Components in Non-alcoholic Fatty Liver Disease Varies According to the Method of Assessment and Adjustment: Findings from the UK Biobank

Sarcopenia may increase non-alcoholic fatty liver disease (NAFLD) risk, but prevalence likely varies with different diagnostic criteria. This study examined the prevalence of sarcopenia and its defining components in adults with and without NAFLD and whether it varied by the method of muscle mass assessment [bioelectrical impedance (BIA) versus dual-energy X-ray absorptiometry (DXA)] and adjustment (height2 versus BMI). Adults (n = 7266) in the UK Biobank study (45-79 years) with and without NAFLD diagnosed by MRI, were included. Sarcopenia was defined by the 2018 European Working Group on Sarcopenia in Older People definition, with low appendicular skeletal muscle mass (ASM) assessed by BIA and DXA and adjusted for height2 or BMI. Overall, 21% of participants had NAFLD and the sex-specific prevalence of low muscle strength (3.6-7.2%) and sarcopenia (0.1-1.4%) did not differ by NAFLD status. However, NAFLD was associated with 74% (males) and 370% (females) higher prevalence of low ASM when adjusted for BMI but an 82% (males) to 89% (females) lower prevalence when adjusted for height2 (all P < 0.05). The prevalence of impaired physical function was 40% (males, P = 0.08) to 123% (females, P < 0.001) higher in NAFLD. In middle-aged and older adults, NAFLD was not associated with a higher prevalence of low muscle strength or sarcopenia but was associated with an increased risk of impaired physical function and low muscle mass when adjusted for BMI. These findings support the use of adiposity-based adjustments when assessing low muscle mass and the assessment of physical function in NAFLD.

Hepatic steatosis and skeletal muscle alterations during the COVID-19 lockdown in a cohort of patients with chronic liver disease in Japan

AIM

Following the coronavirus disease outbreak, a state of public emergency was declared worldwide, which enforced lifestyle changes. This study therefore aimed to investigate the changes in lifestyle, body composition, hepatic steatosis, and fibrosis in patients with chronic liver disease (CLD) under lockdown.

METHODS

During the lockdown period, 1344 patients with CLD answered a lifestyle questionnaire. In 298 patients, body composition and liver stiffness measure (LSM)/controlled attenuation parameter (CAP) were analyzed by InBody and FibroScan, respectively, and serial data were obtained in 137 patients.

RESULTS

More than half of the CLD patients answered decreases in physical activity and frequency of outings during lockdown, while diet was less affected. Overall, 58% of patients showed elevations in CAP values, which were not different statistically over time. Women, but not men, were more likely to increase CAP values during lockdown. Neither LSM nor serum fibrosis markers were elevated chronologically during lockdown. In men, body mass index (BMI), body fat percentage, and visceral fat area (VFA) were significantly increased, whereas in women, lower-limb muscle mass was significantly decreased. Patients with decreased SMI showed elevations in CAP and VFA values, and patients who exercised less showed increases in BMI.

CONCLUSION

In response to lockdown, men tended to increase body fat but the degree of hepatic steatosis was less affected, while women were more likely to exacerbate hepatic steatosis with skeletal muscle loss among CLD patients. Gender-specific approaches need to be established for management of CLD patients to avoid exacerbation or comorbidity of steatotic liver disease.

The aspartate aminotransferase to alanine aminotransferase ratio: A novel indicator for skeletal muscle mass in Chinese community adults

OBJECTIVES

The aspartate aminotransferase to alanine aminotransferase (AST/ALT) ratio, an indicator for liver fibrosis, could be easily detected in clinical practice. The aim of this study was to examine the association between the AST/ALT ratio and skeletal muscle mass among Chinese community adult residents.

METHODS

We enrolled 2644 participants, age ≥18 y, undergoing bioelectrical impedance analysis and liver function test. Univariate and multivariate logistic regression models were used to analyze the effect of the AST/ALT ratio on the presence of low muscle mass (LMM). Multiple linear regression analysis was used to assess the factors associated with the skeletal muscle mass index (SMI) and to construct a formula to calculate the SMI.

RESULTS

When the AST/ALT ratio was regarded as a categorical variable, AST/ALT quartiles 9-2.19) kept independent effects on the presence of LMM status. When it was regarded as a continuous variable, each unit of the AST/ALT ratio was significantly associated with a 49% (P < 0.01) augment of the prevalence of LMM. By multiple general linear regression analysis, the formula was constructed with an adjusted R2 of 0.72: SMI (kg/m2) = -0.14 AST/ALT ratio + 1.35 sex (male: 1; female: 0) + 0.72 overweight status (yes: 1; no: 0) - 0.14 age (≤65: 0; >65: 1) + 6.26.

CONCLUSION

In general, the high AST/ALT ratio was an independent adverse indicator of the presence of LMM.

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.

Relationships between sarcopenia, nutrient intake, and gut microbiota in Chinese community-dwelling older women

BACKGROUND

The relationship among gut microbiota, sarcopenia components, and influencing factors in female sarcopenic patients has been poorly investigated.

METHODS

Female participants completed questionnaires of physical activity and dietary frequency and were assessed for the presence of sarcopenia by the Asian Working Group of Sarcopenia 2019 (AWGS 2019) criteria. Fecal samples were collected from 17 sarcopenia and 30 non-sarcopenia subjects for 16S sequencing and short chain fatty acid (SCFA) detection.

RESULTS

The prevalence of sarcopenia was 19.20% among 276 participants. The dietary protein, fat, dietary fiber, vitamin B1, niacin, vitamin E, phosphorus, magnesium, iron, zinc, and cooper intake of sarcopenia were all remarkably low. In addition, the richness of gut microbiota (Chao1 and ACE indexes) was considerably reduced in sarcopenic patients, and the sarcopenic gut microbiota and its metabolite were decreased in Firmicutes/Bacteroidetes, Agathobacter, Dorea and Butyrate and were enriched in Shigella and Bacteroides. Correlation analysis showed that Agathobacter and Acetate were positively correlated with grip strength and gait speed, respectively, and Bifidobacterium was negatively correlated with grip strength and appendicular skeletal muscle index (ASMI). Moreover, the protein intake was positively related to Bifidobacterium.

CONCLUSIONS

This cross-sectional study revealed the alterations of gut microbiota composition, SCFA, and nutrient intake in women with sarcopenia and their relation to sarcopenic components. These results provide insights into further studies on the role of nutrition and gut microbiota in sarcopenia and its use as a therapeutic approach.

Osteosarcopenia in NAFLD/MAFLD: An Underappreciated Clinical Problem in Chronic Liver Disease

Chronic liver disease (CLD), including non-alcoholic fatty liver disease (NAFLD) and its advanced form, non-alcoholic steatohepatitis (NASH), affects a significant portion of the population worldwide. NAFLD is characterised by fat accumulation in the liver, while NASH is associated with inflammation and liver damage. Osteosarcopenia, which combines muscle and bone mass loss, is an emerging clinical problem in chronic liver disease that is often underappreciated. The reductions in muscle and bone mass share several common pathophysiological pathways; insulin resistance and chronic systemic inflammation are the most crucial predisposing factors and are related to the presence and gravity of NAFLD and to the worsening of the outcome of liver disease. This article explores the relationship between osteosarcopenia and NAFLD/MAFLD, focusing on the diagnosis, prevention and treatment of this condition in patients with CLD.

Factors Influencing Sarcopenic Changes in YUBI-WAKKA Finger-Ring Test Results After One Year: A Retrospective Observational Study

Background

The YUBI-WAKKA (finger-ring) test was developed and validated as a predictor of sarcopenia, physical disability, and even mortality. We focused on the sarcopenic status and subsequent changes after 1 year using this test and analyzed factors related to these changes. We also examined the robustness of this test by administering it alongside annual checkups held in local clinics.

Methods

We conducted the study to investigate the data of the annual checkup of National Health Insurance at primary care clinics in 2017 and 2018 in Tama City. We studied the participants in a retrospective observational way. The participants of the YUBI-WAKKA test were a total of 5,405 and 4,391 residents between the ages of 65 and 74 years. We first compared anthropological biomarkers of two groups, those that had calves larger than their own finger-ring and those that had calves smaller than their own finger-ring. Then, we compared these results to those from the previous year's 1,048 pairs of data. We were particularly interested in changes from larger to smaller, which we defined here as a sarcopenic change, and performed multivariate logistic regression analysis with forced entry methods to determine the related factors. We also calculated the concordant rate of the test results after 1 year.

Results

In total, 14% (men) and 16% (women) each year received a positive (sarcopenic) YUBI-WAKKA test result. The factors related to this sarcopenic change in 1 year were low uric acid in men and a low or decreasing body mass index and increased hemoglobin and alanine aminotransferase in women. The concordant rates of the larger, just fit and smaller groups following finger-ring testing were 72.8%, 63.5%, and 52.0%, respectively.

Conclusions

We propose that low uric acid and low or reducing body weight were related to low muscle mass and that ALT and Hb may be indirectly related to sarcopenia. These could be predictive factors to determine sarcopenia-prone individuals. The YUBI-WAKKA (finger-ring) test results and their change were considered to be a sustainable and reasonable way to use in the community with small effort to find those who are at high risk for sarcopenia among the elderly population and who may require intervention.

Subcutaneous Fat Thickness of the Lower Limb is Associated with Trunk Muscle Mass in Patients with Hepatocellular Carcinoma: A Simple Assessment for Sarcopenia Using Conventional Ultrasonography

OBJECTIVE

Trunk muscle mass can be evaluated by skeletal muscle index (SMI), which is a prognostic factor in patients with hepatocellular carcinoma (HCC); however, this requires the use of computed tomography, and a simpler assessment for trunk muscle mass is urgently needed. We aimed to examine whether an association between SMI and lower extremity compartments including muscle and subcutaneous fat thickness of lower limbs (SFT-LL) could be identified by means of ultrasonography in patients with HCC.

METHODS

We retrospectively enrolled male patients with HCC (n=30). Trunk muscle mass was evaluated by SMI using computed tomography. Ultrasonography was used for assessment of muscle and SFT-LL. Factors associated with SMI were evaluated by decision-tree analysis.

RESULTS

There was no significant correlation between SMI and muscle thickness of lower limbs. However, a significant correlation was seen between SMI and left SFT-LL (r=0.406, P=0.026). In decision-tree analysis for SMI, left SFT-LL was selected as the initial split variable with an optimal cut-off value of 5 mm. In patients with left SFT-LL ≥ 5 mm, SMI was 39.4±3.4 cm²/m², whereas SMI was 31.6±6.3 cm²/m² in patients with left SFT-LL <5 mm.

CONCLUSION

Left SFT-LL evaluated by ultrasonography was associated with SMI. Thus, ultrasonography may be a useful tool to evaluate trunk muscle mass. Moreover, left SFT-LL may be a useful indicator of sarcopenia in patients with HCC.

Low skeletal muscle mass is associated with more severe histological features of non-alcoholic fatty liver disease in male

BACKGROUND/PURPOSE OF THE STUDY

Although low skeletal muscle mass is associated with non-alcoholic fatty liver disease (NAFLD), it is currently uncertain whether there are associations between weight-adjusted appendicular skeletal muscle (ASM%), severity of histological features of NAFLD, and the patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 polymorphism. Our aim was to test for a possible influence of the PNPLA3 rs738409 variant on the association between ASM% and severity of NAFLD histological features.

METHODS

We enrolled 401 Chinese male with biopsy-proven NAFLD. Using a bioelectrical-impedance body composition analyzer (BIA, Inbody 720, Japan Inc., Tokyo), we calculated the ASM% as the percentage of total appendicular skeletal muscle mass (ASM, kg)/total body mass (kg) × 100.

RESULTS

Compared to those with high ASM%, patients with low ASM% (≤ 30.6, i.e., the median value of distribution of the whole sample) had a greater severity of individual histological features of NAFLD. These patients also had a higher risk of severe steatosis and non-alcoholic steatohepatitis (NASH) (adjusted-odds ratio [OR] 2.34, 95% CI 1.39-3.93, and adjusted-OR 2.22, 95% CI 1.30-3.77) even after adjusting for age, body mass index, diabetes, and serum creatinine levels. Carriage of the G allele of PNPLA3 rs738409 plus low ASM% was associated with a higher risk of severe steatosis and presence of liver fibrosis (OR 3.02, 95% CI 1.46-6.26, p = 0.003 and OR 2.18, 95% CI 1.03-4.60, p = 0.041 respectively), and there was a non-significant but borderline increased risk of NASH (OR 2.00, 95% CI 0.98-4.06, p = 0.056).

CONCLUSIONS

Low ASM% and the presence of a G allele within PNPLA3 rs738409 is associated with more severe histological features of NAFLD.

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.

Management of non-alcoholic fatty liver disease in patients with sarcopenia

INTRODUCTION

Sarcopenia usually occurs with aging, sedentary lifestyle, unhealthy dietary habits, and chronic disorders pathophysiologically and bi-directionally linked to obesity and nonalcoholic fatty liver disease (NAFLD). Because of the global increase in aging and obesity populations, patients with concomitant sarcopenia and NAFLD are common, accompanied by various disorders relevant to obesity and sarcopenia, with across-the-board impact on socio-economic and public health life worldwide. Therefore, developing effective and practical management of these patients has become a pressing clinical issue.

AREAS COVERED

The authors searched literature from PubMed and Ovid MEDLINE up until Feb 2020. Emerging data on the management of sarcopenia and nonalcoholic fatty liver disease were examined and discussed.

EXPERT OPINION

Although NAFLD in patients with sarcopenia has become a critical problem worldwide, we still don't know much about the management of such patients. Based on theoretical speculations, we can recommend lifestyle intervention, including diet control with adequate protein intake, exercise intervention, and weight reduction as the mainstay of management at the first stage. More studies are needed in the future to identify the most suitable treatment and solve this important problem.

Calf Circumference as a Useful Predictor of Sarcopenia in Patients With Liver Diseases

BACKGROUND/AIM

To elucidate the influence of calf circumference (CC) on sarcopenia in patients with chronic liver damages (CLDs, n=525, 255 men).

PATIENTS AND METHODS

Anthropometry parameters including arm circumference, arm muscle circumference, CC, arm muscle area, triceps skinfold thickness, waist circumference and body mass index were measured. Patients with both grip strength (GS) decline and skeletal muscle index (SMI) decline were diagnosed as sarcopenic.

RESULTS

Liver cirrhosis was identified in 103 cases (40.4%) in males and 87 cases (32.2%) in females. Sarcopenia was identified in 23 male patients (9.0%) and 38 female patients (14.1%). CC had the strong positive correlation with SMI both in male (r=0.79, p<0.0001) and female (r=0.83, p<0.0001). Among the above mentioned 7 anthropometry parameters, CC had the highest area under the receiver operating characteristics curve (AUC) for sarcopenia both in males (AUC=0.88) and females (AUC=0.86).

CONCLUSION

CC can be helpful for predicting sarcopenia in CLDs.

Nonalcoholic Fatty Liver Disease and Sarcopenia: Where Do We Stand?

The link between metabolic syndrome (MetS) and sarcopenia has not been extensively studied, but it is evident that they share several common features. Crucial mechanisms involved in sarcopenia-nonalcoholic fatty liver disease (NAFLD) interplay are based on effects of insulin resistance, chronic inflammation, oxidative stress, and crosstalk between organs by secretion of cytokines (hepatokines, adipokines, and myokines). Currently, published studies confirm the association of sarcopenia with the degree of NAFLD defined by liver histology. However, prospective studies that will give us information regarding the causal effect of NAFLD and sarcopenia are still needed. Furthermore, there is a need for a patient-friendly, noninvasive, low-cost method for detection of loss of skeletal muscle mass, strength, and physical performance in the context of NAFLD. Moreover, potential treatment strategies such as physical exercise and nutritional supplementation, that are usually a part of management of sarcopenia, should also be investigated in NAFLD patients, especially given the fact that for now, we do not have a good treatment option for NAFLD. Therefore, future investigations should combine studies on NAFLD and sarcopenia in terms of physical activity and nutritional interventions such as vitamin D supplementation. This review aims to report recent evidence concerning the links between sarcopenia and NAFLD and methods to assess sarcopenia.

Sarcopenia in nonalcoholic fatty liver disease: new challenges for clinical practice

Introduction: Sarcopenia is increasingly recognized in patients with nonalcoholic liver disease (NAFLD). Initially recognized as a consequence of advanced liver disease, there is now emerging evidence that sarcopenia may be a novel risk factor for the development of NAFLD, with a role in fibrosis and disease progression.Areas covered: This review examines the epidemiology, pathogenesis, and complex interplay between NAFLD and sarcopenia. Furthermore, the authors discuss the challenges with diagnosis of sarcopenia in the clinic and the evidence-based management of sarcopenia in patients with NAFLD. A MEDLINE and PubMed search was undertaken using the terms; 'sarcopenia,' 'frailty,' 'muscle,' 'obesity,' 'non-alcoholic fatty liver disease,' 'non-alcoholic steatohepatitis', and 'cirrhosis' up to 31 September 2019.Expert opinion: Sarcopenia may be masked by the co-existence of morbid obesity, which is most notable in patients with NAFLD. Sarcopenia is a key indicator of adverse outcomes in patients with cirrhosis, such as hepatic decompensation, poor quality of life and premature mortality. Patients with NAFLD and advanced fibrosis/cirrhosis should undergo anthropometric measures (handgrip strength), dry body mass index, and measures of physical frailty (including muscle function, not just mass) to enable targeted early interventions of nutrition (low fat, 1.5 g/kg/day protein intake, 2-3 hourly food intake) and exercise (combined resistance and aerobic).

Creatinine-to-bodyweight ratio is a predictor of incident non-alcoholic fatty liver disease: A population-based longitudinal study

AIM

Serum creatinine (Cre) is used as a surrogate marker of muscle mass. We investigated the impact of the Cre-to-bodyweight (BW) ratio (Cre/BW) on incident non-alcoholic fatty liver disease (NAFLD).

METHODS

Fatty liver disease was diagnosed by abdominal ultrasonography. In this historical cohort study of 13 728 participants (6397 men and 7331 women), we divided the participants into two groups by sex and into quartiles according to Cre (mg/dL)/BW (kg; Q1-4). We carried out Cox proportional hazard models, adjusting for age, alanine aminotransferase, fasting plasma glucose, systolic blood pressure, alcohol consumption, smoking status, and exercise.

RESULTS

During the 5.1-year follow up for men and 6.0-year follow up for women, 2497 participants (1696 men, 801 women) developed NAFLD. The 4000-days cumulative incidence rates of FLD for men and women were 29.6% and 16.6% in Q1, 28.2% and 10.6% in Q2, 25.5% and 8.8% in Q3, and 22.7% and 7.7% in Q4, respectively. The hazard ratios of incident NAFLD in Q1 (Cre/BW [×100]: men <1.28; women <1.17) were 1.89 (95% confidence interval 1.64-2.17, P < 0.001) in men and 2.96 (2.42-3.62, P < 0.001) in women, compared with Q4 (Cre/BW [×100]: men ≥1.61; women ≥1.51).

CONCLUSIONS

A low Cre/BW is associated with an increased risk of NAFLD. Screening Cre/BW can be used to identify individuals who are at high risk of NAFLD.