Non-alcoholic fatty liver disease (NAFLD) in different populations: A clinical and epidemiological study – sample of São José do Rio Preto

Global epidemiology of type 2 diabetes in patients with NAFLD or MAFLD: a systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) and metabolic-associated fatty liver disease (MAFLD) shares common pathophysiological mechanisms with type 2 diabetes, making them significant risk factors for type 2 diabetes. The present study aimed to assess the epidemiological feature of type 2 diabetes in patients with NAFLD or MAFLD at global levels.

METHODS

Published studies were searched for terms that included type 2 diabetes, and NAFLD or MAFLD using PubMed, EMBASE, MEDLINE, and Web of Science databases from their inception to December 2022. The pooled global and regional prevalence and incidence density of type 2 diabetes in patients with NAFLD or MAFLD were evaluated using random-effects meta-analysis. Potential sources of heterogeneity were investigated using stratified meta-analysis and meta-regression.

RESULTS

A total of 395 studies (6,878,568 participants with NAFLD; 1,172,637 participants with MAFLD) from 40 countries or areas were included in the meta-analysis. The pooled prevalence of type 2 diabetes among NAFLD or MAFLD patients was 28.3% (95% confidence interval 25.2-31.6%) and 26.2% (23.9-28.6%) globally. The incidence density of type 2 diabetes in NAFLD or MAFLD patients was 24.6 per 1000-person year (20.7 to 29.2) and 26.9 per 1000-person year (7.3 to 44.4), respectively.

CONCLUSIONS

The present study describes the global prevalence and incidence of type 2 diabetes in patients with NAFLD or MAFLD. The study findings serve as a valuable resource to assess the global clinical and economic impact of type 2 diabetes in patients with NAFLD or MAFLD.

Impact of Hepatic Steatosis on the Antiviral Effects of PEG-IFNα-2a in Patients with Chronic Hepatitis B and the Associated Mechanism

Objective

To investigate the risk factors for hepatic steatosis in chronic hepatitis B (CHB), to determine its correlation with liver necroinflammation and fibrosis and response to peginterferon alpha-2a (PEG-IFNα-2a) antiviral therapy, and to explore the mechanisms underlying the poor antiviral effect of PEG-IFNα-2a in CHB patients with hepatic steatosis.

Methods

We analysed the impact of hepatic steatosis on the antiviral effect of PEG-IFNα-2a on CHB patients in a cohort of 226 patients who underwent pretherapeutic liver biopsy. To assess the complete response (CR), virological response (VR), and biochemical response (BR), the 226 patients were treated with PEG-IFNα-2a for 48 weeks and were followed-up for 24 weeks. The expressions of hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) in the liver tissue were detected in all patients to explore the possible mechanism of hepatic steatosis with regard to antiviral effects.

Results

The patients were divided into four groups based on the severity of hepatic steatosis: 119 with no steatosis, 76 with mild steatosis, 22 with moderate steatosis, and 9 with severe steatosis. In the hepatic steatosis groups, the proportions of male patients, patients aged >40 years, patients with hyperuricaemia, patients with a BMI > 23 kg/m², and total cholesterol (TC), triglyceride (TG), glucose (GLU), and uric acid (UA) levels were significantly higher than those in the group without steatosis, whereas the alanine aminotransferase (ALT) and aspartate transaminase (AST) levels were significantly lower than those in the group without steatosis. The multivariate analysis results indicated that a BMI > 23 kg/m² was independently associated with CHB patients with hepatic steatosis; the levels of baseline AST and UA were independently associated with CHB patients with significant hepatic steatosis, and the baseline AST level was independently associated with significant liver fibrosis. After 48 weeks of treatment and 24 weeks of follow-up, the rates of CR, VR, and BR had gradually decreased, whereas the severity of hepatic steatosis had increased.

Conclusion

Hepatic steatosis can reduce the efficacy of PEG-IFNα-2a in the treatment of CHB patients, and its mechanism may be related to the different HBcAg expression patterns in liver tissue.

Magnitude of Nonalcoholic Fatty Liver Disease: Western Perspective

The incidence of nonalcoholic fatty liver disease (NAFLD) is continuing to rise worldwide, and it is estimated that this disquieting trend will continue for another 10-15 years before prevalence begins to decrease. NAFLD is the hepatic manifestation of metabolic syndrome. As obesity, diabetes, and other lifestyle-related diseases continue to rise, the spectrum of NAFLD, e.g., nonalcoholic steatohepatitis, liver fibrosis, liver cirrhosis, liver-related morbidity, and mortality, will increase in parallel. Its widespread prevalence and associated economic burden have drawn significant attention, and a multitude of pharmaceutical companies are participating in active research trying to find a "cure". Unfortunately, as of now, no targeted treatment exists to treat this condition, and therefore, emphasis has been on its prevention. The current review focuses on the epidemiology, clinical characteristics, risk factors, and clinical outcomes of NAFLD in Western countries. It is important to understand the magnitude of NAFLD and its risk factors in Western countries where the prevalence of NAFLD has now reached epidemic proportions to identify the best strategy to prevent and possibly control this epidemic.

Non-alcoholic fatty liver disease - A global public health perspective

As the epidemics of obesity and type 2 diabetes mellitus increase worldwide, the prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing proportionately. The subtype of NAFLD which can be characterised as non-alcoholic steatohepatitis (NASH) is a potentially progressive liver disease that can lead to cirrhosis, hepatocellular carcinoma, liver transplantation, and death. NAFLD is also associated with extrahepatic manifestations such as chronic kidney disease, cardiovascular disease and sleep apnoea. NAFLD and NASH carry a large economic burden and create poor health-related quality of life. Despite this important burden, we are only beginning to understand its mechanisms of pathogenesis and the contribution of environmental and genetic factors to the risk of developing a progressive course of disease. Research is underway to identify appropriate non-invasive diagnostic methods and effective treatments. Although the risk of liver-related mortality is increased in patients with NAFLD and liver fibrosis stages F3 or F4, the leading cause of death is cardiovascular disease. Given the rapidly growing global burden of NAFLD and NASH, efforts must continue to find accurate non-invasive diagnostic and prognostic biomarkers, to develop effective treatments for individuals with advanced NASH and prevention methods for individuals at high risk of NAFLD and progressive liver disease.

The association between glycometabolism and nonalcoholic fatty liver disease in patients with obstructive sleep apnea

Purpose

Growing evidence has revealed that nonalcoholic fatty liver disease (NAFLD) is associated with type 2 diabetes. This study aimed to assess the association between glycometabolism and NAFLD in patients with obstructive sleep apnea (OSA).

Methods

Patients with suspected OSA were enrolled consecutively and then underwent polysomnography, liver ultrasound, and biochemical measurements. Logistic regressions were used to identify factors associated with NAFLD.

Results

In total, 415 patients were included. The prevalence of NAFLD in the non-OSA, mild OSA, moderate OSA, and severe OSA groups was 37.21%, 69.09%, 68.34%, and 78.08%, respectively. Stepwise logistic regression suggested that percentage of total sleep time spent with oxygen saturation of < 90% (TS90), lowest oxygen saturation (LaSO₂), and homeostatic model assessment of insulin resistance (HOMA-IR) were independently associated with NAFLD in all subjects, after adjusting for confounders (odds ratio [OR] = 1.037, p = 0.014; OR = 1.056, p = 0.004; OR = 0.732, p = 0.009; respectively). TS90, LaSO₂, and HOMA-IR were also independent predictors for NAFLD in patients with mild and moderate OSA, whereas TS90, LaSO₂, and ODI were independent predictors for NAFLD in patients with severe OSA.

Conclusions

There is a relationship between OSA and NAFLD, and the combination of disordered glycometabolism and intermittent hypoxia may act as a “two hit” mechanism to promote the development of NAFLD. Furthermore, intermittent hypoxia alone was an independent predictor for NAFLD in severe OSA patients.