Insulin resistance is an integral feature of MASLD even in the presence of PNPLA3 variants.

Background & Aims: It has been postulated that carriers of PNPLA3 I148M (CG [Ile/Met] or GG [Met/Met]) develop metabolic dysfunction-associated steatotic liver disease (MASLD) in the absence of insulin resistance or metabolic syndrome. However, the relationship between insulin resistance and MASLD according to the PNPLA3 allele has not been carefully assessed. Methods: A total of 204 participants were recruited and underwent PNPLA3 genotyping, an oral glucose tolerance test, liver proton magnetic resonance spectroscopy and percutaneous liver biopsy if diagnosed with MASLD. A subgroup of patients (n = 55) had an euglycemic hyperinsulinemic clamp with glucose tracer infusion. Results: As expected, patients with the CG/GG genotype had worse intrahepatic triglyceride content and worse liver histology. However, regardless of PNPLA3 genotype, patients with a diagnosis of MASLD had severe whole-body insulin resistance (Matsuda index, an estimation of insulin resistance in glucose metabolic pathways) and fasting and postprandial adipose tissue insulin resistance (Adipo-IR index and free fatty acid suppression during the oral glucose tolerance test, respectively, as measures of insulin resistance in lipolytic metabolic pathways) compared to patients without MASLD. Moreover, for the same amount of liver fat accumulation, insulin resistance was similar in patients with genotypes CC vs. CG/GG. In multiple regression analyses, A1c and Adipo-IR were associated with the presence of MASLD and advanced liver fibrosis, independently of PNPLA3 genotype. Conclusions: PNPLA3 variant carriers with MASLD are equally insulin resistant as non-carriers with MASLD at the level of the liver, muscle, and adipose tissue. This calls for reframing "PNPLA3 MASLD" as an insulin-resistant condition associated with increased hepatic susceptibility to metabolic insults, such as obesity or diabetes, wherein early identification and aggressive intervention are warranted to reverse metabolic dysfunction and prevent disease progression. Impact and implications: It has been proposed that the PNPLA3 G allele is associated with the presence of metabolic dysfunction-associated steatotic liver disease (MASLD) in the absence of insulin resistance. However, our results suggest that regardless of PNPLA3 alleles, the presence of insulin resistance is necessary for the development of MASLD. This calls for reframing patients with "PNPLA3 MASLD" not as insulin sensitive, but on the contrary, as an insulin-resistant population with increased hepatic susceptibility to metabolic insults, such as obesity or diabetes.

The Association between Obesity and Polycystic Ovary Syndrome: An Epidemiologic Study of Observational Data.

BACKGROUND: Polycystic Ovary Syndrome (PCOS) is a common female cardio-metabolic-reproductive disorder. It is unclear whether the global obesity epidemic is impacting the high PCOS prevalence. OBJECTIVE: To determine the extent to which obesity contributes to the PCOS development globally. MATERIALS AND METHODS: A systematic review was conducted to identify population studies on PCOS prevalence globally, through July 2023. Linear regression and random-effect models were applied to examine the association of mean body mass index (BMI) or obesity prevalence with the prevalence of PCOS diagnosed by 1990 National Institute of Health (NIH), 2003 Rotterdam (Rotterdam), and 2006 Androgen Excess-PCOS (AE-PCOS) criteria. Subgroup analyses were also conducted for recruitment methods and study quality. RESULTS: Fifty-eight studies with 85,956 adults from 24 countries were included. Considering all available data, a borderline association was observed between PCOS and obesity prevalence when using the AE-PCOS, but not the NIH or Rotterdam criteria. Alternatively, subgroup analysis of studies with better recruitment methods demonstrated a significant positive association of population mean BMI or obesity prevalence with PCOS prevalence when using the Rotterdam or AE-PCOS criteria, while using only high-quality studies revealed an association using NIH as well as Rotterdam and AE-PCOS criteria. Overall, we observed that a 1% increase in obesity prevalence resulted in an approximately 0.4% increase in PCOS prevalence by the Rotterdam criteria. CONCLUSIONS: These data indicate that obesity increases the development of PCOS, although the effect is modest. Our data also emphasizes the need to undertake only high-quality studies in assessing PCOS epidemiology.

A global survey on the use of the international classification of diseases codes for metabolic dysfunction-associated fatty liver disease.

BACKGROUND: With the implementation of the 11th edition of the International Classification of Diseases (ICD-11) and the publication of the metabolic dysfunction-associated fatty liver disease (MAFLD) nomenclature in 2020, it is important to establish consensus for the coding of MAFLD in ICD-11. This will inform subsequent revisions of ICD-11. METHODS: Using the Qualtrics XM and WJX platforms, questionnaires were sent online to MAFLD-ICD-11 coding collaborators, authors of papers, and relevant association members. RESULTS: A total of 890 international experts in various fields from 61 countries responded to the survey. We also achieved full coverage of provincial-level administrative regions in China. 77.1% of respondents agreed that MAFLD should be represented in ICD-11 by updating NAFLD, with no significant regional differences (77.3% in Asia and 76.6% in non-Asia, p = 0.819). Over 80% of respondents agreed or somewhat agreed with the need to assign specific codes for progressive stages of MAFLD (i.e. steatohepatitis) (92.2%), MAFLD combined with comorbidities (84.1%), or MAFLD subtypes (i.e., lean, overweight/obese, and diabetic) (86.1%). CONCLUSIONS: This global survey by a collaborative panel of clinical, coding, health management and policy experts, indicates agreement that MAFLD should be coded in ICD-11. The data serves as a foundation for corresponding adjustments in the ICD-11 revision.

Endpoints in NASH Clinical Trials: Are We Blind in One Eye?

This narrative review aims to illustrate the notion that nonalcoholic steatohepatitis (NASH), recently renamed metabolic dysfunction-associated steatohepatitis (MASH), is a systemic metabolic disorder featuring both adverse hepatic and extrahepatic outcomes. In recent years, several NASH trials have failed to identify effective pharmacological treatments and, therefore, lifestyle changes are the cornerstone of therapy for NASH. with this context, we analyze the epidemiological burden of NASH and the possible pathogenetic factors involved. These include genetic factors, insulin resistance, lipotoxicity, immuno-thrombosis, oxidative stress, reprogramming of hepatic metabolism, and hypoxia, all of which eventually culminate in low-grade chronic inflammation and increased risk of fibrosis progression. The possible explanations underlying the failure of NASH trials are also accurately examined. We conclude that the high heterogeneity of NASH, resulting from variable genetic backgrounds, exposure, and responses to different metabolic stresses, susceptibility to hepatocyte lipotoxicity, and differences in repair-response, calls for personalized medicine approaches involving research on noninvasive biomarkers. Future NASH trials should aim at achieving a complete assessment of systemic determinants, modifiers, and correlates of NASH, thus adopting a more holistic and unbiased approach, notably including cardiovascular-kidney-metabolic outcomes, without restricting therapeutic perspectives to histological surrogates of liver-related outcomes alone.

Noninvasive tests to identify liver fibrosis in metabolic dysfunction-associated steatotic liver disease are affected by race.

OBJECTIVE: The objective of this study was to assess the performance of noninvasive tests (NITs) across different racial and ethnic groups in a large multiethnic cohort. METHODS: Data were derived from the National Health and Nutrition Examination Survey (NHANES) 2017 through 2020. Participants without valid transient elastography measurements or with alternative etiologies of liver steatosis disease were excluded from the study. RESULTS: Among the 6359 adults included in the study, fatty liver index and nonalcoholic fatty liver disease liver fat scores performed well for the prediction of metabolic dysfunction-associated steatotic liver disease, without significant changes across racial and ethnic groups. However, significant differences were observed across racial and ethnic groups for the prediction of advanced fibrosis and cirrhosis. The fibrosis-4 (FIB-4) index, aspartate aminotransferase to platelet ratio index (APRI), and nonalcoholic fatty liver disease fibrosis score underperformed in non-Hispanic Black patients for the detection of cirrhosis. For the detection of advanced fibrosis, their performance was also numerically worse in non-Hispanic Black patients but only reached statistical significance for APRI. Using a cutoff point of 12 kPa for advanced fibrosis, both APRI and the FIB-4 index performed significantly worse in non-Hispanic Black patients. CONCLUSIONS: In a large, diverse national cohort, the performance of NITs was overall poor compared with transient elastography, and NITs showed differences across racial and ethnic groups. Given the widespread use of NITs, it is imperative that the scores are equitable across racial and ethnic groups.

Adipose Tissue Dysfunction in Polycystic Ovary Syndrome.

PURPOSE: Polycystic ovary syndrome (PCOS) is a complex genetic trait and the most common endocrine disorder of women, clinically evident in 5% to 15% of reproductive-aged women globally, with associated cardiometabolic dysfunction. Adipose tissue (AT) dysfunction appears to play an important role in the pathophysiology of PCOS even in patients who do not have excess adiposity. METHODS: We undertook a systematic review concerning AT dysfunction in PCOS, and prioritized studies that assessed AT function directly. We also explored therapies that targeted AT dysfunction for the treatment of PCOS. RESULTS: Various mechanisms of AT dysfunction in PCOS were identified including dysregulation in storage capacity, hypoxia, and hyperplasia; impaired adipogenesis; impaired insulin signaling and glucose transport; dysregulated lipolysis and nonesterified free fatty acids (NEFAs) kinetics; adipokine and cytokine dysregulation and subacute inflammation; epigenetic dysregulation; and mitochondrial dysfunction and endoplasmic reticulum and oxidative stress. Decreased glucose transporter-4 expression and content in adipocytes, leading to decreased insulin-mediated glucose transport in AT, was a consistent abnormality despite no alterations in insulin binding or in IRS/PI3K/Akt signaling. Adiponectin secretion in response to cytokines/chemokines is affected in PCOS compared to controls. Interestingly, epigenetic modulation via DNA methylation and microRNA regulation appears to be important mechanisms underlying AT dysfunction in PCOS. CONCLUSION: AT dysfunction, more than AT distribution and excess adiposity, contributes to the metabolic and inflammation abnormalities of PCOS. Nonetheless, many studies provided contradictory, unclear, or limited data, highlighting the urgent need for additional research in this important field.

Metabolic Syndrome and Its Association with Nonalcoholic Steatohepatitis.

The relationship between insulin resistance, metabolic syndrome (MetS), and nonalcoholic fatty liver disease (NAFLD) is complicated. Although insulin resistance is almost universal in people with NAFLD and MetS, NAFLD may be present without features of MetS and vice versa. While NAFLD has a strong correlation with cardiometabolic risk factors, these are not intrinsic components of this condition. Taken together, our knowledge gaps call for caution regarding the common assertion that NAFLD is the hepatic manifestation of the MetS, and for defining NAFLD in broad terms as a "metabolic dysfunction" based on a diverse and poorly understood constellation of cardiometabolic features.

Hypercholesterolemia After COVID-19: Time to Include Lipoprotein X Among the Differential Diagnoses.

Background: Lipoprotein X (LpX) is an abnormal lipoprotein composed of phospholipids, free cholesterol, and albumin. Its overaccumulation is an infrequent cause of hyperlipidemia, which oftentimes presents in patients with cholestatic liver disease. The aim is to present the first 2 cases of patients with post-COVID cholangiopathy and LpX overaccumulation. Case Report: We present 2 female patients (ie, a 34-year-old [patient 1] and a 56-year-old [patient 2]), who had complicated courses of COVID-19, requiring prolonged mechanical ventilation (>4 weeks). One month after discharge, patient 1 presented with abdominal pain. Patient 2 had gangrenous cholecystitis and later developed recurrent elevation of alkaline phosphatase and bilirubin. Both patients were diagnosed with cholestatic liver disease. During outpatient follow-up both patients were found to have elevated plasma low-density lipoprotein cholesterol (LDL-C) in routine lipid panels (723 mg/dL and 1389 mg/dL, respectively). Both patients underwent various treatments for elevated LDL-C before referral to endocrinology. Patients were diagnosed with LpX overaccumulation from post-COVID-19 cholangiopathy. In both patients, LDL-C fluctuations seen in routine lipid panels (affected by LpX levels) were tightly correlated with changes in alkaline phosphate and bilirubin. Discussion: Our patients represent the first report of LpX overaccumulation in patients with post-COVID-19 cholangiopathy. Whether LpX accumulation is only the result of liver dysfunction, or COVID-19 infection plays a direct role in elevated LpX levels is still unknown. Conclusion: In patients with complicated courses of COVID-19, LpX overaccumulation should be considered when a routine lipid panel shows significant LDL-C elevations. Awareness among health care providers regarding LpX is important to avoid unnecessary workup and treatment.

Adipose Tissue Insulin Resistance Predicts the Severity of Liver Fibrosis in Patients With Type 2 Diabetes and NAFLD.

CONTEXT: Although type 2 diabetes (T2D) is a risk factor for liver fibrosis in nonalcoholic fatty liver disease (NAFLD), the specific contribution of insulin resistance (IR) relative to other factors is unknown. OBJECTIVE: Assess the impact on liver fibrosis in NAFLD of adipose tissue (adipose tissue insulin resistance index [adipo-IR]) and liver (Homeostatic Model Assessment of Insulin Resistance [HOMA-IR]) IR in people with T2D and NAFLD. DESIGN: Participants were screened by elastography in the outpatient clinics for hepatic steatosis and fibrosis, including routine metabolites, cytokeratin-18 (a marker of hepatocyte apoptosis/steatohepatitis), and HOMA-IR/adipo-IR. SETTING: University ambulatory care practice. PARTICIPANTS: A total of 483 participants with T2D. INTERVENTION: Screening for steatosis and fibrosis with elastography. MAIN OUTCOME MEASURES: Liver steatosis (controlled attenuation parameter), fibrosis (liver stiffness measurement), and measurements of IR (adipo-IR, HOMA-IR) and fibrosis (cytokeratin-18). RESULTS: Clinically significant liver fibrosis (stage F ≥ 2 = liver stiffness measurement ≥8.0 kPa) was found in 11%, having more features of the metabolic syndrome, lower adiponectin, and higher aspartate aminotransferase (AST), alanine aminotransferase, liver fat, and cytokeratin-18 (P < 0.05-0.01). In multivariable analysis including just clinical variables (model 1), obesity (body mass index [BMI]) had the strongest association with fibrosis (odds ratio, 2.56; CI, 1.87-3.50; P < 0.01). When metabolic measurements and cytokeratin-18 were included (model 2), only BMI, AST, and liver fat remained significant. When fibrosis stage was adjusted for BMI, AST, and steatosis (model 3), only Adipo-IR remained strongly associated with fibrosis (OR, 1.51; CI, 1.05-2.16; P = 0.03), but not BMI, hepatic IR, or steatosis. CONCLUSIONS: These findings pinpoint to the central role of dysfunctional, insulin-resistant adipose tissue to advanced fibrosis in T2D, beyond simply BMI or steatosis. The clinical implication is that targeting adipose tissue should be the priority of treatment in NAFLD.

Differences in HDL-Bound Apolipoproteins in Patients With Advanced Liver Fibrosis Due to Nonalcoholic Fatty Liver Disease.

CONTEXT: The mechanisms leading to increased cardiovascular disease in patients with nonalcoholic fatty liver disease (NAFLD) and advanced liver fibrosis remain incompletely understood. OBJECTIVE: This study assessed HDL-bound proteins in patients with NAFLD with or without advanced fibrosis. METHODS: This cross-sectional study at a university hospital included 185 patients with or without type 2 diabetes (T2D). Patients underwent liver proton magnetic resonance spectroscopy to measure intrahepatic triglyceride accumulation and those with NAFLD underwent a percutaneous liver biopsy. Advanced lipid testing with lipoprotein subfraction measurements and targeted proteomics of HDL-bound proteins was performed. RESULTS: Patients with and without advanced fibrosis had similar clinical characteristics, except for lower HDL-C (34 ± 8 vs 38 ± 9 mg/dL, P = 0.024) and higher prevalence of T2D in advanced fibrosis. Patients with advanced fibrosis had lower HDL particle number. A panel of 28 HDL-bound proteins were targeted and quantified by multiple reaction monitoring liquid chromatography-tandem mass spectrometry. Five proteins were found to be decreased in patients with advanced fibrosis (ApoC-I [P < 0.001], ApoC-IV [P = 0.012], ApoM [P = 0.008], LCAT [P = 0.014], and SAA4 [P = 0.016]). No differences were observed in these proteins in patients with vs without NAFLD or steatohepatitis. The pCAD index, associated with coronary artery disease and cardiovascular mortality, was significantly higher in patients with advanced fibrosis (97 ± 5 vs 86 ± 25, P = 0.04). CONCLUSION: Patients with NAFLD with advanced fibrosis showed significant differences in HDL-bound protein levels; this translated into increased cardiovascular risk based on pCAD index. Different lipoprotein composition and function may explain the link between liver disease and increased cardiovascular mortality in these patients.

Assessing strategies to target screening for advanced liver fibrosis among overweight and obese patients.

Aim: The optimal screening strategy for advanced liver fibrosis in overweight and obese patients is unknown. The aim of this study is to compare the performance of different strategies to select patients at high risk of advanced liver fibrosis for screening using non-invasive tools. Methods: All patients underwent: liver 1H-MRS and percutaneous liver biopsy (in those with nonalcoholic fatty liver disease [NAFLD]). Unique selection strategies were compared to determine the best screening algorithm: (A) A "metabolic approach": selecting patients based on HOMA-IR ≥ 3; (B) A "diabetes approach": selecting only patients with type 2 diabetes; (C) An "imaging approach": selecting patients with hepatic steatosis based on 1H-MRS; (D) A "liver biochemistry approach": selecting patients with elevated ALT (i.e., ≥ 30 IU/L for males and ≥ 19 IU/L for females); and (E) Universal screening of overweight and obese patients. FIB-4 index, NAFLD fibrosis score, and APRI were applied as screening strategies. Results: A total of 275 patients were included in the study. Patients with advanced fibrosis (n = 29) were matched for age, gender, ethnicity, and BMI. Selecting patients by ALT elevation provided the most effective strategy, limiting the false positive rate while maintaining the sensitivity compared to universal screening. Selecting patients by any other strategy did not contribute to increasing the sensitivity of the approach and resulted in more false positive results. Conclusion: Universal screening of overweight/obese patients for advanced fibrosis with non-invasive tools is unwarranted, as selection strategies based on elevated ALT levels lead to the same sensitivity with a lower false positive rate (i.e., fewer patients that would require a liver biopsy or referral to hepatology).

Noninvasive Diagnosis of Nonalcoholic Steatohepatitis and Advanced Liver Fibrosis Using Machine Learning Methods: Comparative Study With Existing Quantitative Risk Scores.

BACKGROUND: Nonalcoholic steatohepatitis (NASH), advanced fibrosis, and subsequent cirrhosis and hepatocellular carcinoma are becoming the most common etiology for liver failure and liver transplantation; however, they can only be diagnosed at these potentially reversible stages with a liver biopsy, which is associated with various complications and high expenses. Knowing the difference between the more benign isolated steatosis and the more severe NASH and cirrhosis informs the physician regarding the need for more aggressive management. OBJECTIVE: We intend to explore the feasibility of using machine learning methods for noninvasive diagnosis of NASH and advanced liver fibrosis and compare machine learning methods with existing quantitative risk scores. METHODS: We conducted a retrospective analysis of clinical data from a cohort of 492 patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD), NASH, or advanced fibrosis. We systematically compared 5 widely used machine learning algorithms for the prediction of NAFLD, NASH, and fibrosis using 2 variable encoding strategies. Then, we compared the machine learning methods with 3 existing quantitative scores and identified the important features for prediction using the SHapley Additive exPlanations method. RESULTS: The best machine learning method, gradient boosting (GB), achieved the best area under the curve scores of 0.9043, 0.8166, and 0.8360 for NAFLD, NASH, and advanced fibrosis, respectively. GB also outperformed 3 existing risk scores for fibrosis. Among the variables, alanine aminotransferase (ALT), triglyceride (TG), and BMI were the important risk factors for the prediction of NAFLD, whereas aspartate transaminase (AST), ALT, and TG were the important variables for the prediction of NASH, and AST, hyperglycemia (A1c), and high-density lipoprotein were the important variables for predicting advanced fibrosis. CONCLUSIONS: It is feasible to use machine learning methods for predicting NAFLD, NASH, and advanced fibrosis using routine clinical data, which potentially can be used to better identify patients who still need liver biopsy. Additionally, understanding the relative importance and differences in predictors could lead to improved understanding of the disease process as well as support for identifying novel treatment options.

Treatment of hyperglycemia not associated with NAFLD improvement in children with type 2 diabetes mellitus.

Background and objectives: Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) have become public health problems in the pediatric population. However, the relationship between these two conditions is not well understood. The primary objective of this study was to assess whether treatment of hyperglycemia in obese, treatment-naive children with type 2 diabetes (T2DM) was associated with an improvement of surrogate markers of NAFLD. Materials and methods: This retrospective, longitudinal study included 151 obese children with a diagnosis of T2DM (Age: 14 ± 1 years, 72% female children, BMI: 98.6th percentile, and A1c: 10.3 ± 0.2%). Clinical/demographic information was collected before patients started any diabetes treatment and 1 and 3 years after starting metformin and/or insulin therapy. Results: Forty-eight patients (32%) had abnormal ALT/AST (i.e., >40 U/L), suggestive of NAFLD. After 1 year of therapy, there were no significant differences in plasma ALT among patients started on insulin, metformin, or combination: 5±4 vs. -10 ± 3 vs. -2±2 IU/L, respectively, P = .07. Of note, changes in plasma ALT were small, despite a significant reduction of A1c in patients prescribed insulin (alone or with metformin): -2.8 ± 1.0%, P = .01, and -2.7 ± 0.3%, P < .001, respectively. In line with this, no significant correlations were found between changes in A1c and plasma aminotransferases. In contrast, changes in plasma AST/ALT were more strongly associated with BMI changes (r = 0.32, P < .001, and r = 0.19, P = .04, respectively). Similar results were observed after 3 years of follow-up. Conclusions: Nonalcoholic fatty liver disease is highly prevalent in obese children with T2DM. Treatment of hyperglycemia with metformin and/or insulin did not result in any significant improvement in surrogate markers of NAFLD (i.e., plasma aminotransferases). While changes in ALT and/or AST may not perfectly reflect histological changes in NAFLD, our findings suggest that the treatment of hyperglycemia per se may not be associated with NAFLD improvement.