Noninvasive indices for predicting nonalcoholic fatty liver disease in patients with chronic kidney disease

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.

The Diagnostic and Prognostic Value of the Triglyceride-Glucose Index in Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD): A Systematic Review and Meta-Analysis

Metabolic dysfunction-associated fatty liver disease (MAFLD) has been related to a series of harmful health consequences. The triglyceride-glucose index (TyG index) appears to be associated with MAFLD. However, no consistent conclusions about the TyG index and incident MAFLD have been reached. PubMed, MEDLINE, Web of Science, EMBASE and the Cochrane Library were searched. Sensitivities, specificities and the area under the receiver operating characteristic (AUC) with a random-effects model were used to assess the diagnostic performance of the TyG index in NAFLD/MAFLD participants. Potential threshold effects and publication bias were evaluated by Spearman’s correlation and Deeks’ asymmetry test, respectively. A total of 20 studies with 165725 MAFLD participants were included. The summary receiver operator characteristic (SROC) curve showed that the sensitivity, specificity and AUC were 0.73 (0.69−0.76), 0.67 (0.65, 0.70) and 0.75 (0.71−0.79), respectively. Threshold effects (r = 0.490, p < 0.05) were confirmed to exist. Subgroup analyses and meta-regression showed that some factors including country, number of samples, age and disease situation were the sources of heterogeneity (p < 0.05). Our meta-analysis suggests that the TyG index can diagnose and predict MAFLD patients with good accuracy. The number of studies remains limited, and prospective studies are needed.

Evaluated Glomerular Filtration Rate Is Associated With Non-alcoholic Fatty Liver Disease: A 5-Year Longitudinal Cohort Study in Chinese Non-obese People

Objective

Evidence regarding the association between evaluated glomerular filtration rate (eGFR) and non-alcoholic fatty liver disease (NAFLD) is still limited. On that account, the purpose of our research is to survey the link of evaluated eGFR on NAFLD.

Methods

This study is a retrospective cohort study. Which consecutively and non-selectively collected a total of 16,138 non-obese participants in a Chinese hospital from January 2010 to December 2014. We then used the Cox proportional-hazards regression model to explore the relationship between baseline eGFR and NAFLD risk. A Cox proportional hazards regression with cubic spline functions and smooth curve fitting (the cubic spline smoothing) was used to identify the non-linear relationship between eGFR and NAFLD. Additionally, we also performed a series of sensitivity analyses and subgroup analyses. Data had been uploaded to the DATADRYAD website.

Results

The mean age of the included individuals was 43.21 ± 14.95 years old, and 8,467 (52.47%) were male. The mean baseline eGFR was 98.83 ± 22.80 mL/min per 1.73m2. During a median follow-up time of 35.8 months, 2,317 (14.36%) people experienced NAFLD. After adjusting covariates, the results showed that eGFR was negatively associated with incident NAFLD (HR = 0.983, 95%CI: 0.980, 0.985). There was also a non-linear relationship between eGFR and NAFLD, and the inflection point of eGFR was 103.489 mL/min per 1.73 m2. The effect sizes (HR) on the left and right sides of the inflection point were 0.988 (0.984, 0.991) and 0.971 (0.963, 0.979), respectively. And the sensitive analysis demonstrated the robustness of our results. Subgroup analysis showed that eGFR was more strongly associated with incident NAFLD in diastolic blood pressure (DBP) &lt; 90 mmHg, fasting plasma glucose (FPG) ≤ 6.1 mmol/L, high-density lipoprotein cholesterol (HDL-c) &lt; 1 mmol/L, and alanine aminotransferase (ALT) ≥ 40 U/L participants. In contrast, the weaker association was probed in those with DBP ≥ 90 mmHg, ALT &lt; 40 U/L, FPG &gt; 6.1 mmol/L, and HDL-c ≥ 1 mmol/L.

Conclusion

This study demonstrates a negative and non-linear association between eGFR and incident NAFLD in the Chinese non-obese population. eGFR is strongly related to NAFLD when eGFR is above 103 mL/min per 1.73 m2. From a therapeutic perspective, it makes sense to maintain eGFR levels within the inflection point to 130 mL/min/1.73 m2.

Triglyceride-Glucose Index for Early Prediction of Nonalcoholic Fatty Liver Disease: A Meta-Analysis of 121,975 Individuals

Insulin resistance (IR) is a major contributor to the pathogenesis of nonalcoholic fatty liver disease (NAFLD). The triglyceride-glucose (TyG) index has recently gained popularity for the assessment of IR and NAFLD due to its ease of acquisition and calculation. Therefore, we conducted this systematic review and meta-analysis to summarize the existing studies in the literature and provide a quantitative assessment of the significance of the TyG index in predicting the incidence of NAFLD. A comprehensive literature search in PubMed, EMBASE, and Web of Science databases from inception until 25 March 2022 was conducted. Published observational studies that evaluated the association between TyG index and NAFLD among the adult population and reported the hazard ratio (HR) or odds ratio (OR) for this association after multivariate analysis were included. The random-effects model was used as the primary statistical analysis model in the estimation of pooled ORs and HRs with the corresponding confidence intervals (CIs). A total of 17 observational studies, including 121,975 participants, were included. For studies analyzing the TyG index as a categorical variable, both pooled OR (6.00, CI 4.12–8.74) and HR (1.70, CI 1.28–2.27) were significant for the association between TyG index and incident NAFLD. For studies analyzing the TyG index as a continuous variable, pooled OR (2.25, CI 1.66–3.04) showed similar results. Consistent results were obtained in subgroup analyses according to the study design, sample size, ethnicity, and diabetic status. In conclusion, our meta-analysis demonstrates that a higher TyG index is associated with higher odds of NAFLD. TyG index may serve as an independent predictive tool to screen patients at high risk of NAFLD in clinical practice, especially in primary care settings. Patients with a high TyG index should be referred for a liver ultrasound and start intense lifestyle modifications. However, further large-scale prospective cohort studies are necessary to validate our findings.

Prevalence of Nonalcoholic Fatty Liver Disease in Children with Renal Failure Underwent Treatment with Dialysis

Background

In this study, we aimed to investigate the prevalence of nonalcoholic fatty liver disease (NAFLD) in children with renal failure under treatment with dialysis and its association with biochemical measurements.

Methods

In this cross-sectional study, children aged less than 18 years with chronic kidney disease (CKD) who were under treatment with dialysis at least 3 months ago were enrolled. To evaluate fatty liver in those patients who had no recent liver ultrasonography (last 6 months), liver ultrasonography was performed. The characteristics of patients with renal failure with and without NAFLD based on the ultrasonographic evaluation were compared. The association between NAFLD and the studied variables was evaluated.

Results

In this study, 39 children (31 males and 8 females) with renal failure who underwent treatment with dialysis were included. From the studied population, six (19.4%) had NAFLD based on ultrasonographic evaluation. There were no differences between renal failure patients with and without NAFLD regarding the biochemical and anthropometric characteristics (P > 0.0).

Conclusions

The prevalence of NAFLD in our studied children with renal failure who underwent treatment with dialysis was like the general population and it was not associated with the biochemical and anthropometric characteristics of the patients. Given the importance of NAFLD in renal failure patients as well as its subtle nature, it is recommended to screen patients with CKD for NAFLD.

The triglyceride and glucose index and risk of nonalcoholic fatty liver disease: A dose-response meta-analysis

BACKGROUND

The triglyceride and glucose (TyG) index is associated with the risk of nonalcoholic fatty liver disease (NAFLD), but the dose-response relationship between them is still unknown. We conducted a comprehensive meta-analysis to study the dose-response association between the TyG index and the risk of NAFLD.

METHODS

We systematically searched the Cochrane Library, PubMed, and Embase databases until July 2022 for relevant studies. The robust error meta-regression method was used to investigate the dose-response association between the TyG index and NAFLD. Summary relative risks (ORs) and 95% CIs were estimated by using a random-effects model.

RESULTS

A total of 4 cohort and 8 cross-sectional studies were included, with 28,788 NAFLD cases among the 105,365 participants. A positive association for the risk of NAFLD was observed for each additional unit of the TyG index with a linear association (p=0.82), and the summary OR was 2.84 (95% CI, 2.01-4.01). In the subgroup analyses, a stronger association of the TyG index with NAFLD was shown in females than in males (men: OR=2.97, 95% CI 2.55-3.46, women: OR=4.80, 95% CI 3.90-5.90, P_subgroup<0.001).

CONCLUSION

The TyG index may be a novel independent risk factor for NAFLD beyond traditional risk factors.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero, identifier (CRD42022347813).

Association Between Metabolic Associated Fatty Liver Disease and Chronic Kidney Disease: A Cross-Sectional Study from NHANES 2017-2018

PURPOSE

In 2020, an international expert consensus proposed a novel concept, defined as metabolic associated fatty liver disease (MAFLD). We aimed to investigate the association between MAFLD and chronic kidney disease (CKD).

METHODS

A total of 4869 subjects with demographic data, laboratory tests, and ultrasound transient elastography from National Health and Nutrition Examination Surveys of the United States (NHANES) 2017-2018 were included in the study. Statistical analysis was performed to test the independent association between the demographic data, laboratory tests, and non-invasive liver fibrosis scores in subjects with different subgroups of MAFLD.

RESULTS

A total of 4869 subjects were identified in the NHANES 2017-2018, of which 1032 (21.2%) subjects were diagnosed with CKD. There was a higher prevalence of CKD in MAFLD subjects than in non-MALFD subjects (22.2% vs 19.1, p=0.048). After 1:1 propensity score matching by gender, age and race, we enrolled 1983 subjects with MAFLD diagnosed based on liver ultrasound transient elastography and 1983 PS-matched subjects without MAFLD. MAFLD was not independently associated with CKD after PSM. Further investigation showed that age (OR: 1.05, 95% CI: 1.03~1.05, p<0.001), hypertension (OR: 1.66, 95% CI: 1.38~2.00, p<0.001), DM (OR: 2.21, 95% CI: 1.89~3.11, p<0.001), hyperuricemia (OR: 1.91, 95% CI: 1.55~2.36, p<0.001), ALP (OR: 1.00, 95% CI: 1.00~1.01, p=0.010), and FIB-4 score (OR: 1.23, 95% CI: 1.05~1.01, p=0.011) were independently associated with CKD. In the subgroup analysis, the subgroups of MAFLD complicated with DM, age, hypertension, and hyperuricemia were independently related to the incidence of CKD. In the subgroup of DM without MAFLD, age, hyperuricemia, ALP, and NFS score were independently related to the incidence of CKD. In the subgroup of MAFLD without DM, age, hypertension, hyperuricemia, and ALP were independently related to the incidence of CKD.

CONCLUSION

Based on the NHANES 2017-2018, MAFLD was not independently associated with CKD. Thus, the link between MAFLD and CKD may be mediated by metabolic abnormalities, such as diabetes mellitus and hyperuricemia.

Association Between the Triglyceride-Glucose Index and Outcomes of Nonalcoholic Fatty Liver Disease: A Large-Scale Health Management Cohort Study

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is increasingly becoming a major health burden. Due to the difficulty of liver biopsy, there is no reliable indicator to evaluate the outcomes of NAFLD. The triglyceride-glucose (TyG) index is a simple and convenient marker of insulin resistance for use in medical practice. Whether the TyG index is predictive of later risk of NAFLD remains unknown.

OBJECTIVE

To evaluate the relationship between TyG index with NAFLD progression and improvement during a median follow-up period of 21 months.

MATERIAL AND METHODS

A total of 11,424 subjects (9327 men) diagnosed with NAFLD were included. The TyG index was calculated as follows: ln [fasting triglycerides (mg/dL) * fasting glucose (mg/dL)/2]. Multivariable Cox regression analysis was applied to analyze the data.

RESULTS

In this study, the severity of NAFLD remained the same in 38.8% of subjects, worsened in 17.4% of subjects, and improved in 43.8% of subjects. Compared with the lowest quartile of the TyG index, the adjusted HR of NAFLD progression in the highest quartile (TyG≥9.34) was 1.448 (1.229 to 1.706), and the adjusted HR of NAFLD improvement was 0.817 (0.723 to 0.923). Subgroup analysis found that smoking increased the correlation between the TyG index and the risk of NAFLD progression, while female, vegan diet, and weight control enhanced the correlation between the TyG index and the risk of NAFLD improvement.

CONCLUSION

The TyG index may be a simple and helpful indicator for further risk appraisal of NAFLD in daily clinical practice.