Validation of fatty liver index as a predictor of hepatic steatosis in Asian populations: Impact of alcohol consumption and sex

Usefulness of health checkup-based indices in identifying metabolic dysfunction-associated steatotic liver disease

Aims

The application of indices in the context of metabolic dysfunction-associated steatotic liver disease (MASLD) remains unexplored. We aimed to validate the ability of alanine aminotransferase (ALT), fatty liver index (FLI), and hepatic steatosis index (HSI) to identify MASLD during health checkups.

Methods

We recruited 627 participants and utilized their health checkup data and ultrasound to assess the potential of using ALT, FLI, and HSI as indices for MASLD; this was indicated by the area under the curve (AUC) and restricted cubic spline (RCS) model. The optimal, rule-out (sensitivity ≥90%), and rule-in (specificity ≥90%) cutoff values of each index for identifying MASLD were reported.

Results

Among participants with a median age of 46 years, the prevalence of MASLD was 28% in total (38% in males and 18% in females). RCS models confirmed a linear association between indices and MASLD. ROC analyses indicated that the AUC of ALT in identifying MASLD was 0.79 for the total cohort, 0.81 for males, and 0.69 for females. The optimal, rule-out, and rule-in cutoff values for ALT were 21, 13, and 29, respectively. Similarly, the AUC of FLI/HSI in identifying MASLD was 0.90/0.88 for the total cohort, 0.86/0.85 for males, and 0.93/0.90 for females. Considering the reference cutoff values, distinct cutoff values were observed between the sexes for FLI, while HSI had similar cutoff values.

Conclusion

This study demonstrated that ALT > 30 IU/L is a reasonable cutoff value to rule-in MASLD. ALT, FLI, and HSI are reliable indices for identifying MASLD during health checkups.

Fatty Liver Index (FLI) is the best score to predict MASLD with 50% lower cut-off value in women than in men

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) is defined by the presence of hepatic steatosis, detected on ultrasonography (US) imaging or histology, and at least one of criteria for Metabolic Syndrome diagnosis. Simple non-invasive tests (NITs) have been proposed as an acceptable alternative when US and biopsy are not available or feasible but have not been validated for MASLD. In this observational study, we investigated the reliability of NITs for MASLD detection and whether sex-differences in screening methods should be considered.

METHODS

We included 1069 individuals (48% males and 52% females) who underwent their first clinical examination for Metabolic Syndrome in the period between January 2015 and December 2022. Liver steatosis was detected through US and anthropometric and clinical parameters were recorded.

RESULTS

Liver steatosis was detected in 648 patients and MASLD was diagnosed in 630 subjects (355 males; 275 females). Women with MASLD showed better metabolic profile and lower prevalence of Metabolic Syndrome criteria than men. Among NITs, Fatty Liver Index (FLI) showed the best ability for detection of MASLD, with a cut-off value of 44 (AUC = 0.82). When considering the two sexes for MASLD detection via FLI, despite no substantial differences regarding FLI correlations with metabolic biomarkers except for age, women showed marked lower FLI cut-off value (32; AUC = 0.80) than men (60; AUC = 0.80).

CONCLUSIONS

In this study, we found that FLI is the best non-invasive predictor of both liver steatosis and MASLD. The finding that in women FLI cut-off value for MASLD detection is 50% lower than in men suggests the need of a sex-specific personalized program of screening and prevention of dysmetabolism-related liver diseases, despite outwardly healthy biomarkers profile.

Extrahepatic malignancies in metabolic dysfunction-associated fatty liver disease: A nationwide cohort study

BACKGROUND AND AIMS

Metabolic dysfunction-associated fatty liver disease (MAFLD) encompasses heterogeneous fatty liver diseases associated with metabolic disorders. We aimed to evaluate the association between MAFLD and extrahepatic malignancies based on MAFLD subtypes.

METHODS

This nationwide cohort study included 9 298 497 patients who participated in a health-screening programme of the National Health Insurance Service of Korea in 2009. Patients were further classified into four subgroups: non-MAFLD, diabetes mellitus (DM)-MAFLD, overweight/obese-MAFLD and lean-MAFLD. The primary outcome was the development of any primary extrahepatic malignancy, while death, decompensated liver cirrhosis and liver transplantation were considered competing events. The secondary outcomes included all-cause and extrahepatic malignancy-related mortality.

RESULTS

In total, 2 500 080 patients were diagnosed with MAFLD. During a median follow-up of 10.3 years, 447 880 patients (6.0%) with extrahepatic malignancies were identified. The DM-MAFLD (adjusted subdistribution hazard ratio [aSHR] = 1.13; 95% confidence interval [CI] = 1.11-1.14; p < .001) and the lean-MAFLD (aSHR = 1.12; 95% CI = 1.10-1.14; p < .001) groups were associated with higher risks of extrahepatic malignancy than the non-MAFLD group. However, the overweight/obese-MAFLD group exhibited a similar risk of extrahepatic malignancy compared to the non-MAFLD group (aSHR = 1.00; 95% CI = .99-1.00; p = .42). These findings were reproduced in several sensitivity analyses. The DM-MAFLD was an independent risk factor for all-cause mortality (adjusted hazard ratio [aHR] = 1.41; 95% CI = 1.40-1.43; p < .001) and extrahepatic malignancy-related mortality (aHR = 1.20; 95% CI = 1.17-1.23; p < .001).

CONCLUSION

The diabetic or lean subtype of MAFLD was associated with a higher risk of extrahepatic malignancy than non-MAFLD. As MAFLD comprises a heterogeneous population, appropriate risk stratification and management based on the MAFLD subtypes are required.

Metabolic dysfunction-associated steatotic liver disease increases the risk of incident cardiovascular disease: a nationwide cohort study

Background

The various subcategories under the overarching term of steatotic liver disease (SLD) have been recently proposed by the nomenclature consensus group and endorsed by international academic liver societies. Our aim was to investigate the association between each subtype of SLD and incident cardiovascular disease (CVD) in a nationwide Korean cohort.

Methods

From a nationwide health screening database from Korea, 351,068 individuals aged 47-86 years between January 1, 2009 and December 31, 2010 were included and followed until December 31, 2019 for a median of 9.0 years. Individuals were categorised into no SLD, metabolic dysfunction-associated steatotic liver disease (MASLD), MASLD with increased alcohol intake (MetALD), and alcohol-related liver disease (ALD). Hepatic steatosis was defined as fatty liver index ≥60. The primary outcome was a composite CVD, which includes non-fatal and fatal myocardial infarction and stroke. The subdistribution hazard ratio (SHR) was calculated using the Fine-Gray model with treating non-CVD-related death as a competing risk.

Findings

There were 199,817 male (56.9%) and 151,251 female (43.1%) with a median age of 55 years (interquartile range, 50-61). The prevalence of no SLD, MASLD, MetALD, and ALD was 44.3%, 47.2%, 6.4%, and 2.1%, respectively; and the incidence rate of CVD in each subcategory was 6.2, 8.5, 8.5, and 9.6 per 1000 person-years, respectively. MASLD (SHR, 1.19; 95% confidence interval [CI], 1.15-1.24), MetALD (SHR, 1.28; 95% CI, 1.20-1.36), and ALD (SHR, 1.29; 95% CI, 1.18-1.41) increased the risk of CVD compared to no SLD, which increment was in consecutive order (Ptrend < 0.001).

Interpretation

Individuals with MASLD, MetALD, or ALD are at an increased risk of developing incident CVD. Higher risk of CVD observed in MetALD compared to MASLD suggests the additive impact of alcohol consumption in conjunction with cardiometabolic risk factors on CVD development. These findings support and validate the utility of the new consensus criteria for SLD in predicting CVD.

Funding

The National Research Foundation of Korea and the Korea Centers for Disease Control and Prevention.