Liver fibrosis is associated with impaired bone mineralization and microstructure in obese individuals with non-alcoholic fatty liver disease

Liver-based inter-organ communication: A disease perspective

Inter-organ communication through hormones, cytokines and extracellular vesicles (EVs) has emerged to contribute to the physiological states and pathological processes of the human body. Notably, the liver coordinates multiple tissues and organs to maintain homeostasis and maximize energy utilization, with the underlying mechanisms being unraveled in recent studies. Particularly, liver-derived EVs have been found to play a key role in regulating health and disease. As an endocrine organ, the liver has also been found to perform functions via the secretion of hepatokines. Investigating the multi-organ communication centered on the liver, especially in the manner of EVs and hepatokines, is of great importance to the diagnosis and treatment of liver-related diseases. This review summarizes the crosstalk between the liver and distant organs, including the brain, the bone, the adipose tissue and the intestine in noticeable situations. The discussion of these contents will add to a new dimension of organismal homeostasis and shed light on novel theranostics of pathologies.

Effects of Metabolic Dysfunction-Associated Steatotic Liver Disease on Bone Density and Fragility Fractures: Associations and Mechanisms

Metabolic dysfunction-associated steatotic liver disease (MASLD) has profound adverse effects on bone health and homeostasis. MASLD appears to be associated with changes in bone mineral density (BMD) and fracture rate. However, the data are ambiguous and conflicting. Although several studies have shown that children and adolescents with MASLD have decreased BMD, the data on the prevalence of fragility fractures among children are scarce. In adults, increasing evidence suggests that MASLD decreases BMD and increases the risk of fragility fractures, which appears to be due to deterioration of bone architecture in addition to a decrease in BMD. Effects of MASLD on bone health may also be age- and race-specific. MASLD does not seem to increase fracture risk in children and adolescents but increases the risk of fractures in elderly men, especially those of Asian origin. From a mechanistic perspective, bone remodeling is a continuous process between osteoblasts (bone-forming) and osteoclasts (bone-resorbing), with any imbalance resulting in metabolic bone disease. In individuals with MASLD, loss of anabolic insulin receptor signaling (insulin resistance) in osteoblasts and increased receptor activator of nuclear factor κB (RANK)/RANK ligand signaling in osteoclasts (proinflammatory cytokines) swings the pendulum toward accelerated bone loss. These processes are further complicated by the concomitant presence of obesity, type 2 diabetes mellitus, or sarcopenia in individuals with MASLD. This study reviews the current literature associated with the effects of MASLD on BMD and fragility fractures in children/adolescents and adults. This review also discusses the pathomechanisms that link MASLD with changes in BMD and fragility fractures.

Bone mass, microarchitecture and turnover among young Indian women with non-alcoholic fatty liver disease

PURPOSE

To evaluate comprehensive bone health among young Indian women, including bone mass, microarchitecture, and turnover, in relation to their non-alcoholic fatty liver disease (NAFLD) status.

METHODS

This cross-sectional study (May 2018-November 2019) recruited women with a history of gestational diabetes mellitus (GDM) and normoglycemia in their index pregnancy, who were at least 6 months postpartum. All participants underwent abdominal ultrasonography for determination of NAFLD status (grades 2 and 3: severe NAFLD) and transient elastography (FibroScan) for hepatic fibrosis (LSM >6 kPa). Bone mass was assessed by DXA, bone microarchitecture with trabecular bone score {TBS} (low TBS ≤ 1.310) and bone turnover with markers of bone formation (osteocalcin and P1NP), and resorption (CTX).

RESULTS

Bone mineral density (BMD) at femoral neck (p = 0.026) and total hip (p = 0.007) was significantly higher among women with NAFLD (n = 170) compared to those without (n = 124). There was no significant difference in bone turnover markers between the two groups. The presence of NAFLD [adjusted OR: 1.82 (1.07, 3.11)] was associated with low TBS, with a greater strength of association among women with severe NAFLD [adjusted OR: 2.97 (1.12, 7.88)]. However, these associations were attenuated and no longer significant after additionally adjusting for BMI. Women with NAFLD and hepatic fibrosis manifested significantly higher BMD at lumbar spine, femoral neck, and total hip (p < 0.001 for all) and significantly lower bone turnover markers (osteocalcin, p = 0.009 and CTX, p = 0.029), however, the association with low TBS was not observed.

CONCLUSION

Among young Indian women, NAFLD is associated with increased bone mass and impaired bone microarchitecture, and hepatic fibrosis with increased bone mass and reduced bone turnover.

Risk factors for decreased bone mineral density in patients with metabolic dysfunction-associated steatotic liver disease: A cross-sectional study at a health examination center

BACKGROUND & AIMS

Steatotic liver disease (SLD) is often detected in health examinations. However, although individuals with metabolic dysfunction-associated SLD (MASLD) may have decreased bone mineral density (BMD), the specific risk factors remain unclarified. The objective of this study was to identify the factors associated with decreased BMD in patients with MASLD.

METHODS

Individuals who underwent abdominal ultrasonography and BMD measurements at our healthcare center were included. The BMD of the calcaneus was assessed using an AOS-10SA bone densitometer. Decreased BMD was defined as a T-score below -1.0 SD or the administration of osteoporosis treatment. SLD was diagnosed based on specific ultrasonographic criteria.

RESULTS

A total of 1410 patients were diagnosed with MASLD. The median age was 52 years. Multivariate analysis using a logistic regression model revealed that the independent predictors of decreased BMD were a low body mass index (BMI) or a small waist circumference (odds ratio (OR): 0.48, 95% confidence interval (CI): 0.34-0.67), hypertriglyceridemia (OR: 1.29, 95% CI: 1.00-1.65), and a weak grip strength (OR: 0.98, 95% CI: 0.97-1.00). Subgroup analyses of individuals aged 50 years or older, men, and individuals with a FIB-4 index of 1.3 or greater revealed that the absence of a high BMI or a large waist circumference was associated with decreased BMD. The subgroup analysis of men revealed that a weaker grip strength was associated with decreased BMD.

CONCLUSION

The present study suggested several potential risk factors for decreased BMD in patients with MASLD. Individuals with the abovementioned risk factors should be encouraged to undergo BMD measurement from the perspective of preventive medicine.

The relationship between advanced liver fibrosis and osteoporosis in type 2 diabetes patients with MAFLD

PURPOSE

To investigate the relationship between advanced liver fibrosis and osteoporosis in metabolic-associated fatty liver disease (MAFLD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 1144 T2DM patients were divided into the MAFLD and non-MAFLD groups, 460 T2DM patients with MAFLD (277 males aged ≥50 years and 183 postmenopausal females) were divided into N1 (advanced liver fibrosis excluded), N2 (indeterminate advanced liver fibrosis), and N3 (advanced liver fibrosis) groups according to the non-alcoholic fatty liver fibrosis score (NFS), the differences in bone mineral density (BMD) levels and prevalence of osteoporosis were compared. Based on the tertile levels of BMD of the lumbar spine (L), T2DM patients were divided into three groups (T1, T2, and T3), and the differences in the prevalence of advanced liver fibrosis were compared.

RESULTS

The BMD levels of the L4, and L1-4 in the MAFLD group were lower than those of the non-MAFLD groups in male and female T2DM patients .The BMD levels of the total hip, L4, and L1-4 in the N3 group were lower than those of the N2 and N1 groups in male and female T2DM patients with MAFLD, and the prevalence of osteoporosis in the N3 group of males was higher than that in the N1 group. The BMD levels of the total hip, L4, and L1-4 were negatively correlated with NFS in both males and females. The BMD levels of the total hip and L4 in males, and the BMD level of L4 in females were negatively associated with NFS. The prevalence of advanced liver fibrosis was higher in the T1 group than in the T2 and T3 groups in T2DM patients with MAFLD.

CONCLUSION

The BMD levels in male aged ≥50 years or postmenopausal female diabetic patients with MAFLD were negatively correlated with the degree of advanced liver fibrosis, which means an increased risk of liver fibrosis with decreasing BMD.

Genetic evidence of the causal relationship between chronic liver diseases and musculoskeletal disorders

BACKGROUND

Chronic liver diseases constitute a major global public health burden, posing a substantial threat to patients' daily lives and even survival due to the potential development of musculoskeletal disorders. Although the relationship between chronic liver diseases and musculoskeletal disorders has received extensive attention, their causal relationship has not been comprehensively and systematically investigated.

METHODS

This study aimed to assess the causal relationships between viral hepatitis, primary biliary cholangitis, primary sclerosing cholangitis (PSC), liver cirrhosis, and hepatocellular carcinoma (HCC) with osteoporosis, osteoarthritis, and sarcopenia through bidirectional Mendelian randomization (MR) research. The traits related to osteoporosis and osteoarthritis included both overall and site-specific phenotypes, and the traits linked to sarcopenia involved indicators of muscle mass and function. Random-effect inverse-variance weighted (IVW), weighted median, MR-Egger, and Causal Analysis Using the Summary Effect Estimates were used to evaluate causal effects, with IVW being the main analysis method. To enhance robustness, sensitivity analyses were performed using Cochran's Q test, MR-Egger intercept, MR-PRESSO global test, funnel plots, leave-one-out analyses, and latent causal variable model.

RESULTS

The forward MR analysis indicated that PSC can reduce forearm bone mineral density (beta = - 0.0454, 95% CI - 0.0798 to - 0.0110; P = 0.0098) and increase the risk of overall osteoarthritis (OR = 1.012, 95% CI 1.002-1.022; P = 0.0247), while HCC can decrease grip strength (beta = - 0.0053, 95% CI - 0.008 to - 0.0025; P = 0.0002). The reverse MR analysis did not find significant causal effects of musculoskeletal disorders on chronic liver diseases. Additionally, no heterogeneity or pleiotropy was detected.

CONCLUSIONS

These findings corroborate the causal effects of PSC on osteoporosis and osteoarthritis, as well as the causal impact of HCC on sarcopenia. Thus, the implementation of comprehensive preventive measures is imperative for PSC and HCC patients to mitigate the risk of musculoskeletal disorders, ultimately improving their quality of life.

Association of chronic liver disease with bone diseases and muscle weakness

The liver is a vital organ involved in nutrient metabolism, hormone regulation, immunity, cytokine production, and gut homeostasis. Impairment in liver function can result in malnutrition, chronic inflammation, decreased anabolic hormone levels, and dysbiosis. These conditions eventually cause an imbalance in osteoblast and osteoclast activities, resulting in bone loss. Osteoporosis is a frequent complication of chronic liver disease (CLD) that adversely affects quality of life and increases early mortality. Sarcopenia is another common complication of CLD characterized by progressive loss of skeletal muscle mass and function. Assessment criteria for sarcopenia specific to liver disease have been established, and sarcopenia has been reported to be associated with an increase in the risk of liver disease-related events and mortality in patients with CLD. Owing to their similar risk factors and underlying pathophysiological mechanisms, osteoporosis and sarcopenia often coexist (termed osteosarcopenia), progress in parallel, and further exacerbate the conditions mentioned above. Therefore, comprehensive management of these musculoskeletal disorders is imperative. This review summarizes the clinical implications and characteristics of osteoporosis, extending to sarcopenia and osteosarcopenia, in patients with CLD caused by different etiologies.

Associations of metabolic dysfunction-associated fatty liver disease and hepatic fibrosis with bone mineral density and risk of osteopenia/osteoporosis in T2DM patients

Background

Existing evidence on the associations of liver steatosis and fibrosis with bone mineral density (BMD) and risk of osteopenia/osteoporosis was limited with conflicting results. We aimed to evaluate the associations of metabolic dysfunction-associated fatty liver disease (MAFLD) and hepatic fibrosis with BMD and risk of osteopenia/osteoporosis in type 2 diabetes mellitus (T2DM) patients.

Methods

Baseline information of an ongoing cohort of 249 T2DM patients in Xiamen, China was analyzed. MAFLD was defined as the presence of hepatic steatosis [diagnosed by either hepatic ultrasonography scanning or fatty liver index (FLI) score >60] for T2DM patients. BMD was measured using dual-energy x-ray absorptiometry at total lumbar (L2-4), femur neck (FN), and total hip (TH) and was categorized as normal (T ≥ -1.0), osteopenia (-2.5 < T < -1.0), or osteoporosis (T ≤ -2.5) according to its minimum T-score.

Results

Among the 249 T2DM patients, prevalence rates of MAFLD, osteopenia, and osteoporosis were 57.8%, 50.6%, and 17.7%, respectively. Patients with MAFLD had significantly higher BMD T-scores of L2-4, FN, and TH and the minimum as well as lower prevalence of osteoporosis than patients without MAFLD. Hepatic steatosis indices, including FLI score, fatty liver (FLI ≥ 60 or hepatic ultrasonography scanning), and MAFLD, were significantly and positively associated with all T-scores, while hepatic fibrosis index and FIB-4 score, but not NAFLD fibrosis score (NFS), were negatively associated with all T-scores. MAFLD was significantly associated with the decreased risk of osteopenia/osteoporosis and osteoporosis with unadjusted odds ratios (ORs) (95% CI) of 0.565 (0.324-0.987) and 0.434 (0.224-0.843) (both p-values < 0.05), respectively. As for liver fibrosis, FIB-4 score, but not NFS, was significantly associated with elevated risk of osteoporosis with an unadjusted OR (95% CI) per SD increase of FIB-4 score of 1.446 (1.080-1.936, p-value = 0.013). Adjusting for potential confounding variables, especially body mass index, in the multivariable regression analyses, all associations of hepatic steatosis and fibrosis indices with BMD and risk of osteopenia/osteoporosis were not statistically significant.

Conclusion

MAFLD and hepatic fibrosis were not significantly associated with BMD and risk of osteopenia/osteoporosis independent of obesity. Nevertheless, screening and management of MAFLD and osteopenia/osteoporosis were still important for the prevention of fracture in T2DM patients.

The Current Status of the Liver Liquid Biopsy in MASH Related HCC: Overview and Future Directions

Metabolic dysfunction-associated steatohepatitis (MASH) is one of the major risk factors for chronic liver disease and hepatocellular carcinoma (HCC). The incidence of MASH in Western countries continues to rise, driving HCC as the third cause of cancer-related death worldwide. HCC has become a major global health challenge, partly from the obesity epidemic promoting metabolic cellular disturbances but also from the paucity of biomarkers for its early detection. Over 50% of HCC cases are clinically present at a late stage, where curative measures are no longer beneficial. Currently, there is a paucity of both specific and sensitive biological markers for the early-stage detection of HCC. The search for biological markers in the diagnosis of early HCC in high-risk populations is intense. We described the potential role of surrogates for a liver biopsy in the screening and monitoring of patients at risk for nesting HCC.

Methods for estimating insulin resistance from untargeted metabolomics data

CONTEXT

Insulin resistance is associated with multiple complex diseases; however, precise measures of insulin resistance are invasive, expensive, and time-consuming.

OBJECTIVE

Develop estimation models for measures of insulin resistance, including insulin sensitivity index (SI) and homeostatic model assessment of insulin resistance (HOMA-IR) from metabolomics data.

DESIGN

Insulin Resistance Atherosclerosis Family Study (IRASFS).

SETTING

Community based.

PARTICIPANTS

Mexican Americans (MA) and African Americans (AA).

MAIN OUTCOME

Estimation models for measures of insulin resistance, i.e. SI and HOMA-IR.

RESULTS

Least Absolute Shrinkage and Selection Operator (LASSO) and Elastic Net regression were used to build insulin resistance estimation models from 1274 metabolites combined with clinical data, e.g. age, sex, body mass index (BMI). Metabolite data were transformed using three approaches, i.e. inverse normal transformation, standardization, and Box Cox transformation. The analysis was performed in one MA recruitment site (San Luis Valley, Colorado (SLV); N = 450) and tested in another MA recruitment site (San Antonio, Texas (SA); N = 473). In addition, the two MA recruitment sites were combined and estimation models tested in the AA recruitment sample (Los Angeles, California; N = 495). Estimated and empiric SI were correlated in the SA (r2 = 0.77) and AA (r2 = 0.74) testing datasets. Further, estimated and empiric SI were consistently associated with BMI, low-density lipoprotein cholesterol (LDL), and triglycerides. We applied similar approaches to estimate HOMA-IR with similar results.

CONCLUSIONS

We have developed a method for estimating insulin resistance with metabolomics data that has the potential for application to a wide range of biomedical studies and conditions.