Nonalcoholic fatty liver disease accelerates kidney function decline in patients with chronic kidney disease: a cohort study

Increased risk of chronic kidney disease and mortality in a cohort of people diagnosed with metabolic dysfunction associated steatotic liver disease with hepatic fibrosis

BACKGROUND AND AIMS

Metabolic dysfunction associated steatotic liver disease (MASLD) increases the risk of incident chronic kidney disease (CKD). However, the relative risk of CKD associated with increasing hepatic fibrosis, and consequent mortality risk, remains underexplored in real-world cohorts. In this study, we sought to establish whether hepatic fibrosis is associated with increased CKD risk and explore differences in mortality risk in a cohort of people living with MASLD, contingent on liver fibrosis and CKD status.

METHODS

This was an observational study of people who underwent routine liver function testing in Tayside, Scotland. MASLD was defined as: elevated ALT (>30 U/L) or GGT (>73 U/L); presence of diabetes, and/or hypertension, and/or obesity; weekly alcohol consumption <14 units (112g (+/-8g) alcohol); and negative screen for other aetiologies. Data was collected from digital health records. We used log-binomial models to quantify the risk of CKD among those with and without fibrosis, and Cox regression models to estimate differences in mortality risk dependent on fibrosis and CKD.

RESULTS

In our cohort (n = 2,046), 1,448 (70.8%) people had MASLD without fibrosis and 598 (29.2%) with fibrosis; 161 (11.1%) and 117 (19.6%) respectively also had CKD. After excluding individuals with structural, autoimmune, or malignant CKD (n = 22), liver fibrosis (n = 593; 18.9% with CKD) was associated with increased CKD risk (aRR = 1.31, 1.04-1.64, p = 0.021). Increased mortality risk was observed for those with liver fibrosis (aHR = 2.30, 1.49-3.56, p = <0.001) and was higher again among people with both fibrosis and CKD (aHR = 5.07, 3.07-8.39, p = <0.014).

CONCLUSIONS

Liver fibrosis was an independent risk factor for CKD in this cohort of people living with MASLD. Furthermore, those with MASLD with liver fibrosis had higher risk for mortality and this risk was further elevated among those with co-morbid CKD. Given the increased risk of CKD, and consequent mortality risk, among people living with MASLD fibrosis, renal function screening should be considered within liver health surveillance programmes and guidelines.

The Intersection of Genetic Factors, Aberrant Nutrient Metabolism and Oxidative Stress in the Progression of Cardiometabolic Disease

Cardiometabolic disease (CMD), which encompasses metabolic-associated fatty liver disease (MAFLD), chronic kidney disease (CKD) and cardiovascular disease (CVD), has been increasing considerably in the past 50 years. CMD is a complex disease that can be influenced by genetics and environmental factors such as diet. With the increased reliance on processed foods containing saturated fats, fructose and cholesterol, a mechanistic understanding of how these molecules cause metabolic disease is required. A major pathway by which excessive nutrients contribute to CMD is through oxidative stress. In this review, we discuss how oxidative stress can drive CMD and the role of aberrant nutrient metabolism and genetic risk factors and how they potentially interact to promote progression of MAFLD, CVD and CKD. This review will focus on genetic mutations that are known to alter nutrient metabolism. We discuss the major genetic risk factors for MAFLD, which include Patatin-like phospholipase domain-containing protein 3 (PNPLA3), Membrane Bound O-Acyltransferase Domain Containing 7 (MBOAT7) and Transmembrane 6 Superfamily Member 2 (TM6SF2). In addition, mutations that prevent nutrient uptake cause hypercholesterolemia that contributes to CVD. We also discuss the mechanisms by which MAFLD, CKD and CVD are mutually associated with one another. In addition, some of the genetic risk factors which are associated with MAFLD and CVD are also associated with CKD, while some genetic risk factors seem to dissociate one disease from the other. Through a better understanding of the causative effect of genetic mutations in CMD and how aberrant nutrient metabolism intersects with our genetics, novel therapies and precision approaches can be developed for treating CMD.

Efficacy of finerenone in patients with type 2 diabetes, chronic kidney disease and altered markers of liver steatosis and fibrosis: A FIDELITY subgroup analysis

AIM

Investigating the effect of finerenone on liver function, cardiovascular and kidney composite outcomes in patients with chronic kidney disease and type 2 diabetes, stratified by their risk of liver steatosis, inflammation and fibrosis.

MATERIALS AND METHODS

Post hoc analysis stratified patients (N = 13 026) by liver fibrosis and enzymes: high risk of steatosis (hepatic steatosis index >36); elevated transaminases [alanine transaminase (ALT) >33 (males) and >25 IU/L (females)]; and fibrosis-4 (FIB-4) index scores >3.25, >2.67 and >1.30. Liver enzymes were assessed by changes in ALT, aspartate aminotransferase and gamma-glutamyl transferase. Composite kidney outcome was defined as onset of kidney failure, sustained estimated glomerular filtration rate decline ≥57% from baseline over ≥4 weeks or kidney death. Composite cardiovascular outcome was defined as cardiovascular death, non-fatal myocardial infarction, non-fatal stroke or hospitalization for heart failure.

RESULTS

ALT, aspartate aminotransferase and gamma-glutamyl transferase levels were consistent between treatment groups and remained stable throughout. Finerenone consistently reduced the risk of composite kidney outcome, irrespective of altered liver tests. Higher FIB-4 score was associated with higher incidence rates of composite cardiovascular outcome. Finerenone reduced the risk of composite cardiovascular outcome versus placebo in FIB-4 subgroups by 52% (>3.25), 39% (>2.67) and 24% (>1.30) (p values for interaction = .01, .13 and .03, respectively).

CONCLUSIONS

Finerenone has neutral effects on liver parameters in patients with chronic kidney disease and type 2 diabetes. Finerenone showed robust and consistent kidney benefits in patients with altered liver tests, and profound cardiovascular benefits even in patients with higher FIB-4 scores who were at high risk of developing cardiovascular complications.

SAMM50-rs2073082, -rs738491 and -rs3761472 Interactions Enhancement of Susceptibility to Non-Alcoholic Fatty Liver Disease

BACKGROUND AND AIM

Several studies have identified that three SAMM50 polymorphisms (rs2073082, rs738491, rs3761472) are associated with an increased risk of non-alcoholic fatty liver disease (NAFLD). However, the clinical significance of the SAMM50 SNP in relation to NAFLD remains largely unknown. Therefore, we conducted a clinical study and SNP-SNP interaction analysis to further elucidate the effect of the SAMM50 SNP on the progression of NAFLD in the elderly.

METHODS

A total of 1053 patients over the age of 65 years were recruited. Liver fat and fibrosis were detected by abdominal ultrasound or FibroScan, respectively. Genomic DNA was extracted and then genotyped by Fluidigm 96.96 Dynamic Array. Multivariable logistic regression was used to evaluate the association between NAFLD and SNP. SNP-SNP interactions were analyzed using generalized multivariate dimensionality reduction (GMDR).

RESULTS

The risk of NAFLD was substantially higher in people who carried SAMM50-rs2073082 G and -rs738491 T alleles (OR, 1.962; 95% CI, 1.448-2.659; p < 0.001; OR, 1.532; 95% CI, 1.246-1.884; p = 0.021, respectively) compared to noncarriers. Carriers of the rs738491 T and rs3761472 G alleles in the cohort showed a significant increase in liver stiffness measurements (LSM). The combination of the three SNPs showed the highest predictive power for NAFLD. The rs2073082 G allele, rs738491 T allele and rs3761472 G carriers had a two-fold higher risk of NAFLD compared to noncarriers.

CONCLUSIONS

Our research has demonstrated a strong correlation between the genetic polymorphism of SAMM50 and NAFLD in the elderly, which will contribute to a better understanding of the impact of age and genetics on this condition. Additionally, this study provides a potential predictive model for the early clinical warning of NAFLD.

Five-Aminolevulinic Acid (5-ALA) Induces Heme Oxygenase-1 and Ameliorates Palmitic Acid-Induced Endoplasmic Reticulum Stress in Renal Tubules

Steatosis, or ectopic lipid deposition, is the fundamental pathophysiology of non-alcoholic steatohepatitis and chronic kidney disease. Steatosis in the renal tubule causes endoplasmic reticulum (ER) stress, leading to kidney injury. Thus, ER stress could be a therapeutic target in steatonephropathy. Five-aminolevulinic acid (5-ALA) is a natural product that induces heme oxygenase (HO)-1, which acts as an antioxidant. This study aimed to investigate the therapeutic potential of 5-ALA in lipotoxicity-induced ER stress in human primary renal proximal tubule epithelial cells. Cells were stimulated with palmitic acid (PA) to induce ER stress. Cellular apoptotic signals and expression of genes involved in the ER stress cascade and heme biosynthesis pathway were analyzed. The expression of glucose-regulated protein 78 (GRP78), a master regulator of ER stress, increased significantly, followed by increased cellular apoptosis. Administration of 5-ALA induced a remarkable increase in HO-1 expression, thus ameliorating PA-induced GRP78 expression and apoptotic signals. BTB and CNC homology 1 (BACH1), a transcriptional repressor of HO-1, was significantly downregulated by 5-ALA treatment. HO-1 induction attenuates PA-induced renal tubular injury by suppressing ER stress. This study demonstrates the therapeutic potential of 5-ALA against lipotoxicity through redox pathway.

The impact of non-alcoholic fatty liver disease and liver fibrosis on adverse clinical outcomes and mortality in patients with chronic kidney disease: a prospective cohort study using the UK Biobank

BACKGROUND

Chronic kidney disease (CKD) and non-alcoholic fatty liver disease (NAFLD) frequently co-exist. We assess the impact of having NAFLD on adverse clinical outcomes and all-cause mortality for people with CKD.

METHODS

A total of 18,073 UK Biobank participants identified to have CKD (eGFR < 60 ml/min/1.73 m² or albuminuria > 3 mg/mmol) were prospectively followed up by electronic linkage to hospital and death records. Cox-regression estimated the hazard ratios (HR) associated with having NAFLD (elevated hepatic steatosis index or ICD-code) and NAFLD fibrosis (elevated fibrosis-4 (FIB-4) score or NAFLD fibrosis score (NFS)) on cardiovascular events (CVE), progression to end-stage renal disease (ESRD) and all-cause mortality.

RESULTS

56.2% of individuals with CKD had NAFLD at baseline, and 3.0% and 7.7% had NAFLD fibrosis according to a FIB-4 > 2.67 and NFS ≥ 0.676, respectively. The median follow-up was 13 years. In univariate analysis, NAFLD was associated with an increased risk of CVE (HR 1.49 [1.38-1.60]), all-cause mortality (HR 1.22 [1.14-1.31]) and ESRD (HR 1.26 [1.02-1.54]). Following multivariable adjustment, NAFLD remained an independent risk factor for CVE overall (HR 1.20 [1.11-1.30], p < 0.0001), but not ACM or ESRD. In univariate analysis, elevated NFS and FIB-4 scores were associated with increased risk of CVE (HR 2.42 [2.09-2.80] and 1.64 [1.30-2.08]) and all-cause mortality (HR 2.82 [2.48-3.21] and 1.82 [1.47-2.24]); the NFS score was also associated with ESRD (HR 5.15 [3.52-7.52]). Following full adjustment, the NFS remained associated with an increased incidence of CVE (HR 1.19 [1.01-1.40]) and all-cause mortality (HR 1.31 [1.13-1.52]).

CONCLUSIONS

In people with CKD, NAFLD is associated with an increased risk of CVE, and the NAFLD fibrosis score is associated with an elevated risk of CVE and worse survival.

Non-alcoholic fatty liver disease in diabetes mellitus patients on chronic hemodialysis – A case series addressing cardiovascular and mortality risks

Non-alcoholic fatty liver disease (NAFLD) has an important role in the pathogenesis of cardiovascular diseases in the population with diabetes and it is highly prevalent in end-stage renal disease (ESRD) patients. This case series describes NAFLD associated factors and survival in type 2 diabetes patients (T2DM) who have ESRD treated with hemodialysis. NAFLD prevalence in patients with T2DM and ESRD is 69.2%. A high number of patients (15 out of 18) have obesity evaluated by calculating body mass index (BMI) and bioimpedance measurements. Patients with NAFLD have higher cardiovascular mortality risk, 13 of 18 patients were already diagnosed with coronary heart disease, 6 of 18 had cerebrovascular disease, and 6 of 18 had peripheral artery disease. Fourteen patients were treated with insulin, two patients with sitagliptin (renal adjusted dose of 25mg/day) and two patients with medical nutrition therapy, with an HbA1c ranging from 4.4 to 9.0%. After one-year follow-up 7 of 18 patients died, the causes having roughly equal proportions: myocardial infarction, SARS-CoV2 infection, and pulmonary edema. In conclusion, our population of type 2 diabetic patients with ESRD in hemodialysis had a prevalence of ultrasound-diagnosed NAFLD of 69.2%. Also, this population had a high death rate at one-year follow-up, cardiovascular causes being among the most common.

Prevalence of metabolic dysfunction-associated fatty liver disease in kidney transplant recipients: A cross-sectional study using FibroScan

BACKGROUND AND AIM

Metabolic dysfunction-associated fatty liver disease (MAFLD) is expected to be prevalent among kidney transplant recipients (KTRs). In this study, we evaluated the prevalence of MAFLD among KTRs, data that have not been investigated by any clinical study to date.

MATERIALS AND METHODS

We included a total of 52 KTRs and 53 age-, sex-, and BMI-matched individuals as the control group through prospective consecutive recruitment. We detected the presence of hepatic steatosis and liver fibrosis using the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) defined by FibroScan.

RESULTS

Among the KTRs, 18 (34.6%) had metabolic syndrome. The prevalence of MAFLD among the KTRs and controls was 42.3% and 51.9%, respectively (p=0.375). The CAP and LSM values did not differ significantly between the KTRs and controls (p=0.222 and p=0.119). Among the KTRs, patients with MAFLD had significantly higher age, BMI, waist circumference, LDL, and total cholesterol levels (p<0.001, p=0.011, p=0.033, p=0.022, and p=0.029, respectively). In multivariable analysis, age was the only independent factor for MAFLD among the KTRs (OR: 1.120, 95% confidence interval (CI): 1.039-1.208).

CONCLUSION

MAFLD among KTRs did not show a significantly higher prevalence compared to the normal population. Further clinical studies with larger populations are needed.

Poor Outcomes of Patients With NAFLD and Moderate Renal Dysfunction or Short-Term Dialysis Receiving a Liver Transplant Alone

The outcomes of patients with moderate renal impairment and the impact of liver disease etiology on renal function recovery after liver transplant alone (LTA) are largely unknown. We explored whether NAFLD patients with pre-LTA moderate renal dysfunction (GFR 25-45 ml/min/1.73 m²) may be more susceptible to develop post-LTA severe renal dysfunction (GFR<15 ml/min/1.73 m²) than ALD patients, as well as other overall outcomes. Using the UNOS/OPTN database, we selected patients undergoing liver transplant for NAFLD or ALD (2006-2016), 15,103 of whom received LTA. NAFLD patients with moderate renal dysfunction were more likely to develop subsequent GFR<15 ml/min/1.73 m² than ALD patients (11.1% vs. 7.38%, p < 0.001). Patients on short-term dialysis pre-LTA (≤12 weeks) were more likely to develop severe renal dysfunction (31.7% vs. 18.1%), especially in NAFLD patients, and were more likely to receive a further kidney transplant (15.3% vs. 3.7%) and had lower survival (48.6% vs. 50.4%) after LTA (p < 0.001 for all). NAFLD was an independent risk factor for post-LTA severe renal dysfunction (HR = 1.2, p = 0.02). NAFLD patients with moderate renal dysfunction and those receiving short-term dialysis prior to LTA are at a higher risk of developing subsequent severe renal dysfunction. Underlying etiology of liver disease may play a role in predicting development and progression of renal failure in patients receiving LTA.

Nonalcoholic fatty liver disease and obesity: An Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) 2022

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) provides clinicians an overview of nonalcoholic fatty liver disease (NAFLD), potential progression to nonalcoholic steatohepatitis (NASH), and their application to obesity.

Methods

The scientific information for this CPS is based upon published scientific citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

Topics of this CPS include the prevalence of NAFLD and NASH, the prevalence of NAFLD and NASH among patients with obesity, as well as NAFLD and NASH definitions, diagnosis, imaging, pathophysiology, differential diagnosis, role of high fructose corn syrup and other simple sugars, and treatment (e.g., nutrition, physical activity, medications).

Conclusions

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) regarding NAFLD and obesity is one of a series of OMA CPSs designed to assist clinicians in the care of patients with the disease of obesity. Patients with obesity are at increased risk for NAFLD and NASH. Patients may benefit when clinicians who manage obesity understand the etiology, diagnosis, and optimal treatment of NAFLD with a goal to prevent NASH.

Fibrosis Risk in Nonalcoholic Fatty Liver Disease Is Related to Chronic Kidney Disease in Older Type 2 Diabetes Patients

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is a multisystem disease, associated with fibrosis and an increased risk of type 2 diabetes mellitus (T2DM) and chronic kidney disease (CKD).

OBJECTIVE

This work aimed to investigate the association of NAFLD fibrosis with the development of CKD in aged patients with T2DM.

METHODS

This cross-sectional study enrolled 13 915 participants. A further 1734 individuals who had been followed annually for 5 years comprised the retrospective cohort study. Noninvasive markers, NAFLD fibrosis score (NFS), and fibrosis index based on 4 factors (FIB-4) were applied to determine NAFLD fibrosis risk.

RESULTS

In the cross-sectional study, there was an additive interaction for NAFLD with increased risk of fibrosis and T2DM on CKD incidence. Logistic regression demonstrated that as NAFLD fibrosis risk progressed from low to intermediate and high, there was a stepwise increase in CKD in patients with NAFLD, T2DM, and those with coexistent NAFLD and T2DM when stratified by diabetes and fibrosis stage. FIB-4 had a much higher odds ratio (OR) value than NFS for prediction of CKD incidence. In the cohort study, individuals were grouped according to FIB-4 and NFS. Cox regression analysis showed that FIB-4 intermediate risk (hazard ratio [HR] 1.268; 95% CI, 1.056-1.521) and high risk (HR 2.516; 95% CI, 1.970-3.214) were significant predictors of CKD progression. When NFS was applied, only high risk was a significant predictor.

CONCLUSION

NAFLD with an increased risk of fibrosis and presence of T2DM had an additive interaction on CKD incidence. Increased risk of NAFLD fibrosis was closely associated with CKD incidence and progression in aged T2DM patients. FIB-4 outperformed NFS as a noninvasive means to predict CKD development.

Crosstalk between kidney and liver in non-alcoholic fatty liver disease: mechanisms and therapeutic approaches

Liver and kidney are vital organs that maintain homeostasis and injury to either of them triggers pathogenic pathways affecting the other. For example, non-alcoholic fatty liver disease (NAFLD) promotes the progression of chronic kidney disease (CKD), vice versa acute kidney injury (AKI) endorses the induction and progression of liver dysfunction. Progress in clinical and basic research suggest a role of excessive fructose intake, insulin resistance, inflammatory cytokines production, activation of the renin-angiotensin system, redox imbalance, and their impact on epigenetic regulation of gene expression in this context. Recent developments in experimental and clinical research have identified several biochemical and molecular pathways for AKI-liver interaction, including altered liver enzymes profile, metabolic acidosis, oxidative stress, activation of inflammatory and regulated cell death pathways. This review focuses on the current preclinical and clinical findings on kidney-liver crosstalk in NAFLD-CKD and AKI-liver dysfunction settings and highlights potential molecular mechanisms and therapeutic targets.

Nonalcoholic Fatty Liver Disease and Cardiovascular Disease: a Review of Shared Cardiometabolic Risk Factors

The prevalence of nonalcoholic fatty liver disease (NAFLD) is rising. NAFLD/nonalcoholic steatohepatitis (NASH) is associated not only with hepatic morbidity and mortality but also with an increased cardiovascular risk. NAFLD and cardiovascular disease (CVD) share several risk factors, such as obesity, metabolic syndrome, hypertension, dyslipidemia, type 2 diabetes, and chronic kidney disease. This review summarizes the evidence linking cardiometabolic risk factors and NAFLD in the context of risk for CVD. The cause of NAFLD/NASH is complex, involving a range of factors from genetics to lifestyle and energy balance. Genetically driven high liver fat content does not appear to be causally associated with increased CVD risk. In contrast, metabolic dysfunction not only predisposes to liver pathology but also leads to a significantly higher CVD risk. Given that NAFLD pathophysiology is influenced by multiple factors, each patient is unique as to their risk of developing CVD and liver pathology. At the same time, the rising burden of NAFLD/NASH is closely linked with the global increase in metabolic disorders, including obesity and type 2 diabetes. Therefore, both personalized therapeutic approaches that recognize individual pathophysiology, as well as public health policies that address the root causes of cardiometabolic risk factors for NAFLD may be needed to effectively address the NAFLD/NASH epidemic.

MAFLD and CKD: An Updated Narrative Review

Accumulating evidence now indicates that non-alcoholic fatty liver disease (NAFLD), which is the most common chronic liver disease observed in clinical practice worldwide, is independently associated with an increased risk of incident chronic kidney disease (CKD). Given that NAFLD is linked to insulin resistance, obesity and type 2 diabetes mellitus, an international panel of experts have recently proposed a name change from NAFLD to metabolic associated fatty liver disease (MAFLD). Since the diagnostic criteria for NAFLD and MAFLD are different, observational studies assessing the potential concordance (or even superiority) of MAFLD, compared with NAFLD, in detecting patients at increased risk of hepatic and extra-hepatic complications (including CKD) are required. Hence, in the last two years, some observational studies have investigated the potential relationship between MAFLD and CKD. The result is that, at present, evidence regarding the concordance or even superiority of MAFLD, compared with NAFLD, in detecting patients at higher risk of CKD is still preliminary, although some data indicate that MAFLD identifies patients with CKD as accurately as NAFLD. In this narrative review, we will discuss: (a) the epidemiological evidence assessing the association between NAFLD and risk of incident CKD, (b) the epidemiological data investigating the association between MAFLD and risk of CKD and (c) the biological mechanisms underlying the association between NAFLD/MAFLD and CKD.

Steatosis is involved in the progression of kidney disease in a high-fat-diet-induced non-alcoholic steatohepatitis mouse model

Chronic kidney disease (CKD) and non-alcoholic steatohepatitis (NASH) are major health issues associated with the metabolic syndrome. Although NASH is a known risk factor of CKD, the mechanisms linking these two diseases remain poorly understood. We aimed to investigate alterations in the kidney complicated with dyslipidemia in an established NASH mouse model. Male C57BL6/J mice were fed with control diet or high-fat diet (HFD), containing 40% fat, 22% fructose, and 2% cholesterol for 16 weeks. Metabolic characteristics, histological changes in the kidney, endoplasmic reticulum (ER) stress, apoptosis, and fibrosis were evaluated by histological analysis, immunoblotting, and quantitative reverse transcription-polymerase chain reaction. Levels of serum aspartate aminotransferase, alanine aminotransferase, alkali-phosphatase, total cholesterol, and urinary albumin were significantly higher in mice fed with HFD. Remarkable steatosis, glomerular hypertrophy, and interstitial fibrosis were also shown in in the kidney by leveraging HFD. Furthermore, HFD increased the mRNA expression levels of Casp3, Tgfb1, and Nfe2l2 and the protein level of BiP. We observed the early changes of CKD and speculate that the underlying mechanisms that link CKD and NASH are the induction of ER stress and apoptosis. Further, we observed the activation of Nfe2l2 in the steatosis-induced CKD mouse model. This NASH model holds implications in investigating the mechanisms linking dyslipidemia and CKD.

Metabolic-associated Fatty Liver Disease (MAFLD): A Multi-systemic Disease Beyond the Liver

Nonalcoholic fatty liver disease (NAFLD) is a multisystemic clinical condition that presents with a wide spectrum of extrahepatic manifestations, such as obesity, type 2 diabetes mellitus, metabolic syndrome, cardiovascular diseases, chronic kidney disease, extrahepatic malignancies, cognitive disorders, and polycystic ovarian syndrome. Among NAFLD patients, the most common mortality etiology is cardiovascular disorders, followed by extrahepatic malignancies, diabetes mellitus, and liver-related complications. Furthermore, the severity of extrahepatic diseases is parallel to the severity of NAFLD. In clinical practice, awareness of the associations of concomitant diseases is of major importance for initiating prompt and timely screening and multidisciplinary management of the disease spectrum. In 2020, a consensus from 22 countries redefined the disease as metabolic (dysfunction)-associated fatty liver disease (MAFLD), which resulted in the redefinition of the corresponding population. Although the patients diagnosed with MAFLD and NAFLD mostly overlap, the MAFLD and NAFLD populations are not identical. In this review, we compared the associations of key extrahepatic diseases between NAFLD and MAFLD.

Metabolic dysfunction-associated fatty liver disease and risk of incident chronic kidney disease: A nationwide cohort study

AIMS

The recently proposed metabolic dysfunction-associated fatty liver disease (MAFLD) has been suggested to better reflect the metabolic components of fatty liver disease (FLD), compared to nonalcoholic fatty liver disease (NAFLD). This study investigated whether MAFLD identifies a higher proportion of individuals at risk of developing chronic kidney disease (CKD).

METHODS

268,946 participants aged 40-64 years, who underwent National Health Insurance Service health examinations between 2009 and 2015 were included. Participants were categorized by presence of FLD, according to MAFLD or NAFLD. In participants with FLD, participants were categorized into three groups: non-metabolic risk (non-MR) NAFLD, MAFLD but not NAFLD, and overlapping FLD. Incident CKD was defined as the occurrence of eGFR < 60 mL/min/1.73m² or proteinuria (≥ trace) on two consecutive health examinations.

RESULTS

73,726 (27.4%) and 88,762 (33.0%) participants had NAFLD and MAFLD, respectively. During a median follow-up of 5.1 years, CKD occurred in 8,335 (6.2/1,000 person-years) participants. Compared to non-NAFLD participants, the adjusted hazard ratio (aHR) for incident CKD was 1.33 (95% CI, 1.27-1.39; P < 0.001) for participants with NAFLD. Compared to non-MAFLD participants, the aHR for participants with MAFLD was 1.39 (95% CI, 1.33-1.46; P < 0.001). When the analysis was confined to participants with FLD, compared to non-MR NAFLD participants, the aHRs for participants with MAFLD but not NAFLD, and those with overlapping FLD were 1.18 (95% CI, 1.01-1.39; P = 0.040) and 1.36 (95% CI, 1.19-1.54; P < 0.001), respectively.

CONCLUSION

MAFLD identified a higher proportion of individuals at risk of developing CKD than NAFLD.

Influence of Nonalcoholic Fatty Liver Disease on the Occurrence and Severity of Chronic Kidney Disease

Nonalcoholic fatty liver disease (NAFLD) is reported to affect 20-30% of adults and is accompanied by various metabolic comorbidities, where the economic and clinical burden of NAFLD is attributed to the progression of liver disease as well as the presence of extrahepatic diseases. Chronic kidney disease (CKD), which has a high incidence rate, high morbidity and mortality rates, and high medical costs, has been linked to NAFLD. CKD is associated with some metabolism-related risk factors that overlap with metabolic comorbidities of NAFLD. Therefore, to investigate the potential factors that influence CKD occurrence, the association between NAFLD and CKD should be clarified. Some studies have confirmed that NAFLD influences the occurrence and severity of CKD, whereas some studies have indicated that there is no correlation. In this review, the results of a few studies have been discussed, the potential risk factors for CKD in NAFLD are explored, and the respective biological mechanisms are elaborated to help clinicians identify CKD in patients much earlier than it is diagnosed now and thus help in reducing the incidence of liver and kidney transplants.

Non-Alcoholic Fatty Liver Disease and Risk of Macro- and Microvascular Complications in Patients with Type 2 Diabetes

Non-alcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of metabolic syndrome. To date, NAFLD is the most frequent chronic liver disease seen day by day in clinical practice across most high-income countries, affecting nearly 25–30% of adults in the general population and up to 70% of patients with T2DM. Over the last few decades, it clearly emerged that NAFLD is a “multisystemic disease” and that the leading cause of death among patients with NAFLD is cardiovascular disease (CVD). Indeed, several observational studies and some meta-analyses have documented that NAFLD, especially its advanced forms, is strongly associated with fatal and non-fatal cardiovascular events, as well as with specific cardiac complications, including sub-clinical myocardial alteration and dysfunction, heart valve diseases and cardiac arrhythmias. Importantly, across various studies, these associations remained significant after adjustment for established cardiovascular risk factors and other confounders. Additionally, several observational studies and some meta-analyses have also reported that NAFLD is independently associated with specific microvascular conditions, such as chronic kidney disease and distal or autonomic neuropathy. Conversely, data regarding a potential association between NAFLD and retinopathy are scarce and often conflicting. This narrative review will describe the current evidence about the association between NAFLD and the risk of macro- and microvascular manifestations of CVD, especially in patients with T2DM. We will also briefly discuss the biological mechanisms underpinning the association between NAFLD and its advanced forms and macro- and microvascular CVD.

Association Between the Risk of Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes and Chronic Kidney Disease

OBJECTIVE

To explore the relationship between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 1168 patients with T2DM were divided into the non-CKD and CKD groups, and the difference in the prevalence of NAFLD was compared. The differences in serum creatinine (SCr) and urine albumin-to-creatinine ratio (UACR) levels were compared between the non-NAFLD and NAFLD groups. Patients with T2DM were divided into three groups according to their UACR levels (UACR < 30 mg/g [U1 group]; UACR ≤ 30 mg/g to < 300 mg/g [U2 group]; and UACR ≥ 300 mg/g [U3 group]) or estimated glomerular filtration rate (eGFR) levels (≥ 90 mL/min [G1 group]; eGFR ≤ 60 mL/min to < 90 mL/min [G2 group]; and eGFR < 60 mL/min (G3 group]). The difference in the prevalence and risks of NAFLD in the different UACR or eGFR level groups was analyzed.

RESULTS

The prevalence of NAFLD in the CKD group was higher than that in the non-CKD group (63.5% vs 50.5%, p < 0.001). The SCr and UACR levels in the NAFLD group were higher than those in the non-NAFLD group (both p<0.05). The prevalence of NAFLD in the U3 group (75.6%) was higher than that in the U1 (50.5%, p < 0.05) and U2 (60.1%, p < 0.05) groups, and the prevalence of NAFLD in the U2 group (60.1%) was higher than that in the U1 group (50.5%, p < 0.05). The risk of NAFLD in the U3 group was higher than that in the U2 group (odds ratio [OR] = 3.032 and 1.473). Despite adjusting the parameters further, the NAFLD risk in the U3 group remained higher than that in the U2 group (OR = 1.660 and 2.342).

CONCLUSION

The risk of NAFLD in patients with T2DM is closely related to CKD.

The association between NAFLD and risk of chronic kidney disease: a cross-sectional study

Objective:

The aim of this study was to evaluate the association between nonalcoholic fatty liver disease (NAFLD) and NAFLD with different comorbidities and risk of chronic kidney disease (CKD) and abnormal albuminuria.

Materials and Methods:

A total of 3872 Chinese individuals excluding those with hepatitis B or C infection and absence of alcohol abuse were included in the study. NAFLD was diagnosed by abdominal ultrasonography. The liver fibrosis was assessed by NAFLD fibrosis score (NFS) and fibrosis-4 index (FIB-4). CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² and/or abnormal albuminuria (urinary albumin-to-creatinine ratio ⩾ 3 mg/mmol). The logistic regression analysis was performed to examine the association between NAFLD and NAFLD with different comorbidities and risk of CKD.

Results:

The prevalence of CKD and abnormal albuminuria was higher in individuals with NAFLD than in those without NAFLD (15.8% vs 11.9%, p < 0.001; 14.8% vs 11.0%, p < 0.001). Logistic regression analysis demonstrated that NAFLD was risk factor of CKD. Notably, after adjustment for sex, age, and DM, NAFLD was associated with 1.31-fold higher risk of prevalent CKD ⩾ 1 (p < 0.05). NAFLD individuals with elder age, DM, obesity, hypertension, MetS, and advanced liver fibrosis had higher risks of both prevalent CKD and abnormal albuminuria than those without comorbidities.

Conclusions:

NAFLD and NAFLD with traditional comorbidities are strongly associated with risk of prevalence of CKD and abnormal albuminuria. Patients with NAFLD especially those with coexisting comorbidities were recommended to carefully access the development of CKD.

New Nonalcoholic Fatty Liver Disease and Fibrosis Progression Associate With the Risk of Incident Chronic Kidney Disease

CONTEXT

Little is known about the link between nonalcoholic fatty liver disease (NAFLD) evolution and incident chronic kidney disease (CKD).

OBJECTIVE

We aim to assess the associations of NALFD status changes and NAFLD fibrosis progression with the risk of incident CKD.

METHODS

We conducted a community-based prospective study that included participants aged 40 years or older and free of CKD at baseline in 2010, with follow-up evaluations after a mean of 4.4 years. NAFLD was diagnosed by ultrasonography and NAFLD fibrosis score (NFS) was used to evaluate fibrosis stage and progression. CKD was defined by estimated glomerular filtration rate or urine albumin-to-creatinine ratio. All the measurements were performed at baseline and follow-up examination.

RESULTS

Among 4042 participants with 4 NAFLD status change groups, incident NAFLD was associated with an increased risk of incident CKD (odds ratio [OR] = 1.44; 95% CI, 1.003-2.06; P = 0.048) compared with non-NAFLD after adjustments for the confounders, including evolution of diabetes, hypertension, and obesity, in addition to the baseline levels. However, the risk of incident CKD was not significantly different between NAFLD resolution and persistent NAFLD. Among 534 participants in the persistent NAFLD group, fibrosis progression from low NFS to intermediate or high NFS was associated with a significantly increased risk of incident CKD compared with stable fibrosis in low NFS (OR = 2.82; 95% CI, 1.22-6.56; P = 0.016).

CONCLUSION

NAFLD development and fibrosis progression are associated with increased risk of incident CKD.

NAFLD and renal function in children: is there a genetic link?

Introduction: Over the past decades, a large amount of both adult and pediatric data has shown relationship between Nonalcoholic Fatty Liver Disease (NAFLD) and chronic kidney disease (CKD), resulting in an overall increased cardiometabolic burden. In view of the remarkable role of the genetic background in the NAFLD pathophysiology, a potential influence of the major NAFLD polymorphisms (e.g. the I148M variant of the Patatin-like phospholipase containing domain 3 (PNPLA3) gene, the E167K allele of the Transmembrane 6 superfamily member 2 (TM6SF2), the hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13), and the Membrane bound O-acyltransferase domain containing 7-transmembrane channel-like 4 (MBOAT7-TMC4) genes) on renal function has been supposed. A shared metabolic and proinflammatory pathogenesis has been hypothesized, but the exact mechanism is still unknown.Areas covered: We provide a comprehensive review of the potential genetic link between NAFLD and CKD in children. Convincing both adult and pediatric evidence supports this association, but there is some dispute especially in childhood.Expert opinion: Evidence supporting a potential genetic link between NAFLD and CKD represents an intriguing aspect with a major clinical implication because of its putative role in improving strategy programs to counteract the higher cardiometabolic risk of these patients.

1-year outcomes for lung transplantation recipients with non-alcoholic fatty liver disease

Advanced hepatic fibrosis and cirrhosis are absolute contraindications to lung transplantation. [ 1] However, whether fatty liver disease with mild–moderate fibrosis contributes to increased adverse outcomes post-lung transplantation remains unknown.

 We present a retrospective analysis of patients transplanted at Brigham and Women's Hospital between 2015 and 2017 to identify whether patients with mild–moderate non-alcoholic fatty liver disease (NAFLD) experience increased short-term complications compared to patients with normal liver architecture. Patients with advanced (F3–F4) fibrosis and/or cirrhosis were considered non-suitable transplant candidates, a priori. This study was powered for a difference in index hospital-free days within the first 30 days of 25% (α=0.05, β=0.8). Secondary outcomes included index intensive care unit (ICU)-free days within the first 10 days post-transplant, perioperative blood product transfusion, incidence of index hospitalisation arrhythmias and delirium, need for insulin on discharge post-transplant, tacrolimus dose required to maintain a trough of 8–12 ng·mL⁻¹ at index hospital discharge, and 1-year post-transplant incidence of insulin-dependent diabetes, acute kidney injury, acute cellular rejection, unplanned hospital readmissions and infection.

 150 patients underwent lung transplantation between 2015 and 2017 and were included in the analysis; of these patients 40 (27%) had evidence of NAFLD. Median index hospital-free days for patients with NAFLD were non-inferior to those without (16 days, IQR 10.5–19.5 versus 12 days, IQR 0–18.0, p=0.03). Regarding secondary outcomes, both index hospitalisation and 1-year outcomes were non-inferior between patients with NAFLD and those with normal liver architecture.

 This study demonstrates that mild–moderate severity NAFLD may not be a contraindication to lung transplantation.

In this single-centre, retrospective analysis of lung transplant recipients, we identified that mild–moderate non-alcoholic fatty liver disease is associated with acceptable perioperative and 1-year outcomeshttps://bit.ly/36WNzhi

Position paper on liver and kidney diseases from the Italian Association for the Study of Liver (AISF), in collaboration with the Italian Society of Nephrology (SIN)

Liver and kidney are strictly connected in a reciprocal manner, in both the physiological and pathological condition. The Italian Association for the Study of Liver, in collaboration with the Italian Society of Nephrology, with this position paper aims to provide an up-to-date overview on the principal relationships between these two important organs. A panel of well-recognized international expert hepatologists and nephrologists identified five relevant topics: 1) The diagnosis of kidney damage in patients with chronic liver disease; 2) Acute kidney injury in liver cirrhosis; 3) Association between chronic liver disease and chronic kidney disease; 4) Kidney damage according to different etiology of liver disease; 5) Polycystic kidney and liver disease. The discussion process started with a review of the literature relating to each of the five major topics and clinical questions and related statements were subsequently formulated. The quality of evidence and strength of recommendations were graded according to the GRADE system. The statements presented here highlight the importance of strong collaboration between hepatologists and nephrologists for the management of critically ill patients, such as those with combined liver and kidney impairment.

Non-alcoholic fatty liver and chronic kidney disease: Retrospect, introspect, and prospect

With the growing prevalence of obesity and diabetes in the United States and across the world, a rise in the overall incidence and prevalence of non-alcoholic fatty liver disease (NAFLD) is expected. The risk factors for NAFLD are also associated with the development of chronic kidney disease (CKD). We review the epidemiology, risk factors, genetics, implications of gut dysbiosis, and specific pathogenic mechanisms linking NAFLD to CKD. Mechanisms such as ectopic lipid accumulation, cellular signaling abnormalities, and the interplay between fructose consumption and uric acid accumulation have led to the emergence of potential therapeutic implications for this patient population. Transplant evaluation in the setting of both NAFLD and CKD is also reviewed. Potential strategies for surveillance and management include the monitoring of comorbidities, the use of non-invasive fibrosis scoring systems, and the measurement of laboratory markers. Lastly, we discuss the management of patients with NAFLD and CKD, from preventative measures to experimental interventions.

Non-invasive fibrosis assessments of non-alcoholic fatty liver disease associated with low estimated glomerular filtration rate among CKD patients: the Fukuoka Kidney disease Registry Study

BACKGROUND

A growing body of evidence has shown that non-alcoholic fatty liver disease (NAFLD) is associated with chronic kidney disease (CKD). Non-invasive fibrosis assessments of NAFLD such as Fibrosis-4 (FIB-4) index and NAFLD fibrosis score (NFS) have been developed to substitute liver biopsy. Little is known about the association between FIB-4 index or NFS and the components of CKD.

METHODS

In the present cross-sectional study, we assessed of 3640 Japanese CKD patients. We examined the association between FIB-4index or NFS and the odds of having low estimated glomerular filtration rate (eGFR) defined as eGFR < 60 mL/min/1.73 m² or albuminuria defined as urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. Patients were divided into quartiles according to their baseline FIB-4 index and NFS levels. Linear and logistic regression analysis were conducted, with adjustment for potential confounding factors.

RESULTS

FIB-4 index and NFS were negatively associated with eGFR, but not UACR, after adjustment for potential confounding factors. Both FIB-4 index and NFS were significantly associated with low eGFR after adjustment for potential confounding factors. Meanwhile, in the multivariable-adjusted model, no associations were found between FIB-4 index or NFS and albuminuria. The addition of FIB-4 index or NFS to the established clinical CKD risk factors improved diagnostic accuracy of prevalence of low eGFR. We also found that there was a significant trend of higher FIB-4 index and NFS with more advanced renal fibrosis using the kidney biopsy data.

CONCLUSIONS

Higher non-invasive fibrosis assessments of NAFLD were associated with higher odds of decreased eGFR.

Prevalence of non-alcoholic fatty liver disease among patients with non-diabetic chronic kidney disease detected by transient elastography

PURPOSE

Non-alcoholic fatty liver disease (NAFLD) shares a close relationship with cardiovascular morbidity and mortality. The purpose of this study is to evaluate the frequency of NAFLD in the patients with non-diabetic chronic kidney disease (CKD).

METHODS

This cross-sectional study included 80 patients with non-diabetic CKD, of which, 50 patients were on hemodialysis (HD) and 30 patients had CKD stage G3-5 not on dialysis. These patients were randomly selected from Ain Shams University Hospitals, Cairo, Egypt. Patients with diabetes mellitus, obesity, alcohol intake, viral hepatitis, or drug-induced liver steatosis were excluded from this study. Importantly, the controlled attenuation parameter (CAP) (dB/m) of liver steatosis (S0-S3) and liver stiffness/fibrosis measurement (F0-F4) were measured using transient elastography (Fibroscan^®). Other evaluations included complete blood count, routine blood chemistry, and C-reactive protein (CRP) titer.

RESULTS

In total, 45 (56.25%) (30 males, 15 females) out of total 80 studied patients were reported to have NAFLD. There were 29 patients with end-stage renal disease who were on regular HD and 16 patients with pre-dialysis CKD G3-5. The mean CAP values of hepatic steatosis in the patients with CKD on dialysis and patients with pre-dialysis CKD were 265.41 ± 52.73 and 259 ± 44.8 dB/m, respectively. A significant association between the severity of hepatic steatosis degree with decreased glomerular filtration rate and increased CKD stage was observed in this study. The degree of liver stiffness was significantly related to an increased hepatic steatosis grade. A significant positive correlation was found between the degree of NAFLD and serum levels of alanine aminotransferase, aspartate transaminase, total cholesterol, triglycerides, low-density lipoprotein, and CRP titer (P < 0.05). Importantly, NAFLD was significantly associated with an evident history of cardiovascular disease (CVD) among the studied patients.

CONCLUSION

A high frequency of NAFLD (56%) was observed among the patients with non-diabetic CKD on hemodialysis and patients with pre-dialysis CKD. NAFLD may be associated with an increased liver stiffness grade and CVD among those patients.

Early Kidney Dysfunction in Metabolic-Associated Fatty Liver Disease: Is Transient Elastography Useful as a Screening Method?

INTRODUCTION

Increasing evidence suggests an association between metabolic-associated fatty liver disease (MAFLD) and CKD. Timely prediction of early kidney dysfunction (EKD) is thus essential in this population although a screening method is not stablished. We aimed to evaluate the role of transient elastography (TE) in predicting EKD in patients with MAFLD.

MATERIALS AND METHODS

A prospective cohort study that included patients with MAFLD scheduled for evaluation was performed between May 2019 and January 2020. Demographic, clinical, and laboratory data and TE parameters were prospectively obtained. EKD was defined as microalbuminuria (urinary albumin-to-Cr ratio 30-300 mg/g) and estimated glomerular filtration rate ≥60 mL/min/1.73 m2. Significant liver fibrosis was defined as liver stiffness measurement (LSM) ≥8.2 kPa.

RESULTS

Of the included 45 patients with MALFD, 53.3% were of female gender with mean age of 53.5 ± 10.9 years. EKD was found in 17.8% of patients. MAFLD patients with EKD were significantly more obese (BMI ≥30) (75.0 vs. 32.4%, p = 0.045) and had significantly higher LSM (8.5 ± 4.1 vs. 5.8 ± 2.2 kPa, p = 0.01). After adjustment of potential confounders for EKD, the presence of liver fibrosis remained a significant predictor of EKD, being associated with a 14.3-fold increased risk of EKD (p = 0.04). The optimal cutoff value of LSM to predict EKD was 6.1 kPa (sensitivity: 85.7%; specificity: 67.6%).

CONCLUSION

Significant liver fibrosis is associated with a significant increased risk of EKD in patients with MAFLD, regardless of other comorbidities. Higher levels of LSM, particularly >6.1 kPa, alert for timely identification of EKD and associated comorbidities, as well as their control, in order to prevent the development of CKD in the long term.

Evaluation and management of extrahepatic manifestations of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a multisystemic disease and a rapidly growing cause of chronic liver disease in children and adults worldwide. Diagnosis and management of extrahepatic manifestations of NAFLD, including cardiovascular disease (CVD), type 2 diabetes mellitus, metabolic syndrome, chronic kidney disease, obstructive sleep apnea, polycystic ovarian syndrome, hypothyroidism, psoriasis, and extrahepatic malignancy are crucial for the treatment of patients with NAFLD. The leading cause of death in NAFLD is primarily from CVD, followed by liver-related mortality, extrahepatic cancer, liver cancer, and diabetes-related mortality. Therefore, clinicians need to identify high-risk patients earlier in the disease course and be aware of the extrahepatic manifestations of NAFLD to improve liver disease outcomes. In this review, we focus on the monitoring and management of the extrahepatic manifestations of NAFLD.

Association between anti-acid therapies and advanced fibrosis in type 2 diabetics with biopsy-proven non-alcoholic fatty liver disease

BACKGROUNDS AND AIMS

Data on associations of antacid therapies with advanced fibrosis (AF) in patients with non-alcoholic fatty liver disease (NAFLD) are limited. We aimed to assess the association of histamine-2 receptor antagonists (H₂RAs) and proton pump inhibitors (PPIs) with AF in NAFLD patients with underlying type 2 diabetes (T2D).

METHODS

We retrospectively reviewed patient's charts with T2D who had a liver biopsy for suspected NAFLD. Fibrosis stages were determined as F0-F4, AF being F3-4. Laboratory data and use of various medications within 24 months of liver biopsies were used for the analysis. Univariable and multivariable logistic regression analyses were performed to assess any association.

RESULTS

Our cohort consisted of 1008 T2D patients with biopsy-proven NAFLD. Sixty-six percent were female, 86.2% were Caucasian, and median HbA₁C was 6.4%. AF was present in 32% of the patients. Thirty-four percent were on H₂RAs and 60.6% were on PPI therapy (p < 0.001) for a median duration of 3.6 [0.10, 3.8] (p = 0.20) and 45.6 [0.80, 15.4] (p = 0.17) months, respectively. On multivariable logistic regression analysis being on H₂RAs was associated with a 68% lower risk of AF (odds ratio [OR] [95%CI]: 0.32 [0.24, 0.44]) (p < 0.001), but use of PPIs showed a trend towards higher risk of AF (OR [95%CI]: 1.4 [1.00, 1.8]) (p = 0.053).

CONCLUSION

Our study suggests that H₂RAs are associated with lower risk of AF in NAFLD patients with underlying diabetes and should be considered as the first-line antacid therapy in these patients. Risk stratification should be done if PPIs are indicated in high-risk diabetics with NAFLD.

Baseline liver function tests and full blood count indices and their association with progression of chronic kidney disease and renal outcomes in Aboriginal and Torres Strait Islander people: the eGFR follow- up study

Background

Determination of risks for chronic kidney disease (CKD) progression could improve strategies to reduce progression to ESKD. The eGFR Study recruited a cohort of adult Aboriginal and Torres Strait Islander people (Indigenous Australians) from Northern Queensland, Northern Territory and Western Australia, aiming to address the heavy CKD burden experienced within these communities.

Methods

Using data from the eGFR study, we explored the association of baseline liver function tests (LFTs) (alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (GGT), bilirubin and albumin) and full blood count (FBC) indices (white blood cell and red blood cell counts and haemoglobin) with annual eGFR decline and renal outcomes (first of 30% decline in eGFR with a follow-up eGFR < 60 mL/min/1.73 m², initiation of renal replacement therapy, or renal death). Comparisons of baseline variables across eGFR categories were calculated using analysis of variance and logistic regression as appropriate. Linear and multivariable regression models were used to estimate the annual change in eGFR for changes in FBC indices and LFTs. Cox proportional hazard models were used to estimate the hazard ratio for developing renal outcome for changes in baseline FBC indices and LFTs.

Results

Of 547 participants, 540 had at least one baseline measure of LFTs and FBC indices. The mean age was 46.1 (14.7) years and 63.6% were female. The median follow-up was 3.1 (IQR 2.8–3.6) years. Annual decline in eGFR was associated with low serum albumin (p < 0.001) and haemoglobin (p = 0.007). After adjustment for age, gender, urine albumin/creatinine ratio, diabetes, BMI, CRP, WHR, alcohol consumption, cholesterol and triglycerides, low serum albumin (p < 0.001), haemoglobin (p = 0.012) and bilirubin (p = 0.011) were associated with annual decline in eGFR.

Renal outcomes were inversely associated with serum albumin (p < 0.001), bilirubin (p = 0.012) and haemoglobin (p < 0.001) and directly with GGT (p = 0.007) and ALP (p < 0.001). Other FBC indices and LFTs were not associated with annual decline in eGFR or renal outcomes.

Conclusions

GGT, ALP, bilirubin, albumin and haemoglobin independently associate with renal outcomes. Contrary to findings from other studies, no association was found between renal outcomes and other FBC indices. These findings may help focus strategies to prevent disease progression in this high-risk population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-020-02185-x.

Impact of Fasting Lipid Profile on Chronic Kidney Disease Patients Having Fatty Liver Disease

Background and objectives Chronic kidney disease (CKD) share a common pathophysiology with non-alcoholic fatty liver disease (NAFLD). This study aims to identify the lipid derangements in patients of CKD and to associate them with radiological evidence of NAFLD. Material and methods A cross-sectional observational study was performed in a tertiary care hospital, to include all chronic kidney disease patients (n=238) through non-probability consecutive sampling. The criteria for inclusion were baseline estimated Glomerular filtration rate (eGFR) below 60 ml/min/1.73m2 for at least three months and chronic renal parenchymal changes on ultrasound. Two study groups were identified based on ongoing hemodialysis, while two further study groups were identified based on radiological evidence of fatty liver disease. Results The mean age of the study population was 48.52 ± 9.44 years with no difference amongst hemodialysis status, females elder than males (p= 0.027), those with fatty liver were much younger (p=0.014), and the most common age group below 50 years (p=0.005) among the fatty liver group. Radiological evidence of NAFLD was found amongst two-third of the study group with the status of hemodialysis indifferent among the study population (p=0.436). The mean values amongst fatty liver versus non-fatty liver groups revealed high creatinine, alanine transaminase (ALT), high-density lipoprotein (HDL), triglycerides (TG), and very-low-density lipoprotein (VLDL) in the fatty liver group, low-density lipoprotein (LDL) and total cholesterol (TC) were indifferent amongst the groups, while LDL/HDL ratio was higher in the non-fatty liver group. Conclusion A significantly higher HDL was found in fatty liver associated with CKD as compared to the non-fatty liver group.

Systematic review of the impact of non-alcoholic fatty liver disease on mortality and adverse clinical outcomes for individuals with chronic kidney disease

OBJECTIVES

To investigate if non-alcoholic fatty liver disease (NAFLD) impacts mortality and adverse outcomes for individuals with chronic kidney disease (CKD).

DESIGN

Systematic review.

DATA SOURCES

PubMed, EMBASE and Web of Science were searched up to 1 February 2020 with no restriction on the earliest date.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Observational cohort studies that reported either the risk of all-cause mortality, incidence of non-fatal cardiovascular events (CVE) or progression of kidney disease among adults with established CKD who have NAFLD compared with those without.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted data and assessed bias independently.

RESULTS

Of 2604 records identified, 3 studies were included (UK (n=852), South Korea (n=1525) and USA (n=1413)). All were judged to have a low or moderate risk of bias. Data were insufficient for meta-analysis. Two studies examined the influence of NAFLD on all-cause mortality. One reported a significant positive association for NAFLD with all-cause mortality for individuals with CKD (p<0.05) (cardiovascular-related mortality p=ns), which was lost following adjustment for metabolic risk factors; the second reported no effect in adjusted and unadjusted models. The latter was the only study to report outcomes for non-fatal CVEs and observed NAFLD to be an independent risk factor for this (propensity-matched HR=2.00, p=0.02). Two studies examined CKD progression; in one adjusted rate of percentage decline in estimated glomerular filtration rate per year was found to be increased in those with NAFLD (p=0.002), whereas the other found no significant difference.

CONCLUSIONS

Few studies have examined the influence of NAFLD on prognosis and major adverse clinical outcomes within the CKD population. The studies identified were diverse in design and results were conflicting. This should be a focus for future research as both conditions continue to rise in prevalence and have end-stage events associated with significant health and economic costs.

PROSPERO REGISTRATION NUMBER

CRD42020166508.

Common Drug Pipelines for the Treatment of Diabetic Nephropathy and Hepatopathy: Can We Kill Two Birds with One Stone?

Type 2 diabetes (T2D) is associated with diabetic nephropathy as well as nonalcoholic steatohepatitis (NASH), which can be called "diabetic hepatopathy or diabetic liver disease". NASH, a severe form of nonalcoholic fatty disease (NAFLD), can sometimes progress to cirrhosis, hepatocellular carcinoma and hepatic failure. T2D patients are at higher risk for liver-related mortality compared with the nondiabetic population. NAFLD is closely associated with chronic kidney disease (CKD) or diabetic nephropathy according to cross-sectional and longitudinal studies. Simultaneous kidney liver transplantation (SKLT) is dramatically increasing in the United States, because NASH-related cirrhosis often complicates end-stage renal disease. Growing evidence suggests that NAFLD and CKD share common pathogenetic mechanisms and potential therapeutic targets. Glucagon-like peptide 1 (GLP-1) receptor agonists and sodium-glucose cotransporter 2 (SGLT2) inhibitors are expected to ameliorate NASH and diabetic nephropathy/CKD. There are no approved therapies for NASH, but a variety of drug pipelines are now under development. Several agents of them can also ameliorate diabetic nephropathy/CKD, including peroxisome proliferator-activated receptors agonists, apoptosis signaling kinase 1 inhibitor, nuclear factor-erythroid-2-related factor 2 activator, C-C chemokine receptor types 2/5 antagonist and nonsteroidal mineral corticoid receptor antagonist. This review focuses on common drug pipelines in the treatment of diabetic nephropathy and hepatopathy.

Obesity-Related Glomerulopathy: A Latent Change in Obesity Requiring More Attention

BACKGROUND

Obesity has become a major public health problem, and the prevalence of kidney diseases has increased in parallel. Among kidney diseases caused by metabolic disorders, obesity-related glomerulopathy (ORG) is secondary to obesity.

SUMMARY

ORG is mainly caused by glomerular hyperfiltration, dysregulation of hormone and cytokine secretion in adipose tissues, and ectopic lipid accumulation in renal cells. ORG is pathologically characterized by glomerular hypertrophy, with or without focal and segmental glomerulosclerosis. Patients with ORG usually present with proteinuria concomitant with metabolic disorders such as dyslipidemia and hypertension. Weight loss, RAAS inhibitors, and improved insulin resistance can reduce the progression of ORG.

CONCLUSION

ORG is a growing renal pathological change in obese individuals, and a comprehensive understanding of the disease is pivotal to avoid its occurrence and improve quality of life for those with obesity. Key Messages:This review comprehensively describes the characteristics of ORG in pathological changes, clinical manifestations, pathogeneses and treatments.

Association between Non-Alcoholic Fatty Liver Disease and Chronic Kidney Disease: A Cross-Sectional Study

It is unclear whether the link between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) is mediated by common risk factors. We aimed to elucidate the association between NAFLD and CKD using propensity score (PS)-matched analysis. We assessed 3725 Japanese individuals, excluding those with hepatitis B or C infection and men and women who consumed >30 and >20 g/day of alcohol, respectively. Of these, we enrolled 1097 Japanese subjects with NAFLD diagnosed by ultrasonography and 1097 PS-matched subjects without NAFLD. The prevalence of CKD was higher in subjects with NAFLD than in those without NAFLD before PS matching, but there was no significant difference between these groups in terms of CKD prevalence after PS matching. There was no difference in the prevalence of CKD between those with and without NAFLD in the subgroup analyses. Logistic regression analysis demonstrated that obesity, hypertension, and hyperuricemia were independent predictors of CKD, but NAFLD was not independently associated with CKD. In subjects with NAFLD, obesity, hypertension, and hyperuricemia were independent predictors of CKD. Thus, the link between NAFLD and CKD may be mediated by common risk factors. We recommend screening for CKD when patients with NAFLD have the aforementioned comorbidities.

Therapeutic implications of shared mechanisms in non-alcoholic fatty liver disease and chronic kidney disease

The most common cause of liver disease worldwide is now non-alcoholic fatty liver disease (NAFLD). NAFLD refers to a spectrum of disease ranging from steatosis to non-alcoholic steatohepatitis, causing cirrhosis, and ultimately hepatocellular carcinoma. However, the impact of NAFLD is not limited to the liver. NAFLD has extra-hepatic consequences, most notably, cardiovascular and renal disease. NAFLD and chronic kidney disease share pathogenic mechanisms including insulin resistance, lipotoxicity, inflammation and oxidative stress. Not surprisingly, there has been a recent surge in efforts to manage NAFLD in an integrated way that not only protects the liver but also delays comorbidities such as chronic kidney disease. This concept of simultaneously addressing the main disease target and comorbidities is key to improve outcomes, as recently demonstrated by clinical trials of SGLT2 inhibitors and GLP1 receptor agonists in diabetes. HIF activators, already marketed in China, also have the potential to protect both liver and kidney, as suggested by preclinical data. This review concisely discusses efforts at identifying common pathogenic pathways between NAFLD and chronic kidney disease with an emphasis on potential paradigm shifts in diagnostic workup and therapeutic management.

PNPLA3 I148M gene variant and chronic kidney disease in type 2 diabetic patients with NAFLD: Clinical and experimental findings

BACKGROUND AND AIMS

Emerging evidence suggests an association between patatin-like phospholipase domain-containing protein-3 (PNPLA3) rs738409 (I148M protein variant) and risk of chronic kidney disease (CKD), but the mechanisms underpinning this association are poorly understood.

METHODS

We studied 157 patients with type 2 diabetes (T2DM) who underwent ultrasonography and vibration-controlled transient elastography for diagnosing nonalcoholic fatty liver disease (NAFLD). CKD was defined as estimated glomerular filtration rate (e-GFR) <60 mL/min/1.73 m² and/or abnormal albuminuria. We surveyed PNPLA3 mRNA expression in human tissues, using the liver as a positive control, and also measured PNPLA3 mRNA and protein expression levels in human cell lines represented in the kidney and the liver.

RESULTS

In all, 112 patients had NAFLD and 43 had CKD. Patients homozygous for the I148M variant (n = 11) had lower e-GFR levels (60.6 ± 11.7 vs 77.8 ± 15.9 vs 83.5 ± 16.5 mL/min/1.73 m² , P = .0001) and higher prevalence of CKD (63.6% vs 24.2% vs 25.0%, P = .028), compared to those with I/M (n = 66) and I/I (n = 80) PNPLA3 genotype. The association of I148M homozygosity with lower e-GFR levels (P < .0001) and higher risk of CKD (adjusted-odds ratio 6.65; 95% CI 1.65-26.8, P = .008) was independent of liver disease severity (as detected by liver stiffness ≥7kPa) and other risk factors. PNPLA3 mRNA expression was greatest in liver and renal cortex, and podocytes showed high PNPLA3 mRNA and protein levels, comparable to that of hepatocytes and hepatic stellate cells respectively.

CONCLUSIONS

The PNPLA3 I148M variant was associated with CKD, independently of common renal risk factors and severity of NAFLD PNPLA3 expression levels were particularly high in renal podocytes.

Risk of Kidney Dysfunction IN Nafld

Background:

The timely identification of traditional and non-traditional precursors and risk factors for chronic kidney disease (CKD) (a common systemic disease defined as a decreased kidney function documented by reduced glomerular filtration rate, or markers of kidney damage, or both) is relevant in clinical practice, as CKD increases the risk of end-stage renal disease and other serious comorbidities. A possible relationship between non-alcoholic fatty liver disease (NAFLD) (which is to date the most common chronic disease worldwide) and CKD has recently gained significant attention of researchers.

Methods :

A systematic literature search using appropriate keywords was made in order to identify relevant articles that have investigated the association between NAFLD and CKD.

Results:

Several observational studies and meta-analyses have reported the existence of an independent association between NAFLD and risk of CKD in patients with and without diabetes. However, whilst the association between NAFLD and risk of prevalent CKD is strong across various patient populations, whether NAFLD is independently associated with the development and progression of CKD is still debatable. Moreover, emerging evidence now suggests a potential association between patatin-like phospholipase domain-containing protein-3 (PNPLA3) rs738409 genotype (the most important genetic variant associated to NAFLD) and decreasing kidney function, independent of NAFLD.

Conclusions :

Convincing evidence now indicates that CKD is increased among patients with NAFLD. For this reason, patients with NAFLD should be regularly monitored for renal function and, on the other hand , NAFLD should be considered in all patients with CKD, especially if they are obese or have type 2 diabetes.

21st Century Advances in Multimodality Imaging of Obesity for Care of the Cardiovascular Patient

Although obesity is typically defined by body mass index criteria, this does not differentiate true body fatness, as this includes both body fat and muscle. Therefore, other fat depots may better define cardiometabolic and cardiovascular disease (CVD) risk imposed by obesity. Data from translational, epidemiological, and clinical studies over the past 3 decades have clearly demonstrated that accumulation of adiposity in the abdominal viscera and within tissue depots lacking physiological adipose tissue storage capacity (termed "ectopic fat") is strongly associated with the development of a clinical syndrome characterized by atherogenic dyslipidemia, hyperinsulinemia/glucose intolerance/type 2 diabetes mellitus, hypertension, atherosclerosis, and abnormal cardiac remodeling and heart failure. This state-of-the-art paper discusses the impact of various body fat depots on cardiometabolic parameters and CVD risk. Specifically, it reviews novel and emerging imaging techniques to evaluate adiposity and the risk of cardiometabolic diseases and CVD.

NAFLD as a driver of chronic kidney disease

Non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) are worldwide public health problems, affecting up to 25-30% (NAFLD), and up to 10-15% (CKD) of the general population. Recently, it has also been established that there is a strong association between NAFLD and CKD, regardless of the presence of potential confounding diseases such as obesity, hypertension and type 2 diabetes. Since NAFLD and CKD are both common diseases that often occur alongside other metabolic conditions, such as type 2 diabetes or metabolic syndrome, elucidating the relative impact of NAFLD on the risk of incident CKD presents a substantial challenge for investigators working in this research field. A growing body of epidemiological evidence suggests that NAFLD is an independent risk factor for CKD and recent evidence also suggests that associated factors such as metabolic syndrome, dysbiosis, unhealthy diets, platelet activation and processes associated with ageing could also contribute mechanisms linking NAFLD and CKD. This narrative review provides an overview of the literature on: a) the evidence for an association and causal link between NAFLD and CKD and b) the underlying mechanisms by which NAFLD (and factors strongly linked with NAFLD) may increase the risk of developing CKD.

PNPLA3 gene and kidney disease

Chronic kidney disease (CKD) is a disease regularly seen in clinical practice. At present, CKD is described as a change of kidney structure and/or function and it is classified in relation to cause, values of glomerular filtration rate and albuminuria category. Seeing that CKD is closely linked to the development of end-stage renal disease and other comorbidities, the determination of additional independent predictors for CKD is clinically necessary. At present, there is evidence associating non-alcoholic fatty liver disease (NAFLD) with CKD, thereby suggesting that NAFLD patients may require intensive surveillance to reduce their risk of CKD. In 2008, genome-wide association studies documented an association between the variant rs738409 (C > G p.I148M) in the patatin-like phospholipase domain containing 3 (PNPLA3) gene (mainly implicated in the lipid regulation) and the entire spectrum of NAFLD (i.e., liver steatosis, non-alcoholic steatohepatitis, fibrosis, and hepatocellular carcinoma). In the last years, accumulating epidemiological evidence suggests the existence of a relationship between PNPLA3 rs738409 and risk of CKD, indicating that rs738409 may also contribute to the kidney injury. This is of particular scientific interest, as such association may explain, at least in part, the epidemiological association between liver and kidney disease. In this narrative review, we will discuss the accumulating evidence regarding the association between PNPLA3 rs738409 and risk of CKD, the putative biological mechanisms underpinning such relationship, and the possible future perspective.

Particular aspects of gastroenterological disorders in chronic kidney disease and end-stage renal disease patients: a clinically focused review

Besides renal disease, gastrointestinal (GI) disorders are frequently reported in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Related gastrointestinal symptoms tend to increase as the renal disease progresses. Also, in patients with ESRD, the modality of dialysis is related to particular forms of GI disorders.The kidney can interact with the digestive organs through functional endogenous systems such as the 'kidney-colon axis' and the 'kidney-liver axis'. Digestive diseases are one of the visible manifestations of the disturbance between hemostatic, hemodynamic and immunological balance in such patients.No clear management guidelines currently exist for many of the gastrointestinal problems that accompany renal failure. This review aims to describe the particular aspects of GI diseases present in CKD/ESRD. We focus our discussion in the specificities of epidemiology, diagnosis, and prognosis of such disorders between the different segments of the digestive system.

Urinary fatty acid and retinol binding protein-4 predict CKD progression in severe NAFLD patients with hypertension: 4-year study with clinical and experimental approaches

Detection of the chronic kidney disease (CKD) progression can begin early intervention to improve the prognosis of severe non-alcoholic fatty liver disease (NAFLD). This bi-directional cross-sectional study evaluates the roles of fatty acid-binding protein (FABP) and retinol binding protein (RBP4), which are produced from inflamed liver, adipose tissue and immune cells, for the prediction of CKD progression in severe NAFLD. Ninety severe NAFLD patients with hypertension and proteinuria (NAFLDHTN) were enrolled and divided into CKD (n = 39) and non-CKD groups (n = 51). Among 39 NAFLDHTN patients, 18 cases were categorized as CKD progression group. In comparison with CKD stable group (n = 21), the positive correlation between fold change values of hepatic fibrotic score (KPa), urinary FABP4 or urinary RBP4 versus severity of albuminuria were noted among CKD progression group. On multivariate analysis, high body mass index (BMI, >25 kg/m), high hepatic fibrosis score (>9.5 KPa), high urinary level of vascular cell adhesion molecule-1 (VCAM-1, >2239 μg/g cr), high urinary level of FABP4 (>115 ng/g cr) and high urinary level of RBP4 (>33.5 mg/g cr) are 5 independent predictors for progressive CKD during 24 months of follow-up. Synergetic effect was noted among these 5 risk factors for the prediction of CKD progression in NAFLDHTN patients. The in vitro experiments revealed that both FABP4 and RBP4 directly enhanced albumin-induced ER stress and apoptosis of human renal tubular epithelial cell line HK-2 cells and human podocytes cell lines. Through clinical and experimental approaches, this study revealed new 5 synergetic predictors including high BMI, hepatic fibrosis score, urinary level of VCAM-1, urinary level of FABP4 and RBP4, for the CKD progression in severe NAFLD patients with hypertension and proteinuria.

Nonalcoholic Fatty Liver Disease-Related Chronic Kidney Disease

Nonalcoholic fatty liver disease has become the main concern of hepatologists around the world and the main research topic for identifying effective and safe therapy. Advances in the treatment of chronic viral hepatitis in recent years have opened the way towards reducing mortality in patients with chronic liver disease. This goal has not yet been reached, as the burden of chronic liver disease remains a future major health problem as the incidence of the nonalcoholic fatty liver disease continues to rise. The proportion of patients with liver cirrhosis and those with hepatocellular carcinoma due to nonalcoholic liver disease on the liver transplant waiting list has increased in the last years. The upward trend in the incidence and prevalence of the disease in recent decades raises concern over a possible global epidemic, especially as the disease is still underestimated and underdiagnosed. Chronic kidney disease presented an increase in incidence and prevalence during the last years, and it has been associated not only with increased morbidity and mortality but also with high costs for the health system. During the last decade, several studies have shown the association between nonalcoholic fatty disease and chronic kidney disease, two major worldwide health problems.

Higher NAFLD fibrosis score is associated with impaired eGFR

BACKGROUND/PURPOSE

Chronic kidney disease (CKD) has become a worldwide health problem, leading to high morbidity and mortality, and non-alcoholic fatty liver disease (NAFLD) is considered a risk factor for CKD. The aim of this study was to explore the relationship between NAFLD fibrosis score (NFS) and the estimated glomerular filtration rate (eGFR), and identify possible risk factors related to the NFS among Taiwanese subjects.

METHODS

Subjects were enrolled from the database of the Department of Preventive Medicine of Kaohsiung Municipal Hsiao-Kang Hospital. The eGFR was calculated according to the Taiwanese Modification of Diet in Renal Disease (TMDRD) equation, and the NFS was employed to evaluate the fibrotic level.

RESULTS

In total, 11,376 subjects were enrolled in this study, with a mean age of 52.0 ± 6.81 years, including 4529 (39.8%) males. A fasting sugar level ≥100 mg/dL (OR = 1.70, 95% CI = 1.52-1.87) and an abnormal waist circumference (OR = 1.81, 95% CI = 1.65-1.99) were significant factors associated with NFS (p < 0.05). Trends of a decreasing TMDRD score and an increasing NFS with increasing age were noted (p < 0.05). The NFS was significantly negatively correlated with the TMDRD score (standard coefficients: -0.067, p < 0.001).

CONCLUSION

A higher NFS is associated with an impaired eGFR in Taiwanese subjects. Controlling risk factors, especially fasting sugar level and waist circumference, may be useful in preventing NFS deterioration, which is negatively correlated with the eGFR.