Management of osteoporosis in liver disease

Workup and management of liver transplantation in alcohol-related liver disease

Alcohol-related liver disease (ALD) represents the most common indication for liver transplantation (LT) worldwide. Outcomes of LT for ALD are comparable with those of LT for other etiologies; however, ALD is still considered a controversial indication for LT, mainly because it is considered a self-inflicted disease with a high risk of return to alcohol use after LT. Pre-LT evaluation criteria have changed over time, with a progressive re-evaluation of the required pre-transplant duration of abstinence. Despite the fact that some transplant programs still require 6 months of abstinence in order to consider a patient suitable for LT, there is increasing evidence that a pre-transplant abstinence period of <6 months can be considered for well-selected patients. Early LT for severe alcohol-related hepatitis that has not responded to medical therapy has been shown to be an effective therapeutic option with high survival benefit when performed within strict and well-recognized criteria. However, high variability in LT access exists for these patients due to the presence of social and medical stigma. A psycho-social assessment, together with an evaluation by an addiction specialist, should be mandatory in patients with ALD who are potential candidates for LT in order to assess the risk of post-transplant return to alcohol use and to ensure good long-term outcomes. Finally, before LT, attention should be paid to the presence of other potential comorbidities (i.e., cardiovascular and neurological diseases), which could represent a potential contraindication to LT. Similarly, after LT, patients should be adequately monitored for the development of cardiovascular events and screened for "de novo" tumors, although standardized protocols for this monitoring do not exist at this time.

Assessment of mandibular cortical index in patients with hepatic cirrhosis: A case-control study

AIMS

To assess the presence of alterations suggestive of reduced bone mineral density (BMD) by using mandibular cortical index (MCI) in panoramic radiographs of cirrhotic individuals and to evaluate their relationship with other characteristics of hepatic cirrhosis (HC).

METHODS AND RESULTS

This is an observational case-control study assessing the medical records of 165 cirrhotic patients matched by sex and age with healthy individuals. MELD (model of end stage liver disease) score, etiology, complications, comorbidities, and serum levels of vitamin D were collected. MCI was used to obtain BMD. Binary logistic regression was used to test associations and the risk estimates were expressed in odds ratio. Most of the sample consisted of men (73.93%) with median age of 56 years old. In the study group, the mean value of MELD was 16.5 and hepatitis C was the main etiology of HC (33.9%). Cirrhotic individuals are 3.99 times more likely to present alterations suggestive of reduced BMD (p < .01). There was no statistical significance in the association of MCI with levels of vitamin D, comorbidities, etiology or cirrhosis complications.

CONCLUSIONS

MCI suggestive of reduced BMD is more likely to be identified in panoramic radiographs of cirrhotic individuals than of healthy ones.

RISK FACTORS ASSOCIATED WITH FRACTURE OF THE LUMBOSACRAL SPINE AND ITS COMPROMISE IN THE QUALITY OF LIFE OF CIRRHOTICS

ABSTRACT Background Chronic hepatic disease is associated with osteoporosis, osteopenia or osteomalacia. Osteoporosis and fractures due to bone fragility present high prevalences and are more frequent in patients with liver cirrhosis than in the general population. The search for a diagnosis of osteopenia and osteoporosis in this population may allow early intervention and modify unfavorable outcomes. Objective To know the prevalence of osteopenia or osteoporosis and of fracture due to bone fragility in individuals with liver cirrhosis, the associated risk factors, and its compromise in their quality of life (QoL). Methods Observational, transversal study performed with 71 liver cirrhosis patients of the Hepatology Service of the Hospital de Base do Distrito Federal, Brasília, DF, Brazil, between July 2017 and December 2018. The patients were submitted to bone densitometry (DXA) of the lumbar spine and of the femoral neck, to x-ray of the lumbosacral spine and to the Chronic Liver Disease Questionnaire (CLDQ) for the evaluation of quality of life (QoL). The Fracture Risk Assessment (FRAX) major was calculated for patients >50 years old. The analyses were performed for the evaluation of the risk factors associated with lumbosacral spine fracture. Results The majority (62%) of the 71 evaluated patients was diagnosed with osteoporosis or osteopenia on DXA. Of the 44 patients with osteopenia or osteoporosis, 52.3% were female, with a mean age of 62.6±9.51 years old, with the majority (72.7%) being Child A, cirrhotics of alcoholic etiology (36.4%), and with an intermediate QoL according to the CLDQ (3.3). Regarding the patients with lumbosacral spine fracture, the mean age was 61.6±11.1 years old, 60% were female, most of them Child A (66.7%), of alcoholic etiology (46.7%), and with an intermediary QoL according to the CLDQ (3.5). The presence of osteopenia and/or osteoporosis was associated with lumbosacral fracture (P<0.001), without correlation with the other analyzed variables: age, body mass index, gender, presence and absence of ascites, Child-Pugh classification, vitamin D, calcium, and phosphorus serum concentration, cirrhosis etiology and FRAX major. Conclusion The prevalence of hepatic osteodystrophy was high, and the occurrence of lumbosacral spine fracture was more associated with osteoporosis and/or osteopenia among the cirrhotic patients studied. The QoL was intermediate and with no differences between cirrhotics with and without fracture.

Bone Disease and Liver Transplantation: A Review

Liver transplantation is currently the most effective and almost routine treatment for chronic and acute liver diseases. The survival of transplanted patients has increased exponentially, which has led to more knowledge of the long-term complications secondary to the underlying pathology or the various treatments that must be followed. Bone metabolic disease is a chronic complication of liver transplantation that inhibits quality of life. The factors that contribute to the development of bone disease are different according to the various etiologies of liver damage. All patients should be examined for osteoporosis risk factors because the incidence of new fractures in transplant patients is higher during the first year after transplantation, reflecting the greater bone loss during this time. This article outlines a proposal for a treatment algorithm; we propose that pharmacologic therapy in patients post liver transplant should first consider the diagnosis of osteoporosis by bone mineral density, the patient's personal and family history of spine and femoral neck fractures, and the use glucocorticoids (dose and time) until a tool is available that allows the best estimation of the fracture risk in this population of patients.

Cirrhosis: An evidence-based approach

ABSTRACT

The role of nurses in managing patients with cirrhosis is increasing due to the growing prevalence of the disease. This article reviews the pathophysiology, diagnosis, complications, and management of patients with cirrhosis, with an emphasis on interdisciplinary collaboration and evidence-based practice.

The micro-structural analysis of lumbar vertebrae in alcoholic liver cirrhosis

Although vertebral fracture is more common among alcoholic liver cirrhosis patients when compared to general population, current data on three-dimensional micro-architecture are scarce. Our study showed significant trabecular deterioration in lumbar vertebrae obtained from alcoholic liver cirrhosis donors, suggesting that they should be advised to undergo early-stage screening for osteoporosis.

PURPOSE

Recent studies showed an increased incidence of vertebral fractures in alcoholic liver cirrhosis (ALC) patients, while data about vertebral micro-structure are still limited. The aim of this study was to compare trabecular and cortical micro-architecture of lumbar vertebrae between ALC patients and healthy age- and sex-matched controls.

METHODS

Our study included lumbar vertebral samples of male cadaveric donors, divided into ALC (n = 20, age: 59 ± 6 years) and control group (n = 20, age: 59 ± 8 years). Following pathohistological verification of liver cirrhosis, trabecular and cortical bone micro-architecture was analyzed by micro-computed tomography (micro-CT).

RESULTS

Micro-CT evaluation of the trabecular bone in lumbar vertebrae showed a significant decrease in bone volume fraction, trabecular thickness, trabecular number, and connectivity (p < 0.01). In contrast to trabecular deterioration, prominent alteration in cortical parameters was not observed in lumbar vertebrae of ALC patients (p > 0.05).

CONCLUSIONS

Our data indicate that susceptibility to non-traumatic fractures in ALC patients could be explained by alterations in trabecular bone micro-architecture. Thus, we genuinely recommend osteological screening of the lumbar spine for all ALC patients in order to evaluate individual fracture risk. Graphical abstract.

Chronic Liver Disease and the Risk of Osteoporotic Fractures: A Meta-Analysis

Introduction

Chronic liver disease (CLD) causes more than 1 million deaths every year and remains a pandemic in the last decade affecting more than 600,000 patients in the United States. Previous studies found patients with CLD had increased risk of osteoporosis, so fractures were inferred to be complications of this condition. The aim of this meta-analysis is to summarize the best evidence that correlates CLD patients and the risk to develop osteoporotic fractures versus control patients without CLD.

Methods

A review of the literature using MEDLINE and EMBASE database was performed during December 2017. We included cross-sectional and cohort studies that reported relative risks (RR), odds ratios (OR) and hazard ratios (HR) comparing the risk of developing osteoporotic fractures among patients with CLD versus patients without CLD. Pooled OR and 95% confidence interval (CI) were calculated using generic inverse- variance method. The Newcastle-Ottawa scale was used to determine the quality of the studies. Effect estimates from the individual study were extracted and combined using the random-effect, generic inverse variance method of DerSimonian and Laird. 

Results

After the review of the literature, seven studies fulfilled the eligibility criteria established during the analysis. Significant association was found between CLD and osteoporotic fractures with a pooled OR of 2.13 (95% CI, 1.79 - 2.52). High heterogeneity among the studies was found (I2=88.5). No publication bias was found using Egger regression test (p=0.44).

Conclusion

We found a significant association between CLD and the risk of developing osteoporotic fractures. The calculated risk was 2.13 times higher for patients with CLD when compared with controls. The results showed high heterogeneity but no publication bias. More prospective studies are needed to fully understand the mechanisms involved in loss of bone density and osteoporotic fractures in order to improve the morbidity associated with this disease. 

Cirrhosis: An evidence-based treatment approach

The NP's role in managing cirrhosis is increasing due to the growing prevalence of the disease. The purpose of this article is to review the pathophysiology, diagnosis, and management of patients with cirrhosis with an emphasis on interdisciplinary collaboration and evidence-based practice. Cirrhosis complications are also discussed.

Bone Diseases in Patients with Chronic Liver Disease

Osteoporosis is a frequently observed complication in patients with chronic liver disease, particularly liver cirrhosis and cholestatic liver diseases. In addition, osteoporosis is critical in patients receiving a liver transplant. Nevertheless, few studies have evaluated bone diseases in patients with more frequently observed chronic liver disease, such as chronic viral hepatitis, nonalcoholic fatty liver disease and alcoholic liver disease. Osteoporosis is a disease caused by an imbalance in the activities of osteoblasts and osteoclasts. Over the last few decades, many advances have improved our knowledge of the pathogenesis of osteoporosis. Importantly, activated immune cells affect the progression of osteoporosis, and chronic inflammation may exert an additional effect on the existing pathophysiology of osteoporosis. The microbiota of the intestinal tract may also affect the progression of bone loss in patients with chronic liver disease. Recently, studies regarding the effects of chronic inflammation on dysbiosis in bone diseases have been conducted. However, mechanisms underlying osteoporosis in patients with chronic liver disease are complex and precise mechanisms remain unknown. The following special considerations in patients with chronic liver disease are reviewed: bone diseases in patients who underwent a liver transplant, the association between chronic hepatitis B virus infection treatment and bone diseases, the association between sarcopenia and bone diseases in patients with chronic liver disease, and the association between chronic liver disease and avascular necrosis of the hip. Few guidelines are currently available for the management of low bone mineral density or bone diseases in patients with chronic liver disease. Due to increased life expectancy and therapeutic advances in chronic liver disease, the importance of managing osteoporosis and other bone diseases in patients with chronic liver disease is expected to increase. Consequently, specific guidelines need to be established in the near future.

Hepatic Osteodystrophy-Molecular Mechanisms Proposed to Favor Its Development

Almost all patients with chronic liver diseases (CLD) show altered bone metabolism. Depending on the etiology, this manifests in a severe osteoporosis in up to 75% of the affected patients. Due to high prevalence, the generic term hepatic osteodystrophy (HOD) evolved, describing altered bone metabolism, decreased bone mineral density, and deterioration of bone structure in patients with CLD. Once developed, HOD is difficult to treat and increases the risk of fragility fractures. Existing fractures affect the quality of life and, more importantly, long-term prognosis of these patients, which presents with increased mortality. Thus, special care is required to support the healing process. However, for early diagnosis (reduce fracture risk) and development of adequate treatment strategies (support healing of existing fractures), it is essential to understand the underlying mechanisms that link disturbed liver function with this bone phenotype. In the present review, we summarize proposed molecular mechanisms favoring the development of HOD and compromising the healing of associated fractures, including alterations in vitamin D metabolism and action, disbalances in transforming growth factor beta (TGF-β) and bone morphogenetic protein (BMP) signaling with histone deacetylases (HDACs) as secondary regulators, as well as alterations in the receptor activator of nuclear factor kappa B ligand (RANKL)–osteoprotegerin (OPG) system mediated by sclerostin. Based on these mechanisms, we give an overview on the limitations of early diagnosis of HOD with established serum markers.

Erythrocytosis and fatigue fractures associated with hepatoblastoma in a 3-year-old gelding

Hepatoblastoma was diagnosed in a 3-year-old Thoroughbred gelding presented with forelimb lameness with bilateral fatigue fractures of the proximal third metacarpal bones. An abdominal mass was detected on ultrasound examination of the abdomen. Absolute erythrocytosis was diagnosed after clinical and haematological evaluation. The fractured metacarpal bones were surgically removed but complications after surgery were fatal. The liver mass was diagnosed as a hepatoblastoma based on histology and immunochemical staining. The combination of hepatoblastoma and fatigue fractures has not been described previously in horses. A potential link between the hepatic and orthopaedic pathologies is hypothesised.

Primary sclerosing cholangitis - a comprehensive review

Primary sclerosing cholangitis (PSC) is a rare disorder characterised by multi-focal bile duct strictures and progressive liver disease. Inflammatory bowel disease is usually present and there is a high risk of cholangiocarcinoma and colorectal cancer. Most patients ultimately require liver transplantation, after which disease recurrence may occur. With limited therapeutic options and a lack of proven surveillance strategies, patients currently have significant unmet needs. In the present seminar, we provide a comprehensive review of the status of the field. We emphasise developments related to patient stratification and disease behaviour, and provide an overview of management options from a practical, patient-centered perspective. We survey advances made in the understanding of PSC pathogenesis and summarise the ongoing efforts to develop an effective therapy based on these insights.

Liver Transplantation for Alcoholic Liver Disease

Alcohol-related liver disease is the second most frequent indication for liver transplantation (LT), yet as many as 90% to 95% of patients with alcohol-related end-stage liver disease are never formally evaluated for LT. Furthermore, despite its significance as a cause of chronic liver disease and indication for LT, it has received little attention in recent years for several reasons, including the good posttransplant short-term results, and the lack of specific "drugs" used for this disease. A writing group, endorsed by the International Liver Transplant Society, was convened to write guidelines on Liver Transplantation for Alcoholic Liver Disease to summarize current knowledge and provide answers to controversial and delicate ethical as well as clinical problems. We report here a short version of the guidelines (long version available at www.ilts.org) with the final recommendations graded for level of evidence. The writing group membership is expected to remain active for 5 years, reviewing the guideline annually, and updating the online version when appropriate.

Diagnosis and Management of Cirrhosis-Related Osteoporosis

Management of cirrhosis complications has greatly improved, increasing survival and quality of life of the patients. Despite that, some of these complications are still overlooked and scarcely treated, particularly those that are not related to the liver. This is the case of osteoporosis, the only cirrhosis complication that is not solved after liver transplantation, because bone loss often increases after immunosuppressant therapy. In this review, the definitions of bone conditions in cirrhotic patients are analyzed, focusing on the more common ones and on those that have the largest impact on this population. Risk factors, physiopathology, diagnosis, screening strategies, and treatment of osteoporosis in cirrhotic patients are discussed, presenting the more striking data on this issue. Therapies used for particular conditions, such as primary biliary cirrhosis and liver transplantation, are also presented.

Bone health and vitamin D status in alcoholic liver disease

Alcohol consumption is harmful to many organs and tissues, including bones, and it leads to osteoporosis. Hepatic osteodystrophy is abnormal bone metabolism that has been defined in patients with chronic liver disease (CLD), including osteopenia, osteoporosis, and osteomalacia. Decreased bone density in patients with CLD results from decreased bone formation or increased bone resorption. The prevalence of osteopenia in alcoholic liver disease (ALD) patients is between 34 % and 48 %, and the prevalence of osteoporosis is between 11 % and 36 %. Cirrhosis is also a risk factor for osteoporosis. The liver has an important role in vitamin D metabolism. Ninety percent of patients with alcoholic liver cirrhosis have vitamin D inadequacy (<80 nmol/L). The lowest serum vitamin D levels were observed in patients with Child-Pugh class C. Bone densitometry is used for the definitive diagnosis of osteoporosis in ALD. There are no specific controlled clinical studies on the treatment of osteoporosis in patients with ALD. Alcohol cessation and abstinence are principal for the prevention and treatment of osteoporosis in ALD patients, and the progression of osteopenia can be stopped in this way. Calcium and vitamin D supplementation is recommended, and associated nutritional deficiencies should also be corrected. The treatment recommendations of osteoporosis in CLD tend to be extended to ALD. Bisphosphonates have been proven to be effective in increasing bone mineral density (BMD) in chronic cholestatic disease and post-transplant patients, and they can be used in ALD patients. Randomized studies assessing the management of CLD-associated osteoporosis and the development of new drugs for osteoporosis may change the future. Here, we will discuss bone quality, vitamin D status, mechanism of bone effects, and diagnosis and treatment of osteoporosis in ALD.

Osteoporosis in liver disease: pathogenesis and management

Osteoporosis affects a substantial proportion of patients with chronic liver disease. Pathologic fracture in osteoporosis significantly affects quality of life and life expectancy. By some estimates, 40% of patients with chronic liver disease may experience osteoporotic fracture. In this study we review the pathogenesis, diagnosis and treatment of specific liver disease entities and their relation to osteoporosis.

Crucial Role of Vitamin D in the Musculoskeletal System

Vitamin D is well known to exert multiple functions in bone biology, autoimmune diseases, cell growth, inflammation or neuromuscular and other immune functions. It is a fat-soluble vitamin present in many foods. It can be endogenously produced by ultraviolet rays from sunlight when the skin is exposed to initiate vitamin D synthesis. However, since vitamin D is biologically inert when obtained from sun exposure or diet, it must first be activated in human beings before functioning. The kidney and the liver play here a crucial role by hydroxylation of vitamin D to 25-hydroxyvitamin D in the liver and to 1,25-dihydroxyvitamin D in the kidney. In the past decades, it has been proven that vitamin D deficiency is involved in many diseases. Due to vitamin D’s central role in the musculoskeletal system and consequently the strong negative impact on bone health in cases of vitamin D deficiency, our aim was to underline its importance in bone physiology by summarizing recent findings on the correlation of vitamin D status and rickets, osteomalacia, osteopenia, primary and secondary osteoporosis as well as sarcopenia and musculoskeletal pain. While these diseases all positively correlate with a vitamin D deficiency, there is a great controversy regarding the appropriate vitamin D supplementation as both positive and negative effects on bone mineral density, musculoskeletal pain and incidence of falls are reported.

Relationship between antipsychotic medication, serum prolactin levels and osteoporosis/osteoporotic fractures in patients with schizophrenia: a critical literature review

INTRODUCTION

Using an antipsychotic medication can increase prolactin (PRL) levels, causing hyperprolactinemia (HPRL). Although the occurrence of osteoporosis within the population of patients with schizophrenia has been recognized, the precise nature of the association between antipsychotic treatment, PRL, osteoporosis, and the disease itself seems to be elusive.

AREAS COVERED

The aim of this review is to critically review the literature regarding the association between osteoporosis and PRL and to summarize the available evidence with respect to the impact of PRL-elevating antipsychotics on bone mineral density (BMD) and fractures in non-elderly patients with schizophrenia.

EXPERT OPINION

Although long-standing HPRL can have an impact on the rate of bone metabolism and, when associated with hypogonadism, may lead to decreased bone density in both female and male subjects, the relative contribution of antipsychotic-induced HPRL in bone mineral loss in patients with schizophrenia remains unclear. Methodological shortcomings of existing studies, including the lack of prospective data and the focus on measurements of BMD instead of bone turnover markers, preclude definitive conclusions regarding the relationship between PRL-raising antipsychotics and BMD loss in patients with schizophrenia. Therefore, more well conducted prospective trials of these biomarkers are necessary to establish the precise relationship between antipsychotics, PRL levels and osteoporosis/osteoporotic risk.

The risk of osteoporosis in patients with liver cirrhosis: a meta-analysis of literature studies

OBJECTIVE

Data about the association between cirrhosis and osteoporosis are contrasting. Thus, we have performed a meta-analysis of literature studies on this topic.

DESIGN

MEDLINE, Cochrane library, EMBASE, Scopus and Web of Science databases have been searched to retrieve all articles of interest. Data on prevalence of osteoporosis, bone mineral density (BMD) and bone turnover laboratory parameters were compared among cirrhotic patients and control subjects without cirrhosis.

PATIENTS

Studies on patients with liver cirrhosis screened for the presence of osteoporosis were included.

RESULTS

Six case-control studies (372 cirrhotic patients and 1579 controls) were included. The prevalence of osteoporosis was higher in cirrhotic patients than in controls (34·7% vs 12·8%, OR: 2·52, 95%CI: 1·11, 5·69; P = 0·03, I(2) = 81%; P = 0·005). Accordingly, a reduced lumbar spine BMD (MD: -0·13, 95%CI: -0·24, -0·02; P = 0·02, I(2) = 93%; P < 0·00001) and z-score (MD: -1·06, 95%CI: -1·79, -0·34; P = 0·004, I(2) = 95%; P < 0·00001) were found in cirrhotic patients as compared with controls. In contrast, no significant differences were reported in femoral neck BMD and z-score. Interestingly, bone turnover laboratory parameters widely confirmed these results showing higher levels of ALP and D-Pyr, accompanied by reduced levels of IGF-1, PTH and 25-OH-D in cirrhotic patients as compared with controls.

CONCLUSIONS

Despite the high heterogeneity among studies, data showed an increased prevalence of osteoporosis in patients with cirrhosis. This information suggests the need of an accurate screening of bone mineral density in patients with liver cirrhosis to plan an adequate osteoporosis management.

Brazilian society of hepatology recommendations for the diagnosis and management of autoimmune diseases of the liver

ABSTRACT In order to draw evidence-based recommendations concerning the management of autoimmune diseases of the liver, the Brazilian Society of Hepatology has sponsored a single-topic meeting in October 18th, 2014 at São Paulo. An organizing committee comprised of seven investigators was previously elected by the Governing Board to organize the scientific agenda as well as to select twenty panelists to make a systematic review of the literature and to present topics related to the diagnosis and treatment of autoimmune hepatitis, primary sclerosing cholangitis, primary biliary cirrhosis and their overlap syndromes. After the meeting, all panelists gathered together for the discussion of the topics and the elaboration of those recommendations. The text was subsequently submitted for suggestions and approval of all members of the Brazilian Society of Hepatology through its homepage. The present paper is the final version of the reviewed manuscript organized in topics, followed by the recommendations of the Brazilian Society of Hepatology.

Total, dietary, and supplemental calcium intake and mortality from all-causes, cardiovascular disease, and cancer: A meta-analysis of observational studies

AIMS

This systematic review and meta-analysis of observational studies was conducted to summarize the evidence on the association between calcium intake and mortality.

METHODS AND RESULTS

PubMed, Institute for Scientific Information (ISI) (Web of Science), SCOPUS, SciRUS, Google Scholar, and Excerpta Medica dataBASE (EMBASE) were searched to identify related articles published through May 2014. We found 22 articles that assessed the association between total, dietary, and supplementary intake with mortality from all-causes, cardiovascular disease (CVD), and cancer. Findings from this meta-analysis revealed no significant association between total and dietary calcium intake and mortality from all-causes, CVD, and cancer. Subgroup analysis by the duration of follow-up revealed a significant positive association between total calcium intake and CVD mortality for cohort studies with a mean follow-up duration of >10 years (relative risk (RR): 1.35; 95% confidence interval (CI): 1.09-1.68). A significant inverse association was seen between dietary calcium intake and all-cause (RR: 0.84; 95% CI: 0.70-1.00) and CVD mortality (RR: 0.88; 95% CI: 0.78-0.99) for studies with a mean follow-up duration of ≤10 years. Although supplemental calcium intake was not associated with CVD (RR: 0.95; 95% CI: 0.82-1.10) and cancer mortality (RR: 1.22; 95% CI: 0.81-1.84), it was inversely associated with the risk of all-cause mortality (RR: 0.91; 95% CI: 0.88-0.94).

CONCLUSIONS

We found a significant relationship between the total calcium intake and an increased risk of CVD mortality for studies with a long follow-up time and a significant protective association between dietary calcium intake and all-cause and CVD mortality for studies with a mean follow-up of ≤10 years. Supplemental calcium intake was associated with a decreased risk of all-cause mortality.

Mechanistic Effects of Calcitriol in Cancer Biology

Besides its classical biological effects on calcium and phosphorus homeostasis, calcitriol, the active vitamin D metabolite, has a broad variety of actions including anticancer effects that are mediated either transcriptionally and/or via non-genomic pathways. In the context of cancer, calcitriol regulates the cell cycle, induces apoptosis, promotes cell differentiation and acts as anti-inflammatory factor within the tumor microenvironment. In this review, we address the different mechanisms of action involved in the antineoplastic effects of calcitriol.

Osteoporosis in primary biliary cirrhosis of the liver

Osteoporosis is a metabolic bone disease associated with a reduction in bone mass and deterioration of bone architecture, leading to increased fragility and subsequent low-trauma fractures in the vertebral column, hip, forearm and other bones. In literature, metabolic bone diseases such as osteoporosis and osteomalacia have been recognised as a complication of chronic liver disease, although the mechanisms of this association remain unclear. An increasing body of research data indicates a strong relationship between osteoporosis and primary biliary cirrhosis (PBC), which mainly results from early diagnosis of the disease, usually when it is still asymptomatic. The incidence of osteoporosis in PBC ranges from 20% to 44% and increases with the progression of the disease. Similarly, the incidence of bone fractures is high in this group of patients (10-20%). In this article, current knowledge on risk factors, pathogenesis, diagnosis and treatment of osteoporosis in PBC is reviewed.

Chronic CCl4 intoxication causes liver and bone damage similar to the human pathology of hepatic osteodystrophy: a mouse model to analyse the liver-bone axis

Patients with chronic liver diseases frequently exhibit decreased bone mineral densities (BMD), which is defined as hepatic osteodystrophy (HOD). HOD is a multifactorial disease whose regulatory mechanisms are barely understood. Thus, an early diagnosis and therapy is hardly possible. Therefore, the aim of our study consisted in characterizing a mouse model reflecting the human pathomechanism. Serum samples were collected from patients with chronic liver diseases and 12-week old C57Bl6/N mice after 6-week treatment with carbon tetrachloride (CCl4). Repetitive injections of CCl4 induced liver damage in mice, resembling liver fibrosis in patients, as assessed by serum analysis and histological staining. Although CCl4 did not affect primary osteoblast cultures, μCT analysis revealed significantly decreased BMD, bone volume, trabecular number and thickness in CCl4-treated mice. In both HOD patients and CCl4-treated mice, an altered vitamin D metabolism with decreased CYP27A1, CYP2R1, vitamin D-binding protein GC and increased 7-dehydrocholesterol reductase hepatic gene expression, results in decreased 25-OH vitamin D serum levels. Moreover, both groups exhibit excessively high active transforming growth factor-beta (TGF-β) serum levels, inhibiting osteoblast function in vitro. Summarizing, our mouse model presents possible mediators of HOD, e.g. altered vitamin D metabolism and increased active TGF-β. Liver damage and significant changes in bone structure and mineralization are already visible by μCT analysis after 6 weeks of CCl4 treatment. This fast response and easy transferability makes it an ideal model to investigate specific gene functions in HOD.

Liver disease and malnutrition

Patients with hepatic disorders are exceptionally vulnerable to developing malnutrition because of the key role played by the liver in regulating the nutritional state and the energy balance. Moreover, the presence of chronic liver disorders could reduce the appetite and thus influence the nutrient intake. Poor nutritional status has been shown in various patient groups with hepatic disorders, and particularly in patients with alcoholic cirrhosis who are at high nutritional risk. It is well established that malnourished patients with liver diseases generally have a higher risk of developing adverse clinical outcomes and increased healthcare costs. Nutrition screening with the Subjective Global Assessment and anthropometric measurements are an important first step in the early identification of malnutrition and initiates the whole nutrition care process. It is therefore important for appropriate nutrition policies and protocols to be implemented so that all patients with chronic liver diseases are monitored closely from a nutritional standpoint. Early and evidence-based nutritional interventions are eagerly needed to minimize the nutritional decline associated with chronic liver disorders and ultimately improve the prognosis of such patients. This review includes a comprehensive analysis of methods to identify malnutrition in patients with chronic liver diseases as well as the extent and impact of the malnutrition problem in selected patient populations.

Relationship between vitamin D and chronic liver diseases

Vitamin D is a fat-soluble vitamin with multiple biological effects that is predominantly synthetized in the liver. Various kinds of chronic liver diseases are associated with vitamin D deficiency, and vitamin D supplementation may influence treatment outcome. This article summarizes the role of vitamin D in the pathogenesis and treatment of chronic liver diseases to provide new insight into the treatment of these diseases.

Increased incidence of orthopedic fractures in cirrhotic patients: a nationwide population-based study

BACKGROUND & AIMS

Hepatic encephalopathy (HE) is a reversible neuropsychiatric disorder in cirrhotic patients. The cognitive dysfunction and increased accidental falls in HE and osteodystrophy in cirrhotic patients may contribute to orthopedic fractures. This study investigated the fracture incidence and risk factors in cirrhotic patients with HE.

METHODS

In total, 3764 cirrhotic patients with HE were identified from the Taiwan National Health Insurance database between 2000 and 2009. The fracture incidence of the HE patients was compared with that of 3764 age-, sex-, and comorbidity-matched cirrhotic patients without HE and non-cirrhotic controls. Cox proportional hazard models were used to estimate the risk of fracture in the HE patients.

RESULTS

Cirrhotic patients with and without HE had comparable increased risks of fracture (p <0.05) and cumulative incidences of fracture than controls (log-rank p <0.001). The estimated fracture rates were 7.09% for the HE group, 7.72% for the cirrhosis without HE group, and 4.05% for the controls, during the 18-month follow-up. The HE group had a higher incidence rate of skull fractures (IRR=2.61, 95% CI 1.04-6.57), but a lower rate of upper limb fractures (IRR=0.45, 95% CI 0.29-0.70) than the cirrhosis without HE group. Alcoholism, heart failure, and cerebrovascular disease were associated with increased risk of fracture in HE patients.

CONCLUSIONS

Cirrhotic patients, with or without HE, are at an increased risk of orthopedic fractures. Skull fractures, rather than fractures in weight-bearing bones, are more frequently observed in HE patients, particularly those with comorbidities.

Vitamin D in chronic liver disease

Chronic liver disease (CLD) and several related extrahepatic manifestations such as hepatic osteodystrophy are associated with deficiency of vitamin D, which has therefore been suggested as therapeutic target. Vitamin D undergoes hepatic 25-hydroxylation, rendering the liver critical to the metabolic activation of this vitamin. Vitamin D deficiency is highly prevalent in CLD patients, and vitamin D levels are inversely related to the severity of CLD. Declining levels of carrier proteins such as albumin and vitamin D-binding protein might also be critical in CLD. Intervention studies report improvements of CLD following supplementation, and benefits to health outcomes in particular with respect to hepatitis C virus infection have recently been documented.

CONTENT

We discuss vitamin D sources, functions and metabolism with a focus on the inherent complications of analytical measurements, such as the interference of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D C-3 epimers. Global discrepancies in the definition of optimal serum 25-hydroxyvitamin D levels are covered, and the prevalence of vitamin D deficiency in CLD is reviewed. We also address the functional mechanisms underlying this deficiency, and refer to associations between genetic variation in vitamin D metabolism and CLD. Lastly, we consider the health implications of a vitamin D deficiency in CLD and consider therapeutic options.

SUMMARY

Herein, we focus on the epidemiological and functional relationships between vitamin D deficiency and CLD, followed by a discussion of the potential implications for therapeutic interventions.