Non-alcoholic fatty liver and fibrosis is associated with cardiovascular structure and function in young adults

BACKGROUND: Non-alcoholic fatty liver disease shares many risk factors with other metabolic disorders. We sought to establish whether non-alcoholic fatty liver disease may be associated with cardiovascular health independently of other known risk factors. METHODS: In this prospective, population-based cohort of young adults, controlled attenuation parameter-defined liver steatosis, transient elastography-defined liver fibrosis, echocardiography, carotid ultrasonography, and pulse wave analysis were assessed at age 24 years. We examined associations between liver and cardiovascular measures, with and without accounting for demographics, body mass index, alcohol, smoking, blood pressure, lipidemia, glycemia, and inflammation. RESULTS: We included 2047 participants (mean age 24.4 y; 36.2% female): 212 (10.4%) had steatosis, whereas 38 (1.9%) had fibrosis. Steatosis was associated with cardiovascular measures after adjusting for demographics, but with more comprehensive adjustment, steatosis only remained associated with stroke index [β (95% CI) of -1.85 (-3.29, -0.41) mL/m2] and heart rate [2.17 (0.58, 3.75) beats/min]. Fibrosis was associated with several measures of cardiovascular structure and function after full adjustment for risk factors, including left ventricular mass index [2.46 (0.56, 4.37) g/m2.7], E/A ratio [0.32 (0.13, 0.50)], tricuspid annular plane systolic excursion [0.14 (0.01, 0.26) cm], carotid intima-media thickness [0.024 (0.008, 0.040) mm], pulse wave velocity [0.40 (0.06, 0.75) m/s], cardiac index [-0.23 (-0.41, -0.06) L/min⋅m2], and heart rate [-7.23 (-10.16, -4.29) beats/min]. CONCLUSIONS: Steatosis was not associated with measures of cardiovascular structure and function nor with subclinical atherosclerosis after adjusting for known cardiovascular risk factors. Fibrosis, however, was associated with several cardiovascular measures, including indicators of subclinical atherosclerosis, even after full adjustment. Further follow-up will help determine whether cardiovascular health worsens later with steatosis alone

Exploring changing attitudes to non-invasive liver fibrosis tests in secondary care pathways: comparison of two national surveys

INTRODUCTION: The increasing availability of non-invasive tests (NITs) has created the opportunity to explore their use in improving risk stratification of advanced liver disease. The study aimed to determine the attitudes and practices among UK secondary care specialists, focusing primarily on attitudes to fibrosis assessment and the use of NITs. METHODS: Two web-based surveys were circulated, first between 2014 and 2015 (survey 1), and again in 2021 (survey 2). The surveys were promoted via the British Society of Gastroenterology, the British Association for the Study of the Liver and using Twitter. RESULTS: In survey 1, 215 healthcare professionals (HCPs) completed the online survey. 112 HCPs completed survey 2. 71 acute UK trusts were represented in survey 1 compared with 60 trusts in survey 2. Between the two surveys, the proportion of HCPs performing fibrosis assessment in all or nearly all cases rose from 45.1% to 74.1% (χ2=25.01; p<0.0001). 46.5% (n=33/71) respondents in acute services reported the use of NITs in clinical pathways in survey 1, rising to 70.0% (n=42/60) in survey 2 (χ2=7.35; p=0.007). Availability of tests has increased but is not universal. The proportion reporting availability as a barrier to uptake fell from 57.2% of responses in survey 1 to 38.4% in 2021 χ2=11.01; p=0.0009). CONCLUSION: Between 2014 and 2021, the role of NITs in fibrosis assessment has risen substantially, as has the proportion of clinicians using NITs in clinical pathways to assess risk of liver disease. Poor access to NITs remains the predominant barrier

rs641738C>T near MBOAT7 is associated with liver fat, ALT and fibrosis in NAFLD: A meta-analysis.

BACKGROUND & AIMS: A common genetic variant near MBOAT7 (rs641738C>T) has been previously associated with hepatic fat and advanced histology in NAFLD; however, these findings have not been consistently replicated in the literature. We aimed to establish whether rs641738C>T is a risk factor across the spectrum of NAFLD and to characterise its role in the regulation of related metabolic phenotypes through a meta-analysis. METHODS: We performed a meta-analysis of studies with data on the association between rs641738C>T genotype and liver fat, NAFLD histology, and serum alanine aminotransferase (ALT), lipids or insulin. These included directly genotyped studies and population-level data from genome-wide association studies (GWAS). We performed a random effects meta-analysis using recessive, additive and dominant genetic models. RESULTS: Data from 1,066,175 participants (9,688 with liver biopsies) across 42 studies were included in the meta-analysis. rs641738C>T was associated with higher liver fat on CT/MRI (+0.03 standard deviations [95% CI 0.02-0.05], pz = 4.8×10-5) and diagnosis of NAFLD (odds ratio [OR] 1.17 [95% CI 1.05-1.3], pz = 0.003) in Caucasian adults. The variant was also positively associated with presence of advanced fibrosis (OR 1.22 [95% CI 1.03-1.45], pz = 0.021) in Caucasian adults using a recessive model of inheritance (CC + CT vs. TT). Meta-analysis of data from previous GWAS found the variant to be associated with higher ALT (pz = 0.002) and lower serum triglycerides (pz = 1.5×10-4). rs641738C>T was not associated with fasting insulin and no effect was observed in children with NAFLD. CONCLUSIONS: Our study validates rs641738C>T near MBOAT7 as a risk factor for the presence and severity of NAFLD in individuals of European descent. LAY SUMMARY: Fatty liver disease is a common condition where fat builds up in the liver, which can cause liver inflammation and scarring (including 'cirrhosis'). It is closely linked to obesity and diabetes, but some genes are also thought to be important. We did this study to see whether one specific change ('variant') in one gene ('MBOAT7') was linked to fatty liver disease. We took data from over 40 published studies and found that this variant near MBOAT7 is linked to more severe fatty liver disease. This means that drugs designed to work on MBOAT7 could be useful for treating fatty liver disease.JPM is supported by a Wellcome Trust Fellowship (216329/Z/19/Z