Association between bone mineral density and nonalcoholic fatty liver disease in Korean adults

Low Bone Mineral Density as a Risk Factor for Liver Cirrhosis

CONTEXT

Bone metabolism interplays with liver metabolism, also known as the liver-bone axis. Osteoporosis is a common complication of cirrhosis, but whether bone mineral density (BMD) can predict cirrhosis development is unknown.

OBJECTIVE

This study aims to investigate the relationship between BMD and the risk of incident cirrhosis in the Hong Kong Osteoporosis Study (HKOS).

METHODS

BMD was measured at the lumbar spine, femoral neck, total hip, and trochanter of 7752 participants by dual-energy x-ray absorptiometry (DXA), and the incidence of cirrhosis and mortality were followed by linking to the territory-wide electronic health records database. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% CI.

RESULTS

With a median follow-up of 18.43 years, 42 incident cirrhosis were identified. Higher BMD T-scores at the femoral neck, total hip, and trochanter were significantly associated with a reduced risk of cirrhosis (femoral neck: HR 0.56; 95% CI, 0.39-0.82; total hip: HR 0.60; 95% CI, 0.44-0.82; trochanter: HR 0.63; 95% CI, 0.46-0.88). Similar associations were observed in participants without risk factors of cirrhosis at the baseline and further adjusting for the baseline level of alkaline phosphatase, albumin, and alanine transaminase. Consistent relationships in multiple sensitivity analyses suggest the robustness of the results.

CONCLUSION

Low BMD could be a novel risk factor and early predictor for cirrhosis, with consistent associations observed in multiple sensitivity analyses.

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.

Association between nonalcoholic fatty liver disease and bone mineral density: Mendelian randomization and mediation analysis

Background

Observational studies have reported significant association between non-alcoholic fatty liver disease (NAFLD) and bone mineral density (BMD), a critical indicator of bone health. We aimed to investigate whether NAFLD is a cause for changes in BMD.

Methods

We selected 29 independent SNPs as instrumental variables for NAFLD. A range of Mendelian randomization (MR) methods, namely the inverse variance-weighted (IVW) method, weighted-median, weighted-mode, and MR-Egger regression, were utilized to determine the causal effects of NAFLD on BMD. Two-step MR analysis was conducted to determine the mediating effect of fasting glucose, insulin, glycosylated hemoglobin, low-density cholesterol, and body-mass index on the association between NAFLD and BMD. False-discovery-rate (FDR) was used to correct for multiple testing bias.

Results

The IVW-method indicated a significantly inverse association between genetically predicted NAFLD and total body BMD (β = -0.04, 95 % CI -0.07 to -0.02, FDR = 0.010). Notably, the relationship was more pronounced in participants over 60 years of age (β = -0.06, 95 % CI -0.11 to -0.02, FDR = 0.030). Inverse associations were observed in other subpopulations and in site-specific BMD, though they were not statistically significant after correcting for multiple testing. We observed a significantly positive association between NAFLD and the risk of osteoporosis. Consistency in results was observed across multiple MR methods and in the repeated analysis. Fasting glucose, insulin, and glycosylated hemoglobin mediated 25.4 % (95 % CI 17.6-31.5 %), 18.9 % (12.0-24.9 %), and 27.9 % (19.9-36.7 %) of the effect of NAFLD on BMD, respectively.

Conclusion

Our findings underscore a probable causal negative link between NAFLD and BMD, indicating that NAFLD might detrimentally affect bone health, especially in older individuals.

In vitro osteoclast differentiation enhanced by hepatocyte supernatants from high-fat diet mice

Non-alcoholic fatty liver disease (NAFLD) is associated with abnormal bone metabolism, potentially mediated by elevated levels of proinflammatory cytokines such as tumor necrosis factor alpha (TNF-ɑ) and interleukin 6 (IL-6). This study aims to investigate the direct regulatory effects of liver tissues on osteoblast and osteoclast functions in vitro, focusing on the liver-bone axis in NAFLD. Twelve-week-old C57BL/6 mice were fed either a control diet or a high-fat diet (HFD) for 12 weeks. Bone structural parameters were assessed using microCT. Primary hepatocyte cultures were established from control and HFD-fed C57BL/6 mice, as well as IL-6-/- and TNF-α-/- mice. The supernatants from these hepatocyte cultures were used to induce differentiation in bone marrow cell-derived osteoblasts and osteoclasts in vitro. Results showed that mice on a HFD exhibited increased lipid infiltration in liver and bone marrow tissues, alongside reduced bone mass. Moreover, the supernatants from hepatocyte cultures from mice on a HFD displayed elevated TNF-α and IL-6 levels. These supernatants, particularly those derived from HFD-fed and IL-6-/- mice, significantly enhanced osteoclast differentiation in vitro. In contrast, supernatants from TNF-α-/- mice did not significantly affect osteoblast or osteoclast differentiation in vitro. In conclusions, this current study suggested that fatty liver tissues may negatively impact bone metabolism. Additionally, knockout of TNF-α and IL-6 genes revealed distinct influence on osteoblast and osteoclast functions, highlighting the complex interplay between live pathology and bone health.

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.

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.

Anti-osteoporotic treatments in the era of non-alcoholic fatty liver disease: friend or foe

Over the last years non-alcoholic fatty liver disease (NAFLD) has grown into the most common chronic liver disease globally, affecting 17-38% of the general population and 50-75% of patients with obesity and/or type 2 diabetes mellitus (T2DM). NAFLD encompasses a spectrum of chronic liver diseases, ranging from simple steatosis (non-alcoholic fatty liver, NAFL) and non-alcoholic steatohepatitis (NASH; or metabolic dysfunction-associated steatohepatitis, MASH) to fibrosis and cirrhosis with liver failure or/and hepatocellular carcinoma. Due to its increasing prevalence and associated morbidity and mortality, the disease-related and broader socioeconomic burden of NAFLD is substantial. Of note, currently there is no globally approved pharmacotherapy for NAFLD. Similar to NAFLD, osteoporosis constitutes also a silent disease, until an osteoporotic fracture occurs, which poses a markedly significant disease and socioeconomic burden. Increasing emerging data have recently highlighted links between NAFLD and osteoporosis, linking the pathogenesis of NAFLD with the process of bone remodeling. However, clinical studies are still limited demonstrating this associative relationship, while more evidence is needed towards discovering potential causative links. Since these two chronic diseases frequently co-exist, there are data suggesting that anti-osteoporosis treatments may affect NAFLD progression by impacting on its pathogenetic mechanisms. In the present review, we present on overview of the current understanding of the liver-bone cross talk and summarize the experimental and clinical evidence correlating NAFLD and osteoporosis, focusing on the possible effects of anti-osteoporotic drugs on NAFLD.

"Prevalence, Predictors, and Impact of Hepatic Steatosis in Patients With Ulcerative Colitis: A Prospective Observational Cohort Study"

Background and Aims

There are no prospective studies evaluating effect of non-alcoholic fatty liver disease (NAFLD) in patients with ulcerative colitis (UC). This prospective observational study assessed the prevalence of NAFLD, its predictors, and its effect on long-term outcomes in UC.

Methods

Consecutive UC patients underwent transient elastography, body composition analysis, bone densitometry, anthropometry, and baseline demographic and subjective global assessment. NAFLD was diagnosed by controlled attenuation parameter of >260 dB/m. To evaluate predictors and outcomes, patients of UC with NAFLD (n = 29) were compared with age- and sex-matched patients of UC without NAFLD (n = 27).

Results

Among 107 patients of UC (mean age-29 ± 10.6 years; males = 56%, median disease duration-48 [interquartile range: 24-84] months, left sided/pancolitis = 84%), 27% (n = 29) had NAFLD. Patients with body mass index (BMI) > 23 kg/m2 had higher proportion of NAFLD than with normal or low BMI (54.7% [23/42] vs 10% [5/50] vs 6.7% [1/15]). Patients with NAFLD had high BMI (P < 0.001), waist circumference, and fat mass (P < 0.001) but similar fat-free mass (P = 0.798) compared to patients without NAFLD. There was no difference in immunosuppressant and cumulative steroid exposure between two groups. Dietary parameters including daily energy, protein, fat, and carbohydrate intake were similar between the two groups. On multivariate analysis, high BMI was found to be predictive and low socioeconomic status as a protective factor of NAFLD. On long-term follow-up of three years, there was no difference in steroid, or biologic requirement, disease-related hospitalization, or composite of all three outcomes between two groups.

Conclusion

The prevalence of NAFLD was found in nearly a quarter of patients of UC and was affected by metabolic parameters rather than disease activity.

Micro-scale vertebral features in postmenopausal women with alcohol-associated and metabolic-associated fatty liver disease: ex vivo bone quality analyses

PURPOSE

Although epidemiological studies indicate increased fracture risk in women with alcohol-associated liver disease (AALD) and metabolic-associated fatty liver disease (MAFLD), data about their micro-scale bone features are still limited. We aimed to characterize bone quality changes in the anterior mid-transverse part of the first lumbar vertebral body collected from 32 adult postmenopausal females. Based on pathohistological assessment of the liver tissue, individuals were divided into AALD (n = 13), MAFLD (n = 9), and control group (n = 10).

METHODS

We analyzed trabecular and cortical micro-architecture (using micro-computed tomography), bone mechanical properties (using Vickers microhardness tester), osteocyte lacunar network and bone marrow adiposity morphology (using optic microscopy). Data were adjusted to elude the covariant effects of advanced age and body mass index on our results.

RESULTS

Our data indicated a minor trend toward deteriorated bone quality in MAFLD women, presented in impaired trabecular and cortical micro-architectural integrity, which could be associated with bone marrow adiposity alterations noted in these women. Additionally, we observed a significant decline in micro-architectural, mechanical, and osteocyte lacunar features in lumbar vertebrae collected from the AALD group. Lastly, our data indicated that vertebral bone deterioration was more prominent in the AALD group than in the MAFLD group.

CONCLUSION

Our data suggested that MAFLD and AALD are factors that could play a part in compromised vertebral strength of postmenopausal women. Also, our data contribute to understanding the multifactorial nature of bone fragility in these patients and highlight the necessity for developing more effective patient-specific diagnostic, preventive, and therapeutic strategies.

Relationship between nonalcoholic fatty liver disease and bone mineral density in elderly Chinese

OBJECTIVE

As our society grows older, both bone loss and fatty liver have become important issues. However, the relationship between reduced bone mineral density and fatty liver remains controversial. The purpose of this study was to investigate the relationship between nonalcoholic fatty liver disease and less bone mineral density in the ankles of Chinese people over 65.

METHODS

The research included 716 older adults over the age of 65 who underwent a comprehensive health screening. A logistic regression model was used to investigate the relationship between nonalcoholic fatty liver disease (NAFLD) and ankle bone mineral density.

RESULTS

A logistic regression model was used to analyze the odds ratios of reduced bone mineral density between patients with fatty liver and controls. In the adjusted model, adjustments were made for age, sex, systolic blood pressure, diastolic blood pressure, overweight rate, history of hypertension, history of diabetes, history of smoking, history of alcohol consumption, fasting glucose, hemoglobin, urea, creatinine, triglycerides, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, waist circumference, total protein, albumin, and globulin. The adjusted OR (aOR) for reduced bone mineral density was 0.66 [95% confidence interval (CI) = 0.45-0.97, P = 0.034 < 0.05]. In subgroup analysis by age, sex, and BMI, women, age > 75 years, and BIM < 25 were statistically significant.

CONCLUSION

This study suggested that NAFLD is associated with a reduced risk of reduced heel bone mass. More research needs to be done to back up the results of this study and look into possible problems.

Causal association of NAFLD with osteoporosis, fracture and falling risk: a bidirectional Mendelian randomization study

Introduction

The causal association between non-alcoholic fatty liver disease (NAFLD) and osteoporosis remains controversial in previous epidemiological studies. We employed a bidirectional two-sample Mendelian analysis to explore the causal relationship between NAFLD and osteoporosis.

Method

The NAFLD instrumental variables (IVs) were obtained from a large Genome-wide association study (GWAS) meta-analysis dataset of European descent. Two-sample Mendelian randomization (MR) analyses were used to estimate the causal effect of NAFLD on osteoporosis, fracture, and fall. Reverse Mendelian randomization analysis was conducted to estimate the causal effect of osteoporosis on NAFLD. The inverse-variance weighted (IVW) method was the primary analysis in this analysis. We used the MR-Egger method to determine horizontal pleiotropic. The heterogeneity effect of IVs was detected by MR-Egger and IVW analyses.

Results

Five SNPs (rs2980854, rs429358, rs1040196, rs738409, and rs5764430) were chosen as IVs for NAFLD. In forward MR analysis, the IVW-random effect indicated the causal effect of NAFLD on osteoporosis (OR= 1.0021, 95% CI: 1.0006-1.0037, P= 0.007) but not on fracture (OR= 1.0016, 95% CI: 0.998-1.0053, P= 0.389) and fall (OR= 0.9912, 95% CI: 0.9412-1.0440, P= 0.740). Furthermore, the reverse Mendelian randomization did not support a causal effect of osteoporosis on NAFLD (OR= 1.0002, 95% CI: 0.9997-1.0007, P= 0.231). No horizontal pleiotropic was detected in all MR analyses.

Conclusions

The results of this study indicate a causal association between NAFLD and osteoporosis. NAFLD patients have a higher risk of osteoporosis but not fracture and falling risk. In addition, our results do not support a causal effect of osteoporosis on NAFLD.

Nonalcoholic Fatty Liver Disease Is Associated With Decreased Bone Mineral Density in Adults: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis aimed to investigate the effect of nonalcoholic fatty liver disease (NAFLD) on bone mineral density (BMD) and the risk of osteoporosis and osteoporotic fracture in adults. We searched PubMed, MEDLINE, Embase, CINAHL, Web of Science, Cochrane Library, and Scopus for observational studies published from inception to January 2023 that reported adjusted effect sizes of NAFLD on BMD, osteopenia/osteoporosis, and osteoporotic fracture. The data were synthesized using multilevel and random-effects models. A total of 19 studies were included; of these, nine (21,294 participants) evaluated the effect of NAFLD on BMD, six (133,319 participants) investigated the risk of osteoporosis, and five (227,901 participants) assessed the risk of osteoporotic fracture. This meta-analysis showed that NAFLD was associated with decreased BMD (mean difference -0.019 g/cm2 , 95% confidence interval [CI] -0.036 to -0.002, I2 = 93%) and increased risks of osteoporosis (adjusted risk ratio [RR] = 1.28, 95% CI 1.08 to 1.52, I2 = 84%) and osteoporotic fractures (adjusted RR = 1.17, 95% CI 1.00 to 1.37, I2 = 67%). Subgroup analyses revealed that NAFLD had a significantly detrimental effect on BMD in men and on the BMD of the femoral neck and total hip. Stratified analyses by ethnicity demonstrated that NAFLD was not associated with BMD, osteoporosis, or osteoporotic fracture in non-Asian populations. The publication bias of all included studies was low; however, there was considerable heterogeneity among the studies, warranting a careful interpretation of the findings. Overall, our results suggest that NAFLD is associated with decreased BMD and an increased risk of osteoporosis or osteoporotic fractures. Male sex and the BMD of the femoral neck and total hip may be potential risk factors for decreased BMD in adults with NAFLD. Additionally, ethnic disparities were observed between Asian and non-Asian populations regarding BMD and osteoporotic fractures. © 2023 American Society for Bone and Mineral Research (ASBMR).

Bone Turnover Markers in Adults with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Objective

Previous studies suggested that the level of bone turnover markers (BTMs) could be altered in patients with nonalcoholic fatty liver disease (NAFLD). We aim to provide a comprehensive understanding on the associations between BTMs and NAFLD in adults with a meta-analysis.

Methods

Articles published up to January 31, 2023, were systematically searched in PubMed, Web of Science, Cochrane database, Embase, and CNKI. The search formula is as follows: "nonalcoholic fatty liver disease" combined with the terms that bone turnover markers such as "osteocalcin," "collagen type I trimeric cross-linked peptide," and "procollagen type I N-terminal peptide." Stata 15.0 software was used to calculate the pooled OR (95% CI) and perform the heterogeneity test, sensitivity analysis, and publication bias.

Results

We identified 18 studies with a total of 12,310 participants. Statistical differences were found between patients with NAFLD compared to the control group for osteocalcin (n = 15 studies; SMD: -0.69; 95% CI: -0.73--0.64; P=0.002), procollagen type I N-terminal propeptide (n = 5 studies; SMD: -0.40; 95% CI: -0.80--0.00; P=0.049), and collagen type I cross-linked C-telopeptide (n = 7 studies; SMD: -0.16; 95% CI: -0.23--0.09); P < 0.001).

Conclusion

Bone turnover markers were lower in patients with NAFLD compared to the control group.

Association between the fatty liver index and the risk of fracture among individuals over the age of 50 years: a nationwide population-based study

Background and purpose

The association between fatty liver and fracture risk has not been firmly established. In this study, we investigated the relationship between the fatty liver index (FLI) and the incidence of fractures among individuals ≥50 years of age, using a nationwide population-based cohort.

Methods

Data from the Korean National Health Insurance System between January 2009 and December 2019 were analyzed using the Cox proportional hazards model. Fatty liver status was defined using FLI. Newly diagnosed fractures were identified based on insurance claim data.

Results

Among the 3,384,457 individuals who met our inclusion criteria over the study period, 444,203 cases of incident fractures were identified over a median follow-up of 10.3 years. On multivariate analysis, the risk of fracture was significantly higher among individuals with a higher FLI score compared to those with an FLI<30, with adjusted hazard ratio [aHR] and 95% confidence interval [CI] as follows: FLI 30-59 group, aHR 1.04 and 95% CI 1.03-1.05; and FLI ≥60 group, aHR 1.12 and 95% CI 1.10-1.13. A higher FLI was associated with a greater risk of hip (aHR 1.23 and 1.52 for the FLI 30-59 and FLI ≥60 group, respectively) and vertebral fracture (aHR 1.08 and 1.16 for the FLI 30-59 and FLI≥60 group, respectively). The association between the risk for fracture and FLI ≥60 was prominent for non-obese than obese individuals (aHR 1.25 and 95% CI, 1.22-1.27 versus 1.06 and 1.05-1.08, respectively).

Conclusions

A high FLI is associated with an increased risk of hip and vertebral fractures among individuals ≥50 years of age, suggestive of an association between a higher FLI and osteoporotic fractures.

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.

Non-alcoholic fatty liver disease is associated with decreased bone mineral density in upper Egyptian patients

Nonalcoholic fatty liver disease (NAFLD) has been linked with a number of extra hepatic diseases and could be a potential risk factor of decreasing bone mineral density. To determine whether Upper Egyptian patients with NAFLD are at risk of developing osteoporosis. Cross sectional study was done on a total 100 individuals; 50 patients diagnosed with NAFLD (based on ultrasound imaging) crossed-matched with 50 individuals without NAFLD based on age, sex and body mass index. Bone mineral density, serum calcium and phosphorus levels, serum parathyroid hormone, serum vitamin D and fasting insulin level were assessed. Osteoporosis was prevalent in NAFLD patients versus to controls (19/50 vs. 0/50; P < 0.001). There was significant decrease in bone mineral density in NAFLD patients than controls (- 2.29 ± 0.4 vs. - 1.53 ± 0.1; P < 0.001). There was a statistical significance decrease in serum vitamin D and calcium levels in NAFLD patients than controls. Furthermore, vitamin D levels in the NAFLD group was a predictor for osteoporosis (OR 0.614; 95% CI 0.348-0.825). Patients with NAFLD tend to have a significant decrease in bone density, vitamin D, and serum calcium levels than controls.

Are Nonalcoholic Fatty Liver Disease and Bone Mineral Density Associated? - A Cross-Sectional Study Using Liver Biopsy and Dual-Energy X-Ray Absorptiometry

There is controversy regarding the association between nonalcoholic fatty liver disease (NAFLD) and osteoporosis. Our study aim was to assess bone mineral density (BMD) in patients with biopsy-proven NAFLD and examine if the severity of NAFLD affects BMD. A total of 147 adult women (n = 108) and men (n = 39) aged 18-76 years (mean ± standard deviation [SD] age 45.3 ± 12.5) were recruited in this cross-sectional study and underwent a liver biopsy and dual-energy X-ray absorptiometry (DXA). NAFLD activity score (NAS) based on the degree of steatosis, lobular inflammation and hepatocellular ballooning was used to assess NAFLD severity. The majority of subjects, 53%, had steatosis, 25% had nonalcoholic steatohepatitis (NASH) whereas 23% served as control subjects with no evidence of NAFLD. There were no significant differences in the lumbar spine (1.09 ± 0.12, 1.11 ± 0.18, and 1.12 ± 0.15 g/cm², p = 0.69, in controls, steatosis, and NASH, respectively) or hip BMD (1.10 ± 0.15, 1.12 ± 0.13, and 1.09 ± 0.13 g/cm², p = 0.48, in controls, steatosis, and NASH, respectively) between the groups. Adjusting for age, gender, body mass index, and diabetes in multiple regression models did not alter the results. There was no correlation between NAS and neither lumbar spine BMD (r = 0.06, p = 0.471), nor hip BMD (r = -0.03, p = 0.716). In conclusion, BMD was similar across the spectrum of NAFLD in both genders and not related to the severity of the underlying histological lesions, suggesting that neither steatosis nor NASH exerts a detrimental effect on BMD in these relatively young patients. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Bone loss in chronic liver diseases: Could healthy liver be a requirement for good bone health?

Given that the liver is involved in many metabolic mechanisms, it is not surprising that chronic liver disease (CLD) could have numerous complications. Secondary osteoporosis and increased bone fragility are frequently overlooked complications in CLD patients. Previous studies implied that up to one-third of these individuals meet diagnostic criteria for osteopenia or osteoporosis. Recent publications indicated that CLD-induced bone fragility depends on the etiology, duration, and stage of liver disease. Therefore, the increased fracture risk in CLD patients puts a severe socioeconomic burden on the health system and urgently requires more effective prevention, diagnosis, and treatment measures. The pathogenesis of CLD-induced bone loss is multifactorial and still insufficiently understood, especially considering the relative impact of increased bone resorption and reduced bone formation in these individuals. It is essential to note that inconsistent findings regarding bone mineral density measurement were previously reported in these individuals. Bone mineral density is widely used as the “golden standard” in the clinical assessment of bone fragility although it is not adequate to predict individual fracture risk. Therefore, microscale bone alterations (bone microstructure, mechanical properties, and cellular indices) were analyzed in CLD individuals. These studies further support the thesis that bone strength could be compromised in CLD individuals, implying that an individualized approach to fracture risk assessment and subsequent therapy is necessary for CLD patients. However, more well-designed studies are required to solve the bone fragility puzzle in CLD patients.

Relationship between prevalence and risk of osteoporosis or osteoporotic fracture with non-alcoholic fatty liver disease: A systematic review and meta-analysis

The aim of this study was to investigate the relationship between prevalence and risks of osteoporosis or osteoporotic fracture and NAFLD. Patients with NAFLD should be monitored regularly for bone mineral density and bone metabolism indicators to prevent osteoporosis or osteoporotic fractures.

OBJECTIVES

The aim of this meta-analysis was to investigate the relationship between prevalence and risks of osteoporosis or osteoporotic fracture and non-alcoholic fatty liver disease (NAFLD).

METHODS

Five databases, including PubMed, Web of Science, Embase, Scopus and Cochrane Library, were searched since the conception of these databases until December 2021. The cohort studies, cross-sectional analyses or case-control studies evaluating the relationship between osteoporosis or osteoporotic fracture and NAFLD were retrieved from these databases. Relevant data were extracted from the included studies, and a meta-analysis was performed.

RESULTS

A total of seven studies were included. The prevalence of osteoporosis or osteoporotic fractures was higher in the NAFLD group than in the non-NAFLD group [OR = 1.17, 95%CI(1.04,1.31)], while the prevalence of osteoporosis was higher in the NAFLD group than in the non-NAFLD group [OR = 1.46, 95%CI (1.21,1.77) and OR = 1.48, 95%CI (1.31,1.68), respectively] in men and women. The risk of osteoporosis or osteoporotic fractures was higher in the NAFLD group than in the non-NAFLD group [OR = 1.33,95%CI (1.24,1.44) and OR = 1.57,95%CI (1.08,2.29), respectively]. The risk of osteoporosis or osteoporotic fractures was higher in male and female NAFLD groups than that in the non-NAFLD group [OR = 1.29, 95%CI(1.14,1.47) and OR = 1.36, 95%CI (1.25,1.48), respectively]. After parameter adjustment, the risk of osteoporosis or osteoporotic fracture was higher in the male NAFLD group than in the non-NAFLD group [OR = 2.10, 95%CI(1.36,3.25)], while no significant difference was found among women [OR = 1.13, 95%CI (0.86,1.48)].

CONCLUSIONS

The prevalence and risk of osteoporosis or osteoporotic fractures were significantly associated with NAFLD in men and women.

TRIAL REGISTRATION

PROSPERO 2022 CRD42022304708.

Nonalcoholic fatty liver disease and osteoporosis: A potential association with therapeutic implications

Nonalcoholic fatty liver disease (NAFLD) and osteoporosis are two highly prevalent metabolic diseases. Increasing experimental evidence supports a pathophysiological link between NAFLD and osteoporosis. A key feature could be chronic, low-grade inflammation, which characterizes NAFLD and possibly affects bone metabolism. In this context, several factors, including but not limited to receptor activator of nuclear factor kappa-B ligand, osteoprotegerin, osteopontin and osteocalcin, may serve as mediators. In the clinical setting, most but not all epidemiological evidence indicates that NAFLD is associated with lower bone mineral density or osteoporosis in adults. Although an association between NAFLD and osteoporosis has not yet been established, and thus remains speculative, pharmacological considerations already exist. Some of the current and emerging pharmacological options for NAFLD have shown possible anti-osteoporotic properties (eg, vitamin E, obeticholic acid, semaglutide), while others (eg, pioglitazone, canagliflozin) have been associated with increased risk of fractures and may be avoided in patients with NAFLD and concomitant osteoporosis, especially those at high fracture risk. Conversely, some anti-osteoporotic medications (denosumab) might benefit NAFLD, while others (raloxifene) might adversely affect it and, consequently, may be avoided in patients with osteoporosis and NAFLD. If an association between NAFLD and osteoporosis is established, a medication that could target both diseases would be a great advancement. This review summarizes the main experimental and clinical evidence on the potential association between NAFLD and osteoporosis and focuses on treatment considerations derived from this potential association.

Risk of fractures and subsequent mortality in non-alcoholic fatty liver disease: A nationwide population-based cohort study

BACKGROUND

Studies suggest an association between osteoporosis and non-alcoholic fatty liver disease (NAFLD), but whether patients with NAFLD are at increased risk of fractures is unknown.

OBJECTIVES

The aim was to determine the rate and risk of fractures and the mortality rate after fracture in patients with NAFLD compared to the general population.

METHODS

This was a nationwide population-based cohort study using data from the Swedish National Patient Registry on 10,678 patients with NAFLD from 1987 to 2016. Patients were matched for sex, age, and municipality with 99,176 controls from the Swedish Total Population Registry. Cox regression was used to estimate fracture rates. The risk of fractures was assessed while accounting for competing risks (death and liver transplantation).

RESULTS

A total of 12,312 fractures occurred during 761,176 person-years of follow-up. Patients with NAFLD (17.5 per 1000 person-years) had a slightly higher fracture rate than controls (16.1 per 1000 person-years; adjusted hazard ratio 1.11, 95% confidence interval [CI] 1.05-1.19), although the 5-year risk of fractures was similar (8.0%, 95% CI 7.4-8.6 versus 7.3%, 95% CI 7.2-7.5). Additionally, 1-year mortality after fracture was similar in NAFLD and controls.

CONCLUSIONS

Patients with NAFLD have a slightly higher rate of fractures but long-term risk of fractures comparable to the general population. This suggests that broad surveillance of risk factors for fractures in patients with NAFLD is not motivated.

The association of nonalcoholic fatty liver disease with bone mineral density in type 2 diabetes

Objective

We examined the association between nonalcoholic fatty liver disease and lumbar spine bone mineral density in individuals with and without type 2 diabetes.

Methods

The lumbar BMD of 1088 subjects was measured using dual-energy X-ray absorptiometry (DXA). Liver fat content was quantified via B-mode ultrasound. Multivariable linear regression was used to study the association between NAFLD and lumbar BMD in participants with and without T2DM.

Results

The lumbar BMD in the T2DM group and the non-diabetes group was higher in the NAFLD group than in the non-NAFLD group (P < 0.001). Multivariate regression analysis in the T2DM group showed that after adjusting for confounders, the positive association between lumbar spine BMD and NAFLD remained (P = 0.027). In the non-diabetes group, after adjusting for confounders, the association between NAFLD and lumbar spine BMD disappeared.

Conclusions

The relationship between nonalcoholic fatty liver disease and lumbar bone mineral density may differ in individuals with and without diabetes. The effect of nonalcoholic fatty liver disease on bone mineral density needs to be evaluated in different clinical contexts.

Nonalcoholic Fatty Liver Disease and Endocrine Axes-A Scoping Review

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease. NAFLD often occurs associated with endocrinopathies. Evidence suggests that endocrine dysfunction may play an important role in NAFLD development, progression, and severity. Our work aimed to explore and summarize the crosstalk between the liver and different endocrine organs, their hormones, and dysfunctions. For instance, our results show that hyperprolactinemia, hypercortisolemia, and polycystic ovary syndrome seem to worsen NAFLD's pathway. Hypothyroidism and low growth hormone levels also may contribute to NAFLD's progression, and a bidirectional association between hypercortisolism and hypogonadism and the NAFLD pathway looks likely, given the current evidence. Therefore, we concluded that it appears likely that there is a link between several endocrine disorders and NAFLD other than the typically known type 2 diabetes mellitus and metabolic syndrome (MS). Nevertheless, there is controversial and insufficient evidence in this area of knowledge.

Risk Factors for Nonalcoholic Fatty Liver Disease in Postmenopausal Women with Type 2 Diabetes Mellitus and the Correlation with Bone Mineral Density at Different Locations

OBJECTIVE

To explore the risk factors for nonalcoholic fatty liver disease (NAFLD) in postmenopausal women with type 2 diabetes mellitus (T2DM) and the correlation with bone mineral density (BMD) in different areas of the body.

METHODS

A total of 434 postmenopausal women with T2DM were enrolled and categorized as 198 patients in the NAFLD group and 236 patients in the non-NAFLD group based on color Doppler ultrasound of the liver. The BMD of the lumbar spine, femoral neck, and total hip were measured by dual-energy X-ray absorptiometry.

RESULTS

In postmenopausal women with T2DM, the prevalence of NAFLD was 45.6%. The body mass index (BMI), systolic blood pressure (SBP), glycosylated hemoglobin (HbA1c), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), triacylglycerol (TG), uric acid (UA), and homeostatic model assessment for insulin resistance (HOMA-IR) C-peptide (CP) were significantly higher in the NAFLD group than in the non-NFALD group, and the duration of diabetes, and high-density lipoprotein cholesterol (HDL-C) were lower than in the non-NAFLD group (P < 0.05). Logistic regression analysis revealed that BMI (odds ratio [OR] = 1.303, 95% confidence interval [CI]: 1.152-1.346), HbA1c (OR = 1.263, 95% CI: 1.095-1.392), TG (OR = 1.263, 95% CI: 1.031-1.601), and SUA (OR = 1.005, 95% CI: 1.001-1.007) were correlated with NAFLD (P < 0.05). The BMD of the total hip and femoral neck in the NAFLD group was higher than in the non-NAFLD group (P < 0.05).

CONCLUSION

Complicated NAFLD in postmenopausal women with T2DM is associated with weight gain, poor blood glucose control, abnormal lipid metabolism, and elevated UA levels. In addition, the NAFLD group had higher femoral neck and total hip BMD than the non-NAFLD group, suggesting NAFLD in postmenopausal women with T2DM may reduce the risk of osteoporosis.

Non-alcoholic fatty liver disease (NAFLD) is associated with an increased incidence of osteoporosis and bone fractures

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and osteoporosis are common diseases with a rising incidence worldwide. Both diseases occur in similar patient populations, however, data on their mutual influence are conflicting. Here, we aimed to evaluate the impact of NAFLD on the incidence of osteoporosis and fractures by using the Disease Analyzer database featuring data on diagnoses, prescriptions, and demographic aspects of 7.49 million cases followed in general practices in Germany.

METHODS

A total of 50,689 patients with NAFLD diagnosed between 2000 and 2015 were matched by age, sex, index year, and 3 comorbidities (obesity, diabetes mellitus, and vitamin D/calcium deficiency) to a cohort of equal size without NAFLD. Incidence of osteoporosis and bone fractures were compared between both groups within 10 years from the index date.

RESULTS

Within the observation period, the incidence of osteoporosis was significantly higher in the NAFLD group (6.4%) compared to patients without NAFLD (5.1%; log-rank, p < 0.001). Similar results were observed for bone fractures (12.6 vs. 10.3 %; log-rank p < 0.001). The difference was more pronounced in women compared to men and observed in all age groups >50 years of age.

CONCLUSION

Our data show that NAFLD is significantly associated with osteoporosis as well as bone fractures in a large cohort of patients followed in German general practices. This finding suggests that NAFLD patients might benefit from improved monitoring for the occurrence of bone demineralization and osteoporosis, which in turn could trigger preventive therapeutic measures.

Hepatic fibrosis is associated with an increased rate of decline in bone mineral density in men with nonalcoholic fatty liver disease

BACKGROUND

There is still controversy about the association between nonalcoholic fatty liver disease (NAFLD) and bone mineral density (BMD). The aim of this study was to clarify the association between NAFLD and the decline in BMD in healthcare examinees.

METHODS

Participants who underwent regular health check-ups with BMD and hepatic ultrasonography from 2006 to 2015 with more than one follow-up until 2020 were included. Propensity score matching was performed between the NAFLD group and the control group, and mixed linear regression models were used for the longitudinal analysis.

RESULTS

Of 2623 eligible participants (mean age 58.7 ± 7.3 years; males 31.3%), 888 (33.9%) had NAFLD. At baseline, the NAFLD group had a higher total hip BMD than the non-NAFLD group in men (0.988 vs. 1.015 g/cm², p = 0.007); however, there was no difference in baseline BMD in women (p = 0.253). In longitudinal analysis during a follow-up period of 7.1 years, there was no significant difference in the BMD decline rate between the two groups in the PS-matched cohort (p = 0.816 in men and p = 0.827 in women). However, among men with NAFLD, those with a high and intermediate probability of advanced fibrosis by the FIB-4 showed a significantly increased rate of decline in total hip BMD compared to those with low scores (0.01 vs. - 0.19% change/year, p = 0.011).

CONCLUSIONS

NAFLD was not associated with the total hip BMD decline rate. However, hepatic fibrosis was significantly associated with an increased rate of decline in total hip BMD in men with NAFLD.

CLINICAL TRIAL REGISTRATION

This study is a retrospective observational study and is not a drug trial. There was no need for clinical trial registration.

Decreased Sclerostin Secretion in Humans and Mice With Nonalcoholic Fatty Liver Disease

Objectives

Growing evidence argues for a relationship between liver and bone metabolisms. Sclerostin is a secreted glycoprotein and could antagonize osteoblast-mediated bone formation. Previous studies indicated that circulating sclerostin levels may be associated with metabolic parameters with inconsistent results. This study was designed to evaluate serum sclerostin in patients with or without nonalcoholic fatty liver disease (NAFLD) and to analyze its relationship with metabolic parameters in different populations.

Methods

A cross-sectional study was designed and 168 NAFLD subjects and 85 control subjects were included in this study. Serum sclerostin and metabolic parameters were measured. Mouse models of NAFLD were also induced by high-fat diet. Bone structural parameters were determined using microCT and mRNA expression levels of sclerostin in bone and liver tissues were measured.

Results

Our study suggested that circulating sclerostin levels were significantly lower in NAFLD subjects compared with normal controls. In NAFLD subjects, sclerostin was negatively correlated with multiple metabolic parameters, including waist circumference, urea, hepatic enzyme, gamma-glutamyl transpeptidase, and triglyceride, while such correlation was not significant in control subjects. Circulating sclerostin was also negatively correlated with fatty liver index in NAFLD subjects but not in control subjects. Mice fed on a high-fat diet had reduced bone mass and lower sclerostin expression levels in both the bone and liver tissues.

Conclusions

Our study suggested that the liver-lipid-bone interactions may play a key role in the abnormal bone metabolism in NAFLD, and circulating sclerostin may be a surrogate marker to reflect bone metabolism status in NAFLD subjects.

Association Between Liver Fat and Bone Density is Confounded by General and Visceral Adiposity in a Community-Based Cohort

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) is associated with low bone mineral density (BMD); however, it is not known whether early-stage NAFLD may be associated with BMD after accounting for BMI or visceral adipose tissue (VAT).

METHODS

This was a cross-sectional study of 3,462 Framingham Heart Study participants who underwent computed tomographic measurement of liver fat, VAT volume, volumetric spine BMD, vertebral cross-sectional area (CSA), and vertebral compressive strength. This study excluded heavy alcohol consumers. Multivariable linear regression models were used to assess the association between NAFLD and volumetric BMD, CSA, and vertebral compressive strength after accounting for covariates, including BMI or VAT.

RESULTS

A total of 2,253 participants (mean age, 51.2  [SD 10.7] years; 51.1% women) were included. In multivariable-adjusted models, positive associations between NAFLD and integral BMD, trabecular BMD, and vertebral compressive strength were observed. However, results were attenuated and no longer significant after additionally adjusting for BMI or VAT. NAFLD was observed to be weakly associated with a lower vertebral CSA in adjusted models.

CONCLUSIONS

In a community-based cohort, the associations between NAFLD and BMD and vertebral strength were confounded by BMI and VAT. However, NAFLD was associated with a reduced vertebral CSA in adjusted models.

Study of Cellular Senescence and Vitamin D Deficiency in Nonalcoholic Fatty Liver Disease and The Potential Protective Effect of Vitamin D Supplementation

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a pathological process characterized by excessive hepatic fatty deposition with possible involvement of vitamin D deficiency and cellular senescence. The aim of this study is to investigate the pathophysiologic role of vitamin D deficiency and cellular senescence in NAFLD development. Moreover, it aims to investigate the potential protective role of vitamin D supplementation.

METHODS

This is an experimental Case/Control study. Forty-five male albino rats were enrolled in this study. Animals were divided into four groups: negative and positive control groups (10 for each group), a model of NAFLD (11) and vitamin D-treated NAFLD groups (14). At the end of the experiment, all rats were subjected to the following investigation; biochemical estimation of serum 25 hydroxycholecalciferol, senescence marker protein-30 (SMP-30), lipid profile and calculation of homeostatic model of insulin resistance (HOMA-IR).

RESULTS

NAFLD group shows a significant increase in glucose, insulin levels, and HOMA- IR compared with both normal controls. This finding indicates the intimate association between insulin resistance and NAFLD pathogenesis. Moreover, it was found that NAFLD group shows a significant decrease in SMP-30 level compared with normal controls. While vitamin D-treated NAFLD group shows significant increased SMP-30 and decrease in HOMA-IR in comparison with nontreated NAFLD group.

CONCLUSION

Vitamin D deficiency and increased cellular senescence are key features of NAFLD. Vitamin D supplementation could play a protective role, which needs further investigation including clinical human study.

Pathophysiology of NASH in endocrine diseases

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in the industrialized world. NAFLD encompasses a whole spectrum ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. The latter can lead to hepatocellular carcinoma. Furthermore, NASH is the most rapidly increasing indication for liver transplantation in western countries and therefore represents a global health issue. The pathophysiology of NASH is complex and includes multiple parallel hits. NASH is notably characterized by steatosis as well as evidence of hepatocyte injury and inflammation, with or without fibrosis. NASH is frequently associated with type 2 diabetes and conditions associated with insulin resistance. Moreover, NASH may also be found in many other endocrine diseases such as polycystic ovary syndrome, hypothyroidism, male hypogonadism, growth hormone deficiency or glucocorticoid excess, for example. In this review, we will discuss the pathophysiology of NASH associated with different endocrinopathies.

Association Between 10-Year Fracture Probability and Nonalcoholic Fatty Liver Disease With or Without Sarcopenia in Korean Men: A Nationwide Population-Based Cross-Sectional Study

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD) and sarcopenia, which are common in elderly men, are known as risk factors of fracture. However, few studies have examined the association with fracture in these patients. Therefore, we aimed to investigate the association between NAFLD with or without sarcopenia and 10-year fracture probability in Korean men aged ≥50 years.

MATERIALS AND METHODS

Data of 2,525 individuals from the 2010-2011 Korea National Health and Nutrition Examination Survey were analyzed. NAFLD was defined using the fatty liver index (FLI) and comprehensive NAFLD score (CNS), and liver fibrosis using the fibrosis 4 calculator. Sarcopenia was defined as the lowest quintile for sex-specific sarcopenia index cutoff; values. The Fracture Risk Assessment (FRAX) tool was used to predict the 10-year probability of major osteoporotic and hip fractures.

RESULTS

Compared to the no NAFLD group, the 10-year major osteoporotic fracture probability was significantly associated with the FLI-defined (β = 0.16, P = 0.002) and CNS-defined (β = 0.20, P < 0.001) NAFLD groups with liver fibrosis. Similarly, the 10-year hip fracture probability was significantly associated with the FLI- and CNS-defined NAFLD with liver fibrosis groups compared to the group without NAFLD (FLI-defined group, β = 0.04, P = 0.046; CNS-defined group, β = 0.05, P = 0.048). Furthermore, in the group with sarcopenia, the 10-year major osteoporotic fracture probability was significantly associated with the FLI- and CNS-defined NAFLD with liver fibrosis groups compared to the group without NAFLD (FLI-defined group, β = 0.29, P = 0.003; CNS-defined group, β = 0.38, P < 0.001).

CONCLUSIONS

NAFLD with liver fibrosis is significantly associated with a higher 10-year major osteoporotic and hip fracture probability in Korean men aged ≥50 years, and this positive association was more profound in patients with sarcopenia. Therefore, screening middle-aged to elderly men who have NAFLD combined with liver fibrosis and sarcopenia may help prevent fractures.

Prevalence and Trends in Low Bone Density, Osteopenia and Osteoporosis in U.S. Adults With Non-Alcoholic Fatty Liver Disease, 2005-2014

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) is suggested to be associated with bone mineral density (BMD) alterations; however, this has not been ascertained. The current study aimed to investigate the changes in BMD and the prevalence of osteopenia/osteoporosis in US adults with or without NAFLD and to evaluate their association.

METHODS

The study was conducted based on data collected from the U.S. National Health and Nutrition Examination Survey (NHANES) during the period 2005-2014. A total of 13 837 and 6 177 participants aged > 20 years were eligible for conducting the Hepatic Steatosis Index (HSI) and the US Fatty Liver Index (USFLI) analysis, respectively.

RESULTS

From 2005-2014, a downward trend in femoral neck BMD was observed in subjects with NAFLD aged ≥ 40. After adjustment for potential confounders, an upward shift occurred in the prevalence of osteopenia/osteoporosis at the femoral neck in adults aged ≥ 40, particularly in women ≥ 60 years old and men below the age of 60. Moreover, a negative association was found between BMD and NAFLD markers (USFLI, HSI), whereas NAFLD with advanced fibrosis was positively associated with the prevalence of spine fractures.

CONCLUSIONS

There was a trend toward lower BMD and higher prevalence of osteopenia/osteoporosis at the femoral neck in US adults with NAFLD aged ≥ 40 years during the period of 2005-2014. NAFLD with advanced fibrosis was positively associated with a higher risk of spine fracture. More research is required to fully investigate the mechanism and consequence of poor bone health in NAFLD patients and consider optimum management of osteopenia/osteoporosis for this population.

Relationship Between Non-alcoholic Fatty Liver Disease and Decreased Bone Mineral Density: A Retrospective Cohort Study in Korea

Objectives

The aim of this retrospective cohort study was to investigate whether non-alcoholic fatty liver disease (NAFLD) was associated with incident bone mineral density (BMD) decrease.

Methods

This study included 4536 subjects with normal BMD at baseline. NAFLD was defined as the presence of fatty liver on abdominal ultrasonography without significant alcohol consumption or other causes. Decreased BMD was defined as a diagnosis of osteopenia, osteoporosis, or BMD below the expected range for the patient’s age based on dual-energy X-ray absorptiometry. Cox proportional hazards models were used to estimate the hazard ratio of incident BMD decrease in subjects with or without NAFLD. Subgroup analyses were conducted according to the relevant factors.

Results

Across 13 354 person-years of total follow-up, decreased BMD was observed in 606 subjects, corresponding to an incidence of 45.4 cases per 1000 person-years (median follow-up duration, 2.1 years). In the model adjusted for age and sex, the hazard ratio was 0.65 (95% confidence interval, 0.51 to 0.82), and statistical significance disappeared after adjustment for body mass index (BMI) and cardiometabolic factors. In the subgroup analyses, NAFLD was associated with a lower risk of incident BMD decrease in females even after adjustment for confounders. The direction of the effect of NAFLD on the risk of BMD decrease changed depending on BMI category and body fat percentage, although the impact was statistically insignificant.

Conclusions

NAFLD had a significant protective effect on BMD in females. However, the effects may vary depending on BMI category or body fat percentage.

Association between non-alcoholic fatty liver disease-associated hepatic fibrosis and bone mineral density in postmenopausal women with type 2 diabetes or impaired glucose regulation

INTRODUCTION

To evaluate the association of non-alcoholic fatty liver disease (NAFLD)-associated hepatic fibrosis with bone mineral density (BMD) in postmenopausal women with type 2 diabetes mellitus (T2DM) or impaired glucose regulation (IGR).

RESEARCH DESIGN AND METHODS

Two cohorts including 46 subjects with biopsy-proven NAFLD and 445 subjects with proton magnetic resonance spectrum-proven NAFLD were enrolled in this study. All subjects were postmenopausal women with T2DM or IGR. BMD at the lumbar spine L1-L4 and hip was measured using dual-energy X-ray absorptiometry. NAFLD fibrosis stage and NAFLD fibrosis score were used to evaluate the severity of liver fibrosis.

RESULTS

In subjects with liver biopsy-proven NAFLD, BMD (T-score, Z-score and BMD value) in the advanced fibrosis group were significantly lower than that in the non-advanced fibrosis group (p<0.05). Fibrosis stage was negatively associated with T-score, Z-score and BMD value after adjusting for age, body mass index (BMI) and fasting plasma glucose (FPG). Additionally, fibrosis stage was independently associated with T-score, Z-score and BMD value after adjusting for age, BMI and FPG. These results were validated in a large cohort of 445 subjects. Additionally, bone metabolism-associated factors, including calcium and phosphate, were associated with liver fibrosis, indicating that bone metabolism may play a critical role in the association between liver fibrosis and BMD. Mechanically, parathyroid hormone and biomarkers of bone formation (osteocalcin and procollagen type 1 N-terminal propeptide) and bone resorption (procollagen type I carboxy terminal peptide β special sequence) were increased in subjects with advanced liver fibrosis than in subjects without advanced liver fibrosis, indicating that liver fibrosis decreased BMD probably via increasing bone turnover.

CONCLUSIONS

NAFLD-associated hepatic fibrosis was negatively associated with decreased BMD in postmenopausal women with T2DM or IGR. Liver fibrosis decreased BMD probably via increasing bone turnover. Severe liver fibrosis may represent high risk for osteoporosis in postmenopausal women with T2DM or IGR.

Extra-hepatic manifestations and complications of nonalcoholic fatty liver disease

This review article aims to synthesize the evidence regarding nonalcoholic fatty liver disease (NAFLD) as a systemic disorder. We critically discuss the metabolic syndrome and its components; the cardiovascular and the endocrine system; chronic respiratory disorders; the musculoskeletal system; the skin; and extra-hepatic tumors. We conclude that, while some of these extra-hepatic conditions clearly predispose to the development of secondary forms of NAFLD (typically hypothyroidism-induced NAFLD), others result from pre-existent NAFLD (e.g., certain extra-hepatic tumors) and others (such as Type 2 Diabetes) have, with NAFLD, mutual and bidirectional associations. Analyzed data imply that NAFLD is not merely a hepatic disease. It is also and possibly more importantly, a systemic disorder requiring a special awareness, a multidisciplinary approach and a multidimensional vision.

Association between serum levels of bone turnover markers and bone mineral density in men and women with type 2 diabetes mellitus

Background

In patients with type 2 diabetes mellitus (T2DM), higher risks of impaired bone metabolism are widely reported. To evaluate bone metabolism, bone mineral density (BMD) and bone turnover levels should be included. In this article, we analyzed the relationship between them in T2DM.

Methods

We conducted a hospital‐based cross‐sectional study enrolling 1499 patients hospitalized for T2DM between October 2009 and January 2013. Multivariate linear regression models were used to identify the relationship between bone turnover markers (BTMs) and BMD levels. A two‐sided P‐value < .05 was considered statistically significant.

Results

After adjusting for confounding factors, osteocalcin (OC) showed a negative relationship with total lumbar, femur neck, and total hip BMD in men and women. N‐terminal propeptides of type I collagen (P1NP) and alkaline phosphatase (ALP) showed a negative association with BMD at three sites in men and total lumbar BMD in women, whereas in the femur neck and total hip in women, the relationship was only found for P1NP with total hip. For β‐C‐terminal telopeptides of type I collagen (β‐CTX), a negative relationship was also found in all three sites for BMD in men and total lumbar BMD in women, whereas β‐CTX was not associated in the femoral neck and total hip in women.

Conclusion

In patients with T2DM, serum levels of OC, P1NP, β‐CTX, and ALP were negatively correlated with BMD levels in men in three sites and with total lumbar BMD in women. The relationship varied in femur neck and total hip BMD in women.

Rheumatologic manifestations of hepatic diseases

The course of hepatic diseases may be complicated by a multitude of rheumatologic manifestations, which can complicate the diagnostic approach and alter the natural history of primary liver disease, sometimes worsening prognosis due to associated multiple organ dysfunction. These manifestations can occur in association with a multitude of liver diseases, including viral hepatitis, autoimmune hepatitis, alcoholic liver disease, nonalcoholic fatty liver disease, hemochromatosis, or Wilson’s disease. It is necessary not only for rheumatologists, but also for other clinicians, to be aware that these atypical manifestations may reflect an undiagnosed hepatic disease. On the other hand, it is crucial that, in a patient with known hepatic disease presenting with rheumatologic symptoms, an accurate distinction be made between the rheumatologic manifestations of hepatic disease and primary rheumatologic disease, since the treatment is often different. This review aims to summarize the current evidence regarding rheumatologic manifestations of hepatic diseases, how to distinguish them from primary rheumatologic disorders, and how to provide adequate management.

Systematic review with meta-analysis: non-alcoholic fatty liver disease is associated with a history of osteoporotic fractures but not with low bone mineral density

BACKGROUND

Several studies have explored the effect of non-alcoholic fatty liver disease (NAFLD) on bone mineral density (BMD) and risk of osteoporotic fractures in adults. However, the extent to which NAFLD adversely affects bone health remains uncertain.

AIM

To provide a quantitative estimation of the magnitude of the association of NAFLD with BMD or history of osteoporotic fractures in adults.

METHODS

We searched PubMed, Web of Science, and Scopus using predefined keywords to identify all observational studies, published up to 31 August 2018, in which NAFLD was diagnosed by imaging or histology; BMD was measured by dual energy X-ray absorptiometry; and a self-reported history of osteoporotic fractures was collected with interviewer-assisted questionnaires. Data from selected studies were extracted, and meta-analysis was performed using random-effects modelling.

RESULTS

Twelve cross-sectional or case-control studies with aggregate data on 30 041 adults of predominantly Asian ethnicity (30% with NAFLD) were included in the final analysis. No significant differences in BMD at different skeletal sites (whole body, lumbar spine, or femur) were observed between individuals with and without NAFLD. Conversely, NAFLD was associated with increased odds of osteoporotic fractures, especially in older Chinese men (n = 2 studies; random-effects odds ratio 2.10, 95% CI 1.36-3.25; I²  = 0%). Sensitivity analyses did not alter these findings. The funnel plot and Egger test did not reveal significant publication bias.

CONCLUSIONS

This meta-analysis suggests that imaging-defined or biopsy-proven NAFLD is associated with a self-reported history of osteoporotic fractures (principally in Chinese men), but not with low BMD, in middle-aged and elderly individuals.

Novel insights into the relationship between nonalcoholic fatty liver disease and osteoporosis

Excess fat deposition and insulin resistance are considered the main risk factors for nonalcoholic fatty liver disease (NAFLD), and therefore, not surprisingly, the global prevalence of NAFLD increases in parallel with both obesity and type 2 diabetes. Although deterioration of bone homeostasis in patients with NAFLD is commonly observed, its etiology has not been fully elucidated yet. It was shown in several studies that bone tissue seems to be independently associated with NAFLD. A mechanistic perspective puts the liver at the center of mutual interdependencies obviously involving adipose tissue and muscles and also the bone matrix and bone cells, which are relatively novel. In this review, various pathophysiological mechanisms and possible mediating molecules that may interplay between NAFLD and bone tissue are described. Chronic inflammation, vitamin D3, growth hormone, insulin-like growth factor 1, osteopontin, fetuin-A, irisin, osteocalcin, and osteoprotegerin from osteoblasts have been proposed as mediators of mutual interactions among the skeleton, fatty tissue, and liver. Although to date there are still many issues that have not been elucidated, growing evidence suggests that screening and surveillance of bone mineral density in patients with NAFLD should be considered in future strategies and guidelines for NAFLD management.

Increased risk of osteoporosis in patients with nonalcoholic fatty liver disease: A population-based retrospective cohort study

The study aims to investigate the association between nonalcoholic fatty liver disease (NAFLD) and osteoporosis.We employed a retrospective cohort study design using the National Health Insurance Research Database in Taiwan. Our study included 2 cohorts: 4318 patients with NAFLD and 17,272 patients without NAFLD for comparison. They were matched by sex and age on the date of enrollment between January 1, 2000 and December 31, 2003. The study population in both groups was observed from the enrollment date until December 31, 2013. The incidence and the risk ratios of subsequent osteoporosis were calculated separately in both cohorts. A Cox proportional hazards model was used to assess the potential confounding variables of NAFLD on the pathogenesis of osteoporosis.The eligible study participants comprised 4318 patients in the NAFLD and 17,272 in control cohorts. The median follow-up duration was 10.7 and 10.83 years in the NAFLD and control groups, respectively. The risk of new-onset osteoporosis was higher in patients with NAFLD than in the comparison cohort. In addition, the difference of the incidence of new-onset osteoporosis remained significant among the 2 cohorts in the follow-up durations of within 1 year and more than 10 years. Patients with NAFLD were 1.35 times more likely to develop subsequent osteoporosis compared with those without NAFLD (95% confidence interval = 1.20-1.53).Our finding indicates that NAFLD might increase the risk of developing new-onset osteoporosis. For earlier detection and intervention, screening for osteoporosis in patients with the NAFLD, especially those with lower income and co-morbid with diabetes mellitus and chronic obstructive pulmonary disease, may be recommended.

The Combined Effect of Nonalcoholic Fatty Liver Disease and Metabolic Syndrome on Osteoporosis in Postmenopausal Females in Eastern China

The present study evaluated the potential combined effects of NAFLD and MetS on the development of osteoporosis. The relationship between NAFLD and MetS and osteoporosis was assessed in 938 postmenopausal female participants. Moderate and severe NAFLDs were combined as significant NAFLD (SNAFLD). All the subjects were divided into 4 subgroups based on the status of SNAFLD and MetS. Relative excess risk of interaction (RERI), attributable proportion (AP) of interaction, and synergy index (SI) were used to investigate the additive interaction of those two factors. NAFLD, SNAFLD, and MetS were independent factors for osteoporosis with the adjustment of age and other confounders. The incidence of osteoporosis in MetS (+) SNAFLD (+) group was significantly higher than that in other three groups. RERI was 2.556 (95% CI = 0.475-4.636), AP was 0.454 (95% CI = 0.201-0.706), and SI was 2.231 (95% CI = 1.124 to 4.428), indicating the significant combined interaction of SNAFLD and MetS on the development of osteoporosis. SNAFLD and MetS are independent risk factors for osteoporosis in postmenopausal females, respectively. Moreover, SNAFLD and MetS have an additive effect on the development of osteoporosis.

Nonalcoholic fatty liver disease with elevated alanine aminotransferase levels is negatively associated with bone mineral density: Cross-sectional study in U.S. adults

Background

Nonalcoholic fatty liver disease (NAFLD) has been reported to have a negative effect on bone mineral density (BMD) in Asian populations. Whether such an association exists in Western populations is less clear.

Methods

This cross-sectional analysis of data from NHANES III, a United States national health survey conducted from 1988 to 1994, included 6089 participants aged 40–75 years, selected after excluding people with hepatitis virus serology, elevated alcohol consumption, decreased renal function, or steroid use, and pregnant females. The main outcome, BMD at the femoral neck, was measured using dual-energy X-ray absorptiometry. The primary exposure, NAFLD, was defined as moderate or severe hepatic steatosis diagnosed using abdominal ultrasonography.

Result

After controlling for gender and menopausal status, race/ethnicity, age and body mass index, NAFLD was not significantly associated with BMD (beta coefficient: −0.006, 95%CI: −0.016, 0.003). A secondary analysis categorized participants with NAFLD according to their serum alanine aminotransferase (ALT) levels into high and normal ALT NAFLD groups, and compared these with the non-NAFLD group. NAFLD with higher levels of ALT was associated with lower levels of BMD (beta coefficient: −0.023, 95% CI: −0.044, −0.002).

Conclusion

This study showed a relationship between NAFLD with high ALT and lower BMD in the general U.S. population.

Bone Turnover Markers in Patients With Nonalcoholic Fatty Liver Disease and/or Type 2 Diabetes During Oral Glucose and Isoglycemic Intravenous Glucose

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is associated with type 2 diabetes (T2D) and vice versa, and both conditions are associated with an increased risk of fractures and altered bone turnover. Although patients with NAFLD typically suffer from decreased bone mineral density (BMD), T2D is associated with normal to high BMD. The pathophysiology is uncertain but may involve the gut-bone axis.

OBJECTIVE

We investigated the influence of the gut on glucose-induced changes in plasma bone turnover markers in healthy controls and patients with T2D and/or biopsy-verified NAFLD.

DESIGN

Cross-sectional cohort study.

PATIENTS

Patients with NAFLD with normal glucose tolerance, patients with NAFLD and T2D, patients with T2D without liver disease, and healthy controls.

INTERVENTIONS

Four-hour 50-g oral glucose tolerance test (OGTT) and an isoglycemic intravenous glucose infusion (IIGI).

MAIN OUTCOME MEASURES

Collagen type 1 C-telopeptide (CTX), osteocalcin, procollagen type 1 N-terminal propeptide (P1NP), and parathyroid hormone.

RESULTS

Plasma glucose levels achieved during OGTTs were successfully matched on corresponding IIGI days. Patients with NAFLD and T2D exhibited similar CTX suppression during the two glucose challenges (P = 0.46) and pronounced suppression of P1NP during IIGI compared with OGTT. Conversely, remaining groups showed greater (P < 0.05) CTX suppression during OGTT and similar suppression of bone formation markers during IIGI and OGTT.

CONCLUSIONS

OGTT-induced CTX suppression seems to be impaired in patients with NAFLD and T2D, but preserved in patients with either NAFLD or T2D, suggesting that coexistence of T2D and NAFLD may affect gut-bone axis.

NAFLD/NASH in patients with type 2 diabetes and related treatment options

Type 2 diabetes may reduce life expectancy and patients' quality of life due to its micro- and macro-vascular complications and to the higher risk of several types of cancer. An emerging important factor is represented by the hepatic involvement; it is recognized that excessive hepatic fat accumulation represents a typical feature of diabetic patients and that it also plays an important pathogenic role. It is now evident that non-alcoholic fatty liver disease (NAFLD), generally perceived as a benign condition, may have on the contrary an important deleterious impact for diabetic patients increasing the risk to develop cardiovascular complications but also serious hepatic diseases, in particular non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Lifestyle intervention, bariatric surgery and several drug therapies have now accumulated evidence of efficacy in treating NASH. On the other hand, their durability and safety in the long-term is yet to be proven and their use may be sometimes associated with side effects or higher risk of adverse events limiting the regular administration or contraindicating it. Professional health care providers, building awareness about the importance of these hepatic complications, should put more efforts in primary prevention using a behavioral therapy needing a multidisciplinary approach, in secondary prevention applying on a regular basis in the clinical setting available predictive algorithms to identify the patients at higher cardiovascular and hepatologic risk, and in tertiary prevention treating, when not contraindicated, the diabetic patients preferentially with drugs with proven benefit on NAFLD/NASH.

The relationship between fatty liver index and bone mineral density in Koreans: KNHANES 2010-2011

Analyses using a nationally representative cohort have revealed that high fatty liver index (FLI) is associated with low bone mineral density (BMD) regardless of insulin resistance in men, thereby supporting the deteriorated bone metabolism in nonalcoholic fatty liver disease (NAFLD).

INTRODUCTION

NAFLD is linked to deteriorated bone health. We investigated the association of FLI, a scoring model for NAFLD, with BMD.

METHODS

This was a population-based, cross-sectional study from the Korea National Health and Nutrition Examination Surveys including 4264 Koreans (1908 men and 2356 women). FLI was calculated using body mass index, waist circumference, serum triglyceride, and gamma-glutamyltranspeptidase level. Insulin resistance was evaluated using the homeostasis model assessment-estimated insulin resistance (HOMA-IR) index. BMD was measured using dual-energy X-ray absorptiometry at the lumbar spine, total hip, femoral neck, and whole body.

RESULTS

Men had a higher FLI than women, while the HOMA-IR index was similar between men and women. The significant association between FLI and BMD was observed only in men, but not in women. FLI was negatively correlated with total hip, femoral neck, and whole body BMD in men after adjusting for all potential confounders, including HOMA-IR (P < 0.001 to 0.010). Lumbar spine, total hip, femoral neck, and whole body BMD in men showed a decreasing trend as the FLI tertile increased after adjusting for all potential confounders, including HOMA-IR (P for trends < 0.001 to 0.034). In men aged 50 years or older, odds ratios for combined osteopenia and osteoporosis increased across increasing FLI tertiles after adjusting for confounders (P for trends < 0.011 to 0.029).

CONCLUSION

NAFLD is associated with low bone density regardless of insulin resistance in men. These findings suggest an undiscovered direct link between liver and bone that increases the risk of osteoporosis in men with NAFLD.

Non-alcoholic fatty liver disease and its relationship with cardiovascular disease and other extrahepatic diseases

Key physiological functions of the liver, including glucose and lipid metabolism, become disturbed in the setting of non-alcoholic fatty liver disease (NAFLD) and may be associated with a systemic inflammatory 'milieu' initiated in part by liver-secreted cytokines and molecules. Consequently, the pathophysiological effects of NAFLD extend beyond the liver with a large body of clinical evidence demonstrating NAFLD to be independently associated with both prevalent and incident cardiovascular disease (CVD), chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). The magnitude of risk of developing these extrahepatic diseases parallels the underlying severity of NAFLD, such that patients with non-alcoholic steatohepatitis (NASH) appear to be at greater risk of incident CVD, CKD and T2DM than those with simple steatosis. Other modifiers of risk may include genetic variants (eg, patatin-like phospholipase domain-containing 3 and trans-membrane 6 superfamily member 2 polymorphisms), visceral adipose tissue accumulation, dietary intake and the gut microbiome. Emerging data also suggest that NAFLD may be a risk factor for colonic neoplasia and reduced bone mineral density, especially among men. Importantly, improvement/resolution of NAFLD is associated with a reduced incidence of T2DM and improved kidney function, adding weight to causality and suggesting liver focused treatments may reduce risk of extrahepatic complications. Awareness of these associations is important for the clinicians such that CVD risk factor management, screening for T2DM and CKD are part of the routine management of patients with NAFLD.