BACKGROUNDMetabolic dysfunction-associated steatotic liver disease (MASLD) has a substantial inherited component. Rare variants in apolipoprotein B gene (APOB) have been implicated in susceptibility t Show more
BACKGROUNDMetabolic dysfunction-associated steatotic liver disease (MASLD) has a substantial inherited component. Rare variants in apolipoprotein B gene (APOB) have been implicated in susceptibility to liver steatosis, but their role in disease progression and outcomes is unclear.METHODSWe investigated APOB rare variants in a case-control cohort of people with advanced MASLD versus healthy controls (n = 510 and 261, respectively), a family-based study (n = 43 and literature meta-analysis), the Million Veteran Program (MVP) cohort (n = 94,885), and the UK Biobank (UKBB) (n = 417,657).RESULTSIn the clinical cohort, APOB variants were enriched in people with advanced MASLD (OR 13.8, 95% CI: 2.7-70.7, P = 0.002) and associated with lower circulating lipids, but higher MASLD activity and fibrosis (P < 0.05). In the family study, APOB variants segregated with hepatic steatosis and fibrosis (P < 0.05). Cross-ancestry meta-analysis of the study cohorts yielded pooled ORs for cirrhosis and hepatocellular carcinoma (HCC) of 1.82, 95% CI: 1.33-2.49 and 3.53, 95% CI: 2.09-5.98, respectively. Variants affecting specifically ApoB100 had a 3-fold greater effect on hepatic lipid metabolism compared with those impairing also ApoB48 and were specifically protective against coronary artery disease (P < 0.05). The variants affected cirrhosis risk similarly, but ApoB48/100 had a larger effect on HCC (P < 0.05).CONCLUSIONSRare APOB variants predispose individuals to advanced MASLD and HCC, with distinct contributions from disrupted VLDL and chylomicrons secretion. These findings highlight the interplay between hepatic and intestinal lipid handling, suggesting that APOB genotyping may enhance MASLD risk stratification and patient identification.FUNDINGEuropean Union, Italian Ministry of Health, Swedish Research Council, Veterans Health Administration, NIH. Show less
The relationship between plasma lipoprotein(a) [Lp(a)] levels and metabolic dysfunction-associated steatotic liver disease (MASLD) remains unclear. The aim of this study was to examine the combined ef Show more
The relationship between plasma lipoprotein(a) [Lp(a)] levels and metabolic dysfunction-associated steatotic liver disease (MASLD) remains unclear. The aim of this study was to examine the combined effects of Lp(a) levels on liver and vascular damage. The study was conducted using the Liver-Bible cohort of individuals with metabolic dysfunction (n = 859, 808 with genomic information) and the Milan Biobank (n = 6963). Genome-wide association studies (GWAS) and polygenic risk scores (PRS) were used to evaluate the inherited factors influencing plasma Lp(a) levels. In the Liver-Bible cohort, genetic variation in the LPA gene was the strongest determinant of Lp(a), followed by liver stiffness measurement (LSM). Additionally, circulating Lp(a) levels, but not genetic predisposition, were inversely related to LSM, suggesting that MASLD severity may affect Lp(a) secretion. Among participants with more severe insulin resistance (n = 250), Lp(a) levels (odds ratio 6.7, 95% CI 1.0-53.0, p = 0.046) and LSM (odds ratio 13.7, 95% CI 1.4-172.2, p = 0.023) were associated with greater prevalence of carotid atherosclerotic plaques, regardless of traditional cardiovascular risk factors. In the Milan Biobank, genetically predicted higher Lp(a) levels tended to increase the risk of liver-related outcomes, whereas genetically predicted MASLD was associated with lower circulating Lp(a) levels. The results of this study suggest that liver damage is more likely the cause of reduced plasma Lp(a) levels rather than a consequence. Assessing plasma Lp(a) levels and the extent of liver damage could improve the prediction of vascular damage. Show less