State-of-the-Art Overview of the Pharmacological Treatment of Non-Alcoholic Steatohepatitis

Insulin Resistance, Non-Alcoholic Fatty Liver Disease and Type 2 Diabetes Mellitus: Clinical and Experimental Perspective

It has been generally accepted that insulin resistance (IR) and reduced insulin secretory capacity are the basic pathogenesis of type 2 diabetes mellitus (T2DM). In addition to genetic factors, the persistence of systemic inflammation caused by obesity and the associated threat of lipotoxicity increase the risk of T2DM. In particular, the main cause of IR is obesity and subjects with T2DM have a higher body mass index (BMI) than normal subjects according to recent studies. The prevalence of T2DM with IR has increased with increasing BMI during the past three decades. According to recent studies, homeostatic model assessment of IR was increased compared to that of the 1990s. Rising prevalence of obesity in Korea have contributed to the development of IR, non-alcoholic fatty liver disease and T2DM and cutting this vicious cycle is important. My colleagues and I have investigated this pathogenic mechanism on this theme through clinical and experimental studies over 20 years and herein, I would like to summarize some of our studies with deep gratitude for receiving the prestigious 2023 Sulwon Award.

Association of non-alcoholic fatty liver disease with cardiovascular disease and all cause death in patients with type 2 diabetes mellitus: nationwide population based study

OBJECTIVE

To investigate the risk of non-alcoholic fatty liver disease (NAFLD) for cardiovascular disease and all cause death in patients with type 2 diabetes mellitus (T2DM).

DESIGN

Nationwide population based study.

SETTING

Longitudinal cohort study in Korea.

PARTICIPANTS

7 796 763 participants in the National Health Screening Programme in 2009 were divided into three groups based on NAFLD status: no NAFLD (fatty liver index<30); grade 1 NAFLD (30≤fatty liver index<60); and grade 2 NAFLD (fatty liver index≥60). Median follow-up was 8.13 years.

MAIN OUTCOME MEASURES

The primary outcome was incident cardiovascular disease (myocardial infarction, ischaemic stroke) or all cause death.

RESULTS

Of 7 796 763 participants, 6.49% (n=505 763) had T2DM. More patients with T2DM had grade 1 NAFLD (34.06%) and grade 2 NAFLD (26.73%) than those without T2DM (grade 1 NAFLD: 21.20%; grade 2 NAFLD: 10.02%). The incidence rate (per 1000 person years) of cardiovascular disease and all cause death increased in the order of no NAFLD, grade 1 NAFLD, and grade 2 NAFLD, and the incidence rates in patients with T2DM were higher than those in patients without T2DM. The five year absolute risk for cardiovascular disease and all cause death increased in the order of no NAFLD, grade 1 NAFLD, and grade 2 NAFLD in patients without and with T2DM (no NAFLD, without T2DM: 1.03, 95% confidence interval 1.02 to 1.04, and 1.25, 1.24 to 1.26, respectively; grade 1 NAFLD, without T2DM: 1.23, 1.22 to 1.25, and 1.50, 1.48 to 1.51, respectively; grade 2 NAFLD, without T2DM: 1.42, 1.40 to 1.45, and 2.09, 2.06 to 2.12, respectively; no NAFLD, with T2DM: 3.34, 3.27 to 3.41, and 3.68, 3.61 to 3.74, respectively; grade 1 NAFLD, with T2DM: 3.94, 3.87 to 4.02, and 4.25, 4.18 to 4.33, respectively; grade 2 NAFLD, with T2DM: 4.66, 4.54 to 4.78, and 5.91, 5.78 to 6.05, respectively). Patients with T2DM and without NAFLD had a higher five year absolute risk for cardiovascular disease and all cause death than those without T2DM and with grade 2 NAFLD. Risk differences for cardiovascular disease and all cause death between no NAFLD and grade 1 or grade 2 NAFLD were higher in patients with T2DM than in those without T2DM.

CONCLUSIONS

NAFLD in patients with T2DM seems to be associated with a higher risk of cardiovascular disease and all cause death, even in patients with mild NAFLD. Risk differences for cardiovascular disease and all cause death between the no NAFLD group and the grade 1 or grade 2 NAFLD groups were higher in patients with T2DM than in those without T2DM.

Mitochondrial Quality Control: Its Role in Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD)

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease, is characterized by hepatic steatosis and metabolic dysfunction and is often associated with obesity and insulin resistance. Recent research indicates a rapid escalation in MASLD cases, with projections suggesting a doubling in the United States by 2030. This review focuses on the central role of mitochondria in the pathogenesis of MASLD and explores potential therapeutic interventions. Mitochondria are dynamic organelles that orchestrate hepatic energy production and metabolism and are critically involved in MASLD. Dysfunctional mitochondria contribute to lipid accumulation, inflammation, and liver fibrosis. Genetic associations further underscore the relationship between mitochondrial dynamics and MASLD susceptibility. Although U.S. Food and Drug Administration-approved treatments for MASLD remain elusive, ongoing clinical trials have highlighted promising strategies that target mitochondrial dysfunction, including vitamin E, metformin, and glucagon-like peptide-1 receptor agonists. In preclinical studies, novel therapeutics, including nicotinamide adenine dinucleotide+ precursors, urolithin A, spermidine, and mitoquinone, have shown beneficial effects, such as improving mitochondrial quality control, reducing oxidative stress, and ameliorating hepatic steatosis and inflammation. In conclusion, mitochondrial dysfunction is central to MASLD pathogenesis. The innovative mitochondria-targeted approaches discussed in this review offer a promising avenue for reducing the burden of MASLD and improving global quality of life.

Sodium-glucose cotransporter 2 inhibitors for non-alcoholic fatty liver disease in patients with type 2 diabetes mellitus: A nationwide propensity-score matched cohort study

AIMS

This study was to determine the association between sodium-glucose cotransporter 2 inhibitors (SGLT2i) and nonalcoholic fatty liver disease (NAFLD) in type 2 diabetes.

METHODS

We used data from the Korean National Health Insurance Service from 2014 to 2017. New drug users were screened, dipeptidyl peptidase 4 inhibitors (DPP4i) were set as the active comparator, and the differences between the two groups were corrected through propensity score matching. NAFLD was evaluated by the fatty liver index (FLI), which was calculated using body mass index, waist circumference, triglycerides, and gamma glutamyl peptidase.

RESULTS

After 1:1 matching, 25,371 patients in each group who received medication for an average of 299 days were analyzed. Despite similar baseline FLI of each group, the FLI of the SGLT2i users was 44.4 ± 26.7 and the FLI of the DPP4i users was 48.9 ± 27.3 (P value < 0.001) after treatment. SGLT2i showed more significant decrements than DPP4i in all components of FLI. The more the adherence to the SGLT2i increased, the greater the decrease in FLI.

CONCLUSIONS

SGLT2i showed a significant reduction in FLI and its components. We suggest that SGLT2i may have beneficial effects in reducing the prevalence of NAFLD in type 2 diabetes.