Non-alcoholic fatty liver disease and cognitive function in middle-aged adults: the CARDIA study

Cognitive function and bladder health among midlife adult women in the Coronary Artery Risk Development in Young Adults (CARDIA) study

OBJECTIVE

The aim of this study was to examine whether different aspects of women's cognitive function are associated with lower urinary tract symptoms (LUTS) and their impact.

METHODS

In 2010-2011, women aged 42 to 57 years in the Coronary Artery Risk Development in Young Adults study completed different tests of cognitive function, including the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and Stroop test. Two years later, data on LUTS and their impact were collected. LUTS/impact, a four-level composite variable ranging from bladder health to mild, moderate, and severe LUTS/impact, was regressed on each cognitive test separately, as well as a cognitive function composite variable. The analytic sample was composed of 1,021 women with complete data.

RESULTS

When adjusting for sociodemographic variables (age, race, education) and gynecologic/obstetric variables (parity, menopausal status, hysterectomy, hormonal use), better performance on the cognitive function composite and Digit Symbol Substitution Test were both associated with lower odds of membership to a more severe LUTS/impact category (odds ratio, 0.90 [95% confidence interval, 0.83-0.98] and 0.89 [95% confidence interval, 0.82-0.97], respectively). These associations became nonsignificant when additionally adjusting for mechanisms that might explain an association between cognitive function and LUTS/impact, including health behaviors and health conditions that may covary with cerebral and peripheral vascular health and cognitive function.

CONCLUSIONS

In this sample of midlife adult women, a modest association was found between better cognitive function and lower likelihood of LUTS/impact. Longitudinal studies are needed to further investigate the association between cognitive function and LUTS/impact, as well as potential explanatory mechanisms, particularly as women age and cognitive function varies to a greater degree.

Abdominal fat depots are related to lower cognitive functioning and brain volumes in middle-aged males at high Alzheimer's risk

OBJECTIVE

High BMI, which poorly represents specific fat depots, is linked to poorer cognition and higher dementia risk, with different associations between sexes. This study examined associations of abdominal fat depots with cognition and brain volumes and whether sex modifies this association.

METHODS

A total of 204 healthy middle-aged offspring of Alzheimer's dementia patients (mean age = 59.44, 60% females) underwent abdominal magnetic resonance imaging to quantify hepatic, pancreatic, visceral, and subcutaneous adipose tissue and to assess cognition and brain volumes.

RESULTS

In the whole sample, higher hepatic fat percentage was associated with lower total gray matter volume (β = -0.17, p < 0.01). Primarily in males, higher pancreatic fat percentage was associated with lower global cognition (males: β = -0.27, p = 0.03; females: β = 0.01, p = 0.93) executive function (males: β = -0.27, p = 0.03; females: β = 0.02, p = 0.87), episodic memory (males: β = -0.28, p = 0.03; females: β = 0.07, p = 0.48), and inferior frontal gyrus volume (males: β = -0.28, p = 0.02; females: β = 0.10, p = 0.33). Visceral and subcutaneous adipose tissue was inversely associated with middle frontal and superior frontal gyrus volumes in males and females.

CONCLUSIONS

In middle-aged males at high Alzheimer's dementia risk, but not in females, higher pancreatic fat was associated with lower cognition and brain volumes. These findings suggest a potential sex-specific link between distinct abdominal fat with brain health.

Dietary Inflammatory Index and Cognitive Function: Findings from a Cross-Sectional Study in Obese Chinese Township Population from 45 to 75 Years

Background and Objective

Cognitive dysfunction is highly prevalent in obese people, and food is a key factor in obesity, and dietary inflammatory index (DII) can reflect whether diet has anti-inflammatory or pro-inflammatory potential. In addition, dietary fatty acid consumption is linked to inflammation, obesity, and cognitive impairment. Erythrocyte membrane fatty acids can reflect dietary fatty acid intake. Our hypothesis was that erythrocyte membrane fatty acids might have a significant impact on the relationship between DII and cognition in obese individuals, and we designed experiments to test the hypothesis.

Methods

In three villages in Beijing, we collected 579 respondents from individuals 45 to 75 years old and categorized them by body mass index. The Montreal Cognitive Assessment (MoCA) score and DII score was calculated and gas chromatography was used to measure the proportion of erythrocyte membrane fatty acids. The relationship between the DII score and cognition was examined using multiple linear regression and binary logistic regression. Mediation analysis can help to understand the causal chain between variables, deeply explore the internal relationship and mechanism of action between variables. So a multiple chain mediation model was developed to investigate the mediating factors between the DII score and cognitive association.

Results

According to adjusted linear regression, higher DII scores were linked to lower MoCA scores in the obese group. The negative correlation between DII score and cognitive function score remains in binary linear regression. We discovered through mediation analysis that erythrocyte membrane fatty acids mediate the detrimental link between DII and cognitive function in obese individuals.

Conclusion

We propose that higher DII scores in obese people are associated with a decline in cognitive function. In addition, this effect might be mediated via the fatty acids in the erythrocyte membrane.

Global epidemiology of type 2 diabetes in patients with NAFLD or MAFLD: a systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD) shares common pathophysiological mechanisms with type 2 diabetes, making them significant risk factors for type 2 diabetes. The present study aimed to assess the epidemiological feature of type 2 diabetes in patients with NAFLD or MAFLD at global levels.

METHODS

Published studies were searched for terms that included type 2 diabetes, and NAFLD or MAFLD using PubMed, EMBASE, MEDLINE, and Web of Science databases from their inception to December 2022. The pooled global and regional prevalence and incidence density of type 2 diabetes in patients with NAFLD or MAFLD were evaluated using random-effects meta-analysis. Potential sources of heterogeneity were investigated using stratified meta-analysis and meta-regression.

RESULTS

A total of 395 studies (6,878,568 participants with NAFLD; 1,172,637 participants with MAFLD) from 40 countries or areas were included in the meta-analysis. The pooled prevalence of type 2 diabetes among NAFLD or MAFLD patients was 28.3% (95% confidence interval 25.2-31.6%) and 26.2% (23.9-28.6%) globally. The incidence density of type 2 diabetes in NAFLD or MAFLD patients was 24.6 per 1000-person year (20.7 to 29.2) and 26.9 per 1000-person year (7.3 to 44.4), respectively.

CONCLUSIONS

The present study describes the global prevalence and incidence of type 2 diabetes in patients with NAFLD or MAFLD. The study findings serve as a valuable resource to assess the global clinical and economic impact of type 2 diabetes in patients with NAFLD or MAFLD.

Liver integrity and the risk of Alzheimer's disease and related dementias

INTRODUCTION

We examined midlife (1990-1992, mean age 57) and late-life (2011-2013, mean age 75) nonalcoholic fatty liver disease (NAFLD) and aminotransferase with incident dementia risk through 2019 in the Atherosclerosis Risk in Communities (ARIC) Study.

METHODS

We characterized NAFLD using the fatty liver index and fibrosis-4, and we categorized aminotransferase using the optimal equal-hazard ratio (HR) approach. We estimated HRs for incident dementia ascertained from multiple data sources.

RESULTS

Adjusted for demographics, alcohol consumption, and kidney function, individuals with low, intermediate, and high liver fibrosis in midlife (HRs: 1.45, 1.40, and 2.25, respectively), but not at older age, had higher dementia risks than individuals without fatty liver. A U-shaped association was observed for alanine aminotransferase with dementia risk, which was more pronounced in late-life assessment.

DISCUSSION

Our findings highlight dementia burden in high-prevalent NAFLD and the important feature of late-life aminotransaminase as a surrogate biomarker linking liver hypometabolism to dementia. Highlights Although evidence of liver involvement in dementia development has been documented in animal studies, the evidence in humans is limited. Midlife NAFLD raised dementia risk proportionate to severity. Late-life NAFLD was not associated with a high risk of dementia. Low alanine aminotransferase was associated with an elevated dementia risk, especially when measured in late life.

Impact of smoking cessation on non-alcoholic fatty liver disease prevalence: a systematic review and meta-analysis

OBJECTIVES

The negative effects of smoking on numerous cardiovascular and metabolic diseases have been widely acknowledged. However, the potential effect of smoking cessation is relatively unelucidated. The objective of this study is to explore whether the prevalence of non-alcoholic fatty liver disease (NAFLD) in former smokers differs from the prevalence in current smokers.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Four databases, that is, PubMed, Web of Science, Journal@Ovid and Scopus were searched from inception to 31 January 2023.

ELIGIBILITY CRITERIA

Population-based cross-sectional studies, including the baseline data of cohort studies with identified NAFLD diagnostic methods, and smoking status (current smoker or former smoker) of participants were included.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted the data including cigarette smoking status, country/region of studies, NAFLD diagnostic methods, sex, the average age and body mass index (BMI) of NAFLD participants and assessed the risk of bias with Agency for Healthcare Research and Quality (AHRQ) methodology checklist. Risk ratio (RR) of NAFLD prevalence in former smokers was pooled using the random-effects model.

RESULTS

28 studies involving 4 465 862 participants were included. Compared with current smokers, the RR of overall NAFLD prevalence in former smokers was 1.13 (95% CI: 1.08 to 1.19, prediction interval: 0.92-1.39). This result persisted after adjustment for diagnostic methods, country/region, sex, age and BMI. Sensitivity analysis and risk of bias assessment indicated a stable conclusion.

CONCLUSIONS

NAFLD prevalence in former smokers was at least not lower than that in current smokers and was partially related to increased BMI after smoking cessation, indicating that smoking cessation was possibly not a protective factor against NAFLD. Although the meta-analysis based on cross-sectional studies cannot conclude the causal relationships between smoking cessation and NAFLD onset, the potential onset of NAFLD associated with smoking cessation should be highlighted.

PROSPERO REGISTRATION NUMBER

CRD42023394944.

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.

The association between regional adiposity, cognitive function, and dementia-related brain changes: a systematic review

Background

Adiposity has been previously associated with cognitive impairment and Alzheimer's disease and related disorders (ADRD). Body mass index (BMI) is the most common measure of global adiposity, but inconsistent results were found since it is a global measurement. BMI does not represent regional fat distribution which differs between sexes, race, and age. Regional fat distribution may contribute differently to cognitive decline and Alzheimer's disease (AD)-related brain changes. Fat-specific targeted therapies could lead to personalized improvement of cognition. The goal of this systematic review is to explore whether regional fat depots, rather than central obesity, should be used to understand the mechanism underlying the association between adiposity and brain.

Methods

This systematic review included 33 studies in the English language, conducted in humans aged 18 years and over with assessment of regional adiposity, cognitive function, dementia, and brain measures. We included only studies that have assessed regional adiposity using imaging technics and excluded studies that were review articles, abstract only or letters to editor. Studies on children and adolescents, animal studies, and studies of patients with gastrointestinal diseases were excluded. PubMed, PsychInfo and web of science were used as electronic databases for literature search until November 2022.

Results

Based on the currently available literature, the findings suggest that different regional fat depots are likely associated with increased risk of cognitive impairment, brain changes and dementia, especially AD. However, different regional fat depots can have different cognitive outcomes and affect the brain differently. Visceral adipose tissue (VAT) was the most studied regional fat, along with liver fat through non-alcoholic fatty liver disease (NAFLD). Pancreatic fat was the least studied regional fat.

Conclusion

Regional adiposity, which is modifiable, may explain discrepancies in associations of global adiposity, brain, and cognition. Specific regional fat depots lead to abnormal secretion of adipose factors which in turn may penetrate the blood brain barrier leading to brain damage and to cognitive decline.

Synergistic Effect of Diet and Physical Activity on a NAFLD Cohort: Metabolomics Profile and Clinical Variable Evaluation

Together with its comorbidities, nonalcoholic fatty liver disease (NAFLD) is likely to rise further with the obesity epidemic. However, the literature's evidence shows how its progression can be reduced by the administration of calorie-restrictive dietary interventions and physical activity regimens. The liver function and the gut microbiota have been demonstrated to be closely related. With the aim of ascertaining the impact of a treatment based on the combination of diet and physical activity (versus physical activity alone), we recruited 46 NAFLD patients who were divided into two groups. As a result, we traced the connection between volatile organic compounds (VOCs) from fecal metabolomics and a set of statistically filtered clinical variables. Additionally, we identified the relative abundances of gut microbiota taxa obtained from 16S rRNA gene sequencing. Statistically significant correlations emerged between VOCs and clinical parameters, as well as between VOCs and gut microbiota taxa. In comparison with a physical activity regimen alone, we disclose how ethyl valerate and pentanoic acid butyl ester, methyl valerate, and 5-hepten-2-one, 6-methyl changed because of the positive synergistic effect exerted by the combination of the Mediterranean diet and physical activity regimens. Moreover, 5-hepten-2-one, 6-methyl positively correlated with Sanguinobacteroides, as well as the two genera Oscillospiraceae-UCG002 and Ruminococcaceae UCG010 genera.

Role of Nutrition in the Etiopathogenesis and Prevention of Nonalcoholic Fatty Liver Disease (NAFLD) in a Group of Obese Adults

Nonalcoholic fatty liver disease (NAFLD) is liver damage characterized by an accumulation of triglycerides in hepatocytes of >5% (due to an alteration of the balance of the lipid metabolism in favour of lipogenesis compared to lipolysis) that is not induced by the consumption of alcohol. The pathology includes simple steatosis and nonalcoholic steatohepatitis, or NASH (steatosis associated with microinflammatory activities), which can evolve in 15% of subjects with hepatic fibrosis to cirrhosis and the development of hepatocellular carcinoma. The aim of this study is to report the role of macro- and micronutrients in the pathogenesis and prevention of NAFLD in obese subjects. A total of 22 obese or overweight patients with hepatic steatosis were monitored periodically, evaluating their eating habits, fasting glycaemia, lipid picture, liver enzymes, anthropometric parameters, nutrition status, liver ultrasound, oxidative stress, and adherence to the Mediterranean diet. A statistical analysis shows a significant positive relationship between total cholesterol and the Mediterranean adequacy index (MAI) (r = -0.57; p = 0.005) and a significant negative relationship between ALT transaminases and the MAI (r = -0.56; p = 0.007). Nutrition and diet are important factors in the pathogenesis and prevention of NAFLD. The dietary model, based on the canons of the Mediterranean diet, prevents and reduces the accumulation of fat in hepatocytes. Therefore, in agreement with other studies in the literature, we can state that a dietary model characterized by foods rich in fibre, carotenoids, polyphenols, ω3 fatty acids, folic acid, and numerous other molecules is inversely correlated with the serum levels of ALT transaminases, an enzyme whose level increases when the liver is damaged and before the most obvious symptoms of organ damage appear.

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.

Association of liver disease with brain volume loss, cognitive decline, and plasma neurodegenerative disease biomarkers

Although liver dysfunction has been implicated in Alzheimer's disease (AD), it remains unknown how liver disease may influence the trajectory of brain and cognitive changes in older adults. We related self-reported liver disease to longitudinal measures of brain structure and cognition, as well as baseline measures of plasma AD/neurodegeneration biomarkers in the Baltimore Longitudinal Study of Aging. Liver disease was identified using ICD-9 classification codes. Brain volume and cognition were assessed serially using 3T-MRI and a cognitive battery. 1008, 2157, and 780 participants were included in the MRI, cognitive, and plasma biomarker analysis, respectively. After adjustment for confounders, liver disease was associated with accelerated decline in total brain and white matter volume, but not total gray matter or AD signature region volume. Although liver disease showed no relationship with domain-specific cognitive decline or plasma biomarkers, participants with a history of hepatitis demonstrated accelerated decline in verbal fluency and elevated neurofilament light. Results suggest all-cause liver disease may accelerate brain volume loss but does not appear to promote AD-specific neurocognitive changes.

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.

Severe Hepatic Steatosis by Controlled Attenuation Parameter Predicts Quality of Life Independent of Fibrosis

BACKGROUND & AIM

Liver fibrosis is associated with poor patient-reported outcomes (PROs), but the impact of steatosis is unknown. We aimed to evaluate the impact of steatosis on PROs independent of liver fibrosis.

METHODS

We evaluated the impact of steatosis, measured by Controlled-Attenuation Parameter (CAP) on transient elastography, and PROs using the 2017-2018 National Health and Nutrition Examination Survey (NHANES) database. We used univariate and multivariate logistic and ordinal regression to evaluate categorical CAP score with PROs measuring physical disability, general health and depression.

RESULTS

Of 4,509 participants included, 38% had severe steatosis (> 280 dB/m). Those with severe steatosis were older and more likely to be male (56% vs. 43% and 51%). On univariate analysis, severe steatosis was associated with more difficulty walking (P = 0.01), dressing (P = 0.005), lifting objects (P = 0.02), bending (P < 0.001), and moving large objects (P = 0.0006). After multivariate adjustment, severe steatosis remained associated with difficulty lifting objects (odds ratio [OR]: 1.7, 95% confidence interval [CI]: 1.2-2.4, P = 0.01) and difficulty bending (OR: 1.8, 95% CI: 1.2-2.7, P = 0.006). Severe steatosis increased risk of having any of the disabilities (OR: 1.7, 95% CI: 1.2-2.4, P = 0.008) and had higher ordinal disability index (OR: 1.6, 95% CI: 1.2-2.2, P = 0.007). Lastly, severe steatosis was also associated with worse self-perceived health status (OR: 1.5, 95% CI: 1.2-1.9, P = 0.002), while general health compared to one year ago and depression trended toward significance.

CONCLUSION

Patients with severe steatosis are at increased risk of physical disability and have worse self-perceived health status independent of liver fibrosis.

Non-alcoholic fatty liver disease, serum cytokines, and dementia among rural-dwelling older adults in China: a population-based study

BACKGROUND

Little is known about whether non-alcoholic fatty liver disease (NAFLD) is associated with dementia as well as the role of serum pro-inflammatory cytokines in the association. We aimed to investigate the interrelationships of NAFLD, serum cytokines, and dementias among rural-dwelling older adults.

METHODS

This population-based cross-sectional study included 5,129 participants (age ≥60 years; 61.79% women) who were living in rural communities and examined in March-September 2018. NAFLD was defined through transabdominal ultrasound examination in the absence of hepatitis B or excessive alcohol consumption. Serum cytokines were measured in a subsample (n=1,686). Dementia, Alzheimer's disease (AD), and vascular dementia (VaD) were diagnosed following international criteria. Data were analyzed with logistic regression and mediation models.

RESULTS

Of the 5,129 participants, 455 (8.87%) were detected with moderate-to-severe NAFLD and 292 (5.69%) were diagnosed with dementia (188 with AD and 96 with VaD). The multivariable-adjusted odds ratios (ORs) associated with moderate-to-severe (vs. no-to-mild) NAFLD were 2.22 (95% confidence interval, 1.41-3.49) for all-cause dementia, 1.88 (1.01-3.50) for AD, and 2.62 (1.33-5.17) for VaD. In the cytokine subsample, controlling for multiple potential confounders, moderate-to-severe NAFLD was significantly associated with higher levels of serum monocyte chemotactic protein-1 (MCP-1), interleukin-17A (IL-17A), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α) (P<0.05). The mediation analysis showed that IL-6 mediated 12.56% of the association between NAFLD and VaD.

CONCLUSIONS

Moderate-to-severe NAFLD is associated with dementia and AD, especially with VaD, among rural-dwelling Chinese older adults, in which the association with VaD is partly mediated by serum inflammatory cytokines.

Association of chronic liver disease with cognition and brain volumes in two randomized controlled trial populations

BACKGROUND AND PURPOSE

We examined the association of chronic liver disease with cognition and brain imaging markers of cognitive impairment using data from two large randomized controlled trials that included participants based on diabetes and hypertension, two common systemic risk factors for cognitive impairment and dementia.

METHODS

We performed post hoc analyses using data from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) and Systolic Blood Pressure Intervention Trial (SPRINT) studies, which included participants with diabetes and hypertension, respectively. Data were from the NHLBI Biologic Specimen and Data Repository Information Coordinating Center. In ACCORD, our measure of chronic liver disease was the Dallas Steatosis Index (DSI). In SPRINT, we used self-reported chronic liver disease. We used linear regression to evaluate the association between the measure of chronic liver disease and both baseline and longitudinal cognitive test performance and brain magnetic resonance imaging volume measurements.

RESULTS

Among 2969 diabetic participants in ACCORD, the mean age of participants was 62 years, 47% were women. The median DSI was 1.0 (IQR, 0.2-1.8); a DSI of 1.0 corresponds to approximately a > 70% probability of having NAFLD. Among 2890 hypertensive participants in SPRINT, the mean age was 68 years, and 37% were women, and 60 (2.1%) had chronic liver disease. There were no consistent associations between liver disease and cognitive performance or brain volumes at baseline or longitudinally after adjustment.

CONCLUSION

Markers of chronic liver disease were not associated with cognitive impairment or related brain imaging markers among individuals with diabetes and hypertension.

Non-Alcoholic Fatty Liver Disease, Liver Fibrosis, and Regional Amyloid-β and Tau Pathology in Middle-Aged Adults: The Framingham Study

BACKGROUND

Liver steatosis and fibrosis are emerging as risk factors for multiple extrahepatic health conditions; however, their relationship with Alzheimer's disease pathology is unclear.

OBJECTIVE

To examine whether non-alcoholic fatty liver disease (NAFLD) and FIB-4, a non-invasive index of advanced fibrosis, are associated with brain amyloid-β (Aβ) and tau pathology.

METHODS

The study sample included Framingham Study participants from the Offspring and Third generation cohorts who attended exams 9 (2011-2014) and 2 (2008-2011), respectively. Participants underwent 11C-Pittsburgh Compound-B amyloid and 18F-Flortaucipir tau positron emission tomography (PET) imaging and abdomen computed tomography, or had information on all components of the FIB-4 index. Linear regression models were used to assess the relationship of NAFLD and FIB-4 with regional tau and Aβ, adjusting for potential confounders and multiple comparisons.

RESULTS

Of the subsample with NAFLD information (N = 169; mean age 52±9 y; 57% males), 57 (34%) had NAFLD. Of the subsample with information on liver fibrosis (N = 177; mean age 50±10 y; 51% males), 34 (19%) had advanced fibrosis (FIB-4 >  1.3). Prevalent NAFLD was not associated with Aβ or tau PET. However, FIB-4 index was significantly associated with increased rhinal tau (β= 1.03±0.33, p = 0.002). Among individuals with prevalent NAFLD, FIB-4 was related to inferior temporal, parahippocampal gyrus, entorhinal and rhinal tau (β= 2.01±0.47, p <  0.001; β= 1.60±0.53, p = 0.007, and β= 1.59±0.47, p = 0.003 and β= 1.60±0.42, p = 0.001, respectively) and to Aβ deposition overall and in the inferior temporal and parahippocampal regions (β= 1.93±0.47, p <  0.001; β= 1.59±0.38, p <  0.001, and β= 1.52±0.54, p = 0.008, respectively).

CONCLUSION

This study suggests a possible association between liver fibrosis and early Alzheimer's disease pathology, independently of cardio-metabolic risk factors.

Association between the Erythrocyte Membrane Fatty Acid Profile and Cognitive Function in the Overweight and Obese Population Aged from 45 to 75 Years Old

Dietary fatty acid intake is closely related to the cognitive function of the overweight and obese population. However, few studies have specified the correlation between exact fatty acids and cognitive functions in different body mass index (BMI) groups. We aimed to explain these relationships and reference guiding principles for the fatty acid intake of the overweight and obese population. Normal weight, overweight, and obese participants were recruited to receive a cognitive function assessment and dietary survey, dietary fatty acids intake was calculated, and the erythrocyte membrane fatty acid profile was tested by performing a gas chromatography analysis. The percentages of saturated fatty acids (SFAs) in the obese group were higher, while monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were lower than in the normal weight and overweight groups. In the erythrocyte membrane, the increase of n-3 PUFAs was accompanied by cognitive decline in the overweight group, which could be a protective factor for cognitive function in the obese group. High n-6 PUFAs intake could exacerbate the cognitive decline in the obese population. Dietary fatty acid intake had different effects on the cognitive function of overweight and obese people, especially the protective effect of n-3 PUFAs; more precise dietary advice is needed to prevent cognitive impairment.

Cholesterol metabolism in aging simultaneously altered in liver and nervous system

In humans, aging, triggers increased plasma concentrations of triglycerides, cholesterol, low-density lipoproteins and lower capacity of high-density lipoproteins to remove cellular cholesterol. Studies in rodents showed that aging led to cholesterol accumulation in the liver and decrease in the brain with reduced cholesterol synthesis and increased levels of cholesterol 24-hydroxylase, an enzyme responsible for removing cholesterol from the brain. Liver diseases are also related to brain aging, inducing changes in cholesterol metabolism in the brain and liver of rats. It has been suggested that late onset Alzheimer's disease is associated with metabolic syndrome. Non-alcoholic fatty liver is associated with lower total brain volume in the Framingham Heart Study offspring cohort study. Furthermore, disorders of cholesterol homeostasis in the adult brain are associated with neurological diseases such as Niemann-Pick, Alzheimer, Parkinson, Huntington and epilepsy. Apolipoprotein E (apoE) is important in transporting cholesterol from astrocytes to neurons in the etiology of sporadic Alzheimer's disease, an aging-related dementia. Desmosterol and 24S-hydroxycholesterol are reduced in ApoE KO hypercholesterolemic mice. ApoE KO mice have synaptic loss, cognitive dysfunction, and elevated plasma lipid levels that can affect brain function. In contrast to cholesterol itself, there is a continuous uptake of 27- hydroxycholesterol in the brain as it crosses the blood-brain barrier and this flow can be an important link between intra- and extracerebral cholesterol homeostasis. Not surprisingly, changes in cholesterol metabolism occur simultaneously in the liver and nervous tissues and may be considered possible biomarkers of the liver and nervous system aging.

Association between age at onset of multimorbidity and incidence of dementia: 30 year follow-up in Whitehall II prospective cohort study

OBJECTIVE

To examine the association of midlife and late life multimorbidity, including severity of multimorbidity, with incident dementia.

DESIGN

Prospective cohort study.

SETTING

Civil service departments in London (Whitehall II study, study inception in 1985-88).

PARTICIPANTS

10 095 participants, aged 35 to 55 at baseline.

MAIN OUTCOME MEASURE

Incident dementia at follow-up between 1985 and 2019. Cause specific Cox proportional hazards regression was used to examine the association of multimorbidity overall and at age 55, 60, 65, and 70 with subsequent dementia, taking into account the competing risk of death.

RESULTS

The prevalence of multimorbidity (≥2 chronic diseases) was 6.6% (655/9937) at age 55 and 31.7% (2464/7783) at age 70; 639 cases of incident dementia occurred over a median follow-up of 31.7 years. After adjustment for sociodemographic factors and health behaviours, multimorbidity at age 55 was associated with subsequent risk of dementia (difference in incidence rate per 1000 person years 1.56, 95% confidence interval 0.62 to 2.77; hazard ratio 2.44, 95% confidence interval 1.82 to 3.26). The association weakened progressively with older age at onset of multimorbidity. At age 65, onset of multimorbidity before age 55 was associated with 3.86 (1.80 to 6.52) per 1000 person years higher incidence of dementia (hazard ratio 2.46, 1.80 to 2.26) and onset between 60 and 65 was associated with 1.85 (0.64 to 3.39) per 1000 person years higher incidence (1.51, 1.16 to 1.97). Severity of multimorbidity (≥3 chronic diseases) at age 55 was associated with a 5.22 (1.14 to 11.95) per 1000 person years higher incidence of dementia (hazard ratio 4.96, 2.54 to 9.67); the same analyses at age 70 showed 4.49 (2.33 to 7.19) per 1000 person years higher incidence (1.65, 1.25 to 2.18).

CONCLUSION

Multimorbidity, particularly when onset is in midlife rather than late life, has a robust association with subsequent dementia. The increasingly younger age at onset of multimorbidity makes prevention of multimorbidity in people with a first chronic disease important.

Fatty liver and cerebrovascular disease: plausible association and possible mechanisms

PURPOSE OF REVIEW

Nonalcoholic fatty liver disease (NAFLD) is a common comorbidity and has wide ranging extrahepatic manifestations, including through cardiometabolic pathways. As such, there is growing interest in the impact of NAFLD on cerebrovascular disease and brain health more broadly. In this review, we assess recent research into understanding the association between NAFLD and brain health while highlighting potential clinical implications.

RECENT FINDINGS

Mechanistically, NAFLD is characterized by both a proinflammatory and proatherogenic state, which results in vascular inflammation and neurodegeneration, potentially leading to clinical and subclinical cerebrovascular disease. Mounting epidemiological evidence suggests an association between NAFLD and an increased risk and severity of stroke, independent of other vascular risk factors. Studies also implicate NAFLD in subclinical cerebrovascular disease, such as carotid atherosclerosis and microvascular disease. In contrast, there does not appear to be an independent association between NAFLD and cognitive impairment.

SUMMARY

The current literature supports the formulation of NAFLD as a multisystem disease that may also have implications for cerebrovascular disease and brain health. Further prospective studies are needed to better assess a temporal relationship between the two diseases, confirm these early findings, and decipher mechanistic links.

A clinical overview of non-alcoholic fatty liver disease: A guide to diagnosis, the clinical features, and complications-What the non-specialist needs to know

Non-alcoholic fatty liver disease (NAFLD) has a rapidly rising prevalence worldwide and is the most common cause of liver disease in developed countries. In this article, we discuss the spectrum of disease of NAFLD with a focus on the earlier spectrum of the disease that is commonly encountered by non-specialists, as well as the hepatic and extra-hepatic associations of the disease. We discuss in detail the two common presentations of NAFLD, incidentally detected hepatic steatosis and asymptomatic raised liver enzymes, and provide an algorithm for management and continued to follow up for these patients. Considerations for the management of cardiovascular comorbidities in these patients are also discussed. Finally, we cover the topic of screening for NAFLD in high-risk populations.

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.