Insulin resistance in adipose tissue and metabolic diseases

Interaction between trouble sleeping and diabetes on metabolic dysfunction-associated fatty liver disease and liver fibrosis in adults results from the National Health and Nutrition Examination Survey 2017-2018

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD), trouble sleeping, and diabetes, as major public health problems, were closely related. The study examined the interaction between trouble sleeping and diabetes on MAFLD and liver fibrosis in adults with MAFLD.

METHODS

The data were obtained from the National Health and Nutrition Examination Survey 2017-2018. Multivariate logistic regression model and subgroup analyses were conducted to assess the relationship between either trouble sleeping or diabetes on MAFLD and liver fibrosis. Relative excess risk due to interaction (RERI), attributable proportion of interaction (AP), and synergy index (S) were utilized to assess the additive interaction.

RESULTS

Ultimately, 3747 participants were included, with 2229 known MAFLD subjects. Compared with participants without diabetes, those with diabetes had a higher risk of MAFLD [odds ratio (OR) = 5.55; 95% confidence interval (CI) = 4.07-7.56] and liver fibrosis risk (OR = 3.61; 95% CI = 2.67-4.89). We also found a significant association of trouble sleeping with an increased risk of MAFLD (OR = 1.54; 95% CI = 1.17-2.02) and liver fibrosis risk (OR = 1.51; 95% CI = 1.06-2.16), compared with those without trouble sleeping. Moreover, there was a significant interaction between diabetes and trouble sleeping on MAFLD [RERI = 1.76 (95% CI: -0.22 to 3.73), AP = 0.35 (95% CI: 0.08-0.63), S = 1.80 (95% CI: 1.02-3.16)] and liver fibrosis risk [RERI = 1.79 (95% CI: 0.37-3.21), AP = 0.44 (95% CI: 0.20-0.69), S = 2.44 (95% CI: 1.18-5.08)].

CONCLUSION

The findings highlight that trouble sleeping and diabetes had a synergistic effect on MAFLD and liver cirrhosis. The study highlights the importance of addressing both trouble sleeping and diabetes management in adults to mitigate the risk of MAFLD and liver fibrosis.

Clinical care guidance in patients with diabetes and metabolic dysfunction-associated steatotic liver disease: A joint consensus

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease worldwide, affecting >30% of the global population. Metabolic dysregulation, particularly insulin resistance and its subsequent manifestation as type 2 diabetes mellitus, serves as the fundamental pathogenesis of metabolic liver disease. Clinical evidence of the recent nomenclature evolution is accumulating. The interaction and impacts are bidirectional between MASLD and diabetes in terms of disease course, risk, and prognosis. Therefore, there is an urgent need to highlight the multifaceted links between MASLD and diabetes for both hepatologists and diabetologists. The surveillance strategy, risk stratification of management, and current therapeutic achievements of metabolic liver disease remain the major pillars in a clinical care setting. Therefore, the Taiwan Association for the Study of the Liver (TASL), Taiwanese Association of Diabetes Educators, and Diabetes Association of the Republic of China (Taiwan) collaboratively completed the first guidance in patients with diabetes and MASLD, which provides practical recommendations for patient care.

Metabolic-Associated Fatty Liver Disease: The Influence of Oxidative Stress, Inflammation, Mitochondrial Dysfunctions, and the Role of Polyphenols

Metabolic-Associated Fatty Liver Disease (MAFLD) is a clinical-pathological scenario that occurs due to the accumulation of triglycerides in hepatocytes which is considered a significant cause of liver conditions and contributes to an increased risk of death worldwide. Even though the possible causes of MAFLD can involve the interaction of genetics, hormones, and nutrition, lifestyle (diet and sedentary lifestyle) is the most influential factor in developing this condition. Polyphenols comprise many natural chemical compounds that can be helpful in managing metabolic diseases. Therefore, the aim of this review was to investigate the impact of oxidative stress, inflammation, mitochondrial dysfunction, and the role of polyphenols in managing MAFLD. Some polyphenols can reverse part of the liver damage related to inflammation, oxidative stress, or mitochondrial dysfunction, and among them are anthocyanin, baicalin, catechin, curcumin, chlorogenic acid, didymin, epigallocatechin-3-gallate, luteolin, mangiferin, puerarin, punicalagin, resveratrol, and silymarin. These compounds have actions in reducing plasma liver enzymes, body mass index, waist circumference, adipose visceral indices, lipids, glycated hemoglobin, insulin resistance, and the HOMA index. They also reduce nuclear factor-KB (NF-KB), interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), blood pressure, liver fat content, steatosis index, and fibrosis. On the other hand, they can improve HDL-c, adiponectin levels, and fibrogenesis markers. These results show that polyphenols are promising in the prevention and treatment of MAFLD.

Metabolic dysfunction-associated steatotic liver disease and diabetes: the cross-talk between hepatologist and diabetologist

INTRODUCTION

Metabolic dysfunction-associated steatotic liver disease (MASLD) and type 2 diabetes mellitus (DM) are the most prevalent metabolic disorders globally. The numbers affected in both disorders are also rapidly increasing with alarming trends in children and young adults.

AREAS COVERED

Insulin resistance (IR) and the subsequent metabolic dysregulation are the fundamental pathogenesis pathways of the prevalent metabolic disorders. The interaction and impacts are bidirectional between MASLD and DM in terms of disease mechanisms, disease course, risks, and prognosis. There's a pressing issue for highlighting the links between MASLD and DM for both care specialists and primary care providers. The review collected the scientific evidence addressing the mutual interactions between the two disorders. The strategies for surveillance, risk stratification, and management are discussed in a practical manner. It also provides individualized viewpoints of patient care in hepatology and diabetology.

EXPERT OPINION

Both MASLD and DM shared similar disease mechanisms, and affected the disease development and progression in a bidirectional manner. The high prevalence and the cross-link between the two disorders raise clinical issues from awareness, screening, risk stratification, optimal referral, to appropriate management for primary care providers.

Thrombospondin-1 promotes liver fibrosis by enhancing TGF-β action in hepatic stellate cells

Insulin resistance in adipose tissue is thought to be a key contributor to the pathogenesis of various metabolic disorders including metabolic dysfunction-associated steatotic liver disease/metabolic dysfunction-associated steatohepatitis (MASLD/MASH), but the mechanism underlying this contribution to MASLD/MASH has remained unknown. We previously showed that dysregulation of the PDK1-FoxO1 signaling axis in adipocytes plays a role in the development of MASLD/MASH by analysis of adipocyte-specific PDK1 knockout (A-PDK1KO) and adipocyte-specific PDK1/FoxO1 double-knockout (A-PDK1/FoxO1DKO) mice. We here focused on the role of the extracellular matrix protein thrombospondin-1 (TSP-1) as a secreted factor whose expression in adipose tissue is increased in A-PDK1KO mice and normalized in A-PDK1/FoxO1DKO mice. Genetic ablation of TSP-1 markedly ameliorated liver fibrosis in A-PDK1KO mice fed a high-fat diet. With regard to the potential mechanism of this effect, TSP-1 augmented the expression of fibrosis-related genes induced by TGF-β in LX-2 human hepatic stellate cells. We also showed that TSP-1 expression and secretion were negatively regulated by insulin signaling via the PDK1-FoxO1 axis in cultured adipocytes. Our results thus indicate that TSP-1 plays a key role in the pathogenesis of liver fibrosis in MASH. Regulation of TSP-1 expression by PDK1-FoxO1 axis in adipocytes may provide a basis for targeted therapy of hepatic fibrosis in individuals with MASH.

FoxO1 as a tissue-specific therapeutic target for type 2 diabetes

Forkhead box O (FoxO) proteins are transcription factors that mediate many aspects of physiology and thus have been targeted as therapeutics for several diseases including metabolic disorders such as type 2 diabetes mellitus (T2D). The role of FoxO1 in metabolism has been well studied, but recently FoxO1's potential for diabetes prevention and therapy has been debated. For example, studies have shown that increased FoxO1 activity in certain tissue types contributes to T2D pathology, symptoms, and comorbidities, yet in other tissue types elevated FoxO1 has been reported to alleviate symptoms associated with diabetes. Furthermore, studies have reported opposite effects of active FoxO1 in the same tissue type. For example, in the liver, FoxO1 contributes to T2D by increasing hepatic glucose production. However, FoxO1 has been shown to either increase or decrease hepatic lipogenesis as well as adipogenesis in white adipose tissue. In skeletal muscle, FoxO1 reduces glucose uptake and oxidation, promotes lipid uptake and oxidation, and increases muscle atrophy. While many studies show that FoxO1 lowers pancreatic insulin production and secretion, others show the opposite, especially in response to oxidative stress and inflammation. Elevated FoxO1 in the hypothalamus increases the risk of developing T2D. However, increased FoxO1 may mitigate Alzheimer's disease, a neurodegenerative disease strongly associated with T2D. Conversely, accumulating evidence implicates increased FoxO1 with Parkinson's disease pathogenesis. Here we review FoxO1's actions in T2D conditions in metabolic tissues that abundantly express FoxO1 and highlight some of the current studies targeting FoxO1 for T2D treatment.