Correspondence on Letter regarding “Non-alcoholic fatty liver disease: Definition and subtypes” (original) (raw)

Articles

Correspondence

Clinical and Molecular Hepatology 2023;29(3):817-819.
Published online: May 17, 2023

1Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea

2Regenerative Medicine Research Center, Yonsei University Wonju College of Medicine, Wonju, Korea

3Cell Therapy and Tissue Engineering Center, Yonsei University Wonju College of Medicine, Wonju, Korea

Corresponding author : Moon Young Kim Division of Gastroenterology and Hepatology, Department of Internal Medicine, Yonsei University Wonju College of Medicine, 20 Ilsan-ro, Wonju 26426, Korea Tel: +82-33-741-1229, Fax: +82-33-741-0951, E-mail: drkimmy@yonsei.ac.kr

• Received: April 25, 2023 • Revised: May 13, 2023 • Accepted: May 15, 2023

Copyright © 2023 by The Korean Association for the Study of the Liver

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Full Article

Dear Editor,

We appreciate the constructive recommendation of Jeong et al. [1], which was a meaningful insight regarding fatty liver conceptualization. Fatty liver disease is characterized by fat accumulation resulting in hepatic inflammation, cirrhosis, and carcinoma. Currently, non-alcoholic fatty liver disease (NAFLD) is phenotypically considered a systemic metabolic syndrome. In metabolic syndrome, fatty liver is represented by one phenotype of a high-energy state, and various other complications resulting from this high-energy state can exist beyond the liver.

A recent review provided evidence that NAFLD is a risk factor for cerebrovascular disease (CVD) [2]. Kasper et al. [2] reported that NAFLD and CVD share a common pathophysiology, such as, PNPLA3, HSD 17B13, and PGC1a were related to genetic factors. Endothelial dysfunction, atherogenic dyslipidemia, systemic inflammation, coagulopathy, and altered gut microbiome are relevant factors. Moreover, NAFLD is reported as an independent risk factor for a CVD event, after adjusting other known risk factors. In some meta-analyses, outcomes were inconsistent; although, this may be due to the diversity in NAFLD definitions.

However, controversies regarding NAFLD as a risk factor for dementia are ongoing (Tables 1 and 2) [3-11]. In a recent study that included a large number of patients with NAFLD, the patients had a higher dementia rate, including vascular dementia [10]. This outcome is similar to that reported in a previous study [7]. However, primary care data from Germany have reported that NAFLD is not related to dementia occurrence [9]. Insulin resistance and hyperglycemia are known to cause dementia through glucose neurotoxicity and glycated end products [12]; however, they share some similarities with CVD. NAFLD is associated with arterial hypertension, atherosclerosis, coronary artery disease, and atrial fibrillation. Furthermore, NAFLD is often diagnosed at a young age and dementia at an old age; thus a limitation in revealing a direct relationship between the two diseases exists. Therefore, additional direct evidence is required. However, accumulating and updated data suggest that some mechanisms between NAFLD and brain dysfunction that result in dementia and Alzheimer’s disease are not fully investigated. This can be inferred from the fact that one author reported opposing results in 2 years.

Our review paper describes the simple, basic classification of NAFLD and its subtypes and summarizes the well-accepted contents for NAFLD. Relevance to other diseases and the latest concepts of prognosis are beyond the scope of our review. The productive opinion of Jeong et al. is also acceptable, and we hope that more evidence will be accumulated and new findings will be revealed throughout active investigations.

FOOTNOTES

Authors’ contribution

All authors contributed to the article conception and design, material preparation. The first draft of the manuscript was written by Seul Ki Han and Moon Young Kim. All authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Conflicts of Interest

The authors have no conflicts to disclose.

Table 1.

Published papers suggesting the correlation between NAFLD and dementia

Table 1.

Author Title Year
Shang et al. [3] Nonalcoholic fatty liver disease and risk of dementia: A population-based cohort study 2022
Elliott et al. [4] Functional impairment in alcoholic liver disease and non-alcoholic fatty liver disease is significant and persists over 3 years of follow-up 2013
Doward et al. [5] Development of a patient-reported outcome measure for non-alcoholic steatohepatitis (NASH-CHECK): Results of a qualitative study 2020
Kim et al. [6] Association between non-alcoholic fatty liver disease and the risk of dementia: A nationwide cohort study 2022
Jeong et al. [7] Association of non-alcoholic fatty liver disease with incident dementia later in life among elder adults 2022

Table 2.

Published papers that do not suggest a correlation between NAFLD and dementia

Table 2.

Author Title Year
Gerber et al. [8] Non-alcoholic fatty liver disease and cognitive function in middle-aged adults: the CARDIA study 2021
Labenz et al. [9] Incident dementia in elderly patients with nonalcoholic fatty liver disease in Germany 2021
Shang et al. [10] Non-alcoholic fatty liver disease does not increase dementia risk although histology data might improve risk prediction 2020
Ye [11] Association of nonalcoholic fatty liver disease with incident dementia later in life among elderly adults 2022

Abbreviations

NAFLD

non-alcoholic fatty liver disease

REFERENCES

Figure & Data

References

Citations

Citations to this article as recorded by Crossref logo

Download Citation

Download a citation file in RIS format that can be imported by all major citation management software, including EndNote, ProCite, RefWorks, and Reference Manager.

Format:

Include:

Correspondence on Letter regarding “Non-alcoholic fatty liver disease: Definition and subtypes”

Clin Mol Hepatol. 2023;29(3):817-819. Published online May 17, 2023

Correspondence on Letter regarding “Non-alcoholic fatty liver disease: Definition and subtypes”

Correspondence on Letter regarding “Non-alcoholic fatty liver disease: Definition and subtypes”

Author Title Year
Shang et al. [3] Nonalcoholic fatty liver disease and risk of dementia: A population-based cohort study 2022
Elliott et al. [4] Functional impairment in alcoholic liver disease and non-alcoholic fatty liver disease is significant and persists over 3 years of follow-up 2013
Doward et al. [5] Development of a patient-reported outcome measure for non-alcoholic steatohepatitis (NASH-CHECK): Results of a qualitative study 2020
Kim et al. [6] Association between non-alcoholic fatty liver disease and the risk of dementia: A nationwide cohort study 2022
Jeong et al. [7] Association of non-alcoholic fatty liver disease with incident dementia later in life among elder adults 2022
Author Title Year
Gerber et al. [8] Non-alcoholic fatty liver disease and cognitive function in middle-aged adults: the CARDIA study 2021
Labenz et al. [9] Incident dementia in elderly patients with nonalcoholic fatty liver disease in Germany 2021
Shang et al. [10] Non-alcoholic fatty liver disease does not increase dementia risk although histology data might improve risk prediction 2020
Ye [11] Association of nonalcoholic fatty liver disease with incident dementia later in life among elderly adults 2022

Table 1. Published papers suggesting the correlation between NAFLD and dementia

NAFLD, non-alcoholic fatty liver disease.

Table 2. Published papers that do not suggest a correlation between NAFLD and dementia

NAFLD, non-alcoholic fatty liver disease.

Table 1.

Table 2.