Metabolic profiles and fibrosis of nonalcoholic fatty liver disease in the elderly: A community-based study

The Roles of Lipid Metabolism in the Pathogenesis of Chronic Diseases in the Elderly

Lipid metabolism plays crucial roles in cellular processes such as hormone synthesis, energy production, and fat storage. Older adults are at risk of the dysregulation of lipid metabolism, which is associated with progressive declines in the physiological function of various organs. With advancing age, digestion and absorption commonly change, thereby resulting in decreased nutrient uptake. However, in the elderly population, the accumulation of excess fat becomes more pronounced due to a decline in the body's capacity to utilize lipids effectively. This is characterized by enhanced adipocyte synthesis and reduced breakdown, along with diminished peripheral tissue utilization capacity. Excessive lipid accumulation in the body, which manifests as hyperlipidemia and accumulated visceral fat, is linked to several chronic lipid-related diseases, including cardiovascular disease, type 2 diabetes, obesity, and nonalcoholic fatty liver disease. This review provides a summary of the altered lipid metabolism during aging, including lipid digestion, absorption, anabolism, and catabolism, as well as their associations with age-related chronic diseases, which aids in developing nutritional interventions for older adults to prevent or alleviate age-related chronic diseases.

Coral calcium carried hydrogen ameliorates the severity of non-alcoholic steatohepatitis induced by a choline deficient high carbohydrate fat-free diet in elderly rats

Hydrogen has been reported to act as an antioxidant, anti-apoptosis and anti-inflammatory agent. Coral calcium carried hydrogen (G2-SUISO) is a safer and more convenient form of hydrogen agent than others. The mechanism underlying the hepatoprotective effects of G2-SUISO using an elderly non-alcoholic steatohepatitis (NASH) rat model was investigated. Two days after fasting, six-month-old elderly male F344/NSlc rats were given a choline deficient high carbohydrate fat-free (CDHCFF) diet from day 0 to day 3 as CDHCFF control group, and then switched to a normal diet from days 4 to 7 with or without 300 mg/kg G2-SUISO. Rats in each group were finally being sacrificed on day 3 or day 7. In the CDHCFF diet group, G2-SUISO decreased the liver weight-to-body weight ratio, the serum AST, ALT, total cholesterol levels, inflammatory infiltration, pro-inflammatory cytokine expression and lipid droplets with inhibiting lipogenic pathways by reducing sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase and fatty acid synthase gene expression compared with the CDHCFF diet alone. G2-SUISO had beneficial effects of anti-apoptosis as well the down-regulation of pro-apoptotic molecules including NF-κB, caspase-3, caspase-9 and Bax. These findings suggest that G2-SUISO treatment exerts a significant hepatoprotective effect against steatosis, inflammation and apoptosis in elderly NASH rats.

Biomarkers of aging

Aging biomarkers are a combination of biological parameters to (i) assess age-related changes, (ii) track the physiological aging process, and (iii) predict the transition into a pathological status. Although a broad spectrum of aging biomarkers has been developed, their potential uses and limitations remain poorly characterized. An immediate goal of biomarkers is to help us answer the following three fundamental questions in aging research: How old are we? Why do we get old? And how can we age slower? This review aims to address this need. Here, we summarize our current knowledge of biomarkers developed for cellular, organ, and organismal levels of aging, comprising six pillars: physiological characteristics, medical imaging, histological features, cellular alterations, molecular changes, and secretory factors. To fulfill all these requisites, we propose that aging biomarkers should qualify for being specific, systemic, and clinically relevant.

Clinical and Metabolic Characteristics of Hyperuricemia with Risk of Liver Fibrosis: A Cross-Sectional Study

The role of serum uric acid (SUA) in the role of advanced fibrosis is not fully explored. The study assesses the risk of advanced fibrosis according to SUA in an Asian population with a total of 3612 subjects enrolled in one health management center between 2006 and 2008. The fibrosis-4 score was used for the prediction of the high risk of advanced fibrosis. SUA scores higher than 7.6 mg/dL in men and 6.6 mg/dL in women were defined as hyperuricemia. A proportional odds model was used to assess cumulative risks of advanced fibrosis. The prevalence of high risk of advanced fibrosis was 2.5% in the hyperuricemia group and 0.6% in the normal SUA group (p < 0.001). After adjustment for confounding factors, the odds ratios (OR) for more severe advanced fibrosis were 1.37 (95% confidence interval [CI]: 1.07−1.78) in the hyperuricemia group. Hyperuricemia only increased the risk of advanced fibrosis in the non-T2DM group (OR, 1.29; 95% CI, 1.04 to 1.74) instead of T2DM group (OR, 1.85; 95% CI, 0.97 to 3.53). SUA is a risk factor for a higher risk of advanced fibrosis, with the disease likely progressing from a steatotic to a fibrotic picture. The focus should be more emphasized in non-T2DM groups.

Non-alcoholic Fatty Liver Disease and Liver Fibrosis during Aging

Non-alcoholic fatty liver disease (NAFLD) and its progressive form non-alcoholic steatohepatitis (NASH) have emerged as the leading causes of chronic liver disease-related mortality. The prevalence of NAFLD/NASH is expected to increase given the epidemics of obesity and type 2 diabetes mellitus. Older patients are disproportionally affected by NASH and related complications such as progressive fibrosis, cirrhosis and hepatocellular carcinoma; however, they are often ineligible for liver transplantation due to their frailty and comorbidities, and effective medical treatments are still lacking. In this review we focused on pathways that are key to the aging process in the liver and perpetuate NAFLD/NASH, leading to fibrosis. In addition, we highlighted recent findings and cross-talks of normal and/or senescent liver cells, dysregulated nutrient sensing, proteostasis and mitochondrial dysfunction in the framework of changing metabolic milieu. Better understanding these pathways during preclinical and clinical studies will be essential to design novel and specific therapeutic strategies to treat NASH in the elderly.

The Change in Metabolic Syndrome Status and the Risk of Nonviral Liver Cirrhosis

Background: Nonalcoholic fatty liver disease is considered to be the hepatic component of metabolic syndrome (MetS). However, the association between changes in MetS status and the risk of liver cirrhosis (LC) has not been investigated to date. This study assessed the association between changes in MetS and subsequent nonviral LC development. Methods: Data were obtained from the Korean National Health Insurance Service. Individuals who participated in health screenings from both 2009 to 2010 and 2011 to 2012 were included. The primary outcome was LC development according to the static and dynamic MetS status. Subjects were stratified into four groups according to the change in MetS status observed from the two-year interval screening (2009–2011). Cox regression analysis was used to examine the hazard ratios of LC. Results: During a median of 7.3 years of follow-up, 24,923 incident LC cases developed among 5,975,308 individuals. After adjusting for age, sex, smoking, alcohol, regular exercise, and body mass index, the adjusted hazard ratios (95% confidence intervals) for LC development were 1.39 (1.33–1.44) for the MetS-Developed group, 1.32 (1.26–1.37) for the MetS-Recovered group, and 1.51 (1.45–1.56) for the MetS-Sustained group, relative to the MetS-Free group. Stratified analyses according to age, sex, smoking, alcohol intake, exercise, diabetes mellitus, hypertension, dyslipidemia, and chronic kidney disease showed similar results. Conclusions: Both static and dynamic MetS status are independent risk factors for LC development. The risk of LC was the highest in people with sustained MetS and was lower in the MetS-Recovered group than in the MetS-Sustained group. These results suggest that improving a person’s MetS status may be helpful in preventing LC.

Metabolically healthy obesity and risk of non-alcoholic fatty liver disease severity independent of visceral fat

BACKGROUND AND AIM

Obesity and metabolic conditions may be related to non-alcoholic fatty liver disease (NAFLD). The study assesses the risk of NAFLD according to obesity and metabolic health status in a community-based population.

METHODS

A total of 1651 subjects were recruited from the community. Individuals were categorized into four groups according to obesity status (defined as a body mass index ≥ 25 kg/m² ) and metabolically healthy status: metabolically healthy nonobesity (MHNO), metabolically healthy obesity (MHO), metabolically unhealthy nonobesity (MUHNO), and metabolically unhealthy obesity (MUHO). NAFLD was diagnosed based on a semiquantitative ultrasonography measurement. Visceral fat was assessed through bioelectrical impedance analysis and is shown by tertile (T1, T2, and T3). A proportional odds model was used to assess the cumulative risk of NAFLD.

RESULTS

The NAFLD prevalence was 26.7%, 62.8%, 47.0%, and 76.7% in subjects with MHNO, MHO, MUHNO, and MUHO, respectively (P < 0.0001). After adjustment for age, sex, exercise habits, alcohol consumption, cigarette smoking, and visceral fat, the odds ratios for more severe NAFLD were 2.44 (95% confidence interval [CI]: 1.64-3.65), 2.75 (95% CI: 1.91-3.94), and 7.41 (95% CI: 4.94-11.12) in the MHO, MUHNO, and MUHO groups, respectively, compared with the MHNO group. In addition, the odds ratios for more severe NAFLD significantly increased with the increase in visceral fat level (T2 vs T1: 3.83, 95% CI: 2.65-5.53; T3 vs T1: 9.17, 95% CI: 5.33-15.79).

CONCLUSION

Both obesity and metabolically unhealthy status were associated with a higher risk of NAFLD independent of visceral fat level.

Association of Nonalcoholic Fatty Liver Disease (NAFLD) with Peripheral Diabetic Polyneuropathy: A Systematic Review and Meta-Analysis

Aims. The relationship between nonalcoholic fatty liver disease (NAFLD) and diabetic polyneuropathy (DPN) has been demonstrated in many studies, although results were conflicting. This meta-analysis aims to summarize available data and to estimate the DPN risk among NAFLD patients. Materials and methods. We performed a comprehensive literature review until 4 June 2021. Clinical trials analyzing the association between NAFLD and DPN were included. Results. Thirteen studies (9614 participants) were included. DPN prevalence was significantly higher in patients with NALFD, compared to patients without NAFLD (OR (95%CI) 2.48 (1.42–4.34), p = 0.001; I2 96%). This finding was confirmed in type 2 diabetes (OR (95%CI) 2.51 (1.33–4.74), p = 0.005; I2 97%), but not in type 1 diabetes (OR (95%CI) 2.44 (0.85–6.99), p = 0.100; I2 77%). Also, body mass index and diabetes duration were higher in NAFLD subjects compared to those without NAFLD (p < 0.001), considering both type 2 and type 1 diabetes. Conclusion. Despite a high heterogeneity among studies, a significantly increased DPN prevalence among type 2 diabetes subjects with NAFLD was observed. This result was not found in type 1 diabetes, probably due to the longer duration of disease. Physicians should pay more attention to the early detection of DPN, especially in patients with NAFLD.

The Association Between Different Obesity Phenotypes and Liver Fibrosis Scores in Elderly Individuals with Fatty Liver in Taiwan

PURPOSE

To examine the association between different phenotypes of obesity or metabolic syndromes and liver fibrosis score in a Taiwanese elderly population with fatty liver.

PATIENTS AND METHODS

This cross-sectional study included 1817 participants aged ≥65 years with fatty liver diagnosed by sonography. We used ethnicity-specific criteria for body mass index and metabolic syndrome, and to define obesity phenotypes as metabolically healthy non-obese (MHNO), metabolically unhealthy non-obese (MUNO), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO). Correlated fibrosis severity was calculated using the nonalcoholic fatty liver disease (NAFLD) fibrosis score (NFS) and Fibrosis-4 (FIB-4). Fibrosis severity was divided into two categories according to NFS (no-to-mild fibrosis and advanced fibrosis, defined as NFS ≤ 0.676 and >0.676, respectively) and FIB-4 score (no-to-mild fibrosis and advanced fibrosis, defined as FIB-4 score ≤2.67 and >2.67, respectively).

RESULTS

Compared with that in the MHNO group, the associated risk (odds ratio [OR], 95% confidence interval [CI]) of advanced fibrosis by NFS was 2.43 (1.50-3.93), 2.35 (1.25-4.41), and 6.11 (3.90-9.59), whereas that of advanced fibrosis by FIB-4 score was 1.34 (0.83-2.18), 2.37 (1.36-4.13), and 1.38 (0.82-2.31) in the MUNO, MHO, and MUO groups, respectively.

CONCLUSION

Both metabolic syndrome and obesity were positively associated with more advanced fibrosis according to NFS. The detrimental effect of obesity appears to be more than metabolic abnormalities per se in the elderly with more advanced fibrosis severity according to the FIB-4 score.