PNPLA3 rs738409 is associated with renal glomerular and tubular injury in NAFLD patients with persistently normal ALT levels

From nonalcoholic fatty liver disease to metabolic-associated fatty liver disease: Big wave or ripple?

There is some dissatisfaction with the term "nonalcoholic fatty liver disease (NAFLD)," which overemphasizes alcohol and underemphasizes the importance of metabolic risk factors in this disease. Recently, a consensus recommended "metabolic (dysfunction)-associated fatty liver disease (MAFLD)" as a more appropriate term to describe fatty liver diseases (FLD) associated with metabolic dysfunction. During the definition change from NAFLD to MAFLD, subjects with FLD and metabolic abnormalities, together with other etiologies of liver diseases such as alcohol, virus, or medication who have been excluded from the NAFLD criteria, were added to the MAFLD criteria, while subjects with FLD but without metabolic abnormality, who have been included in the NAFLD criteria, were excluded from the MAFLD criteria. This means that there is an emphasis on the metabolic dysfunction in MAFLD which may underestimate the prognostic value of hepatic steatosis itself, whereas the MAFLD criteria might better identify subjects who are at a higher risk of hepatic or cardiovascular outcomes. However, non-metabolic risk NAFLD subjects who are excluded from the MAFLD criteria are missed from the diagnosis, and their potential risk can be the cause of future diseases. Although huge controversies remain, this review focused on summarizing recent studies that compared the clinical and prognostic characteristics between subjects with NAFLD and MAFLD.

[Chronic kidney injury in patients with liver diseases - Reappraising pathophysiology and treatment options]

Acute and chronic kidney disease concurs commonly with liver disease and is associated with a wide array of complications including dialysis dependency and increased mortality. Patients with liver disease or liver cirrhosis show a higher prevalence of chronic kidney disease. This is attributed to concomitant comorbidities, such as metabolic syndrome, chronic inflammation, hypercoagulability, hyperfibrinolysis, diabetes mellitus and dyslipidaemias. But chronic progressive kidney disease is not always due to hepatorenal syndrome. Beyond that, other diseases or disease entities should be considered. Among them are diabetic nephropathy, secondary IgA nephropathy, hepatitis C -associated membranoproliferative Glomerulonephritis (MPGN) and hepatitis B-associated membranous nephropathy.Coexisting diseases, similar underlying pathophysiologic mechanisms, or simultaneously concurring pathophysiological processes and overlapping clinical manifestations, impede the etiologic diagnosis and corresponding treatment of chronic kidney disease in the setting of chronic liver disease. In this review, we focus on common and rare pathologies, which can lead to chronic kidney disease in this particular patient group and try to summarize the most recent therapeutic modalities.

Individualized Polygenic Risk Score Identifies NASH in the Eastern Asia Region: A Derivation and Validation Study

INTRODUCTION

Strong evidence indicates that multiple genetic and environmental risk factors play a role in the pathogenesis of nonalcoholic steatohepatitis (NASH). We aimed to develop and validate a novel nomogram, incorporating both genetic and clinical factors, for predicting NASH.

METHODS

A total of 1,070 Asian individuals with biopsy-confirmed nonalcoholic fatty liver disease (NAFLD) from 2 countries (China and South Korea) were recruited. The histological spectrum of NAFLD was classified according to the NASH clinical research network scoring system. The nomogram was developed in the Chinese training set (n = 402), and then, it was validated in both the Chinese internal validation set (n = 136) and the external Korean validation cohort (n = 532), respectively.

RESULTS

Sex, metabolic syndrome, insulin resistance, serum aspartate aminotransferase levels, and PNPLA3 (rs738409) and HSD17B13 (rs72613567) genetic variants were strongly associated with NASH. Based on their regression coefficients, we developed a nomogram with good discriminatory ability (area under the receiver operating characteristic curve: 0.81, 95% confidence interval [CI] 0.77-0.85) and good calibration (Hosmer-Lemeshow test, P = 0.794) for identifying NASH. In the 2 validation cohorts, the nomogram showed high area under the receiver operating characteristic curves (internal validation set: 0.80, 95% CI 0.72-0.88; external validation cohort: 0.76, 95% CI 0.72-0.80) and good calibration.

DISCUSSION

Our newly developed and externally validated nomogram, incorporating both genetic and clinical risk factors, may be conveniently used to predict NASH. Further validation studies in other ethnic groups are warranted to confirm its diagnostic utility to identify NASH, among patients with biopsy-proven NAFLD.

FIB-4 First in the Diagnostic Algorithm of Metabolic-Dysfunction-Associated Fatty Liver Disease in the Era of the Global Metabodemic

The prevalence of obesity or metabolic syndrome is increasing worldwide (globally metabodemic). Approximately 25% of the adult general population is suffering from nonalcoholic fatty liver disease (NAFLD), which has become a serious health problem. In 2020, global experts suggested that the nomenclature of NAFLD should be updated to metabolic-dysfunction-associated fatty liver disease (MAFLD). Hepatic fibrosis is the most significant determinant of all cause- and liver -related mortality in MAFLD. The non-invasive test (NIT) is urgently required to evaluate hepatic fibrosis in MAFLD. The fibrosis-4 (FIB-4) index is the first triaging tool for excluding advanced fibrosis because of its accuracy, simplicity, and cheapness, especially for general physicians or endocrinologists, although the FIB-4 index has several drawbacks. Accumulating evidence has suggested that vibration-controlled transient elastography (VCTE) and the enhanced liver fibrosis (ELF) test may become useful as the second step after triaging by the FIB-4 index. The leading cause of mortality in MAFLD is cardiovascular disease (CVD), extrahepatic malignancy, and liver-related diseases. MAFLD often complicates chronic kidney disease (CKD), resulting in increased simultaneous liver kidney transplantation. The FIB-4 index could be a predictor of not only liver-related mortality and incident hepatocellular carcinoma, but also prevalent and incident CKD, CVD, and extrahepatic malignancy. Although NITs as milestones for evaluating treatment efficacy have never been established, the FIB-4 index is expected to reflect histological hepatic fibrosis after treatment in several longitudinal studies. We here review the role of the FIB-4 index in the management of MAFLD.

Association between positivity of serum autoantibodies and liver disease severity in patients with biopsy-proven NAFLD

BACKGROUND AND AIMS

Some previous studies reported serum autoantibody positivity in patients with nonalcoholic fatty liver disease (NAFLD). The clinical significance of these findings remains uncertain. We aimed to investigate the association between the presence of serum autoantibodies and liver disease severity in NAFLD.

METHODS AND RESULTS

A total of 388 consecutive patients with biopsy-proven NAFLD were included in the study. Various serum autoantibodies (including also anti-nuclear antibodies [ANA]) were detected by indirect immunofluorescent or immunoblotting assays. Overall, 84 (21.6%) patients with biopsy-confirmed NAFLD had positivity for at least one of the measured serum autoantibodies. ANA positivity was present in 50 (12.9%) patients, whereas anti-U1RNP or pANCA antibodies were detectable in 9 (2.3%) and 6 (1.5%) patients, respectively. Multivariate logistic regression analysis showed that ANA positivity (adjusted-odds ratio: 4.51, 95%CI: 1.77-11.5; P = 0.002) or positivity of any serum autoantibodies (adjusted-odds ratio: 3.14, 95%CI: 1.30-7.62; P = 0.01) were independently associated with advanced liver fibrosis (stages F3-F4). In serum autoantibody/ANA-positive patients, the proportion of those with advanced fibrosis was also greater among carriers of PNPLA3 rs738409 GG or CG than among those carrying PNPLA3 rs738409 CC genotype.

CONCLUSIONS

Serum autoantibody positivity was independently associated with advanced liver fibrosis in patients with biopsy-proven NAFLD. The presence of serum autoantibodies in patients with advanced fibrosis occurred more frequently amongst those carrying PNPLA3 rs738409 GG or CG genotypes.

PNPLA3 polymorphism influences the association between high-normal TSH level and NASH in euthyroid adults with biopsy-proven NAFLD

AIM

We aimed to evaluate the association between serum thyroid stimulating hormone (TSH) levels, within the reference range, and the histological severity of nonalcoholic fatty liver disease (NAFLD), and whether this association was modulated by the patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 polymorphism.

MATERIALS AND METHODS

We enrolled 327 euthyroid individuals with biopsy-proven NAFLD, who were subdivided into two groups, i.e., a 'strict-normal' TSH group (TSH level 0.4 to 2.5mIU/L; n=283) and a 'high-normal' TSH group (TSH level 2.5 to 5.3mIU/L with normal thyroid hormones; n=44). Logistic regression analyses were performed to assess the association between TSH status and presence of nonalcoholic steatohepatitis (NASH) after stratifying subjects by PNPLA3 genotypes.

RESULTS

Compared to strict-normal TSH group, patients with high-normal TSH levels were younger and had a greater prevalence of NASH and higher histologic NAFLD activity score. After stratifying by PNPLA3 genotypes, the significant association between high-normal TSH levels and presence of NASH was restricted only to carriers of the PNPLA3 G risk allele and remained significant even after adjustment for potential confounding factors (adjusted-odds ratio: 3.279; 95% CI: 1.298-8.284; P=0.012).

CONCLUSION

In euthyroid individuals with biopsy-proven NAFLD, we found a significant association between high-normal TSH levels and NASH. After stratifying by PNPLA3 rs738409 genotypes, this association was observed only among carriers of the PNPLA3 G risk allele.

Development and validation of a novel non-invasive test for diagnosing fibrotic non-alcoholic steatohepatitis in patients with biopsy-proven non-alcoholic fatty liver disease

BACKGROUND AND AIM

There is an immediate need for non-invasive accurate tests for diagnosing liver fibrosis in patients with non-alcoholic steatohepatitis (NASH). Previously, it has been suggested that MACK-3 (a formula that combines homeostasis model assessment-insulin resistance with serum serum aspartate aminotransferase and cytokeratin [CK]18-M30 levels) accurately identifies patients with fibrotic NASH. Our aim was to assess the performance of MACK-3 and develop a novel, non-invasive algorithm for diagnosing fibrotic NASH.

METHODS

Six hundred and thirty-six adults with biopsy-proven non-alcoholic fatty liver disease (NAFLD) from two independent Asian cohorts were enrolled in our study. Liver stiffness measurement (LSM) was assessed by vibration-controlled transient elastography (Fibroscan). Fibrotic NASH was defined as NASH with a NAFLD activity score (NAS) ≥ 4 and F ≥ 2 fibrosis.

RESULTS

Metabolic syndrome (MetS), platelet count and MACK-3 were independent predictors of fibrotic NASH. On the basis of their regression coefficients, we developed a novel nomogram showing a good discriminatory ability (area under receiver operating characteristic curve [AUROC]: 0.79, 95% confidence interval [CI 0.75-0.83]) and a high negative predictive value (NPV: 94.7%) to rule out fibrotic NASH. In the validation set, this nomogram had a higher AUROC (0.81, 95%CI 0.74-0.87) than that of MACK-3 (AUROC: 0.75, 95%CI 0.68-0.82; P < 0.05) with a NPV of 93.2%. The sequential combination of this nomogram with LSM data avoided the need for liver biopsy in 56.9% of patients.

CONCLUSIONS

Our novel nomogram (combining MACK-3, platelet count and MetS) shows promising utility for diagnosing fibrotic NASH. The sequential combination of this nomogram and vibration-controlled transient elastography limits indeterminate results and reduces the number of unnecessary liver biopsies.

Pediatric non-alcoholic fatty liver disease and kidney function: Effect of HSD17B13 variant

BACKGROUND

Growing evidence supports a genetic link between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD). Interesting data demonstrated that both the major NAFLD risk polymorphisms such as the I148M polymorphism in the patatin like phospholipase containing domain 3 (PNPLA3) and the E167K allele in the transmembrane 6 superfamily member 2 gene (TM6SF2) affect renal function. Recently the hydroxysteroid 17-beta dehydrogenase 13 (HSD17B13) gene has been recognized as a novel genetic variant involved in NAFLD pathophysiology. In particular, it has been showed the protective effect of the rs72613567:TA variant of this gene against liver damage both in adults and children.

AIM

To investigate the impact of the rs72613567:TA variant of the HSD17B13 gene on estimated glomerular filtration rate (eGFR) in obese children.

METHODS

We enrolled 684 obese children (mean age 10.56 ± 2.94 years; mean BMI-SDS 2.98 ± 0.78) consecutively attending our Obesity Clinic. All the patients underwent a careful clinical assessment and a comprehensive biochemical evaluation. To detect hepatic steatosis, a liver ultrasound was performed. NAFLD was defined by ultrasound detected liver steatosis and/or alanine aminotransferase (ALT) levels > 40 IU/L. The study population was divided on the basis of the NAFLD presence. Genotyping for the rs72613567:TA variant of the HSD17B13 gene in all the enrolled subjects was also made.

RESULTS

Patients carrying the HSD17B13 rare A allele showed higher eGFR levels compared with homozygous patients both among subjects with and without NAFLD. A general linear model confirmed a direct and significant association of eGFR values with HSD17B13 genotype independently of PNPLA3 and TM6SF2 polymorphisms both in patients with and without NAFLD. A comparison of regression line confirmed the influence of HSD17B13 genotype on the relationship between eGFR and age both among patients with and without NAFLD. Homozygous patients for HSD17B13 genotype with NAFLD showed a significantly higher decline of eGFR with the increase of the age compared with the patients with NAFLD carrying the HSD17B13 rare A allele (P value for intercepts = 0.005; P value for slopes = 0.94). The same effect was observed among patients without NAFLD (P value for intercepts = 0.0012; P value for slopes = 0.87).

CONCLUSION

Carriers of the HSD17B13 rare A allele showed higher eGFR levels than homozygous subjects both among subjects with and without NAFLD and independently of PNPLA3 I148M and TM6SF6 E167K polymorphisms.

Lower levels of plasma NT-proBNP are associated with higher prevalence of NASH in patients with biopsy-proven NAFLD

BACKGROUND AND AIMS

Emerging evidence suggests that plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) levels are decreased in patients with imaging-defined nonalcoholic fatty liver disease (NAFLD), but no data are currently available on the association between plasma NT-proBNP levels and the histological severity of NAFLD.

METHODS AND RESULTS

We enrolled 351 (73.5% men) consecutive adult patients with biopsy-proven NAFLD without a prior history of cardiovascular disease (CVD). Plasma NT-proBNP levels were measured using a commercially available immunochemical system (VITROS® 5600, Johnson, New Jersey). Fifty-three percent of these subjects had nonalcoholic steatohepatitis (NASH). After stratification of patients by plasma NT-proBNP tertiles; compared to those in the 1st tertile (NT-proBNP ≤16 pg/ml), the odds ratio for NASH was 0.52 (95% CI 0.29-0.95) in patients in the 2nd tertile (NT-proBNP of 17-33 pg/ml) and 0.49 (95% CI 0.26-0.93) in those in the 3rd tertile (NT-proBNP ≥34 pg/ml) of plasma NT-proBNP levels, even after adjustment for age, sex, body mass index, homeostasis model assessment (HOMA)-estimated insulin resistance, pre-existing diabetes, hypertension, and dyslipidemia.

CONCLUSION

In subjects with biopsy-proven NAFLD without known CVD, this cross-sectional study shows for the first time, that lower plasma NT-proBNP levels are strongly associated with a higher prevalence of NASH.

Effect of PNPLA3 polymorphism on diagnostic performance of various noninvasive markers for diagnosing and staging nonalcoholic fatty liver disease

BACKGROUND AND AIM

Patatin-like phospholipase domain-containing protein 3 (PNPLA3) I148M (rs738409) genotype influences clinical/biochemical characteristics in patients with nonalcoholic fatty liver disease (NAFLD), but whether PNPLA3-I148M (rs738409) genotype also influences the diagnostic performance of noninvasive diagnostic tests for NAFLD is uncertain. Our aim was to investigate the differences in diagnostic performance of noninvasive diagnostic tests for NAFLD according to PNPLA3-I148M (rs738409) genotype.

METHODS

Fifty-eight healthy controls and 349 patients with biopsy-proven NAFLD were included. Areas under the receiver operating characteristic curve (AUROCs) were calculated to predict hepatic steatosis (fatty liver index and hepatic steatosis index), nonalcoholic steatohepatitis (cytokeratin-18 M30 and M65), and significant fibrosis (≥F2 fibrosis) (fibrosis-4 and BARD), stratifying by rs738409 genotypes (CC and CG + GG groups).

RESULTS

Fatty liver index and hepatic steatosis index showed good diagnostic performance for diagnosing steatosis only in the CG + GG group with AUROCs ranging from 0.819 to 0.832. Cytokeratin-18 M30 (AUROC = 0.688) and M65 (AUROC = 0.678) had suboptimal performance for diagnosing nonalcoholic steatohepatitis in the CG + GG group, whereas both had good performance (AUROC = 0.814 and 0.813, respectively) in the CC group. BARD score showed good performance in the CG + GG group compared with the CC group (AUROC = 0.805 and 0.532, respectively). Fibrosis-4 had suboptimal performance in the CG + GG group and good performance in the CC group (AUROC = 0.662 and 0.801, respectively).

CONCLUSIONS

Diagnostic performance of noninvasive tests for NAFLD varied markedly according to PNPLA3 genotypes. Clinicians should be aware that PNPLA3 genotype limits the clinical utility of noninvasive diagnostic tests for diagnosing NAFLD.

Association between NAFLD and risk of prevalent chronic kidney disease: why there is a difference between east and west?

BACKGROUNDS

There is a discrepancy between west and east on the relationship between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD). This study aimed to find out the possible reason for this and to clarify the association between NAFLD and CKD by analyzing two population-based datasets from the US and China.

METHODS

Two health examination datasets from China and the US were used. CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73m2 or and/or abnormal albuminuria and/or overt proteinuria. Binary logistic regression was used to examine the association between NAFLD and CKD.

RESULTS

A total of 60,965 participants were analyzed, including 11,844 from the US and 51,229 from China. The prevalence of NAFLD was 27.12% in the Chinese population and 36.08% in the US population (p < 0.001). The proportions of CKD and late stage CKD (stages 3-5) were higher in the US population than the Chinese one. NAFLD was independently associated with an increased risk of CKD in Chinese population, whereas in the US population, the NAFLD was not an independent risk factor of CKD. In subgroup analyses which excluded late stages CKD (stages 3-5), the risks of mild renal function decline became consistent: NAFLD was associated with early stages of CKD but not the late stages of CKD in both populations.

CONCLUSION

NAFLD increased the risk of early stages of CKD in both Chinese and the US population. The conflicting results reported by previous studies might result from the different proportion of late stages of CKD.

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.

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.

Proportion of NAFLD patients with normal ALT value in overall NAFLD patients: a systematic review and meta-analysis

Background

ALT value is often used to reflect the hepatic inflammation and injury in NAFLD patients, but many studies proved that ALT values were normal in many NAFLD patients. The aim of this study was to identify the summarized proportion of NAFLD patients with normal ALT value in the overall NAFLD patients.

Methods

Electronic databases PubMed, EMBASE, Ovid, and the Cochrane Library were searched for potential studies published from January 1, 2000 to September 30, 2019. Studies that have reported the number of NAFLD or NASH patients with normal and abnormal ALT value were included and analyzed. Abstracts, reviews, case reports, and letters were excluded.

Results

A total of 11 studies with 4084 patients were included for assessing the summarized proportion of NAFLD patients with normal ALT in overall NAFLD patients. As the results shown, the summarized proportion of NAFLD patients with normal ALT value in overall NAFLD patients was 25% (95%CI: 20–31%) which was calculated by the random-effects model. The summarized proportion of NASH patients with normal ALT value in overall NASH patients was 19% (95%CI: 13–27%). Subgroup analysis includes region, study type, diagnostic method, and group size were conducted to investigate the resource of heterogeneity in the summarized proportion of NAFLD and NASH patients with normal ALT value.

Conclusions

25% NAFLD patients and 19% NASH patients possess the normal ALT value in the clinical manifestation. The value of ALT in the clinical diagnosis of NAFLD and NASH remains need be further testified.

FIB-4 Index and Diabetes Mellitus Are Associated with Chronic Kidney Disease in Japanese Patients with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is associated with chronic kidney disease (CKD). The aim of this retrospective study was to determine the risk factors for progression of CKD in patients with biopsy-proven NAFLD including patatin-like phospholipase domain containing 3 (PNPLA3) polymorphism. A total of 344 patients with biopsy-proven NAFLD were enrolled consecutively in this study. Multivariate analysis identified males (odds ratio (OR) 5.46), age (per 1 year, OR 1.07), and FIB-4 index (≥1.30, OR 3.85) as factors associated with CKD. Of the 154 patients with a baseline estimated glomerular filtration rate (eGFR) ≥60 mL/min, 30 had a deterioration in CKD stage and 15 developed CKD after 3 years. Multivariate analysis identified diabetes mellitus (OR 2.44) as a risk factor for deterioration in CKD stage, while diabetes mellitus (OR 21.54) and baseline eGFR (per 1 mL/min OR 0.88) were risk factors for development of CKD. PNPLA3 did not affect the change in eGFR. In NAFLD patients, a high FIB-4 index was associated with CKD to increases in the index linked to reductions in eGFR. In order to prevent development of CKD, an appropriate therapy focusing on renal function is needed for NAFLD patients, especially those with diabetes.