Subclinical liver traits are associated with structural and hemodynamic brain imaging markers.

BACKGROUND & AIMS: Impaired liver function affects brain health and therefore understanding potential mechanisms for subclinical liver disease is essential. We assessed the liver-brain associations using liver measures with brain imaging markers, and cognitive measures in the general population. METHODS: Within the population-based Rotterdam Study, liver serum and imaging measures (ultrasound and transient elastography), metabolic dysfunction-associated fatty liver disease (MAFLD), non-alcoholic fatty liver disease (NAFLD) and fibrosis phenotypes, and brain structure were determined in 3493 non-demented and stroke-free participants in 2009-2014. This resulted in subgroups of n = 3493 for MAFLD (mean age 69 ± 9 years, 56% ♀), n = 2938 for NAFLD (mean age 70 ± 9 years, 56% ♀) and n = 2252 for fibrosis (mean age 65 ± 7 years, 54% ♀). Imaging markers of small vessel disease and neurodegeneration, cerebral blood flow (CBF) and brain perfusion (BP) were acquired from brain MRI (1.5-tesla). General cognitive function was assessed by Mini-Mental State Examination and the g-factor. Multiple linear and logistic regression models were used for liver-brain associations and adjusted for age, sex, intracranial volume, cardiovascular risk factors and alcohol use. RESULTS: Higher gamma-glutamyltransferase (GGT) levels were significantly associated with smaller total brain volume (TBV, standardized mean difference (SMD), -0.02, 95% confidence interval (CI) (-0.03 to -0.01); p = 8.4·10-4 ), grey matter volumes, and lower CBF and BP. Liver serum measures were not related to small vessel disease markers, nor to white matter microstructural integrity or general cognition. Participants with ultrasound-based liver steatosis had a higher fractional anisotropy (FA, SMD 0.11, 95% CI (0.04 to 0.17), p = 1.5·10-3 ) and lower CBF and BP. MAFLD and NAFLD phenotypes were associated with alterations in white matter microstructural integrity (NAFLD ~ FA, SMD 0.14, 95% CI (0.07 to 0.22), p = 1.6·10-4 ; NAFLD ~ mean diffusivity, SMD -0.12, 95% CI (-0.18 to -0.05), p = 4.7·10-4 ) and also with lower CBF and BP (MAFLD ~ CBF, SMD -0.13, 95% CI (-0.20 to -0.06), p = 3.1·10-4 ; MAFLD ~ BP, SMD -0.12, 95% CI (-0.20 to -0.05), p = 1.6·10-3 ). Furthermore, fibrosis phenotypes were related to TBV, grey and white matter volumes. CONCLUSIONS: Presence of liver steatosis, fibrosis and elevated serum GGT are associated with structural and hemodynamic brain markers in a population-based cross-sectional setting. Understanding the hepatic role in brain changes can target modifiable factors and prevent brain dysfunction.

Systematically comparing epidemiological and clinical features of MAFLD and NAFLD by meta-analysis: Focusing on the non-overlap groups.

BACKGROUND & AIMS: The applicability of the novel metabolic dysfunction associated fatty liver disease (MAFLD) definition has been studied in numerous cohorts and compared to non-alcoholic fatty liver disease (NAFLD). No consensus has been reached on which definition is preferred. Therefore, this meta-analysis aims to compare the epidemiological and clinical features of NAFLD and MAFLD in the general and non-general population. METHODS: We searched Medline, Embase and Web of Science for studies comparing MAFLD to NAFLD. Based on MAFLD and NAFLD status, the following subgroups were investigated for liver health: overlap fatty liver disease (FLD), NAFLD-only and MAFLD-only. Data were pooled using random-effects models. RESULTS: We included 17 studies comprising 9 808 677 individuals. In the general population, MAFLD was present in 33.0% (95% CI 29.7%-36.5%) and NAFLD in 29.1% (95% CI 27.1%-31.1%). Among those with FLD, 4.0% (95% CI 2.4%-6.4%) did not meet the MAFLD criteria but had NAFLD (NAFLD-only) and 15.1% (95% CI 11.5%-19.5%) was exclusively captured by the novel MAFLD definition (MAFLD-only). Notably, this MAFLD-only group was at significantly increased risk for fibrosis (RR 4.2; 95% CI 1.3-12.9) and had higher alanine aminotransferase (mean difference: 8.0 U/L, 95% CI 2.6-13.5) and aspartate aminotransferase (mean difference: 6.4 U/L, 95% CI 3.0-9.7), compared to NAFLD-only. Similar results were obtained among the non-general population. CONCLUSIONS: Metabolic dysfunction associated fatty liver disease and NAFLD are highly prevalent in the general population, with considerable overlap between them. However, compared to NAFLD, significantly more individuals were additionally identified by MAFLD than were missed. Importantly, by using the MAFLD criteria, more individuals with liver damage were identified. Therefore, the novel MAFLD definition is superior to NAFLD on a population level.

Metabolic dysfunction-associated fatty liver disease improves detection of high liver stiffness: The Rotterdam Study.

BACKGROUND AND AIMS: Recently metabolic dysfunction-associated fatty liver disease (MAFLD) has been introduced and was defined as hepatic steatosis with either overweight, diabetes, and/or a combination of other metabolic risk factors. We investigated the application of the MAFLD criteria as compared with NAFLD. APPROACH AND RESULTS: We performed a cross-sectional analysis within the Rotterdam Study, a large prospective population-based cohort. Participants who attended the liver ultrasound and transient elastography program between 2009 and 2014 were eligible for inclusion. Subsequently, individuals with viral hepatitis, alcohol intake >60 g/day, missing alcohol data, and/or missing body mass index were excluded. According to their NAFLD and MAFLD status based on metadata and ultrasound, participants were allocated in overlap fatty liver disease (FLD), NAFLD-only, MAFLD-only, or no FLD. Fibrosis was defined as liver stiffness ≥8.0 kPa. In our analysis, 5445 participants were included: 1866 (34.3%) had MAFLD and 1604 (29.5%) [Correction added on December 27, 2021 after first online publication: The preceding fragment was changed from "1623 (29.8%)"] had NAFLD. This resulted in 1547 (28.4%) [Correction added on December 27, 2021 after first online publication: The preceding fragment was changed from "1566 (28.8%)"] individuals with overlap FLD, 319 (5.9%) [Correction added on December 27, 2021 after first online publication: The preceding fragment was changed from "300 (5.5%)"] with MAFLD-only, 57 (1.0%) with NAFLD-only, and 3522 (64.7%) with no FLD. The MAFLD-only group was strongly associated with fibrosis (adjusted OR 5.30 [Correction added on December 27, 2021 after first online publication: The preceding fragment was changed from "OR 5.27"], p < 0.001) and log-transformed liver stiffness (adjusted beta 0.116, p < 0.001), as opposed to the NAFLD-only group, in which no cases of fibrosis were identified and no association with liver stiffness (adjusted beta 0.006, p = 0.90) was found. CONCLUSIONS: FLD is highly prevalent in the general population. However, not the NAFLD-only, but the MAFLD-only group was associated with fibrosis and higher liver stiffness-independent of demographic and lifestyle factors. We believe that using the MAFLD criteria will help improve the identification and treatment of patients with FLD at risk for fibrosis.

Microbiomics, Metabolomics, Predicted Metagenomics, and Hepatic Steatosis in a Population-Based Study of 1,355 Adults.

BACKGROUND AND AIMS: Previous small studies have appraised the gut microbiome (GM) in steatosis, but large-scale studies are lacking. We studied the association of the GM diversity and composition, plasma metabolites, predicted functional metagenomics, and steatosis. APPROACH AND RESULTS: This is a cross-sectional analysis of the prospective population-based Rotterdam Study. We used 16S ribosomal RNA gene sequencing and determined taxonomy using the SILVA reference database. Alpha diversity and beta diversity were calculated using the Shannon diversity index and Bray-Curtis dissimilarities. Differences were tested across steatosis using permutational multivariate analysis of variance. Hepatic steatosis was diagnosed by ultrasonography. We subsequently selected genera using regularized regression. The functional metagenome was predicted based on the GM using Kyoto Encyclopedia of Genes and Genomes pathways. Serum metabolomics were assessed using high-throughput proton nuclear magnetic resonance. All analyses were adjusted for age, sex, body mass index, alcohol, diet, and proton-pump inhibitors. We included 1,355 participants, of whom 472 had steatosis. Alpha diversity was lower in steatosis (P = 1.1∙10-9 ), and beta diversity varied across steatosis strata (P = 0.001). Lasso selected 37 genera of which three remained significantly associated after adjustment (Coprococcus3: ß = -65; Ruminococcus Gauvreauiigroup: ß = 62; and Ruminococcus Gnavusgroup: ß = 45, Q-value = 0.037). Predicted metagenome analyses revealed that pathways of secondary bile-acid synthesis and biotin metabolism were present, and D-alanine metabolism was absent in steatosis. Metabolic profiles showed positive associations for aromatic and branched chain amino acids and glycoprotein acetyls with steatosis and R. Gnavusgroup, whereas these metabolites were inversely associated with alpha diversity and Coprococcus3. CONCLUSIONS: We confirmed, on a large-scale, the lower microbial diversity and association of Coprococcus and Ruminococcus Gnavus with steatosis. We additionally showed that steatosis and alpha diversity share opposite metabolic profiles.

The Association Between Cholecystectomy, Metabolic Syndrome, and Nonalcoholic Fatty Liver Disease: A Population-Based Study.

OBJECTIVES: Obesity is a risk factor for several phenotypes such as gallstones, metabolic syndrome (MS), and nonalcoholic fatty liver disease (NAFLD). It has been suggested that cholecystectomy is a risk factor for metabolic abnormalities and NAFLD. We aimed to determine whether cholecystectomy is associated with MS or NAFLD in a Dutch population-based study. METHODS: The Rotterdam Study is an ongoing prospective population-based cohort. We included participants who underwent a liver ultrasound between 2009 and 2014 to assess steatosis. The prevalence of MS and NAFLD was calculated, and we performed regression analyses relating cholecystectomy with MS and NAFLD and adjusted for age, sex, study cohort, education level, physical activity, energy intake, time since cholecystectomy, body mass index, presence of hypertension, diabetes mellitus, and steatosis/MS. RESULTS: We included 4,307 participants (57.5% women, median age 66.0 years [interquartile range 58-74]). In total, 265 participants (6.2%) underwent a cholecystectomy. The median age at the time of cholecystectomy was 57.0 years (47.5-66.5), and the median time from cholecystectomy to imaging of the liver was 10.0 years (0.5-19.5). The prevalence of MS in participants with cholecystectomy was 67.2% and 51.9% in participants without cholecystectomy (P < 0.001). Ultrasound diagnosed moderate/severe NAFLD was present in, respectively, 42.7% and 34.2% of the participants (P = 0.008). After multivariable adjustments for metabolic factors, cholecystectomy was no longer associated with the presence of MS or NAFLD. DISCUSSION: The prevalence of MS and NAFLD is higher in participants after cholecystectomy. However, our trial shows that cholecystectomy may not be independently associated with the presence of MS and NAFLD after correction for metabolic factors.

Adherence to a plant-based, high-fibre dietary pattern is related to regression of non-alcoholic fatty liver disease in an elderly population.

Dietary lifestyle intervention is key in treating non-alcoholic fatty liver disease (NAFLD). We aimed to examine the longitudinal relation between well-established dietary patterns as well as population-specific dietary patterns and NAFLD. Participants from two subsequent visits of the Rotterdam Study were included. All underwent serial abdominal ultrasonography (median follow-up: 4.4 years) and filled in a food frequency questionnaire. Secondary causes of steatosis were excluded. Dietary data from 389 items were collapsed into 28 food groups and a posteriori dietary patterns were identified using factor analysis. Additionally, we scored three a priori dietary patterns (Mediterranean Diet Score, Dutch Dietary Guidelines and WHO-score). Logistic mixed regression models were used to examine the relation between dietary patterns and NAFLD. Analyses were adjusted for demographic, lifestyle and metabolic factors. We included 963 participants of whom 343 had NAFLD. Follow-up data was available in 737 participants. Incident NAFLD was 5% and regressed NAFLD was 30%. We identified five a posteriori dietary patterns (cumulative explained variation [R2] = 20%). The patterns were characterised as: vegetable and fish, red meat and alcohol, traditional, salty snacks and sauces, high fat dairy & refined grains pattern. Adherence to the traditional pattern (i.e. high intake of vegetable oils/stanols, margarines/butters, potatoes, whole grains and sweets/desserts) was associated with regression of NAFLD per SD increase in Z-score (0.40, 95% CI 0.15-1.00). Adherence to the three a priori patterns all showed regression of NAFLD, but only the WHO-score showed a distinct association (0.73, 95% CI 0.53-1.00). Hence, in this large elderly population, adherence to a plant-based, high-fibre and low-fat diet was related to regression of NAFLD.

Integration of epidemiologic, pharmacologic, genetic and gut microbiome data in a drug-metabolite atlas.

Progress in high-throughput metabolic profiling provides unprecedented opportunities to obtain insights into the effects of drugs on human metabolism. The Biobanking BioMolecular Research Infrastructure of the Netherlands has constructed an atlas of drug-metabolite associations for 87 commonly prescribed drugs and 150 clinically relevant plasma-based metabolites assessed by proton nuclear magnetic resonance. The atlas includes a meta-analysis of ten cohorts (18,873 persons) and uncovers 1,071 drug-metabolite associations after evaluation of confounders including co-treatment. We show that the effect estimates of statins on metabolites from the cross-sectional study are comparable to those from intervention and genetic observational studies. Further data integration links proton pump inhibitors to circulating metabolites, liver function, hepatic steatosis and the gut microbiome. Our atlas provides a tool for targeted experimental pharmaceutical research and clinical trials to improve drug efficacy, safety and repurposing. We provide a web-based resource for visualization of the atlas (http://bbmri.researchlumc.nl/atlas/).

A Peripheral Blood DNA Methylation Signature of Hepatic Fat Reveals a Potential Causal Pathway for Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is a risk factor for type 2 diabetes (T2D). We aimed to identify the peripheral blood DNA methylation signature of hepatic fat. We conducted epigenome-wide association studies of hepatic fat in 3,400 European ancestry (EA) participants and in 401 Hispanic ancestry and 724 African ancestry participants from four population-based cohort studies. Hepatic fat was measured using computed tomography or ultrasound imaging and DNA methylation was assessed at >400,000 cytosine-guanine dinucleotides (CpGs) in whole blood or CD14+ monocytes using a commercial array. We identified 22 CpGs associated with hepatic fat in EA participants at a false discovery rate <0.05 (corresponding P = 6.9 × 10-6) with replication at Bonferroni-corrected P < 8.6 × 10-4 Mendelian randomization analyses supported the association of hypomethylation of cg08309687 (LINC00649) with NAFLD (P = 2.5 × 10-4). Hypomethylation of the same CpG was also associated with risk for new-onset T2D (P = 0.005). Our study demonstrates that a peripheral blood-derived DNA methylation signature is robustly associated with hepatic fat accumulation. The hepatic fat-associated CpGs may represent attractive biomarkers for T2D. Future studies are warranted to explore mechanisms and to examine DNA methylation signatures of NAFLD across racial/ethnic groups.

Diet-Dependent Acid Load-The Missing Link Between an Animal Protein-Rich Diet and Nonalcoholic Fatty Liver Disease?

OBJECTIVE: Our group recently showed that animal protein was independently associated with nonalcoholic fatty liver disease (NAFLD). We hypothesize that this may be explained by a high diet-dependent acid load [dietary acid load (DAL)]. METHODS: This cross-sectional study is embedded in a prospective population-based cohort. We estimated DAL proxies via food-frequency questionnaires using potential renal acid load (PRAL; using dietary protein, phosphorus, potassium, calcium, and magnesium intake), net endogenous acid production (NEAP; using protein and potassium intake), and the animal protein-to-potassium ratio (A:P). We defined NAFLD using ultrasound after excluding secondary steatogenic causes. We used logistic regression models-adjusted for sociodemographic, lifestyle, and metabolic traits-on categorized [quartile (Q)1 to 4] and continuous DAL proxies (allowing for nonlinearity) and NAFLD. RESULTS: We included 3882 participants, of which 1337 had NAFLD. All DAL proxies were higher, meaning more acidic, in individuals with NAFLD (PRAL, -2.9 vs -5.5 mEq/d; NEAP, 37.0 vs 35.1 mEq/d; and A:P, 13.3 vs 12.4; all P < 0.001). The highest Q of DAL proxies was associated with NAFLD independent of sociodemographic and lifestyle confounders, but significance dissipated after correction for metabolic confounders and multiple testing. However, the P value for nonlinearity was significant in all DAL proxies (P < 0.001). Natural cubic splines performed better with than without DAL proxies in the fully adjusted model (all P ≤ 0.038). The highest probability of NAFLD was found for an acidic diet. CONCLUSIONS: This study showed an independent nonlinear association between an acidic diet and NAFLD. Further studies with acid-base biomarkers are needed, but our findings might provide a mechanistic explanation for the harmful association between an animal protein-rich diet and NAFLD.

Potential Mechanisms Underlying the Role of Coffee in Liver Health.

Coffee, the most consumed hot beverage worldwide, is composed of many substances, of which polyphenols, caffeine, and diterpenoids are well studied. Evidence on potential effects of coffee on human health has been accumulating over the past decades. Specifically, coffee has been postulated to be hepatoprotective in several epidemiological and clinical studies. Several underlying molecular mechanisms as to why coffee influences liver health have been proposed. In this review, the authors summarized the evidence on potential mechanisms by which coffee affects liver steatosis, fibrosis, and hepatic carcinogenesis. The experimental models reviewed almost unanimously supported the theorem that coffee indeed may benefit the liver. Either whole coffee or its specific compounds appeared to decrease fatty acid synthesis (involved in steatogenesis), hepatic stellate activation (involved in fibrogenesis), and hepatic inflammation. Moreover, coffee was found to induce apoptosis and increased hepatic antioxidant capacity, which are involved in carcinogenesis.

Low skeletal muscle mass is associated with increased hospital costs in patients with cirrhosis listed for liver transplantation-a retrospective study.

Low skeletal muscle mass (sarcopenia) is associated with increased morbidity and mortality in liver transplant candidates. We investigated the association between sarcopenia and hospital costs in patients listed for liver transplantation. Consecutive patients with cirrhosis listed for liver transplantation between 2007 and 2014 in a Eurotransplant centre were identified. The skeletal muscle index (SMI, cm2 /m2 ) was measured on CT performed within 90 days from waiting list placement. The lowest sex-spe cific quartile represented patients with sarcopenia. In total, 224 patients were included. Median time on the waiting list was 170 (IQR 47-306) days, and median MELD score was 16 (IQR 11-20). The median total hospital costs in patients with sarcopenia were €11 294 (IQR 3570-46 469) compared with €6878 (IQR 1305-20 683) in patients without sarcopenia (P = 0.008). In multivariable regression analysis, an incremental increase in SMI was significantly associated with a decrease in total costs (€455 per incremental SMI, 95% CI 11-900, P = 0.045), independent of the total time on the waiting list. In conclusion, sarcopenia is independently associated with increased health-related costs for patients on the waiting list for liver transplantation. Optimizing skeletal muscle mass may therefore lead to a decrease in hospital expenditure, in addition to greater health benefit for the transplant candidate.

Coffee and herbal tea consumption is associated with lower liver stiffness in the general population: The Rotterdam study.

BACKGROUND & AIMS: Coffee and tea have been proposed to limit the progression of liver fibrosis in established liver disease, but it is unknown if this is also true for subclinical fibrosis. We therefore aimed to evaluate whether coffee and tea consumption are associated with liver stiffness in the general population. METHODS: The Rotterdam Study is an ongoing prospective population-based cohort. We included participants who underwent transient elastography, ultrasound and completed a food frequency questionnaire. Coffee and tea consumption were categorized into no, moderate (>0-3), or frequent (⩾3) intake (cups/day), and tea further into green, black and herbal tea (no/any). Significant fibrosis was defined as liver stiffness measurements (LSM) ⩾8.0kPa. We performed regression analyses relating coffee and tea intake with fibrosis, steatosis and log-transformed LSM and adjusted for energy, sugar and creamer intake, age, gender, BMI, steatosis/LSM, HOMA-IR, ALT, alcohol, smoking, soda, healthy diet index and physical activity. RESULTS: We included 2,424 participants (age 66.5±7.4; 43% male) of whom 5.2% had LSM ⩾8.0kPa and 34.6% steatosis. Proportion of LSM ⩾8.0kPa decreased with higher coffee consumption (7.8%, 6.9% and 4.1% for no, moderate and frequent respectively; Ptrend=0.006). This inverse association was confirmed in multivariable regression (ORmod 0.75, 95% CI 0.33-1.67; ORfreq 0.39, 95% CI 0.18-0.86; p=0.005). Amongst tea consumers, only herbal tea consumers (36.3%) had lower log-transformed LSM after adjustment (Beta-0.05, 95% CI-0.08;-0.02, p=0.001). Subtypes of tea were associated with steatosis in univariate but not multivariable analysis. CONCLUSIONS: In the general population, frequent coffee and herbal tea consumption were inversely related with liver stiffness but not steatosis. Longitudinal analyses, as well as studies validating and unravelling underlying mechanisms are needed. LAY SUMMARY: The Rotterdam Study is a large ongoing population study of suburban inhabitants of Rotterdam in whom data on liver stiffness, as proxy for liver fibrosis, presence of fatty liver on ultrasound and detailed information on coffee and tea consumption were obtained in 2,424 participants. The consumption of herbal tea and daily consumption of three or more cups of coffee was related to the presence of lower liver stiffness, independent of a great number of other lifestyle and environmental factors. Previous studies have found a protective effect of coffee on established liver disease and we now show for the first time that this effect is already measurable in the general population.

The impact of infections on delisting patients from the liver transplantation waiting list.

Approximately 20% of the patients listed for liver transplantation die before transplantation can be accomplished. Understanding risk factors for waiting list mortality may help to improve survival and organ allocation. Infections are very common in patients with cirrhosis and are associated with significant morbidity and mortality. This study analysed the frequency and characteristics of infections in patients awaiting liver transplantation, identified risk factors for withdrawal from the waiting list and evaluated the impact of infections on the clinical outcome. A retrospective analysis of consecutive patients listed for liver transplantation in Rotterdam, the Netherlands from 2007 to 2014 was conducted. Infections occurred in 144 of 327 studied patients (44%). In this cohort, 23.4% of the patients on the liver transplantation waiting list were delisted or died before transplantation. Patients with an infection were 5.2 times more likely to become delisted than noninfected patients. In the 30 days after the first infection, patients were 33.8 times more likely to become delisted compared to noninfected patients. High age, high MELD score, refractory ascites and inappropriate antibiotic therapy were independent predictors for delisting due to infection. Infections occur frequently in patients on the liver transplantation waiting list. Emphasis on appropriate and timely antimicrobial therapy is required.