Apolipoproteins and liver parameters optimize cardiovascular disease risk-stratification in nonalcoholic fatty liver disease

Circulating lipoprotein(a) in patients with nonalcoholic fatty liver disease: a systematic review and meta-analysis

BACKGROUND AND AIM

Although nonalcoholic fatty liver disease (NAFLD) and lipoprotein(a) [Lp(a)] are associated with cardiovascular diseases, existing data on Lp(a) in NAFLD are conflicting. The aim of this systematic review and meta-analysis was to summarize and compare data on circulating Lp(a) between NAFLD patients and non-NAFLD controls.

METHODS

A systematic literature search was performed in PubMed, Scopus, and Cochrane Library. This meta-analysis included 18 studies containing data on 74 691 individuals (20 220 patients with NAFLD and 54 471 controls).

RESULTS

Circulating Lp(a) was similar between patients with NAFLD and controls (standardized mean difference [SMD] 0.09; 95% confidence interval [95% CI] -0.21, 0.38). The heterogeneity among studies was high (I2 = 100%); no publication bias was detected (Egger's test P = 0.941). However, in subgroup analysis, Lp(a) was lower in NAFLD patients than controls, when Lp(a) was measured with nephelometry (SMD -0.26; 95% CI -0.46, -0.06), but not turbidimetry; this analysis also resulted in mild reduction of heterogeneity within the subgroup of nephelometry (I2 = 87%). The sensitivity analyses, based on the exclusion of studies with Newcastle-Ottawa Scale score ≤6 (n = 5), studies in which liver biopsy was used for NAFLD diagnosis (n = 4) or studies that adopted the criteria of metabolic dysfunction-associated fatty liver disease (n = 2), and meta-regression analysis did not explain the high heterogeneity among studies.

CONCLUSIONS

Overall, circulating Lp(a) was similar between NAFLD patients and non-NAFLD controls; however, patients with NAFLD had lower circulating Lp(a) compared with controls, when Lp(a) was measured with nephelometry. These results should be cautiously interpreted, because of the high heterogeneity among studies.

An international multidisciplinary consensus statement on MAFLD and the risk of CVD

BACKGROUND

Fatty liver disease in the absence of excessive alcohol consumption is an increasingly common condition with a global prevalence of ~ 25-30% and is also associated with cardiovascular disease (CVD). Since systemic metabolic dysfunction underlies its pathogenesis, the term metabolic (dysfunction)-associated fatty liver disease (MAFLD) has been proposed for this condition. MAFLD is closely intertwined with obesity, type 2 diabetes mellitus and atherogenic dyslipidemia, which are established cardiovascular risk factors. Unlike CVD, which has received attention in the literature on fatty liver disease, the CVD risk associated with MAFLD is often underestimated, especially among Cardiologists.

METHODS AND RESULTS

A multidisciplinary panel of fifty-two international experts comprising Hepatologists, Endocrinologists, Diabetologists, Cardiologists and Family Physicians from six continents (Asia, Europe, North America, South America, Africa and Oceania) participated in a formal Delphi survey and developed consensus statements on the association between MAFLD and the risk of CVD. Statements were developed on different aspects of CVD risk, ranging from epidemiology to mechanisms, screening, and management.

CONCULSIONS

The expert panel identified important clinical associations between MAFLD and the risk of CVD that could serve to increase awareness of the adverse metabolic and cardiovascular outcomes of MAFLD. Finally, the expert panel also suggests potential areas for future research.

Novel metabolic classification for extrahepatic complication of metabolic associated fatty liver disease: A data-driven cluster analysis with international validation

BACKGROUND

Traditional classification systems of metabolic-associated fatty liver disease (MAFLD) do not account for the high rate of extrahepatic complications. To create a new classification of MAFLD using metabolic parameters to identify risks of complications more accurately.

METHODS

The retrospective study included MAFLD patients from the First Affiliated Hospital of Sun Yat-sen University for model development, and the model was validated respectively using Chinese cohort and UK Biobank database. Cluster analysis with k-means cluster was built using age, body mass index (BMI), glycosylated hemoglobin (HbA1c), total cholesterol/high density lipoprotein cholesterol (HDL-C) ratio, triglyceride, and lipoprotein(a) [Lp(a)] levels. Cox regression models were used to compare the risk of type 2 diabetes (T2DM), chronic heart disease (CHD), stroke and mortality between the clusters.

RESULTS

1038 MAFLD patients from cross-sectional population were recruited for the model derivation, with 10,451 cases (33.4 % of MAFLD) from Chinese cohort and 304,141 cases (34.9 % of MAFLD, 1010 cases with magnetic resonance imaging proton density fat fraction measurement [MRI-PDFF]) from the international cohort validated. Five replicable clusters of MAFLD patients were identified: Cluster 1(mild obesity and dyslipidemia-related), Cluster 2 (age related), Cluster 3 (severe insulin resistance-related), Cluster 4[high Lp(a)-related], and Cluster 5 (severe mixed hyperlipidemia-related). Patients in different clusters exhibited differences in the development of T2DM, CHD, stroke and all-causes mortality. Patients in Cluster 3 had significantly worst survival outcomes and higher risks of T2DM and CVD than those in other clusters.

CONCLUSION

The novel classification offers improved discrimination of new-onset MAFLD patients with different metabolic complications.

The Ability of Lipoprotein (a) Level to Predict Early Carotid Atherosclerosis Is Impaired in Patients With Advanced Liver Fibrosis Related to Metabolic-Associated Fatty Liver Disease

INTRODUCTION

Hepatic fibrosis reduces the serum level of lipoprotein (a) (Lp(a)) and may affect its accuracy in cardiovascular disease prediction of metabolic-associated fatty liver disease (MAFLD). We aimed to estimate the association between Lp(a) levels and the risk of carotid atherosclerosis in MAFLD patients with advanced fibrosis.

METHODS

This was a cross-sectional study enrolling 4,348 consecutive individuals (1,346 patients with MAFLD and 3,002 non-MAFLD patients) who were admitted to the First Affiliated Hospital, Sun Yat-sen University, and underwent abdominal and carotid ultrasonography from 2015 to 2021. Lp(a) levels, liver biochemical markers, metabolic indices, and anthropometric parameters were measured. Liver fat content and fibrosis severity were assessed by MRI-PDFF, using the NAFLD fibrosis score (NFS) and liver stiffness measurement (LSM) of two-dimensional shear wave elastography, respectively.

RESULTS

There was an L-shaped relationship between Lp(a) levels and LSMs in patients with MAFLD, and Lp(a) levels had a different relationship with liver fat content in MAFLD patients with F1-2 versus those with F3-4. Non-MAFLD patients had higher levels of Lp(a) than MAFLD patients with or without advanced fibrosis (both P < 0.05). Lp(a) levels and degree of liver fibrosis were both positively correlated with carotid atherosclerosis in patients with MAFLD. Lp(a) levels performed well on carotid atherosclerosis risk prediction for non-MAFLD patients with an area under the curve (AUC) of 0.819, which was significantly better than the carotid atherosclerosis risk prediction for MAFLD patients with NFS ≤ -1.836 (AUC: 0.781), NFS > -1.836 (AUC: 0.692), and LSM ≥ 9.0 kPa (AUC: 0.635) (all P < 0.05).

DISCUSSION

Advanced liver fibrosis significantly reduces the predictive value of Lp(a) levels for the risk of carotid atherosclerosis in patients with MAFLD.