Lean Nonalcoholic Fatty Liver Disease and Risk of Incident Type 2 Diabetes mellitus: A Literature Review and Meta-analysis

Cardiometabolic and Metabolic Profiles of Lean/Normal, Overweight and Obese Patients with Nonalcoholic Fatty Liver Disease

Purpose

Disagreements about the risk of non-obese, non-alcoholic fatty liver disease for cardiometabolic outcomes occurred widely. This study aims to characterize the cardiometabolic and metabolic profile of lean/normal, overweight and obese patients with nonalcoholic fatty liver disease on a big sample.

Patients and methods

Appeared healthy adults who participated in health examinations during the year of 2019-2022 were screened for fatty liver diagnosis. BMI classified fatty livers as lean, overweight and obese. Eleven cardiometabolic metrics (SBP: systolic blood pressure; DBP: diastolic blood pressure; TC: total cholesterol; TG: triglycerides; HDL: high-density lipoprotein cholesterol; LDL: low-density lipoprotein cholesterol) and metabolic metrics (GLU: blood glucose; GHB: glycated haemoglobin; UA: uric acid; AST: aspartate aminotransferase; ALT: alanine aminotransferase) were included, described and compared among BMI categories.

Results

There were 56,496 fatty livers diagnosed by ultrasound in this study. In total, the lean fatty liver had lowest mean SBP, DBP, GLU, TG, UA, AST, and ALT but highest TC and HDL among BMI categories (all p < 0.001). The number of abnormal metrics in total was 2.5, 2.9 and 3.4 in lean, overweight, and obesity, respectively (p < 0.001, p_trend < 0.001). Visualized data showed that lean fatty liver was similar but milder in all metabolic metrics than overweight and obesity at the young ages. However, lean fatty liver had higher coefficients of age and risk of metabolic abnormality regression (p <0.001 for SBP, DBP, GLU, GHB, TC).

Conclusion

The lean type of fatty livers at a younger age has a relatively favourable cardiometabolic and metabolic profile compared to overweight and obese fatty livers. Due to the possible catch-up effect of metabolic dysfunctions in young lean fatty liver, lean fatty liver may have the same health outcomes as overweight/obesity fatty liver in long term. The evaluation and intervention may be critical for young lean fatty liver management to slowdown the rapid progress of metabolic dysfunction.

Fatty liver is associated with significant liver inflammation and increases the burden of advanced fibrosis in chronic HBV infection

BACKGROUND

Concurrent non-alcoholic fatty liver disease (NAFLD) is common in patients with chronic HBV infection. But the impact of fatty liver on the histologic progression of HBV infection remains controversial.

METHODS

Consecutive HBV-infected patients who underwent liver biopsy between 2016 and 2021 were included. Alcohol consumption and other types of viral hepatitis were excluded. All biopsies were scored for grading and staging by Scheuer's score, and the steatosis was scored as an estimate of the percentage of liver parenchyma replaced by fat. Logistic regression analyses were applied to assess the associated factors for significant liver inflammation (G ≥ 2), significant fibrosis (S ≥ 2) and advanced fibrosis (S ≥ 3).

RESULTS

Among the 871 HBV-infected patients, hepatic steatosis was prevalent in 255 patients (29.28%). Significant liver inflammation was present in 461 patients (52.93%). Significant fibrosis was observed in 527 patients (60.51%), while advanced liver fibrosis was observed in 171 patients (19.63%). Patients with concomitant NAFLD were more likely to have significant liver inflammation and advanced fibrosis. Fatty liver was an independent risk factor for significant liver inflammation (OR: 2.117, 95% CI: 1.500-2.988), but it could not predict the development of fibrosis. Especially, in HBV-infected patients with persistent normal ALT (immune tolerant and inactive carrier phase), the presence of significant liver inflammation was higher in NAFLD than those without NAFLD. The prevalence of advanced liver fibrosis was higher in NAFLD than non-NAFLD only in the immune tolerant phase, while NAFLD did not increase fibrosis burden in other stages of HBV infection. We developed a predictive model for significant liver inflammation with the area under receiver operating characteristic curve (AUROC) of 0.825, and a model for significant fibrosis with the AUROC of 0.760.

CONCLUSIONS

NAFLD is independently associated with significant liver inflammation, and increases the burden of advanced liver fibrosis in HBV-infected patients. The influence of NAFLD on the degree of liver inflammation and fibrosis is different in distinct clinical phases of chronic HBV infection.