Functional impairment in alcoholic liver disease and non-alcoholic fatty liver disease is significant and persists over 3 years of follow-up

Causal relationships between neuropsychiatric disorders and nonalcoholic fatty liver disease: A bidirectional Mendelian randomization study

BACKGROUND

Increasing evidences suggest that nonalcoholic fatty liver disease (NAFLD) is associated with neuropsychiatric disorders. Nevertheless, whether there were causal associations between them remained vague. A causal association between neuropsychiatric disorders and NAFLD was investigated in this study.

METHODS

We assessed the published genome-wide association study summary statistics for NAFLD, seven mental disorder-related diseases and six central nervous system dysfunction-related diseases. The causal relationships were first assessed using two-sample and multivariable Mendelian randomization (MR). Then, sensitivity analyses were performed, followed by a reverse MR analysis to determine whether reverse causality is possible. Finally, we performed replication analyses and combined the findings from the above studies.

RESULTS

Our meta-analysis results showed NAFLD significantly increased the risk of anxiety disorders (OR = 1.016, 95% CI = 1.010-1.021, P value < 0.0001). In addition, major depressive disorder was the potential risk factor for NAFLD (OR = 1.233, 95% CI = 1.063-1.430, P value = 0.006). Multivariable MR analysis showed that the causal effect of major depressive disorder on NAFLD remained significant after considering body mass index, but the association disappeared after adjusting for the effect of waist circumference. Furthermore, other neuropsychiatric disorders and NAFLD were not found to be causally related.

CONCLUSIONS

These results implied causal relationships of NAFLD with anxiety disorders and Major Depressive Disorder. This study highlighted the need to recognize and understand the connection between neuropsychiatric disorders and NAFLD to prevent the development of related diseases.

Non-alcoholic Fatty Liver Disease: Also a Disease of the Brain? A Systematic Review of the Preclinical Evidence

Non-alcoholic fatty liver disease (NAFLD) currently affects 25% of the global adult population. Cognitive impairment is a recently recognised comorbidity impeding memory, attention, and concentration, affecting the patients' activities of daily living and reducing their quality of life. This systematic review provides an overview of the evidence for, and potential pathophysiological mechanisms behind brain dysfunction at a neurobiological level, in preclinical NAFLD. We performed a systematic literature search for animal models of NAFLD studying intracerebral conditions using PubMed, Embase and Scopus. We included studies that reported data on neurobiology in rodent and pig models with evidence of steatosis or steatohepatitis assessed by liver histology. 534 unique studies were identified, and 30 studies met the selection criteria, and were included. Findings of neurobiological changes were divided into five key areas: (1) neuroinflammation, (2) neurodegeneration, (3) neurotransmitter alterations, (4) oxidative stress, and (5) changes in proteins and synaptic density. Despite significant heterogeneity in the study designs, all but one study of preclinical NAFLD reported changes in one or more of the above key areas when compared to control animals. In conclusion, this systematic review supports an association between all stages of NAFLD (from simple steatosis to non-alcoholic steatohepatitis (NASH)) and neurobiological changes in preclinical models.

Serum albumin and white matter hyperintensities

People living with HIV and those diagnosed with alcohol use disorders (AUD) relative to healthy individuals commonly have low levels of serum albumin, substantiated as an independent predictor of cardiovascular events. White matter hyperintensities (WMH)-a neuroimaging feature of cerebral small vessel disease-are also related to cardiovascular disease. Despite consensus regarding associations between high levels of urine albumin and WMH prevalence, and low serum albumin levels and impaired cognitive functioning, relations between serum albumin and WMH burdens have rarely been evaluated. Here, a sample including 160 individuals with AUD, 142 living with HIV, and 102 healthy controls was used to test the hypothesis that serum albumin would be inversely related to WMH volumes and directly related to cognitive performance in the two diagnostic groups. Although serum albumin and periventricular WMH volumes showed an inverse relationship in both AUD and HIV groups, this relationship persisted only in the HIV group after consideration of traditional cardiovascular (i.e., age, sex, body mass index (BMI), nicotine use, hypertension, diabetes), study-relevant (i.e., race, socioeconomic status, hepatitis C virus status), and disease-specific (i.e., CD4 nadir, HIV viral load, HIV duration) factors. Further, serum albumin contributed more significantly than periventricular WMH volume to variance in performance on a verbal learning and memory composite score in the HIV group only. Relations in both HIV and AUD groups between albumin and hematological red blood cell markers (e.g., hemoglobin, hematocrit) suggest that in this sample, serum albumin reflects hematological abnormalities. Albumin, a simple serum biomarker available in most clinical settings, may therefore help identify periventricular WMH burden and performance levels in specific cognitive domains in people living with HIV. Whether serum albumin contributes mechanistically to periventricular WMH in HIV will require additional investigation.

Effect of Helicobacter Pylori Infection on Glucose Metabolism, Lipid Metabolism and Inflammatory Cytokines in Nonalcoholic Fatty Liver Disease Patients

Objective

To probe into the influence of Helicobacter pylori (Hp) infection on glucose metabolism, lipid metabolism, and inflammatory cytokines in patients with nonalcoholic fatty liver disease (MASLD).

Methods

A total of 140 MASLD patients admitted to our Hospital between June 2020 and May 2021 were selected as the research objects. Based on the presence or absence of Hp infection, they were divided into the study group (73 cases with infection) and control group (67 cases without infection). Glucose metabolism indicators [fasting blood glucose (FBG), 2-hour postprandial glucose (2hPG), fasting insulin (FINS), glycated hemoglobin (HbAlc)], lipid metabolism indicators [total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C)], and inflammatory indicators [interleukin-37 (IL-37), interleukin-18 (IL-18)] were measured and compared between the two groups.

Results

In terms of glucose metabolism indicators, the study group exhibited higher levels of FBG (5.84±0.49 vs 5.40±0.51, t=2.535, P=0.012), 2hPG (7.26±1.30 vs 6.50±1.53, t=3.321, P<0.001), and FINS (11.13±4.13 vs 9.12±3.72, t=3.224, P<0.001), and Insulin resistance index (HOMA-IR) (2.97±0.35 VS 2.13±0.54, t=3.761, P<0.001) and a lower level of HbAlc (5.25±0.56 vs 6.12±0.57, t=5.473, P<0.001) compared to the control group. Regarding lipid metabolism indicators, the study group exhibited higher levels of TC (5.64±1.49 vs 5.01±1.32, t=3.332, P<0.001), TG (1.89±0.34 vs 1.32±0.43, t=3.411, P<0.001), and LDL-C (3.31±0.43 vs 2.12±0.29, t=4.142, P<0.001), and a lower level of HDL-C (1.45±0.21 vs 1.78±0.42, t=4.347, P<0.001) compared to the control group. As for the inflammatory indicators, the study group exhibited higher levels of IL-37 (45.56±6.02 vs 34.02±3.28, t=9.332, P<0.001) and IL-18 (73.57±5.82 vs 60.34±4.84, t=10.141, P<0.001) compared to the control group.

Conclusion

It is crucial to place appropriate emphasis on the impact of Hp infection on the glucose metabolism, lipid metabolism, and inflammatory response in MASLD patients, warranting careful consideration during the treatment of these patients.

Serum albumin and white matter hyperintensities

Urine albumin, high in kidney disease, predicts cardiovascular incidents and CNS white matter hyperintensity (WMH) burdens. Serum albumin - a more general biomarker which can be low in several disorders - including kidney and liver disease, malnutrition, and inflammation - also predicts cardiovascular events and is associated with cognitive impairment in several clinical populations; relations between serum albumin and WMH prevalence, however, have rarely been evaluated. In a sample of 160 individuals with alcohol use disorder (AUD), 142 infected with HIV, and 102 healthy controls, the hypothesis was tested that lower serum albumin levels would predict larger WMH volumes and worse cognitive performance irrespective of diagnosis. After considering traditional cardiovascular risk factors (e.g., age, sex, body mass index (BMI), nicotine use, hypertension, diabetes) and study-relevant variables (i.e., primary diagnoses, race, socioeconomic status, hepatitis C virus status), serum albumin survived false discovery rate (FDR)-correction in contributing variance to larger periventricular but not deep WMH volumes. This relationship was salient in the AUD and HIV groups, but not the control group. In secondary analyses, serum albumin and periventricular WMH along with age, sex, diagnoses, BMI, and hypertension were considered for hierarchical contribution to variance in performance in 4 cognitive domains. Albumin survived FDR-correction for significantly contributing to visual and verbal learning and memory performance after accounting for diagnosis. Relations between albumin and markers of liver integrity [e.g., aspartate transaminase (AST)] and blood status (e.g., hemoglobin, red blood cell count, red cell distribution width) suggest that in this sample, albumin reflects both liver dysfunction and hematological abnormalities. The current results suggest that albumin, a simple serum biomarker available in most clinical settings, can predict variance in periventricular WMH volumes and performance in visual and verbal learning and memory cognitive domains. Whether serum albumin contributes mechanistically to periventricular WMH prevalence will require additional investigation.

Risk of dementia in the elderly with non-alcoholic fatty liver disease: A nested case-control study in the Republic of Korea

Introduction

Non-alcoholic fatty liver disease (NAFLD) is known to be associated with metabolic syndrome of which diabetes is an important component. Although diabetes is a known risk factor for dementia, studies on the association between NAFLD and dementia still produce conflicting results. This study aimed to determine whether NAFLD would be a risk factor for the development of dementia in an elderly population.

Method

This study included 107,369 subjects aged ≥60 years in the Korean National Health Insurance Service-Senior cohort, entered in 2009 and followed up until 2015. NAFLD was diagnosed by calculating fatty liver index (FLI). Subjects were screened for dementia at baseline using a Korean Dementia Screening Questionnaire, and dementia was diagnosed using ICD-10 codes. Controls were randomly selected at a ratio of 1:5 from individuals who were at risk of becoming the case subjects at the time of selection.

Results

From 107,369 subjects, 65,690 stroke- and dementia-free subjects without chronic hepatitis B or C or excessive alcohol drinking were selected for evaluation. Having NAFLD, determined by FLI, was associated with increased risk of dementia development (adjusted odds ratio [AOR] 1.493; 95% confidence interval [CI] 1.214-1.836). The increased risk of dementia in NAFLD subjects was independent of type 2 diabetes (AOR 1.421; 95% CI 1.013-1.994, in subjects with diabetes: AOR 1.540; 95% CI 1.179- 2.010, in subjects without diabetes).

Conclusion

In this population-based nested case-control study, having NAFLD increased the risk of dementia in elderly individuals, independent of accompanying diabetes.

Role of ammonia in NAFLD: An unusual suspect

Mechanistically, the symptomatology and disease progression of non-alcoholic fatty liver disease (NAFLD) remain poorly understood, which makes therapeutic progress difficult. In this review, we focus on the potential importance of decreased urea cycle activity as a pathogenic mechanism. Urea synthesis is an exclusive hepatic function and is the body's only on-demand and definitive pathway to remove toxic ammonia. The compromised urea cycle activity in NAFLD is likely caused by epigenetic damage to urea cycle enzyme genes and increased hepatocyte senescence. When the urea cycle is dysfunctional, ammonia accumulates in liver tissue and blood, as has been demonstrated in both animal models and patients with NAFLD. The problem may be augmented by parallel changes in the glutamine/glutamate system. In the liver, the accumulation of ammonia leads to inflammation, stellate cell activation and fibrogenesis, which is partially reversible. This may be an important mechanism for the transition of bland steatosis to steatohepatitis and further to cirrhosis and hepatocellular carcinoma. Systemic hyperammonaemia has widespread negative effects on other organs. Best known are the cerebral consequences that manifest as cognitive disturbances, which are prevalent in patients with NAFLD. Furthermore, high ammonia levels induce a negative muscle protein balance leading to sarcopenia, compromised immune function and increased risk of liver cancer. There is currently no rational way to reverse reduced urea cycle activity but there are promising animal and human reports of ammonia-lowering strategies correcting several of the mentioned untoward aspects of NAFLD. In conclusion, the ability of ammonia-lowering strategies to control the symptoms and prevent the progression of NAFLD should be explored in clinical trials.

Nonalcoholic fatty liver disease and cognitive impairment: A prospective cohort study

BACKGROUND & AIMS

Nonalcoholic fatty liver disease (NAFLD) is prevalent and may affect cognitive function. We studied associations of NAFLD with risk of cognitive impairment. Secondarily we evaluated liver biomarkers (alanine aminotransferase (ALT), aspartate aminotransferase (AST), their ratio, and gamma-glutamyl transpeptidase).

METHODS

In a prospective cohort study, the REasons for Geographic and Racial Differences in Stroke, among 30,239 black and white adults aged ≥45,495 cases of incident cognitive impairment were identified over 3.4 years follow up. Cognitive impairment was identified as new impairment in two of three cognitive tests administered every two years during follow up; word list learning and recall, and verbal fluency. 587 controls were selected from an age, race, sex-stratified sample of the cohort. The fatty liver index was used to define baseline NAFLD. Liver biomarkers were measured using baseline blood samples.

RESULTS

NAFLD at baseline was associated with a 2.01-fold increased risk of incident cognitive impairment in a minimally adjusted model (95% CI 1.42, 2.85). The association was largest in those aged 45-65 (p interaction by age = 0.03), with the risk 2.95-fold increased (95% CI 1.05, 8.34) adjusting for cardiovascular, stroke and metabolic risk factors. Liver biomarkers were not associated with cognitive impairment, except AST/ALT >2, with an adjusted OR 1.86 (95% CI 0.81, 4.25) that did not differ by age.

CONCLUSIONS

A laboratory-based estimate of NAFLD was associated with development of cognitive impairment, particularly in mid-life, with a tripling in risk. Given its high prevalence, NAFLD may be a major reversible determinant of cognitive health.

Novel insights into non-alcoholic fatty liver disease and dementia: insulin resistance, hyperammonemia, gut dysbiosis, vascular impairment, and inflammation

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disease characterized by multiple pathologies. The progression of dementia with NAFLD may be affected by various risk factors, including brain insulin resistance, cerebrovascular dysfunction, gut dysbiosis, and neuroinflammation. Many recent studies have focused on the increasing prevalence of dementia in patients with NAFLD. Dementia is characterized by cognitive and memory deficits and has diverse subtypes, including vascular dementia, Alzheimer’s dementia, and diabetes mellitus-induced dementia. Considering the common pathological features of NAFLD and dementia, further studies on the association between them are needed to find appropriate therapeutic solutions for diseases. This review summarizes the common pathological characteristics and mechanisms of NAFLD and dementia. Additionally, it describes recent evidence on association between NAFLD and dementia progression and provides novel perspectives with regard to the treatment of patients with dementia secondary to NAFLD.

Olive- and Coconut-Oil-Enriched Diets Decreased Secondary Bile Acids and Regulated Metabolic and Transcriptomic Markers of Brain Injury in the Frontal Cortexes of NAFLD Pigs

The objective of this study was to investigate the effect of dietary fatty acid (FA) saturation and carbon chain length on brain bile acid (BA) metabolism and neuronal number in a pig model of pediatric NAFLD. Thirty 20-day-old Iberian pigs, pair-housed in pens, were randomly assigned to receive one of three hypercaloric diets for 10 weeks: (1) lard-enriched (LAR; n = 5 pens), (2) olive-oil-enriched (OLI, n = 5), and (3) coconut-oil-enriched (COC; n = 5). Pig behavior and activity were analyzed throughout the study. All animals were euthanized on week 10 and frontal cortex (FC) samples were collected for immunohistochemistry, metabolomic, and transcriptomic analyses. Data were analyzed by multivariate and univariate statistics. No differences were observed in relative brain weight, neuronal number, or cognitive functioning between diets. Pig activity and FC levels of neuroprotective secondary BAs and betaine decreased in the COC and OLI groups compared with LAR, and paralleled the severity of NAFLD. In addition, OLI-fed pigs showed downregulation of genes involved in neurotransmission, synaptic transmission, and nervous tissue development. Similarly, COC-fed pigs showed upregulation of neurogenesis and myelin repair genes, which caused the accumulation of medium-chain acylcarnitines in brain tissue. In conclusion, our results indicate that secondary BA levels in the FCs of NAFLD pigs are affected by dietary FA composition and are associated with metabolic and transcriptomic markers of brain injury. Dietary interventions that aim to replace saturated FAs by medium-chain or monounsaturated FAs in high-fat hypercaloric diets may have a negative effect on brain health in NAFLD patients.

The burden of non-alcoholic steatohepatitis: A systematic review of health-related quality of life and patient-reported outcomes

Background & Aims

Non-alcoholic steatohepatitis (NASH) is associated with increased mortality and a high clinical burden. NASH adversely impacts patients' health-related quality of life (HRQoL), but published data on the humanistic burden of disease are limited. This review aimed to summarise and critically evaluate studies reporting HRQoL or patient-reported outcomes (PROs) in populations with NASH and identify key gaps for further research.

Methods

Medline, EMBASE, the Cochrane Library and PsycINFO were searched for English-language publications published from 2010 to 2021 that reported HRQoL/PRO outcomes of a population or subpopulation with NASH.

Results

Twenty-five publications covering 23 unique studies were identified. Overall, the data showed a substantial impact of NASH on HRQoL, particularly in terms of physical functioning and fatigue, with deterioration of physical and mental health as NASH progresses. Prevalent symptoms, including fatigue, abdominal pain, anxiety/depression, cognition problems, and poor sleep quality, adversely impact patients' ability to work and perform activities of daily living and the quality of relationships. However, some patients fail to attribute symptoms to their disease because of a lack of patient awareness and education. NASH is associated with high rates of comorbidities such as obesity and type 2 diabetes, which contribute to reduced HRQoL. Studies were heterogeneous in terms of diagnostic methods, population, outcomes, follow-up time, and measures of HRQoL/utility. Most studies were rated 'moderate' at quality assessment, and all evaluable studies had inadequate control of confounders.

Conclusions

NASH is associated with a significant HRQoL burden that begins early in the disease course and increases with disease progression. More robust studies are needed to better understand the humanistic burden of NASH, with adequate adjustment for confounders that could influence outcomes.

Lay summary

Non-alcoholic steatohepatitis (NASH) has a significant impact on quality of life, with individuals experiencing worse physical and mental health compared with the general population. NASH and its symptoms, which include tiredness, stomach pain, anxiety, depression, poor focus and memory, and impaired sleep, affect individuals' relationships and ability to work and perform day-to-day tasks. However, not all patients are aware that their symptoms may be related to NASH. Patients would benefit from more education on their disease, and the importance of good social networks for patient health and well-being should be reinforced. More studies are needed to better understand the patient burden of NASH.

Nonalcoholic Fatty Liver Disease and Risk of Dementia: A Population-Based Cohort Study

BACKGROUND AND OBJECTIVES

Nonalcoholic fatty liver disease (NAFLD) and dementia share common risk factors including metabolic disorders. However, whether NAFLD is associated with dementia risk is unclear. We investigated the association between NAFLD and dementia risk as well as the role of cardiovascular complications including heart disease and stroke.

METHODS

In this population-based matched cohort study, we identified all Swedish patients aged 65 years or older with NAFLD identified from the National Patient Register (NPR) between 1987 and 2016. These were matched with up to 10 reference individuals from the general population on age, sex, and municipality at the year of diagnosis. Incident dementia diagnosis was derived from the NPR or the Cause of Death Register until 2016. Adjusted hazard ratios (aHRs) and 95% CIs were estimated with Cox regression models.

RESULTS

A total of 2,898 patients with NAFLD and 28,357 matched controls were identified (median age at entry, interquartile range [IQR], 70 [8]; 55.1% female). During a median follow-up of 5.5 years (IQR: 8.5 years), 145 (5.0%) patients with NAFLD and 1,291 (4.6%) reference individuals were diagnosed with dementia. Compared with the reference individuals, patients with NAFLD had higher rates of dementia (aHR 1.38, 95% CI 1.10-1.72) and vascular dementia (aHR 1.44, 95% CI 0.96-2.23, p = 0.07). Comorbid NAFLD and either heart disease (aHR 1.50 95% 1.08-2.05) or stroke (aHR 2.60 95% CI 1.95-3.47) conferred a greater risk of dementia.

DISCUSSION

NAFLD had a modest association with increased rates of dementia. This was stronger among patients with NAFLD diagnosed with cardiovascular comorbidities.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that nonalcoholic fatty liver disease is associated with the development of vascular and nonvascular dementia.

The Mediation Role of the Risk of Non-Alcoholic Fatty Liver Disease in Relationship between Lutein and Zeaxanthin and Cognitive Functions among Older Adults in the United States

Background: Previous studies showed lutein and zeaxanthin (L and Z) may influence cognitive function by different mechanisms. Our study aimed to be the first to examine whether the risk of non-alcoholic fatty liver disease (NAFLD) mediated the possible association between the dietary intake of L and Z and cognitive function. Methods: We conducted a cross-sectional analysis of participants aged 60 years or over in the National Health and Nutrition Examination Survey (NHANES) 2011–2014. Multivariable linear regression was used to investigate the association between the dietary intake of L and Z and cognitive function, and structural equation modeling tested the mediation effect. Results: The fatty liver index for the United States population (US FLI) acted as a mediator in the association between the higher intake of L and Z and the Animal Fluency Test, the Digit Symbol Substitution Test (DSST), and composite score and mediated 13.89%, 17.87%, and 13.79% of the total association in dietary L and Z intake (14.29%, 13.68%, and 10.34% of the total association in total L and Z intake), respectively. Conclusion: Our study indicated the potential role of the risk of NAFLD as a mediator of associations between the dietary intake of L and Z and cognitive function in the geriatric American population.

Non-alcoholic Fatty Liver Disease and Longitudinal Cognitive Changes in Middle-Aged and Elderly Adults

Background and Purpose

Non-alcoholic fatty liver disease (NAFLD) and cognitive impairment are common aging-related disorders. This study aims to explore the changes of cognitive function in middle-aged and elderly population with NAFLD from a Jidong impairment cohort.

Methods

A total of 1,651 middle-aged and elderly participants (&gt;40 years) without cognitive impairment were recruited into the current study in 2015 and were followed up until to 2019. Abdominal ultrasonography was used for diagnosis of NAFLD. Global cognitive function was assessed with the Mini-Mental State Examination (MMSE). Cognitive impairment was defined as a score &lt;18 for illiterates, a score &lt;21 for primary school graduates, and a score &lt;25 for junior school graduates or above. Multivariable regression analysis was performed to evaluate the association between NAFLD and the four-year cognitive changes.

Results

Out of 1,651 participants, 795 (48.2%) of them had NAFLD in 2015. Cognitive impairment occurred in 241 (14.6%) participants in 2019. Patients with NAFLD had higher 4-year incidence of cognitive impairment than non-NAFLD patients did (17.7 vs. 11.7%, p &lt; 0.001). Multivariable linear regression analysis showed significant association of baseline NAFLD with lower MMSE score in 2019 (β = −0.36, p &lt; 0.05). Multivariable logistic analysis found that the adjusted odds ratio (OR) with 95% confidence interval (CI) of baseline NAFLD was 1.45 (1.00–2.11) for cognitive impairment in 2019 (p = 0.05). We also identified effects of baseline NAFLD on subsequent cognitive impairment as modified by age (interaction p &lt; 0.01) and carotid stenosis (interaction p = 0.05) but not by gender.

Conclusions

NAFLD is associated with cognitive decline, especially in middle-aged and with carotid stenosis population.

Is there an association between non-alcoholic fatty liver disease and cognitive function? A systematic review

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is represented as the most common liver disease worldwide. NAFLD is associated with metabolic risk factors underpinned by insulin resistance, inflammation and endothelial dysfunction, leading to extrahepatic changes in central nervous diseases such as cognitive impairment, Alzheimer's disease and dementia. The aim of the review is to explore the association between NAFLD and cognitive function.

METHODS

Using the PRISMA guidelines, a systematic electronic literature search was conducted in four databases: MEDLINE, PsychINFO, Embase and CINAHL from inception until March 2021. Neuropsychological tests utilised within each study were grouped into relevant cognitive domains including 'general cognition', 'reasoning', 'mental speed, attention and psychomotor speed', 'memory and learning', 'language', 'visuospatial perception' and 'ideas, abstraction, figural creations and mental flexibility'.

RESULTS

Eleven observational studies that involved 7978 participants with a mean age of 51 years were included. Those with NAFLD had poor cognitive performance in three cognitive domains, including 'general cognition', 'mental speed, attention and psychomotor speed', and 'ideas, abstraction, figural creations and mental flexibility'.

CONCLUSION

The observed results from the 11 included studies showed that NAFLD was associated with lower cognitive performance across several domains. However, studies conducted to date are limited to observational designs and are heterogeneous with varying diagnostic tools used to assess cognitive function.

TRIAL REGISTRATION

PROSPERO Registration: CRD42020161640 .

Anatomical Brain Changes and Cognitive Abilities in Patients with Obstructive Sleep Apnea Syndrome and Nonalcoholic Fatty Liver Disease

Obstructive sleep apnea (OSA) is characterized by repetitive complete or partial collapse of the upper airway and reduction of airflow during sleep. It is associated with significantly increased daytime muscle sympathetic nerve activity thought to result from the repetitive intermittent periods of hypoxemia during sleep and brain alterations that are likely to result. Different brain regions are affected by subsequent hypoxia/anoxia. Neurodegenerative processes result in measurable atrophy of cortical gray matter in the temporal lobes and posterior cingulate cortex, as well as in subcortical structures such as the hippocampus, amygdala, and thalamus. This study involved a group of firstly diagnosed, therapy-naive, nonalcoholic fatty liver disease (NAFLD) patients, out of which 144 (96 males and 48 females), aged 34-57 (mean 47.88 ± 6.07), satisfied the recruiting criteria for the study and control groups. All the patients underwent MRI scanning, polysomnography testing, and cognitive evaluation. Cognitively, worse results were obtained in the group with OSA (p < 0.05) and NAFLD (p=0.047). A significant decrease in volumes of cortical and subcortical structures was revealed (p < 0.001). In conclusion, brain deterioration followed by cognitive impairment is, most likely, the result of intermittent hypoxia and anoxia episodes that initiate the domino process of deteriorating biochemical reactions in the brain.

Associations between nut intake, cognitive function and non-alcoholic fatty liver disease (NAFLD) in older adults in the United States: NHANES 2011-14

BACKGROUND

Nuts are nutrient-rich and reported to provide some cognitive and cardiometabolic health benefits, but limited studies have focused on older adults. This study investigated the cross-sectional relationship between habitual nut intake, dietary pattern and quality, cognition and non-alcoholic fatty liver disease (NAFLD) in older adults.

METHODS

Older adults (≥ 60 years) from the NHANES 2011-12 and 2013-14 cohorts, who had complete data on cognitive function (as CERAD total, delayed recall, animal fluency and digit-symbol substitution test) and variables to calculate the Fatty Liver Index (FLI), an indicator of NAFLD, were included (n = 1848). Nut intake and diet quality (Healthy Eating Index 2015) were determined using two 24-hour diet recalls. Participants were categorised into one of four groups based on their habitual nut intake: non-consumers (0 g/d), low intake (0.1-15.0 g/d), moderate intake (15.1-30.0 g/d) or met recommendation (> 30 g/d), with all outcomes compared between these nut intake groups.

RESULTS

Cognitive scores of older adults were the lowest in non-consumers and significantly highest in the moderate intake group, with no further increase in those who consumed nuts more than 30 g/d (p < 0.007). FLI was the lowest among older adults with moderate nut intake but the associations disappeared after adjusting for covariates (p = 0.329). Moderate nut intake was also associated with better immediate and delayed memory in older adults with high risk of NAFLD (FLI ≥ 60) (B = 1.84 and 1.11, p < 0.05 respectively). Higher nutrient intake and better diet quality (p < 0.001) were seen with higher nut intake but did not influence energy from saturated fat intake. Factor analysis revealed 'Nuts and oils' as one of the four major dietary patterns associated with better cognition and lower FLI scores.

CONCLUSIONS

Moderate nut intake (15.1-30.0 g/d) may be sufficient for better cognitive performance, but not NAFLD risk of older adults in the US.

Cognitive Dysfunction in Non-Alcoholic Fatty Liver Disease-Current Knowledge, Mechanisms and Perspectives

Non-alcoholic fatty liver disease (NAFLD) has emerged as the hepatic component of the metabolic syndrome and now seemingly affects one-fourth of the world population. Features associated with NAFLD and the metabolic syndrome have frequently been linked to cognitive dysfunction, i.e. systemic inflammation, vascular dysfunction, and sleep apnoea. However, emerging evidence suggests that NAFLD may be a cause of cognitive dysfunction independent of these factors. NAFLD in addition exhibits dysbiosis of the gut microbiota and impaired urea cycle function, favouring systemic ammonia accumulation and further promotes systemic inflammation. Such disruption of the gut–liver–brain axis is essential in the pathogenesis of hepatic encephalopathy, the neuropsychiatric syndrome associated with progressive liver disease. Considering the growing burden of NAFLD, the morbidity from cognitive impairment is expected to have huge societal and economic impact. The present paper provides a review of the available evidence for cognitive dysfunction in NAFLD and outlines its possible mechanisms. Moreover, the clinical challenges of characterizing and diagnosing cognitive dysfunction in NAFLD are discussed.

The Efficacy of Levocarnitine Treatment in Relieving Fatigue in Patients with Cirrhosis but without Overt Hepatic Encephalopathy

Objective In the present study, we prospectively examined the efficacy of levocarnitine in relieving symptoms of fatigue in patients with cirrhosis but without overt hepatic encephalopathy. Methods Twenty-one cirrhotic patients who were able to undergo fatigue symptom evaluations at our institution were enrolled. A total of 12 cirrhotic patients underwent levocarnitine treatment (1,200-1,800 mg/day), while 9 did not undergo levocarnitine treatment. As primary endpoints, we investigated whether or not levocarnitine treatment exerted any beneficial effects by assessing the symptoms of fatigue [8-item Short-Form Health Survey (SF-8) and Fisk Fatigue Severity Score (FFSS)] at baseline and three months after treatment. Furthermore, as exploratory secondary endpoints, we investigated whether or not levocarnitine treatment exerted ameliorative effects on oxidative stress by assessing the serum thioredoxin (TRX) and urinary 8-hydroxydeoxyguanosine (8-OHdG) levels. Results The median age of the patients was 73 years old. Three men and 18 women were categorized by their Child-Pugh class (A and B in 14 and 7 patients, respectively). There were no significant differences in the clinical laboratory values between the two groups. The FFSS and SF-8 scores were significantly improved in the patients with cirrhosis who underwent levocarnitine treatment (p<0.01) but not in those who did not undergo levocarnitine treatment. Furthermore, three months after levocarnitine treatment, the serum carnitine concentrations were significantly increased, and the serum thioredoxin levels were decreased in the patients with cirrhosis who underwent levocarnitine treatment (p<0.05). Conclusion These results suggest that levocarnitine treatment may relieve symptoms of fatigue in cirrhotic patients by reducing oxidative stress.

[Mixed steatohepatitis: more questions than answers (Part 1)]

The term steatohepatitis is used for a heterogeneous group of diseases of various etiologies, characterized by a similar morphological picture. Earlier the diagnosis of non-alcoholic fatty liver disease implied the exclusion of other causes of steatohepatitis, in recent years it has been suggested that a combination of various etiological variants of steatohepatitis is possible. The review considers the terminological, epidemiological and pathogenetic aspects of the most common combination: metabolic and alcoholic genesis, the issues of the mutual influence of etiopathogenetic factors and the identification of the predominant process. Issues of existing and prospective pathogenetic and symptomatic therapy are discussed in detail. Treatment of steatohepatitis is based on the elimination of known causal factors and lifestyle modification; therapy includes medications, that have been proven to be effective in certain types of steatohepatitis and symptomatic therapy as well.

Non-alcoholic fatty liver disease does not increase dementia risk although histology data might improve risk prediction

Background & Aims

Non-alcoholic fatty liver disease (NAFLD) is common in the general population, but its association with dementia is unclear. We aimed to assess the risk of dementia related to NAFLD, and to determine whether histological parameters could improve the predictive capacity of a conventional risk model for dementia in patients with biopsy-proven NAFLD.

Methods

A retrospective matched cohort study of 656 NAFLD patients underwent liver biopsy at 2 hospitals between 1971 and 2009. Up to 10 individuals (controls) from the general population (n = 6,436) were matched for age, sex, and municipality to each patient. Dementia was ascertained from National registers until 2014. Using Cox regression, we estimated hazard ratios for dementia with 95% confidence intervals. In the biopsy cohort, the discriminative power of adding histological markers to a conventional risk model was assessed by Harrell’s C-index and compared with a likelihood-ratio test.

Results

During a mean follow-up of 19.7 ± 8.7 years, 3.3% of the NAFLD patients and 4.9% of the controls developed dementia (p = 0.07). Overall, NAFLD was not significantly associated with incident dementia. In the biopsy cohort, the model of conventional risk factors (age, sex, hypertension, and cardiovascular diseases) had a C-index of 0.912 to predict incident dementia. Adding individual histological parameters significantly increased the prediction of dementia, with the most pronounced improvement for fibrosis stage (C-index = 0.938, p <0.05).

Conclusions

Although NAFLD was not associated with the risk of dementia, we found that adding histological markers to a conventional risk model for dementia enhanced the predictive capacity, indicating a shared metabolic origin.

Lay summary

Both non-alcoholic fatty liver disease (NAFLD) and dementia are increasing in prevalence because of a more sedentary lifestyle, increased prevalence of obesity and population ageing. However, the link between these 2 diseases is not well studied. We investigated the association between NAFLD and the risk of dementia and found no association. However, liver histology parameters, especially fibrosis, could significantly improve the prediction of dementia risk.

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The link between NAFLD and dementia is unclear.

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We assessed the association between biopsy-proven NAFLD and dementia.

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NAFLD is not associated with an increased risk of dementia.

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Adding histological markers to a conventional risk model for dementia enhanced its predictive capacity.

Psychological Biomarkers and Fibrosis: An Innovative Approach to Non-alcoholic Fatty Liver Disease

Background: It is unknown how perceived social support and the progression of liver damage influence the psychosocial profile of patients with non-alcoholic fatty liver disease (NAFLD). In the present study, we therefore investigated which biomarkers influence the quality of life, mental health, and coping strategies of NAFLD patients. Methods: Quality of life (SF-12 and CLDQ-NAFLD), mental health (HADS and BDI-II), and coping strategies (COPE-28) were evaluated by high or low perceived social support (MSPSS) and the presence of non-alcoholic steatohepatitis (NASH) and significant fibrosis in 492 biopsy-proven NAFLD patients. The results were compared with quality of life normality tables for the general Spanish population. We also determined whether liver histology and biopsychosocial variables predicted participants' quality of life. Results: Interactive effects were found in vitality (p = 0.05), activity (p = 0.005), anxiety (p = 0.04), and denial (p = 0.04), with NASH patients showing a higher-risk biopsychosocial profile when they perceived less social support. Furthermore, patients with low perceived social support showed lower quality of life, worse mental health, and more maladaptive coping than those with high perceived social support, regardless of NASH presence. Patients with significant fibrosis showed lower quality of life compared to those without or the general Spanish population. Patients with significant fibrosis also reported worse mental health and more maladaptive coping. Lastly, significant fibrosis, female sex, greater anxiety and depressive symptoms, and worse physical and mental health-related quality of life were found to be independent determinants of worse disease-specific quality of life in these patients. Conclusions: Low perceived social support, significant fibrosis, and female sex were independently associated with a higher-risk psychosocial profile in NAFLD. These findings support the role of psychological biomarkers based on quality of life, mental health, and coping strategies in the management of these patients and suggest the potential benefits of a psychological intervention.

Depression and Cognitive Impairment-Extrahepatic Manifestations of NAFLD and NASH

Non-alcoholic fatty liver disease (NAFLD) and its complication non-alcoholic steatohepatitis (NASH) are important causes of liver disease worldwide. Recently, a significant association between these hepatic diseases and different central nervous system (CNS) disorders has been observed in an increasing number of patients. NAFLD-related CNS dysfunctions include cognitive impairment, hippocampal-dependent memory impairment, and mood imbalances (in particular, depression and anxiety). This review aims at summarizing the main correlations observed between NAFLD development and these CNS dysfunctions, focusing on the studies investigating the mechanism(s) involved in this association. Growing evidences point at cerebrovascular alteration, neuroinflammation, and brain insulin resistance as NAFLD/NASH-related CNS manifestations. Since the pharmacological options available for the management of these conditions are still limited, further studies are needed to unravel the mechanism(s) of NAFLD/NASH and their central manifestations and identify effective pharmacological targets.

Health-related quality of life and patient-reported outcome measures in NASH-related cirrhosis

BACKGROUND & AIMS

Non-alcoholic steatohepatitis (NASH) is known to have a negative impact on patients' health-related quality of life (HRQoL), even before progression to cirrhosis has occurred. The burden of NASH-related cirrhosis from the patient perspective remains poorly understood. Herein, we aimed to identify the burden of disease and HRQoL impairment among patients with NASH-related compensated cirrhosis.

METHODS

This targeted literature review sought first to identify the humanistic burden of disease from the perspective of patients with diagnosed NASH-cirrhosis and, secondly, to identify generic or disease-specific patient-reported outcome measures (PROMs) used to assess the impact of NASH-cirrhosis. Searches were conducted in bibliographical databases, grey or unpublished literature, liver disease websites, support group websites and online blogs. A quality assessment of specific PROMs was conducted.

RESULTS

Patients with NASH-cirrhosis are reported to suffer from lower HRQoL than patients with non-cirrhotic NASH and the general population with respect to physical health/functioning, emotional health and worry, and mental health. Thirteen PROMs were identified, of which 4 were liver-disease specific: CLDQ, CLDQ-NAFLD, LDQoL and LDSI. The most commonly used measures do not comply with current industry or regulatory standards for PROMs and/or are not validated for use in a cirrhotic NASH population.

CONCLUSIONS

Patients with NASH-cirrhosis have lower HRQoL and poorer physical health than patients with non-cirrhotic NASH. However, the literature lacked detail of the everyday impact on patients' lives. Currently, a number of PROMs are available to measure the impact of the disease in patients with chronic liver conditions. The lack of studies that include qualitative insights in this population mandates further exploration and research.

LAY SUMMARY

It is not well understood how having non-alcoholic fatty liver disease (NAFLD)-related cirrhosis affects a person's everyday wellbeing and quality of life. Some research has been done with patients who have early stages of liver disease but not people with cirrhosis. We found that patients with NAFLD-related cirrhosis tended to have poorer health than patients without cirrhosis. But there was not very much information from patients themselves and there were no tools or questionnaires just for this group of patients.

A Comprehensive Review of Patient-reported Outcomes in Patients With Chronic Liver Diseases

Chronic liver disease (CLD) is a global health problem with chronic viral hepatitis, alcohol-related liver disease, and nonalcoholic fatty liver disease being important causes of mortality. Besides its clinical burden, patients with CLD also suffer from impairment of their health-related quality of life and other patient-reported outcomes (PRO). In this context, a combination of both clinical and PROs will allow assessment of the comprehensive burden of liver disease on patients. PROs cannot be observed directly and must be assessed by validated questionnaires or tools. Various tools have been developed to accurately measure PROs in patients with CLD, including generic and disease-specific questionnaires such as Short Form-36, Chronic Liver Disease Questionnaire and its subtypes. It is important to note that PRO instruments can be used to appreciate the impact of the natural history of CLD or of treatment on patients' experiences. This review summarizes PRO assessment in different types of liver disease and different tools useful to investigators and clinicians who are interested in this aspect of patients' experience.

Ademethionine in the treatment of fatigue in liver diseases: a systematic review

Fatigue has a significant effect on the condition of patients with liver disease. Ademethionine is considered one of the most promising drugs for its treatment. Aim. To systematize the published data on the treatment of hepatogenic fatigue with аdemethionine. Materials and methods. Search was performed using databases PubMed, EMBASE, Embase®, Medline®, eLIBRARY.ru, published in 1952-2018. Results and discussion. 16 articles were found on the use of ademethionine in liver diseases and the assessment of the dynamics of the symptom of fatigue, including 1 double-blind, randomized, placebo-controlled study, 3 open randomized studies; most of the works were multicenter open observation programs. The studies included 3238 patients (of which 2820 were included in the final data analysis) and a wide range of liver diseases: alcoholic liver disease, nonalcoholic fatty liver disease, primary biliary cholangitis, primary sclerosing cholangitis, cirrhosis of different causes, viral hepatitis, drug-induced liver injury. Different doses, routes of administration of аdemethionine and the duration of the course were used. Conclusions. Ademethionine, regardless of the route of administration, is effective in the treatment of fatigue due to different liver disease in the short and long term. The dose-dependent effect of the drug and the possibility of maintaining post-effect after end of the treatment course should be assumed, but this requires further study in randomized clinical trials.

Fatigue in chronic liver disease: New insights and therapeutic approaches

The management of fatigue associated with chronic liver disease is a complex and major clinical challenge. Although fatigue can complicate many chronic diseases, it is particularly common in diseases with an inflammatory component. Fatigue can have both peripheral (i.e., neuromuscular) and central (i.e., resulting from changes in neurotransmission within the brain) causes. However, fatigue in chronic liver disease has strong social/contextual components and is often associated with behavioural alterations including depression and anxiety. Given the increasing awareness of patient-reported outcomes as important components of treatment outcomes and clinical research, there is a growing need to better understand and manage this poorly understood yet debilitating symptom. Although several pathophysiological mechanisms for explaining the development of fatigue have been generated, our understanding of fatigue in patients with chronic liver disease remains incomplete. A better understanding of the pathways and neurotransmitter systems involved may provide specific directed therapies. Currently, the management of fatigue in chronic liver disease can involve a combined use of methods to beneficially alter behavioural components and pharmacological interventions, of which several treatments have potential for the improved management of fatigue in chronic liver disease. However, evidence and consensus are lacking on the best approach and the most appropriate biochemical target(s) whilst clinical trials to address this issue have been few and limited by small sample size. In this review, we outline current understanding of the impact of fatigue and related symptoms in chronic liver disease, discuss theories of pathogenesis, and examine current and emerging approaches to its treatment.

Cognitive assessment of patients with nonalcoholic fatty liver disease

OBJECTIVE

The aim of this study was to investigate cognitive performance for the first time in participants with nonalcoholic fatty liver disease (NAFLD) using the Montreal Cognitive Assessment (MoCA).

PARTICIPANTS AND METHODS

In total, 70 participants with NAFLD and 73 age-matched and sex-matched healthy participants were enrolled in this prospective cross-sectional study. The diagnosis of NAFLD was made on the basis of abdominal ultrasonography findings. Anthropometric indices were calculated, and routine laboratory analyses were carried out for each participant. All participants provided sociodemographic data and completed the Beck Depression Inventory-II. Cognitive functions were evaluated using the Turkish version of the MoCA, with a cut-off score for mild cognitive impairment of less than 21 points.

RESULTS

The MoCA scores were significantly lower in participants with NAFLD than in the healthy group (P<0.05). In addition, more NAFLD participants than healthy participants presented with deficits in the visuospatial (P<0.05) and executive function domains (P<0.05). In the multivariate model, education level [2.79 (1.12-6.96); P<0.05] and area of residence [5.68 (2.24-14.38); P<0.001] were associated independently with cognitive dysfunction in both the NAFLD and the healthy groups. The MoCA scores were correlated negatively with fibrosis 4 scores in NAFLD participants (r=-0.359; P<0.05). However, hepatosteatosis grade and the presence of metabolic syndrome were not correlated with MoCA scores in the NAFLD group (P>0.05).

CONCLUSION

Our results show that NAFLD patients may have early or subtle cognitive dysfunction, including in the visuospatial and executive function domains, as indexed by scores on the MoCA test. Further targeted psychometric testing will be required to confirm the presence of cognitive impairment in this population.

Exercising the hepatobiliary-gut axis. The impact of physical activity performance

BACKGROUND

Physical inactivity puts the populations at risk of several health problems, while regular physical activity brings beneficial effects on cardiovascular disease, mortality and other health outcomes, including obesity, glycaemic control and insulin resistance. The hepatobiliary tract is greatly involved in several metabolic aspects which include digestion and absorption of nutrients in concert with intestinal motility, bile acid secretion and flow across the enterohepatic circulation and intestinal microbiota. Several metabolic abnormalities, including nonalcoholic fatty liver as well as cholesterol cholelithiasis, represent two conditions explained by changes of the aforementioned pathways.

MATERIALS AND METHODS

This review defines different training modalities and discusses the effects of physical activity in two metabolic disorders, that is nonalcoholic fatty liver disease (NAFLD) and cholelithiasis. Emphasis is given to pathogenic mechanisms involving intestinal bile acids, microbiota and inflammatory status.

RESULTS

A full definition of physical activity includes the knowledge of aerobic and endurance exercise, metabolic equivalent tasks, duration, frequency and intensity, beneficial and harmful effects. Physical activity influences the hepatobiliary-gut axis at different levels and brings benefits to fat distribution, liver fat and gallbladder disease while interacting with bile acids as signalling molecules, intestinal microbiota and inflammatory changes in the body.

CONCLUSIONS

Several beneficial effects of physical activity are anticipated on metabolic disorders linking liver steatosis, gallstone disease, gut motility, enterohepatic circulation of signalling bile acids in relation to intestinal microbiota and inflammatory changes.

Protective Effects of Luteolin on Lipopolysaccharide-Induced Acute Renal Injury in Mice

Background

Sepsis can cause serious acute kidney injury in bacterium-infected patients, especially in intensive care patients. Luteolin, a bioactive flavonoid, has renal protection and anti-inflammatory effects. This study aimed to investigate the effect and underlying mechanism of luteolin in attenuating lipopolysaccharide (LPS)-induced renal injury.

Material/Methods

ICR mice were treated with LPS (25 mg/kg) with or without luteolin pre-treatment (40 mg/kg for three days). The renal function, histological changes, degree of oxidative stress, and tubular apoptosis in these mice were examined. The effects of luteolin on LPS-induced expression of renal tumor necrosis factor-α (TNF-α), NF-κB, MCP-1, ICAM-1, and cleaved caspase-3 were evaluated.

Results

LPS resulted in rapid renal damage of mice, increased level of blood urea nitrogen (BUN), and serum creatinine (Scr), tubular necrosis, and increased oxidative stress, whereas luteolin pre-treatment could attenuate this renal damage and improve the renal functions significantly. Treatment with LPS increased TNF-α, NF-κB, IL-1β, cleaved caspase-3, MCP-1, and ICAM-1 expression, while these disturbed expressions were reversed by luteolin pre-treatment.

Conclusions

These results indicate that luteolin ameliorates LPS-mediated nephrotoxicity via improving renal oxidant status, decreasing NF-κB activation and inflammatory and apoptosis factors, and then disturbing the expression of apoptosis-related proteins.

Economic and Quality-of-Life Implications of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a very common chronic liver disease worldwide, is on the rise following the trend of increasing prevalence of obesity, is the second most common indication for liver transplantation, and is an important cause for hepatocellular carcinoma. Despite the increasing recognition of NAFLD as an important chronic liver disease, little has been published on the economic and health-related quality of life (HR-QOL) impact of NAFLD. We reviewed the current literature related to the economics and HR-QOL of NAFLD and found that increased costs and decreased HR-QOL were associated with NAFLD.

Liver Fibrosis Predicts Cognitive Function Following Bariatric Surgery: A Preliminary Investigation

OBJECTIVE

Obesity is a well-established risk factor for poor neurological outcomes, and bariatric surgery has been shown to improve many aspects of cognitive function. Factors underlying improved cognition following surgery are not yet fully established. A recent study of bariatric surgery patients demonstrated lower preoperative alkaline phosphatase concentrations were linked to greater postoperative cognitive improvement, but this link has not been examined via liver biopsy. The current study examined postoperative cognitive function in individuals with and without fibrosis at the time of bariatric surgery. It expected that those with fibrosis would demonstrate poorer postoperative cognition.

METHODS

Thirty-six bariatric surgery patients underwent routine liver biopsy at the time of surgery and completed cognitive testing 1 month postoperatively.

RESULTS

Bariatric surgery patients with fibrosis demonstrated poorer performance on a task of executive function (maze errors, P = 0.01) and verbal memory (recognition memory, P = 0.01).

CONCLUSIONS

Bariatric surgery patients with fibrosis demonstrated poorer cognition following surgery, providing further evidence for the connection between liver disease and cognitive function. Future work examining mechanisms underlying bariatric postoperative cognitive changes should include examination of broader metabolic functions, particularly liver function.

Amyloid-β pathology and APOE genotype modulate retinoid X receptor agonist activity in vivo

Previous data demonstrate that bexarotene (Bex), retinoid X receptor (RXR) agonist, reduces soluble and insoluble amyloid-β (Aβ) in Alzheimer disease (AD)-transgenic mice either by increasing the levels of mouse apolipoprotein E (apoE) or increasing ABCA1/ABCG1-induced apoE lipoprotein association/lipidation. However, although the mechanism of action of RXR agonists remains unclear, a major concern for their use is human (h)-APOE4, the greatest AD genetic risk factor. If APOE4 imparts a toxic gain-of-function, then increasing apoE4 may increase soluble Aβ, likely the proximal AD neurotoxin. If the APOE4 loss-of-function is lipidation of apoE4, then induction of ABCA1/ABCG1 may be beneficial. In novel EFAD-Tg mice (overexpressing h-Aβ42 with h-APOE), levels of soluble Aβ (Aβ42 and oligomeric Aβ) are highest in E4FAD hippocampus (HP) > E3FAD-HP > E4FAD cortex (CX) > E3FAD-CX, whereas levels of lipoprotein-associated/lipidated apoE have the opposite pattern (6 months). In E4FAD-HP, short-term RXR agonist treatment (Bex or LG100268; 5.75-6 months) increased ABCA1, apoE4 lipoprotein-association/lipidation, and apoE4/Aβ complex, decreased soluble Aβ, and increased PSD95. In addition, hydrogel delivery, which mimics low sustained release, was equally effective as gavage for Bex and LG100268. RXR agonists induced no beneficial effects in the E4FAD-HP in a prevention protocol (5-6 months) and actually increased soluble Aβ levels in E3FAD-CX and E4FAD-CX with the short-term protocol, possibly the result of systemic hepatomegaly. Thus, RXR agonists address the loss-of-function associated with APOE4 and exacerbated by Aβ pathology, i.e. low levels of apoE4 lipoprotein association/lipidation. Further studies are vital to address whether RXR agonists are an APOE4-specific AD therapeutic and the systemic side effects that limit translational application.

The effects of cystatin C and alkaline phosphatase changes on cognitive function 12-months after bariatric surgery

BACKGROUND

The mechanisms for improved cognitive function post-bariatric surgery are not well understood. Markers of kidney and liver function (i.e., cystatin C and alkaline phosphatase (ALP)) are elevated in obese individuals and associated with poor neurocognitive outcomes in other samples. Bariatric surgery can improve cystatin C and ALP levels, but no study has examined whether such changes correspond to post-operative cognitive benefits.

METHODS

78 bariatric surgery patients completed a computerized cognitive test battery prior to and 12-months after surgery. All participants underwent an eight-hour fasting blood draw to quantify cystatin C and ALP concentrations.

RESULTS

Cognitive function improved after surgery. Cystatin C levels decreased at the 12-month follow-up; however, no changes were found in ALP concentrations. At baseline, higher cystatin C levels predicted worse attention/executive function, but no such effects emerged for ALP. Regression analyses controlling for possible medical and demographic confounds and baseline factors revealed that decreased ALP levels following surgery predicted better attention/executive function and memory abilities. Post-surgery changes in cystatin C did not correspond to cognitive improvements.

CONCLUSIONS

Decreased ALP levels predicted better cognition following bariatric surgery, suggesting improved liver function as a possible mechanism of post-operative cognitive benefits. Future studies with neuroimaging and longer follow-up periods are needed to determine whether bariatric surgery can decrease risk for adverse brain changes and dementia in severely obese persons via improved metabolic function.

Role of exercise in optimizing the functional status of patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is frequently concomitant with obesity. This article discusses factors that influence health and functional outcomes of people who develop NAFLD, including increased burden of illness, whole body function, performance, and perception of self-efficacy. Changes in macronutrients, amount of calories consumed, and decreased physical activity all negatively influence patient outcome. The benefits of exercise in this population are also discussed. To be effective, exercise must be performed, regularly and in conjunction with dietary and other behavioral change. Therefore, a lifelong commitment to exercise, activity, and diet are needed if NAFLD is to be successfully treated.