Physical Activity Modulating Lipid Metabolism in Gallbladder Diseases

[New Progress in Longitudinal Research on the Risk Factors for Cholelithiasis]

Cholelithiasis is a common disease of the digestive system. The risk factors for cholelithiasis have been reported and summarized many times in the published literature, which primarily focused on cross-sectional studies. Due to the inherent limitations of the study design, the reported findings still need to be validated in additional longitudinal studies. Moreover, a number of new risk factors for cholelithiasis have been identified in recent years, such as bariatric surgery, hepatitis B virus infection, hepatitis C virus infection, kidney stones, colectomy, osteoporosis, etc. These new findings have not yet been included in published reviews. Herein, we reviewed the 101 cholelithiasis-associated risk factors identified through research based on longitudinal investigations, including cohort studies, randomized controlled trials, and nested case control studies. The risk factors associated with the pathogenesis of cholelithiasis were categorized as unmodifiable and modifiable factors. The unmodifiable factors consist of age, sex, race, and family history, while the modifiable factors include 37 biological environmental factors, 25 socioenvironmental factors, and 35 physiochemical environmental factors. This study provides thorough and comprehensive ideas for research concerning the pathogenesis of cholelithiasis, supplying the basis for identifying high-risk groups and formulating relevant prevention strategies.

Ramadan intermittent fasting reduces visceral fat and improves gastrointestinal motility

BACKGROUND

Ramadan is a model of intermittent fasting linked with possible beneficial effects. Scarce information, however, is available about the combined effects of Ramadan intermittent fasting (RIF) on anthropometric and metabolic indices, gastrointestinal symptoms, and motility.

METHODS

In 21 healthy Muslims, we assessed the impact of RIF on caloric intake, physical activity, gastrointestinal symptoms and motility (gastric/gallbladder emptying by ultrasonography, orocaecal transit time by lactulose breath test), anthropometric indices, subcutaneous and visceral fat thickness (ultrasonography), glucose and lipid homeostasis.

RESULTS

Mean caloric intake decreased from a median of 2069 kcal (range 1677-2641) before Ramadan to 1798 kcal (1289-3126) during Ramadan and increased again to 2000 kcal (1309-3485) after Ramadan. Although physical activity remained stable before, during, and after RIF, body weight, body mass index and waist circumference decreased in all subjects and in both genders, together with a significant decrease in subcutaneous and visceral fat thickness and insulin resistance. The postprandial gastric emptying speed was significantly faster after than before RIF. Fasting gallbladder volume was about 6% smaller after, than before Ramadan, with a stronger and faster postprandial gallbladder contraction. After RIF, lactulose breath test documented increased microbiota carbohydrate fermentation (postprandial H2 peak), and faster orocaecal transit time. RIF also significantly improved gastric fullness, epigastric pain and heartburn.

CONCLUSIONS

RIF generates, in healthy subjects, multiple systemic beneficial effects in terms of fat burden, metabolic profile, gastrointestinal motility and symptoms. Further comprehensive studies should assess the potential beneficial effects of RIF in diseased people.

Multi-omics analysis explores the effect of chronic exercise on liver metabolic reprogramming in mice

Background: The effect of exercise on human metabolism is obvious. However, the effect of chronic exercise on liver metabolism in mice is less well described. Methods: The healthy adult mice running for 6 weeks as exercise model and sedentary mice as control were used to perform transcriptomic, proteomic, acetyl-proteomics, and metabolomics analysis. In addition, correlation analysis between transcriptome and proteome, and proteome and metabolome was conducted as well. Results: In total, 88 mRNAs and 25 proteins were differentially regulated by chronic exercise. In particular, two proteins (Cyp4a10 and Cyp4a14) showed consistent trends (upregulated) at transcription and protein levels. KEGG enrichment analysis indicated that Cyp4a10 and Cyp4a14 are mainly involved in fatty acid degradation, retinol metabolism, arachidonic acid metabolism and PPAR signaling pathway. For acetyl-proteomics analysis, 185 differentially acetylated proteins and 207 differentially acetylated sites were identified. Then, 693 metabolites in positive mode and 537 metabolites in negative mode were identified, which were involved in metabolic pathways such as fatty acid metabolism, citrate cycle and glycolysis/gluconeogenesis. Conclusion: Based on the results of transcriptomic, proteomics, acetyl-proteomics and metabolomics analysis, chronic moderate intensity exercise has certain effects on liver metabolism and protein synthesis in mice. Chronic moderate intensity exercise may participate in liver energy metabolism by influencing the expression of Cyp4a14, Cyp4a10, arachidonic acid and acetyl coenzyme A and regulating fatty acid degradation, arachidonic acid metabolism, fatty acyl metabolism and subsequent acetylation.

Increasing gallstone disease prevalence and associations with gallbladder and biliary tract mortality in the US

BACKGROUND AND AIMS

We examined gallbladder and biliary tract mortality predictors in the US National Health and Nutrition Examination Survey (NHANES), 1988-1994, with 31 years of linked mortality data, and gallstone disease prevalence trends and associations in NHANES 2017-March 2020 prepandemic data.

APPROACH AND RESULTS

In NHANES 1988-1994, 18,794 participants were passively followed for mortality, identified by death certificate underlying or contributing causes, by linkage to the National Death Index through 2019. In NHANES 2017-March 2020, gallstone disease history was ascertained from 9232 adults. During NHANES 1988-2019 follow-up (median, 23.3 y), 8580 deaths occurred from all causes and 72 deaths with gallbladder or biliary tract disease. In multivariable-adjusted analysis, older age, male sex, prediabetes or diabetes, and physical inactivity were associated with gallbladder and biliary tract mortality, and non-Hispanic Black and Mexican American race-ethnicity were inversely associated. Between 1988-1994 and 2017-March 2020, gallstone disease prevalence increased from 7.4% to 13.9% and gallbladder surgery from 6.0% to 11.6%. In 2017-March 2020 in multivariable-adjusted analysis, female sex, diabetes, liver disease, proton pump inhibitors, abdominal pain, increased age, BMI, and liver stiffness were associated with gallstone disease, and non-Hispanic Black and non-Hispanic Asian race and alcohol were inversely associated.

CONCLUSIONS

In the US population, gallstone disease prevalence doubled over 3 decades, possibly because of the worsening of metabolic risk factors and growth of laparoscopic cholecystectomy. Gallbladder and biliary tract mortality and gallstone disease associations included factors such as prediabetes or diabetes, liver stiffness and proton pump inhibitors.

Mitochondria Matter: Systemic Aspects of Nonalcoholic Fatty Liver Disease (NAFLD) and Diagnostic Assessment of Liver Function by Stable Isotope Dynamic Breath Tests

The liver plays a key role in systemic metabolic processes, which include detoxification, synthesis, storage, and export of carbohydrates, lipids, and proteins. The raising trends of obesity and metabolic disorders worldwide is often associated with the nonalcoholic fatty liver disease (NAFLD), which has become the most frequent type of chronic liver disorder with risk of progression to cirrhosis and hepatocellular carcinoma. Liver mitochondria play a key role in degrading the pathways of carbohydrates, proteins, lipids, and xenobiotics, and to provide energy for the body cells. The morphological and functional integrity of mitochondria guarantee the proper functioning of β-oxidation of free fatty acids and of the tricarboxylic acid cycle. Evaluation of the liver in clinical medicine needs to be accurate in NAFLD patients and includes history, physical exam, imaging, and laboratory assays. Evaluation of mitochondrial function in chronic liver disease and NAFLD is now possible by novel diagnostic tools. "Dynamic" liver function tests include the breath test (BT) based on the use of substrates marked with the non-radioactive, naturally occurring stable isotope 13C. Hepatocellular metabolization of the substrate will generate 13CO2, which is excreted in breath and measured by mass spectrometry or infrared spectroscopy. Breath levels of 13CO2 are biomarkers of specific metabolic processes occurring in the hepatocyte cytosol, microsomes, and mitochondria. 13C-BTs explore distinct chronic liver diseases including simple liver steatosis, non-alcoholic steatohepatitis, liver fibrosis, cirrhosis, hepatocellular carcinoma, drug, and alcohol effects. In NAFLD, 13C-BT use substrates such as α-ketoisocaproic acid, methionine, and octanoic acid to assess mitochondrial oxidation capacity which can be impaired at an early stage of disease. 13C-BTs represent an indirect, cost-effective, and easy method to evaluate dynamic liver function. Further applications are expected in clinical medicine. In this review, we discuss the involvement of liver mitochondria in the progression of NAFLD, together with the role of 13C-BT in assessing mitochondrial function and its potential use in the prevention and management of NAFLD.