PNPLA3 rs738409, age, diabetes, sex, and advanced fibrosis jointly contribute to the risk of major adverse liver outcomes in metabolic dysfunction-associated steatotic liver disease.

BACKGROUND AND AIMS: The patatin-like phospholipase domain-containing protein 3 ( PNPLA3 ) rs738409 variant is associated with steatotic liver disease and its progression. We examined the association between PNPLA3 and the development of major adverse liver outcomes (MALOs) and how nonmodifiable and modifiable conditions modify this relationship. APPROACH AND RESULTS: A total of 2075 adults with biopsy-confirmed metabolic dysfunction-associated steatotic liver disease (MASLD) were enrolled in the metabolic dysfunction-associated steatohepatitis Clinical Research Network (MASH CRN) studies and followed prospectively until death, transplant, or withdrawal of consent. One hundred four MALOs were recorded during an average of 4.3 years. PNPLA3 G-allele (Adj. sub-hazard ratio (sHR): 1.4, 95% CI: 1.07-1.8), advanced fibrosis (AF) (Adj. sHR: 7.8, 95% CI: 4.4-13.8), age >60 years (Adj. sHR: 2.9, 95% CI: 1.3-6.8), and type 2 diabetes mellitus (Adj. sHR: 2.8, 95% CI: 1.8-4.2) were associated with MALO. Among participants with AF, those carrying the G-allele displayed the highest cumulative incidence of MALO (85%) versus noncarriers (53%), p =0.03, and p -value for interaction <0.01. The strength of the association between PNPLA3 and MALO was statistically significantly greater among older than 60 years (sHR: 2.1, 95% CI: 1.5-2.8), women (sHR: 1.4, 95% CI: 1.1-1.9), and those with AF (sHR: 1.9, 95% CI: 1.5-2.4) or type 2 diabetes mellitus (sHR: 2.1, 95% CI: 1.5-2.8) as compared with their counterparts, p -value for interaction between PNPLA3 and each factor<0.01. CONCLUSIONS: The deleterious effects of PNPLA3 rs738409 on the risk of MALO are significantly worsened by AF, age, type 2 diabetes mellitus, and sex.

Low MBOAT7 expression, a genetic risk for MASH, promotes a pro-fibrotic pathway involving hepatocyte TAZ upregulation.

BACKGROUND AND AIMS: The common genetic variant rs641738 C>T is a risk factor for metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH), including liver fibrosis, and is associated with decreased expression of the phospholipid-remodeling enzyme MBOAT7 (LPIAT1). However, whether restoring MBOAT7 expression in established MASLD dampens the progression to liver fibrosis and, importantly, the mechanism through which decreased MBOAT7 expression exacerbates MASH fibrosis remain unclear. APPROACH AND RESULTS: We first showed that hepatocyte MBOAT7 restoration in mice with diet-induced steatohepatitis slows the progression to liver fibrosis. Conversely, when hepatocyte-MBOAT7 was silenced in mice with established hepatosteatosis, liver fibrosis but not hepatosteatosis was exacerbated. Mechanistic studies revealed that hepatocyte-MBOAT7 restoration in MASH mice lowered hepatocyte-TAZ (WWTR1), which is known to promote MASH fibrosis. Conversely, hepatocyte-MBOAT7 silencing enhanced TAZ upregulation in MASH. Finally, we discovered that changes in hepatocyte phospholipids due to MBOAT7 loss-of-function promote a cholesterol trafficking pathway that upregulates TAZ and the TAZ-induced profibrotic factor Indian hedgehog (IHH). As evidence for relevance in humans, we found that the livers of individuals with MASH carrying the rs641738-T allele had higher hepatocyte nuclear TAZ, indicating higher TAZ activity, and increased IHH mRNA. CONCLUSIONS: This study provides evidence for a novel mechanism linking MBOAT7-LoF to MASH fibrosis; adds new insight into an established genetic locus for MASH; and, given the druggability of hepatocyte TAZ for MASH fibrosis, suggests a personalized medicine approach for subjects at increased risk for MASH fibrosis due to inheritance of variants that lower MBOAT7.

Prospective Study of Outcomes in Adults with Nonalcoholic Fatty Liver Disease.

BACKGROUND: The prognoses with respect to mortality and hepatic and nonhepatic outcomes across the histologic spectrum of nonalcoholic fatty liver disease (NAFLD) are not well defined. METHODS: We prospectively followed a multicenter patient population that included the full histologic spectrum of NAFLD. The incidences of death and other outcomes were compared across baseline histologic characteristics. RESULTS: A total of 1773 adults with NAFLD were followed for a median of 4 years. All-cause mortality increased with increasing fibrosis stages (0.32 deaths per 100 person-years for stage F0 to F2 [no, mild, or moderate fibrosis], 0.89 deaths per 100 persons-years for stage F3 [bridging fibrosis], and 1.76 deaths per 100 person-years for stage F4 [cirrhosis]). The incidence of liver-related complications per 100 person-years increased with fibrosis stage (F0 to F2 vs. F3 vs. F4) as follows: variceal hemorrhage (0.00 vs. 0.06 vs. 0.70), ascites (0.04 vs. 0.52 vs. 1.20), encephalopathy (0.02 vs. 0.75 vs. 2.39), and hepatocellular cancer (0.04 vs. 0.34 vs. 0.14). As compared with patients with stage F0 to F2 fibrosis, patients with stage F4 fibrosis also had a higher incidence of type 2 diabetes (7.53 vs. 4.45 events per 100 person-years) and a decrease of more than 40% in the estimated glomerular filtration rate (2.98 vs. 0.97 events per 100 person-years). The incidence of cardiac events and nonhepatic cancers were similar across fibrosis stages. After adjustment for age, sex, race, diabetes status, and baseline histologic severity, the incidence of any hepatic decompensation event (variceal hemorrhage, ascites, or encephalopathy) was associated with increased all-cause mortality (adjusted hazard ratio, 6.8; 95% confidence interval, 2.2 to 21.3). CONCLUSIONS: In this prospective study involving patients with NAFLD, fibrosis stages F3 and F4 were associated with increased risks of liver-related complications and death. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; NAFLD DB2 ClinicalTrials.gov number, NCT01030484.).

Antimullerian Hormone, a Marker of Ovarian Reserve, Is Protective Against Presence and Severity of NASH in Premenopausal Women.

BACKGROUND & AIMS: Antimüllerian hormone (AMH) is a marker of ovarian reserve with emerging data linking lower levels to some metabolic and inflammatory diseases in women. Whether AMH levels influence nonalcoholic fatty liver disease (NAFLD) is unknown. METHODS: Leveraging the NASH Clinical Research Network we determined the association of AMH levels within 6 months of liver biopsy with presence and severity of histologic measures of NAFLD in premenopausal women. Outcomes included presence of nonalcoholic steatohepatitis (NASH), presence and severity of fibrosis, and NAFLD Activity Score and its components. Logistic and ordinal logistic regression models were adjusted for age, race/ethnicity, homeostatic model assessment for insulin resistance, body mass index, dyslipidemia, polycystic ovary syndrome, estrogen-progestin use, and menstrual cyclicity. RESULTS: Median cohort age was 35 years; 73% were white and 24% Hispanic. Thirty-three percent had diabetes, 81% had obesity, and 95% had dyslipidemia. On biopsy 71% had NASH, 68% had any fibrosis, and 15% had advanced fibrosis. On adjusted analysis (n = 205), higher AMH quartiles were inversely associated with NAFLD histology including prevalent NASH (adjusted odds ratio [AOR], 0.64; 95% confidence interval [CI], 0.41-1.00), NAFLD Activity Score ≥5 (AOR, 0.52; 95% CI, 0.35-0.77), Mallory hyaline (AOR, 0.54; 95% CI, 0.35-0.82), and higher fibrosis stage (AOR, 0.70; 95% CI, 0.51-0.98). The protective effects of AMH were more pronounced among women without polycystic ovary syndrome (n = 164), including lower odds of NASH (AOR, 0.53; 95% CI, 0.32-0.90) and any NASH fibrosis (AOR, 0.54; 95% CI, 0.32-0.93). CONCLUSIONS: AMH may reflect a unique biomarker of NASH in premenopausal women and findings suggest a novel link between reproductive aging and histologic severity of NAFLD in women.

Age, BMI, and Type 2 Diabetes Modify the Relationship Between PNPLA3 and Advanced Fibrosis in Children and Adults With NAFLD.

BACKGROUND & AIMS: PNPLA3 G-allele is an important determinant of disease severity in nonalcoholic fatty liver disease (NAFLD). Here, we investigated the effect of age, body mass index (BMI), and type 2 diabetes mellitus (T2DM) on the relationship between PNPLA3 G-allele and advanced fibrosis in adults and children with histologically characterized NAFLD. METHODS: A total of 1047 children and 2057 adults were included. DNA was genotyped for rs738409 in duplicate. Primary outcome of interest was advanced fibrosis (fibrosis stage ≥3). Regression analyses were performed after controlling for relevant covariates. An additive model was used to assess the effect of PNPLA3 G-allele (CC vs CG vs GG). RESULTS: PNPLA3 G-allele was significantly associated with advanced fibrosis in children (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.16-2.09) and adults (OR, 1.55; 95% CI, 1.16-1.54). Across the cohort, older age significantly increased the risk for advanced fibrosis for PNPLA3 CC (OR, 1.019; 95% CI, 1.013-1.026), CG (OR, 1.024; 95% CI, 1.018-1.030), and GG (OR, 1.03; 95% CI, 1.023-1.037) genotypes. BMI significantly increased the relationship between PNPLA3 genotypes and advanced fibrosis in children and adults. A BMI of 30 kg/m2 was the cutoff beyond which PNPLA3 G-allele had exponential effect on the risk for advanced fibrosis in children and adults. T2DM significantly worsened the relationship between PNPLA3 G-allele and advanced fibrosis in children and adults (interaction P < .01 for both). CONCLUSIONS: Age, BMI, and T2DM modify the risk of advanced fibrosis associated with PNPLA3 G-allele. Preventing or reversing T2DM and obesity in persons carrying PNPLA3 G-allele may lower the risk for advanced fibrosis in NAFLD.

Non-Hispanic Black Persons With Nonalcoholic Fatty Liver Disease Have Lower Rates of Advanced Fibrosis, Cirrhosis, and Liver-Related Events Even After Controlling for Clinical Risk Factors and PNPLA3 Genotype.

INTRODUCTION: Nonalcoholic fatty liver disease (NAFLD) is less frequent in non-Hispanic persons (NHB), but there are knowledge gaps in our understanding of disease severity and outcomes of NAFLD in NHB. We compared liver histology and clinical outcomes of NAFLD in non-Hispanic Black persons (NHB) and non-Hispanic White persons (NHW). METHODS: We compared liver histology and outcomes of 109 NHB and 1,910 NHW adults with biopsy-proven NAFLD participating in the Nonalcoholic Steatohepatitis Clinical Research Network observational studies. The relationship between self-reported NHB race/ethnicity and advanced fibrosis was assessed through multivariable logistic regression after controlling for clinical covariates and PNPLA3 genotype. RESULTS: NHB and NHW with NAFLD had similar NAFLD activity scores (NAS, 4.4 vs 4.3, P = 0.87) and proportions with definite metabolic dysfunction-associated steatohepatitis (59% vs 58%, P = 1.0), but NHB had significantly lower rates of advanced fibrosis (22% vs 34%, P = 0.01) or cirrhosis (4.6% vs 12.1%, P = 0.010). Compared with NHW, NHB had significantly lower frequency of advanced fibrosis (Odds Ratio: 0.48, 95% Confidence Interval: 27-0.86, P = 0.01). In a comparison between 24 NHB and 655 NHW with advanced fibrosis, the NAS (5.6 vs 4.9, P = 0.01) and lobular inflammation grade (2.2 vs 1.7, P < 0.002) were significantly higher among NHB with advanced fibrosis. One NHB and 23 NHW died during follow-up (0.30 vs 0.28 per 100 person-year follow-up). Seven and zero liver-related deaths occurred in NHW and NHB with NAFLD, respectively. DISCUSSION: The risk of advanced fibrosis in NHB with NAFLD is significantly lower, after controlling for clinical risk factors and PNPLA3 genotype. Although their risk of advanced fibrosis was low, NHB with NAFLD and advanced fibrosis had higher NAS and lobular inflammation, indicating a difference in their relationship between necroinflammation and fibrosis.

Nonalcoholic fatty liver disease risk and histologic severity are associated with genetic polymorphisms in children.

BACKGROUND AND AIMS: NAFLD is the most common chronic liver disease in children. Large pediatric studies identifying single nucleotide polymorphisms (SNPs) associated with risk and histologic severity of NAFLD are limited. Study aims included investigating SNPs associated with risk for NAFLD using family trios and association of candidate alleles with histologic severity. APPROACH AND RESULTS: Children with biopsy-confirmed NAFLD were enrolled from the NASH Clinical Research Network. The Expert Pathology Committee reviewed liver histology. Genotyping was conducted with allele-specific primers for 60 candidate SNPs. Parents were enrolled for trio analysis. To assess risk for NAFLD, the transmission disequilibrium test was conducted in trios. Among cases, regression analysis assessed associations with histologic severity. A total of 822 children with NAFLD had mean age 13.2 years (SD 2.7) and mean ALT 101 U/L (SD 90). PNPLA3 (rs738409) demonstrated the strongest risk ( p = 2.24 × 10 -14 ) for NAFLD. Among children with NAFLD, stratifying by PNPLA3 s738409 genotype, the variant genotype associated with steatosis ( p = 0.005), lobular ( p = 0.03) and portal inflammation ( p = 0.002). Steatosis grade associated with TM6SF2 ( p = 0.0009), GCKR ( p = 0.0032), PNPLA3 rs738409 ( p = 0.0053), and MTTP ( p = 0.0051). Fibrosis stage associated with PARVB rs6006473 ( p = 0.0001), NR1I2 ( p = 0.0021), ADIPOR2 ( p = 0.0038), and OXTR ( p = 0.0065). PNPLA3 rs738409 ( p = 0.0002) associated with borderline zone 1 NASH. CONCLUSIONS: This study demonstrated disease-associated SNPs in children with NAFLD. In particular, rs6006473 was highly associated with severity of fibrosis. These hypothesis-generating results support future mechanistic studies of development of adverse outcomes such as fibrosis and generation of therapeutic targets for NAFLD in children.

Renal impairment is prevalent in pediatric NAFLD/MASLD and associated with disease severity.

OBJECTIVES: Renal impairment is prevalent in adults with nonalcoholic fatty liver disease (NAFLD/metabolic dysfunction associated steatotic liver disease [MASLD]) and is associated with increased mortality. Pediatric data are limited. Our objective was to determine the prevalence of hyperfiltration or chronic kidney disease (CKD) in children with NAFLD/MASLD and determine links with liver disease severity. METHODS: Data from children who had previously participated in prospective, multicenter, pediatric studies by the Nonalcoholic Steatohepatitis Clinical Research Network (NASH-CRN) were collected. Renal function was determined using the calculated glomerular filtration rate (cGFR). Hyperfiltration was defined as cGFR > 135 mL/min/1.73m2, while CKD stage 2 or higher as cGFR < 90 mL/min/1.73 m2. Renal dysfunction progression was defined as transition from normal to hyperfiltration or to CKD stage ≥ 2, or change in CKD by ≥1 stage. Multinomial logistic regression models were used to determine the prevalence of CKD and independent associations between CKD and liver disease severity. RESULTS: The study included 1164 children (age 13 ± 3 years, 72% male, 71% Hispanic). The median cGFR was 121 mL/min/1.73 m2; 12% had CKD stage 2-5, while 27% had hyperfiltration. Hyperfiltration was independently associated with significant liver fibrosis (odds ratio: 1.45). Baseline renal function was not associated with progression in liver disease over a 2-year period (n = 145). Renal dysfunction worsened in 19% independently of other clinical risk factors. Progression of renal impairment was not associated with change in liver disease severity. CONCLUSIONS: Renal impairment is prevalent in children with NAFLD/MASLD and hyperfiltration is independently associated with significant liver fibrosis. Almost 1/5 children have evidence of progression in renal dysfunction over 2 years, not associated with change in liver disease severity. Future assessments including additional renal impairment biomarkers are needed.

Low Vitamin D Levels in Patients with Symptoms of Gastroparesis: Relationships with Nausea and Vomiting, Gastric Emptying and Gastric Myoelectrical Activity.

Patients with gastroparesis (Gp) often have diets deficient in calories, electrolytes, and vitamins. Vitamin D levels have been reported to be low in some patients with Gp but has not been systematically studied. AIMS: To determine vitamin D levels and relationships among symptoms, gastric emptying and gastric myoelectrical activity (GMA) in patients with symptoms of Gp. METHODS: 25-hydroxy-vitamin D was measured in patients at enrollment in the Gastroparesis Clinical Consortium Registry. Gastroparesis Cardinal Symptoms Index (GCSI), gastric emptying, and GMA before and after water load satiety test (WLST) were measured. GMA, expressed as percentage distribution of activity in normal and dysrhythmic ranges, was recorded using electrogastrography. RESULTS: Overall, vitamin D levels were low (< 30 ng/ml) in 288 of 513 (56.1%) patients with symptoms of Gp (206 of 376 (54.8%) patients with delayed gastric emptying (Gp) and 82 of 137 (59.9%) patients with symptoms of Gp and normal gastric emptying). Low vitamin D levels were associated with increased nausea and vomiting (P < 0.0001), but not with fullness or bloating subscores. Low vitamin D levels in patients with Gp were associated with greater meal retention at four hours (36% retention) compared with Gp patients with normal vitamin D levels (31% retention; P = 0.05). Low vitamin D in patients with normal gastric emptying was associated with decreased normal 3 cpm GMA before (P = 0.001) and increased tachygastria after WLST (P = 0.01). CONCLUSIONS: Low vitamin D levels are present in half the patients with symptoms of gastroparesis and are associated with nausea and vomiting and gastric neuromuscular dysfunction.

Defining the serum proteomic signature of hepatic steatosis, inflammation, ballooning and fibrosis in non-alcoholic fatty liver disease.

BACKGROUND & AIMS: Despite recent progress, non-invasive tests for the diagnostic assessment and monitoring of non-alcoholic fatty liver disease (NAFLD) remain an unmet need. Herein, we aimed to identify diagnostic signatures of the key histological features of NAFLD. METHODS: Using modified-aptamer proteomics, we assayed 5,220 proteins in each of 2,852 single serum samples from 636 individuals with histologically confirmed NAFLD. We developed and validated dichotomized protein-phenotype models to identify clinically relevant severities of steatosis (grade 0 vs. 1-3), hepatocellular ballooning (0 vs. 1 or 2), lobular inflammation (0-1 vs. 2-3) and fibrosis (stages 0-1 vs. 2-4). RESULTS: The AUCs of the four protein models, based on 37 analytes (18 not previously linked to NAFLD), for the diagnosis of their respective components (at a clinically relevant severity) in training/paired validation sets were: fibrosis (AUC 0.92/0.85); steatosis (AUC 0.95/0.79), inflammation (AUC 0.83/0.72), and ballooning (AUC 0.87/0.83). An additional outcome, at-risk NASH, defined as steatohepatitis with NAFLD activity score ≥4 (with a score of at least 1 for each of its components) and fibrosis stage ≥2, was predicted by multiplying the outputs of each individual component model (AUC 0.93/0.85). We further evaluated their ability to detect change in histology following treatment with placebo, pioglitazone, vitamin E or obeticholic acid. Component model scores significantly improved in the active therapies vs. placebo, and differential effects of vitamin E, pioglitazone, and obeticholic acid were identified. CONCLUSIONS: Serum protein scanning identified signatures corresponding to the key components of liver biopsy in NAFLD. The models developed were sufficiently sensitive to characterize the longitudinal change for three different drug interventions. These data support continued validation of these proteomic models to enable a "liquid biopsy"-based assessment of NAFLD. CLINICAL TRIAL NUMBER: Not applicable. IMPACT AND IMPLICATIONS: An aptamer-based protein scan of serum proteins was performed to identify diagnostic signatures of the key histological features of non-alcoholic fatty liver disease (NAFLD), for which no approved non-invasive diagnostic tools are currently available. We also identified specific protein signatures related to the presence and severity of NAFLD and its histological components that were also sensitive to change over time. These are fundamental initial steps in establishing a serum proteome-based diagnostic signature of NASH and provide the rationale for using these signatures to test treatment response and to identify several novel targets for evaluation in the pathogenesis of NAFLD.

Machine Learning Approaches to the Prediction of Osteoarthritis Phenotypes and Outcomes.

PURPOSE OF REVIEW: Osteoarthritis (OA) is a complex heterogeneous disease with no effective treatments. Artificial intelligence (AI) and its subfield machine learning (ML) can be applied to data from different sources to (1) assist clinicians and patients in decision making, based on machine-learned evidence, and (2) improve our understanding of pathophysiology and mechanisms underlying OA, providing new insights into disease management and prevention. The purpose of this review is to improve the ability of clinicians and OA researchers to understand the strengths and limitations of AI/ML methods in applications to OA research. RECENT FINDINGS: AI/ML can assist clinicians by prediction of OA incidence and progression and by providing tailored personalized treatment. These methods allow using multidimensional multi-source data to understand the nature of OA, to identify different OA phenotypes, and for biomarker discovery. We described the recent implementations of AI/ML in OA research and highlighted potential future directions and associated challenges.

Progress in Gastroparesis - A Narrative Review of the Work of the Gastroparesis Clinical Research Consortium.

The Gastroparesis Clinical Research Consortium is a multicenter coalition created and funded by the National Institutes of Diabetes and Digestive and Kidney Disorders, with a mission to advance understanding of the pathophysiology of gastroparesis and develop an effective treatment for patients with symptomatic gastroparesis. In this review, we summarize the results of the published Gastroparesis Clinical Research Consortium studies as a ready and convenient resource for gastroenterologists and others to provide a clear understanding of the consortium's experience and perspective on gastroparesis and related disorders.

Effect of Domperidone Therapy on Gastroparesis Symptoms: Results of a Dynamic Cohort Study by NIDDK Gastroparesis Consortium.

BACKGROUND & AIMS: The use of domperidone (DOM) for gastroparesis (GP) remains controversial and limited. We aimed to present outcomes of DOM therapy for treatment of patients participating in the multicenter National Institute of Diabetes and Digestive and Kidney Diseases Gastroparesis Clinical Research Consortium (GpCRC) Registries (GpR). METHODS: The GpCRC cohort consisted of patients with GP (75%) and with GP-like symptoms but with normal gastric emptying (25%). The DOM group initiated therapy during the 96 weeks of enrollment in GpR1 and GpR2. Patients who had previously taken or who were on DOM therapy at enrollment were excluded from this analysis. The control group did not use domperidone (non-DOM group) before or after enrollment. The following outcome measures were identified: change from baseline in Gastroparesis Cardinal Symptom Index total score, with 3 subscales, plus Gastroesophageal Reflux Disease and Patient Assessment of Upper Gastrointestinal Disorders-Quality of Life scores. RESULTS: Overall, of 748 patients, 181 (24%) were in the DOM group, whereas 567 were in the non-DOM group. Sixty-three percent of participants had idiopathic GP. At baseline, DOM patients compared with non-DOM patients were significantly younger, had lower body mass index, non-Hispanic ethnicity, a higher annual household income, lower narcotic utilization, lower supplemental and complimentary medication use, and were more likely to have delayed gastric emptying time, as well as worse nausea and fullness scores. Compared with non-DOM patients, DOM patients experienced moderate but significantly more improvement in GP outcome measures: Gastroparesis Cardinal Symptom Index total score (P = .003), nausea (P = .003), and fullness subscales (P =.005), upper abdominal pain score (P = .04), Gastroesophageal Reflux Disease score (P = .05), and Patient Assessment of Upper Gastrointestinal Disorders-Quality of Life score (P = .05). CONCLUSIONS: Utilizing the method of pragmatic modeling to evaluate long-term treatment of GP in a large GpCRC database, DOM treatment resulted in moderately but significantly improved GP. NOTE: This project was based on data generated by 2 GpCRC Registry studies recognized under the Clinicaltrial.gov numbers: NCT00398801 and NCT01696747 symptoms compared with a group receiving standard-of-care but not DOM.

Functional Dyspepsia and Gastroparesis in Tertiary Care are Interchangeable Syndromes With Common Clinical and Pathologic Features.

BACKGROUND: The aim of this study was to clarify the pathophysiology of functional dyspepsia (FD), a highly prevalent gastrointestinal syndrome, and its relationship with the better-understood syndrome of gastroparesis. METHODS: Adult patients with chronic upper gastrointestinal symptoms were followed up prospectively for 48 weeks in multi-center registry studies. Patients were classified as having gastroparesis if gastric emptying was delayed; if not, they were labeled as having FD if they met Rome III criteria. Study analysis was conducted using analysis of covariance and regression models. RESULTS: Of 944 patients enrolled during a 12-year period, 720 (76%) were in the gastroparesis group and 224 (24%) in the FD group. Baseline clinical characteristics and severity of upper gastrointestinal symptoms were highly similar. The 48-week clinical outcome was also similar but at this time 42% of patients with an initial diagnosis of gastroparesis were reclassified as FD based on gastric-emptying results at this time point; conversely, 37% of patients with FD were reclassified as having gastroparesis. Change in either direction was not associated with any difference in symptom severity changes. Full-thickness biopsies of the stomach showed loss of interstitial cells of Cajal and CD206+ macrophages in both groups compared with obese controls. CONCLUSIONS: A year after initial classification, patients with FD and gastroparesis, as seen in tertiary referral centers at least, are not distinguishable based on clinical and pathologic features or based on assessment of gastric emptying. Gastric-emptying results are labile and do not reliably capture the pathophysiology of clinical symptoms in either condition. FD and gastroparesis are unified by characteristic pathologic features and should be considered as part of the same spectrum of truly "organic" gastric neuromuscular disorders. CLINICALTRIALS. GOV IDENTIFIER: NCT00398801, NCT01696747.

Low Testosterone Is Associated With Nonalcoholic Steatohepatitis and Fibrosis Severity in Men.

With rising prevalence of obesity and diabetes, nonalcoholic fatty liver disease (NAFLD) is now a leading cause of chronic liver disease. One-third of obese or diabetic men have subnormal free and bioavailable testosterone concentrations.1 Several studies have further shown low testosterone to be associated with imaging-confirmed NAFLD in men,2 although it is unknown whether low testosterone confers increased risk of more clinically relevant manifestations of NAFLD, including nonalcoholic steatohepatitis (NASH) and NASH fibrosis. We therefore aimed to evaluate the association of testosterone with histologic features of NAFLD among a representative cohort of men from the multicenter NASH Clinical Research Network (NASH CRN).

Testosterone is Associated With Nonalcoholic Steatohepatitis and Fibrosis in Premenopausal Women With NAFLD.

BACKGROUND & AIMS: Higher testosterone contributes to imaging-confirmed nonalcoholic fatty liver disease (NAFLD) in women, but whether testosterone influences their disease severity is unknown. METHODS: The association of free testosterone (free T) with nonalcoholic steatohepatitis (NASH) was determined in pre-menopausal women with biopsy-confirmed NAFLD (n = 207). Interaction testing was performed for age and free T given decline in testosterone with age, and association of aging with NASH. Regression models adjusted for abdominal adiposity, diabetes, and dyslipidemia. RESULTS: Median age was 35 yrs (interquartile range, 29-41); 73% were white, 25% Hispanic; 32% had diabetes, 93% abdominal adiposity, and 95% dyslipidemia. 69% had NASH, 67% any fibrosis, and 15% advanced fibrosis. Higher free T levels were associated with NAFLD severity in younger women (interaction P value <.02). In the youngest age quartile, free T was independently associated with NASH (odds ratio [OR], 2.3; 95% CI, 1.2-4.4), NASH fibrosis (OR, 2.1; 95% CI, 1.1-3.8), and higher fibrosis stage (OR, 1.9; 95% CI, 1.1-3.4), P value .02. In these women, the proportion with NASH steadily rose from 27% to 88%, and with NASH fibrosis rose from 27% to 81%, with higher free T quartiles (P < .01). Free T was additionally associated with abdominal adiposity among all pre-menopausal women (OR, 2.2; 95% CI, 1.2-4.1: P = .02). CONCLUSIONS: In young women with NAFLD, higher testosterone levels conferred a 2-fold higher risk of NASH and NASH fibrosis, and increased risk of abdominal adiposity, supporting a potential mechanistic link of abdominal fat on testosterone-associated liver injury. Testosterone may represent an early risk factor for NASH progression in young women, prior to their onset of more dominant, age-related metabolic risk factors.

Progression of Fatty Liver Disease in Children Receiving Standard of Care Lifestyle Advice.

BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) is the most common pediatric chronic liver disease. Little is known about outcomes in recognized youth. METHODS: We compared paired liver biopsies from 122 of 139 children with NAFLD (74% male; 64% white; 71% Hispanic; mean age, 13 ± 3 years; age range, 8-17 years) who received placebo and standard of care lifestyle advice in 2 double-blind, randomized clinical trials within the nonalcoholic steatohepatitis (NASH) clinical research network from 2005 through 2015. We analyzed histologic changes with respect to baseline and longitudinal change in clinical variables using regression analysis. RESULTS: At enrollment, 31% of the children had definite NASH, 34% had borderline zone 1 NASH, 13% had borderline zone 3 NASH, and 21% had fatty liver but not NASH. Over a mean period of 1.6 ± 0.4 years, borderline or definite NASH resolved in 29% of the children, whereas 18% of the children with fatty liver or borderline NASH developed definite NASH. Fibrosis improved in 34% of the children but worsened in 23%. Any progression to definite NASH and/or in fibrosis was associated with adolescent age, and higher waist circumference, levels of alanine or aspartate aminotransferase, total and low-density lipoprotein cholesterol at baseline (<0.05), and over follow-up time, with increasing level of alanine aminotransferase, hemoglobin A1C (P<.05), gamma-glutamyl transferase and development of type 2 diabetes (P<.01). Increasing level of gamma-glutamyl transferase was also associated with reduced odds of any improvement (P = .003). CONCLUSIONS: One-third of children with NAFLD enrolled in placebo groups of clinical trials had histologic features of progression within 2 years, in association with increasing obesity and serum levels of aminotransferases and loss of glucose homeostasis.

Relationship of Enhanced Liver Fibrosis Score with Pediatric Nonalcoholic Fatty Liver Disease Histology and Response to Vitamin E or Metformin.

OBJECTIVES: To study the diagnostic performance of the enhanced liver fibrosis score (ELF) for detecting different stages of fibrosis and its usefulness in detecting histologic response to vitamin E or metformin in children with nonalcoholic fatty liver disease who participated in the Vitamin E or Metformin for the Treatment Of NAFLD In Children (TONIC) trial. STUDY DESIGN: ELF was measured at baseline and weeks 24, 48, and 96 on sera from 166 TONIC participants. Associations between ELF with baseline and end of trial (EOT) fibrosis stages and other histologic features were assessed using χ2 tests and logistic regression models. RESULTS: ELF was significantly associated with severity of fibrosis at baseline and EOT. ELF areas under the curve for discriminating patients with clinically significant and advanced fibrosis were 0.70 (95% CI, 0.60-0.80) and 0.79 (95% CI, 0.69-0.89), respectively. A 1-unit decrease in ELF at EOT was associated with overall histologic improvement (OR, 1.86; 95% CI, 1.11-3.14; P = .02), resolution of steatohepatitis (OR, 1.88; 95% CI, 1.09-3.25; P = .02), improvement in steatosis grade (OR, 1.76; 95% CI, 1.06-2.82; P = .03), and hepatocellular ballooning (OR, 1.79; 95% CI, 1.06-3.00; P = .03), but not with improvement in fibrosis stage (OR, 1.26; 95% CI, 0.78-2.03; P = .34). CONCLUSIONS: ELF was associated with fibrosis stage in children who participated in TONIC. Although not associated with improvement in fibrosis, a decrease in ELF at EOT was associated with Nonalcoholic Steatohepatitis resolution and improvement in nonalcoholic fatty liver disease histology. ELF may be a useful noninvasive test to monitor treatment response in children with nonalcoholic fatty liver disease.

Characterization of GDF2 Mutations and Levels of BMP9 and BMP10 in Pulmonary Arterial Hypertension.

Rationale: Recently, rare heterozygous mutations in GDF2 were identified in patients with pulmonary arterial hypertension (PAH). GDF2 encodes the circulating BMP (bone morphogenetic protein) type 9, which is a ligand for the BMP2 receptor.Objectives: Here we determined the functional impact of GDF2 mutations and characterized plasma BMP9 and BMP10 levels in patients with idiopathic PAH.Methods: Missense BMP9 mutant proteins were expressed in vitro and the impact on BMP9 protein processing and secretion, endothelial signaling, and functional activity was assessed. Plasma BMP9 and BMP10 levels and activity were assayed in patients with PAH with GDF2 variants and in control subjects. Levels were also measured in a larger cohort of control subjects (n = 120) and patients with idiopathic PAH (n = 260).Measurements and Main Results: We identified a novel rare variation at the GDF2 and BMP10 loci, including copy number variation. In vitro, BMP9 missense proteins demonstrated impaired cellular processing and secretion. Patients with PAH who carried these mutations exhibited reduced plasma levels of BMP9 and reduced BMP activity. Unexpectedly, plasma BMP10 levels were also markedly reduced in these individuals. Although overall BMP9 and BMP10 levels did not differ between patients with PAH and control subjects, BMP10 levels were lower in PAH females. A subset of patients with PAH had markedly reduced plasma levels of BMP9 and BMP10 in the absence of GDF2 mutations.Conclusions: Our findings demonstrate that GDF2 mutations result in BMP9 loss of function and are likely causal. These mutations lead to reduced circulating levels of both BMP9 and BMP10. These findings support therapeutic strategies to enhance BMP9 or BMP10 signaling in PAH.

Microbiome Signatures Associated With Steatohepatitis and Moderate to Severe Fibrosis in Children With Nonalcoholic Fatty Liver Disease.

BACKGROUND & AIMS: The intestinal microbiome might affect the development and severity of nonalcoholic fatty liver disease (NAFLD). We analyzed microbiomes of children with and without NAFLD. METHODS: We performed a prospective, observational, cross-sectional study of 87 children (age range, 8-17 years) with biopsy-proven NAFLD and 37 children with obesity without NAFLD (controls). Fecal samples were collected and microbiome composition and functions were assessed using 16S ribosomal RNA amplicon sequencing and metagenomic shotgun sequencing. Microbial taxa were identified using zero-inflated negative binomial modeling. Genes contributing to bacterial pathways were identified using gene set enrichment analysis. RESULTS: Fecal microbiomes of children with NAFLD had lower α-diversity than those of control children (3.32 vs 3.52, P = .016). Fecal microbiomes from children with nonalcoholic steatohepatitis (NASH) had the lowest α-diversity (control, 3.52; NAFLD, 3.36; borderline NASH, 3.37; NASH, 2.97; P = .001). High abundance of Prevotella copri was associated with more severe fibrosis (P = .036). Genes for lipopolysaccharide biosynthesis were enriched in microbiomes from children with NASH (P < .001). Classification and regression tree model with level of alanine aminotransferase and relative abundance of the lipopolysaccharide pathway gene encoding 3-deoxy-d-manno-octulosonate 8-phosphate-phosphatase identified patients with NASH with an area under the receiver operating characteristic curve value of 0.92. Genes involved in flagellar assembly were enriched in the fecal microbiomes of patients with moderate to severe fibrosis (P < .001). Classification and regression tree models based on level of alanine aminotransferase and abundance of genes encoding flagellar biosynthesis protein had good accuracy for identifying case children with moderate to severe fibrosis (area under the receiver operating characteristic curve, 0.87). CONCLUSIONS: In an analysis of fecal microbiomes of children with NAFLD, we associated NAFLD and NASH with intestinal dysbiosis. NAFLD and its severity were associated with greater abundance of genes encoding inflammatory bacterial products. Alterations to the intestinal microbiome might contribute to the pathogenesis of NAFLD and be used as markers of disease or severity.