Association of Nonalcoholic Fatty Liver Disease with Incident Dementia Later in Life Among Elder Adults

Role of metabolic dysfunction and inflammation along the liver-brain axis in animal models with obesity-induced neurodegeneration

The interaction between metabolic dysfunction and inflammation is central to the development of neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease. Obesity-related conditions like type 2 diabetes and non-alcoholic fatty liver disease exacerbate this relationship. Peripheral lipid accumulation, particularly in the liver, initiates a cascade of inflammatory processes that extend to the brain, influencing critical metabolic regulatory regions. Ceramide and palmitate, key lipid components, along with lipid transporters lipocalin-2 and apolipoprotein E, contribute to neuroinflammation by disrupting blood-brain barrier integrity and promoting gliosis. Peripheral insulin resistance further exacerbates brain insulin resistance and neuroinflammation. Preclinical interventions targeting peripheral lipid metabolism and insulin signaling pathways have shown promise in reducing neuroinflammation in animal models. However, translating these findings to clinical practice requires further investigation into human subjects. In conclusion, metabolic dysfunction, peripheral inflammation, and insulin resistance are integral to neuroinflammation and neurodegeneration. Understanding these complex mechanisms holds potential for identifying novel therapeutic targets and improving outcomes for neurodegenerative diseases.

Factor modification in the association between high-density lipoprotein cholesterol and liver cancer risk in a nationwide cohort

BACKGROUND/AIMS

The effect modification by smoking and menopausal status in the association between high-density lipoprotein cholesterol (HDL-C) and liver cancer risk has not been reported.

METHODS

This population-based cohort study included 4.486 million cancer-free individuals among those who underwent national cancer screening in 2010 and were followed up until December 2017. We conducted analyses in populations that excluded people with chronic hepatitis B, chronic hepatitis C and liver cirrhosis (Model I) and that included those diseases (Model III). HDL-C level was classified into eight groups at 10-mg/dL intervals. Liver cancer risk by HDL-C was measured using adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

During follow-up, 18 795 liver cancers in Model I and 20 610 liver cancers in Model III developed. In Model I, low HDL-C levels (aHR 1.83; 95% CI 1.65-2.04) and extremely high HDL-C levels (aHR 1.24; 95% CI 1.10-1.40) were associated with an increased liver cancer risk compared with a moderate HDL-C level of 50-59mg/dL. This association was similar in both men and women with larger effect size in men (aHR, 1.91; 95% CI, 1.70-2.15). The hazardous association between low HDL-C and liver cancer risk was remarkable in current smokers (aHR, 2.19; 95% CI, 1.84-2.60) and in pre-menopausal women (aHR, 2.91; 95% CI, 1.29-6.58) compared with post-menopausal women (aHR, 1.45; 95% CI, 1.10-1.93). This association was similarly observed in Model III.

CONCLUSIONS

Low and extremely high HDL-C levels were associated with an increased liver cancer risk. The unfavourable association between low HDL-C and liver cancer was remarkable in smokers and pre-menopausal women.

Peripheral amyloid-β clearance mediates cognitive impairment in non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a prevalent risk factor for cognitive impairment. Cerebral amyloid-β (Aβ) accumulation, as an important pathology of cognitive impairment, can be caused by impaired Aβ clearance in the periphery. The liver is the primary organ for peripheral Aβ clearance, but the role of peripheral Aβ clearance in NAFLD-induced cognitive impairment remains unclear.

METHODS

We examined correlations between NAFLD severity, Aβ accumulation, and cognitive performance in female Sprague-Dawley rats. The impact of NAFLD on hepatic Aβ clearance and the involvement of low-density lipoprotein receptor-related protein 1 (LRP-1) were assessed in rat livers and cultured hepatocytes. Additionally, a case-control study, including 549 NAFLD cases and 549 controls (782 males, 316 females), investigated the interaction between NAFLD and LRP-1 rs1799986 polymorphism on plasma Aβ levels.

FINDINGS

The severity of hepatic steatosis and dysfunction closely correlated with plasma and cerebral Aβ accumulations and cognitive deficits in rats. The rats with NAFLD manifested diminished levels of LRP-1 and Aβ in liver tissue, with these reductions inversely proportional to plasma and cerebral Aβ concentrations and cognitive performance. In vitro, exposure of HepG2 cells to palmitic acid inhibited LRP-1 expression and Aβ uptake, which was subsequently reversed by a peroxisome proliferator-activated receptor α (PPARα) agonist. The case-control study revealed NAFLD to be associated with an increment of 8.24% and 10.51% in plasma Aβ40 and Aβ42 levels, respectively (both P < 0.0001). Moreover, the positive associations between NAFLD and plasma Aβ40 and Aβ42 levels were modified by the LRP-1 rs1799986 polymorphism (P for interaction = 0.0017 and 0.0015, respectively).

INTERPRETATION

LRP-1 mediates the adverse effect of NAFLD on peripheral Aβ clearance, thereby contributing to cerebral Aβ accumulation and cognitive impairment in NAFLD.

FUNDING

Major International (Regional) Joint Research Project, National Key Research and Development Program of China, National Natural Science Foundation of China, and the Angel Nutrition Research Fund.

Disentangling the contributions of alcohol use disorder and alcohol-related liver disease towards dementia: A population-based cohort study

AIMS

The aim of the study was to disentangle the contributions of alcohol and alcohol-related liver disease (ALD) towards dementia by independently measuring the association between alcohol use disorder (AUD) alone and ALD with dementia.

DESIGN

This was a nation-wide cohort study.

SETTING

The study was conducted in Sweden from 1987 to 2020.

PARTICIPANTS

DELIVER (DEcoding the epidemiology of LIVER disease in Sweden) cohort, containing administrative codes on patients with chronic liver disease from the National Patient Register and other registers between 1987 and 2020.

MEASUREMENTS

International Classification of Disease 9th (ICD-9) and 10th (ICD-10) version codes were used to define the presence of AUD, ALD and dementia. The associations of AUD alone and ALD with incident dementia were estimated using Cox regression models adjusting for potential confounders. Cumulative incidences were also calculated accounting for competing risks of death.

FINDINGS

A total of 128 884 individuals with AUD alone, 17 754 with ALD and 2 479 049 controls were identified. During a median follow-up of 8.9 years, 13 395 (10.4%), 2187 (12.3%) and 138 925 (5.6%) dementia cases were identified in these groups, respectively. Dementia rates were increased in AUD alone [adjusted hazard ratio (aHR) = 4.6, 95% confidence interval (CI) = 4.5-4.6] and in ALD (aHR = 8.6, 95% CI = 8.3-9.0) compared with controls. AUD alone was also associated with increased rates of vascular dementia (aHR = 2.3, 95% CI = 2.2-2.5) and Alzheimer's disease (aHR = 1.4, 95% CI = 1.3-1.4), while ALD was only associated with vascular dementia (aHR = 2.7, 95% CI = 2.3-3.2). The median age at dementia diagnosis was 67 years [interquartile range (IQR) = 56-76] in AUD alone and 63 years (IQR = 56-71) in ALD compared with 85 years (IQR = 79-89) in controls.

CONCLUSION

In Sweden, patients with alcohol use disorder (AUD) appear to have increased rates of dementia and diagnosis at a younger age, compared with patients without AUD. Concurrent alcohol-related liver disease appears to increase the diagnosis rate and lower the median age further.

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.

Association of Metabolic Dysfunction-Associated Fatty Liver Disease with Cognitive Impairment and All-Cause Dementia: A Comprehensive Review

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a significant public health concern, affecting one-third of the global population and posing a risk for progressive liver disease. MAFLD is characterized by hepatic steatosis and impaired metabolic status, which not only impact the liver but also other systems of the human body, making it a multisystemic disorder. Emerging evidence suggests that MAFLD and its associated pathological pathways may contribute to cognitive impairment, potentially through neuroinflammation and neurodegeneration. Studies have detected cognitive impairment in patients with MAFLD using magnetic resonance imaging, which revealed decreased brain volume and cerebral perfusion, in addition to self-reported cognitive tests. While numerous studies have demonstrated an association between MAFLD and cognitive impairment, the relationship between MAFLD and all-cause dementia remains controversial. However, the shared pathological pathways between MAFLD and dementia, such as systemic inflammation, insulin resistance, gut dysbiosis, hyperammonemia, and vascular dysfunction, indicate the possibility of a common prevention strategy for both diseases. In this review, we provide a summary of the current evidence regarding the association between cognitive impairment, all-cause dementia, and MAFLD.

Association of Thyroid Hormone Medication Adherence With Risk of Dementia

CONTEXT

Recent studies suggest that hypothyroidism is a risk factor for dementia. Based on existing literature, it is unclear if treatment or compliance to treatment is associated with decreased dementia risk in hypothyroidism patients.

OBJECTIVE

To determine the association between thyroid hormone medication adherence and risk of dementia.

METHODS

A population-based cohort study following patients with newly diagnosed hypothyroidism until incidence of dementia, death, or December 31, 2020, whichever came earliest. The study comprised 41 554 older adults age 50 and above with newly diagnosed hypothyroidism between 2004 and 2008 who underwent health screening. Risk of dementia was evaluated using multivariable-adjusted Cox proportional hazards regression.

RESULTS

Among 5188 men (12.5%) and 36 366 (87.5%) women, 2120 cases of incident dementia were identified. After stratification of the participants according to the interquartile range of the medication possession ratio (MPR), the fourth quartile (highest adherence) showed a 14% lower risk of overall dementia compared with the first quartile (lowest adherence) (adjusted hazard ratio 0.86; 95% CI 0.76-0.97). No consistent association was observed between thyroid hormone medication adherence and vascular dementia. After a dichotomous stratification of the MPR, higher MPR (≥0.8) showed a lower risk of Alzheimer disease (adjusted hazard ratio 0.91; 95% CI 0.84-0.99) than lower MPR (<0.8).

CONCLUSION

Better adherence to thyroid hormone medication may be beneficial in preventing incident dementia, especially Alzheimer disease, in older adults with newly diagnosed hypothyroidism. Along with the resolution of hypothyroid symptoms and the reduction of cardiovascular risk factors, the reduction of dementia risk may be another potential benefit of thyroid hormone medication.

Magnetic resonance elastography-based prediction model for hepatic decompensation in NAFLD: A multicenter cohort study

BACKGROUND AND AIMS

Magnetic resonance elastography (MRE) is an accurate, continuous biomarker of liver fibrosis; however, the optimal combination with clinical factors to predict the risk of incident hepatic decompensation is unknown. Therefore, we aimed to develop and validate an MRE-based prediction model for hepatic decompensation for patients with NAFLD.

APPROACH AND RESULTS

This international multicenter cohort study included participants with NAFLD undergoing MRE from 6 hospitals. A total of 1254 participants were randomly assigned as training (n = 627) and validation (n = 627) cohorts. The primary end point was hepatic decompensation, defined as the first occurrence of variceal hemorrhage, ascites, or HE. Covariates associated with hepatic decompensation on Cox-regression were combined with MRE to construct a risk prediction model in the training cohort and then tested in the validation cohort. The median (IQR) age and MRE values were 61 (18) years and 3.5 (2.5) kPa in the training cohort and 60 (20) years and 3.4 (2.5) kPa in the validation cohort, respectively. The MRE-based multivariable model that included age, MRE, albumin, aspartate aminotransferase, and platelets had excellent discrimination for the 3- and 5-year risk of hepatic decompensation (c-statistic 0.912 and 0.891, respectively) in the training cohort. The diagnostic accuracy remained consistent in the validation cohort with a c-statistic of 0.871 and 0.876 for hepatic decompensation at 3 and 5 years, respectively, and was superior to Fibrosis-4 in both cohorts ( p < 0.05).

CONCLUSIONS

An MRE-based prediction model allows for accurate prediction of hepatic decompensation and assists in the risk stratification of patients with NAFLD.

Metabolic dysfunction-associated steatotic liver disease increases the risk of incident cardiovascular disease: a nationwide cohort study

Background

The various subcategories under the overarching term of steatotic liver disease (SLD) have been recently proposed by the nomenclature consensus group and endorsed by international academic liver societies. Our aim was to investigate the association between each subtype of SLD and incident cardiovascular disease (CVD) in a nationwide Korean cohort.

Methods

From a nationwide health screening database from Korea, 351,068 individuals aged 47-86 years between January 1, 2009 and December 31, 2010 were included and followed until December 31, 2019 for a median of 9.0 years. Individuals were categorised into no SLD, metabolic dysfunction-associated steatotic liver disease (MASLD), MASLD with increased alcohol intake (MetALD), and alcohol-related liver disease (ALD). Hepatic steatosis was defined as fatty liver index ≥60. The primary outcome was a composite CVD, which includes non-fatal and fatal myocardial infarction and stroke. The subdistribution hazard ratio (SHR) was calculated using the Fine-Gray model with treating non-CVD-related death as a competing risk.

Findings

There were 199,817 male (56.9%) and 151,251 female (43.1%) with a median age of 55 years (interquartile range, 50-61). The prevalence of no SLD, MASLD, MetALD, and ALD was 44.3%, 47.2%, 6.4%, and 2.1%, respectively; and the incidence rate of CVD in each subcategory was 6.2, 8.5, 8.5, and 9.6 per 1000 person-years, respectively. MASLD (SHR, 1.19; 95% confidence interval [CI], 1.15-1.24), MetALD (SHR, 1.28; 95% CI, 1.20-1.36), and ALD (SHR, 1.29; 95% CI, 1.18-1.41) increased the risk of CVD compared to no SLD, which increment was in consecutive order (Ptrend < 0.001).

Interpretation

Individuals with MASLD, MetALD, or ALD are at an increased risk of developing incident CVD. Higher risk of CVD observed in MetALD compared to MASLD suggests the additive impact of alcohol consumption in conjunction with cardiometabolic risk factors on CVD development. These findings support and validate the utility of the new consensus criteria for SLD in predicting CVD.

Funding

The National Research Foundation of Korea and the Korea Centers for Disease Control and Prevention.

Sex-specific relationship between non-alcoholic fatty liver disease and amyloid-β in cognitively unimpaired individuals

Background

Non-alcoholic fatty liver disease (NAFLD) is known to be associated with a high risk of clinically diagnosed Alzheimer's disease (AD). Additionally, the prevalence of NAFLD and AD is higher in elderly females than in males. However, a sex-specific association between NAFLD and amyloid-beta (Aβ) deposition remains unclear. Therefore, we investigated the sex-specific relationship between NAFLD and Aβ deposition in a large-sized cohort of cognitively unimpaired (CU) individuals.

Methods

We enrolled 673 (410 [60.9%] females and 263 [39.1%] males) CU individuals aged ≥45 years who underwent Aβ positron emission tomography (PET). The presence of NAFLD, assessed using the hepatic steatosis index, and the severity of NAFLD, assessed using the Fibrosis-4 index, were considered predictors. Aβ deposition on PET was considered as an outcome.

Results

Females had a higher frequency of NAFLD than males (48 and 23.2%, p < 0.001). Among females, the presence of NAFLD (β = 0.216, p < 0.001) was predictive of increased Aβ deposition, whereas among males, the presence of NAFLD (β = 0.191, p = 0.064) was not associated with Aβ deposition. Among females, the presence of NAFLD with low (β = 0.254, p = 0.039), intermediate (β = 0.201, p = 0.006), and high fibrosis (β = 0.257, p = 0.027) was predictive of increased Aβ deposition. Aβ deposition also increased as the severity of NAFLD increased in females (p for trend = 0.001).

Conclusion

We highlight the marked influence of NAFLD and its severity on the risk of Aβ deposition in relation to sex. Furthermore, our findings suggest that sex-specific strategies regarding the management of NAFLD are necessary for the prevention of Aβ deposition.

HOMA-IR is an effective biomarker of non-alcoholic fatty liver disease in non-diabetic population

OBJECTIVES

This study aimed to investigate the correlation between homeostasis model assessment of insulin resistance (HOMA-IR) and non-alcoholic fatty liver disease (NAFLD) in the non-diabetic population and establish its diagnostic efficacy.

METHODS

This observational study involved participants divided into NAFLD and non-NAFLD groups, and baseline data were analyzed. Univariate and multivariate logistic regression analyses were used to correlate HOMA-IR with the risk of NAFLD. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy of HOMA-IR for NAFLD. Subgroup analyses of non-obese individuals were performed.

RESULTS

Overall, 2234 non-diabetic participants were included. The HOMA-IR was significantly higher in the NAFLD group than in the non-NAFLD group. Multivariate logistic regression analysis showed that HOMA-IR was a strong and independent risk factor for NAFLD after correcting for confounding factors. The area under the ROC curve (AUC) value of HOMA-IR for predicting NAFLD was 0.792. In the non-obese non-diabetic population, HOMA-IR was an independent risk factor for increased risk of lean NAFLD after correcting for confounding factors. The AUC value of HOMA-IR for predicting lean NAFLD was 0.770.

CONCLUSIONS

HOMA-IR is independently associated with the risk of NAFLD in the non-diabetic and non-obese non-diabetic populations and has good diagnostic value.

Impact of ectopic fat on brain structure and cognitive function:A systematic review and meta-analysis from observational studies

Ectopic fat, defined as a specific organ or compartment with the accumulation of fat tissue surrounding organs, is highly associated with obesity which has been identified as a risk factor for cognitive impairment and dementia. However, the relationship between ectopic fat and changes in brain structure or cognition is yet to be elucidated. Here, we investigated the effects of ectopic fat on brain structure and cognitive function via systemic review and meta-analysis. A total of 22 studies were included, encompassing 1,003,593 participants-obtained from electronic databases up to July 9, 2022. We found ectopic that fat was associated with decreased total brain volume and increased lateral ventricle volume. In addition, ectopic was associated with decreased cognitive scores and negatively correlated with cognitive function. More specifically, dementia development was correlated with increased levels of visceral fat. Overall, our data suggest that increased ectopic fat is associated with prominent structural changes in the brain and cognitive decline, an effect driven mainly by increases in visceral fat, while subcutaneous fat may be protective. Our results suggest that patients with increased visceral fat are at risk of developing cognitive impairment and, therefore, represent a subset of population in whom appropriate and timely preventive measures could be implemented.

Regulation of mild cognitive impairment associated with liver disease by humoral factors derived from the gastrointestinal tract and MRI research progress: a literature review

Patients with liver disease are prone to various cognitive impairments. It is undeniable that cognitive impairment is often regulated by both the nervous system and the immune system. In this review our research focused on the regulation of mild cognitive impairment associated with liver disease by humoral factors derived from the gastrointestinal tract, and revealed that its mechanisms may be involved with hyperammonemia, neuroinflammation, brain energy and neurotransmitter metabolic disorders, and liver-derived factors. In addition, we share the emerging research progress in magnetic resonance imaging techniques of the brain during mild cognitive impairment associated with liver disease, in order to provide ideas for the prevention and treatment of mild cognitive impairment in liver disease.

Non-Alcoholic Fatty Liver Disease, Atherosclerosis, and Cardiovascular Disease in Asia

The prevalence of non-alcoholic fatty liver disease (NAFLD) is estimated to increase to over half of the adult population by 2040 globally. Since the final diagnosis of NAFLD is made by a liver biopsy, several non-invasive approaches have been developed and validated to define NAFLD and evaluate NAFLD-associated diseases. Presently, NAFLD has been identified as an important and independent risk factor for developing several extrahepatic diseases, including atherosclerosis, cardiovascular disease (CVD), diabetes, and dementia. This review discusses current findings of up-to-date literature regarding the effects of NAFLD on the risk of atherosclerosis and CVD in Asia along with potential underlying biological mechanisms and therapeutic approaches to lower the NAFLD-related CVD risk. We further focus on the difference between NAFLD and metabolic dysfunction-associated fatty liver disease (MAFLD) on the risk of CVD and its implication by comparing the risk of NAFLD and MAFLD.

NAFLD does not increase the risk of incident dementia: A prospective study and meta-analysis

The association between nonalcoholic fatty liver disease (NAFLD) and incident dementia remains unclear. This study aimed to explore whether NAFLD was associated with the risk of incident dementia. We conducted a prospective analysis of 179,222 UK Biobank participants. NAFLD was diagnosed based on the fatty liver index. Cox proportional hazards models were used to estimate the adjusted hazard ratio (HR) and 95% confidence interval (CI) of NAFLD for incident dementia. The results from this and six previous prospective studies were combined in meta-analyses. During a median follow-up of 12.4 years (2,149,839 person-years), 4950 incident dementia cases, including 2318 Alzheimer's disease (AD) cases and 1135 vascular dementia (VD) cases, were identified. There was no significant association between NAFLD and the risks of all-cause dementia (HR: 0.97, 95% CI: 0.90-1.06; P = 0.528). NAFLD was also not significantly associated with AD or VD (HR: 0.95, 95% CI: 0.84-1.07, P = 0.401; HR: 1.03, 95% CI: 0.88-1.22, P = 0.689, respectively). Our meta-analyses of prospective studies included 879,749 subjects. The pooled HR of NAFLD for all-cause dementia was 1.01 (95% CI: 0.94-1.08), and that for VD was 0.99 (95% CI: 0.86-1.13). All included cohort studies were of high quality as assessed by the Newcastle‒Ottawa scale. We found no evidence of an association between NAFLD and incident dementia.

Immunotherapy for NAFLD and NAFLD-related hepatocellular carcinoma

The progression of non-alcoholic fatty liver disease (NAFLD), the most common liver disease, leads to non-alcoholic steatohepatitis and hepatocellular carcinoma. Despite the increasing incidence and prevalence of NAFLD, its therapeutic and preventive strategies to lower the disease burden is limited. In recent years, immunotherapy, including anti-programmed cell death 1/programmed cell death 1 ligand 1 treatment, has emerged as a potential approach to reach satisfactory modulation for the progression of NAFLD and treatment of NAFLD-related hepatocellular carcinoma. However, the effectiveness of immunotherapy against NAFLD and NAFLD-related hepatocellular carcinoma is in the early phase and it is yet not advanced. In addition, conflicting results are being reported regarding the prognosis of patients with NAFLD-related hepatocellular carcinoma and high expression of programmed cell death 1/programmed cell death 1 ligand 1. Herein, this review will discuss and elucidate the attempts and underlying mechanisms of immunotherapy against NAFLD and NAFLD-related hepatocellular carcinoma.

Emerging Links between Nonalcoholic Fatty Liver Disease and Neurodegeneration

The association between liver and brain health has gained attention as biomarkers of liver function have been revealed to predict neurodegeneration. The liver is a central regulator in metabolic homeostasis. However, in nonalcoholic fatty liver disease (NAFLD), homeostasis is disrupted which can result in extrahepatic organ pathologies. Emerging literature provides insight into the mechanisms behind the liver-brain health axis. These include the increased production of liver-derived factors that promote insulin resistance and loss of neuroprotective factors under conditions of NAFLD that increase insulin resistance in the central nervous system. In addition, elevated proinflammatory cytokines linked to NAFLD negatively impact the blood-brain barrier and increase neuroinflammation. Furthermore, exacerbated dyslipidemia associated with NAFLD and hepatic dysfunction can promote altered brain bioenergetics and oxidative stress. In this review, we summarize the current knowledge of the crosstalk between liver and brain as it relates to the pathophysiology between NAFLD and neurodegeneration, with an emphasis on Alzheimer's disease. We also highlight knowledge gaps and future areas for investigation to strengthen the potential link between NAFLD and neurodegeneration.

Effect of Comorbidities on Ten-Year Survival in Patients with Dementia

BACKGROUND

There is a verified association between comorbidity and survival in patients with dementia.

OBJECTIVE

To describe the ten-year survival probability of patients with dementia and to identify the impact of comorbidity.

METHODS

The prognostic retrospective cohort study was conducted using data from adults with dementia who had visited the outpatient departments at Maharaj Nakorn Chiang Mai hospital between 2006 and 2012. Dementia was verified in accordance with standard practice guidelines. Secondary data detailing about patient age, gender, date of dementia diagnosis and death, types of dementia, and comorbidities at the time of dementia diagnosis was obtained from electronic medical records. The association between comorbidity, patients' underlying disease at dementia diagnosis, and overall survival were analyzed using a multivariable Cox proportional hazard model adjusted for age, gender, types of dementia, and other comorbidities.

RESULTS

Of the 702 patients, 56.9% were female. Alzheimer's disease (39.6%) was the most prevalent type of dementia. Median overall survival was 6.0 years (95% CI 5.5- 6.7). The comorbidities associated with a high risk of mortality included liver disease (aHR 2.70, 95% CI 1.46- 5.00), atrial fibrillation (aHR 2.15, 95% CI 1.29- 3.58), myocardial infarction (aHR 1.55, 95% CI 1.07- 2.26), and type 2 diabetes mellitus (aHR 1.40, 95% CI 1.13- 1.74).

CONCLUSION

Overall survival rate of patients with dementia in Thailand was comparable to previous studies. Several comorbidities were associated with a ten-year survival. The prognosis of patients with dementia may be improved by appropriate care of comorbidities.

Risk of dementia or cognitive impairment in non-alcoholic fatty liver disease: A systematic review and meta-analysis

Objectives

To investigate whether non-alcoholic fatty liver disease (NAFLD) increases the risk of dementia or cognitive impairment.

Methods

A systematic search of the literature in the PubMed, Excerpta Medica Database (EMBASE), Cochrane Library, and Web of Science databases was conducted, covering the period from the inception of each database to 22 May 2022. Statistical analysis of non-alcoholic fatty liver disease and the risk of cognitive impairment or dementia based on data extracted from each article was performed using Stata software v. 16.0. The quality of this study was assessed using the Newcastle-Ottawa Scale (NOS) for assessing the quality of cohort and case-control studies and the American Agency for Healthcare Research and Quality (AHRQ) methodology checklist for assessing the quality of cross-sectional studies. Funnel plots and the Egger's test were used to assess publication bias.

Results

We included 7 studies comprising 891,562 individuals from 6 countries, which were published between 2020 and 2022. The pooling analysis showed that a history of NAFLD was associated with cognitive impairment [odds ratio (OR) = 1.44; 95% CI: 1.17-1.78; heterogeneity (I 2) = 0%; P = 0.001]. A history of NAFLD was not associated with an increased risk of all-cause dementia (OR = 1.03; 95% CI: 0.97-1.09; I 2 = 84.7%; P = 0.341) or Alzheimer disease (OR = 0.95; 95% CI: 0.83-1.09; I 2 = 61.0%; P = 0.489). In contrast, NAFLD was associated with an obvious reduction of the risk of vascular dementia (OR = 0.88; 95% CI: 0.79-0.98; I 2 = 0.0%; P = 0.020). In the subgroup analysis, male and female patients with NAFLD showed an equal risk of dementia or cognitive impairment. The risk of dementia or cognitive impairment in the cross-sectional study (OR = 1.49; 95% CI: 1.19-1.88; I 2 = 0.0%; P = 0.001) was slightly higher than that in the retrospective cohort (OR = 1.03; 95% CI: 0.97-1.09; I 2 = 84.3%; P = 0.294).

Conclusions

NAFLD was associated with an increased risk of cognitive impairment and a decreased risk of vascular dementia. More studies are needed to clarify the pathophysiological mechanism underlying the association between NAFLD and dementia or cognitive impairment.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#recordDetails, identifier: CRD42022334492.