A multi-omics approach to overeating and inactivity-induced muscle atrophy in db/db mice.

BACKGROUND: Overeating and inactivity are associated with type 2 diabetes. This study aimed to investigate its pathological basis using integrated omics and db/db/mice, a model representing this condition. METHODS: The study involved housing 8-week-old db/m and db/db mice for 8 weeks. Various analyses were conducted, including gene expression in skeletal muscle and small intestine using next-generation sequencing; cytokine arrays of serum; assessment of metabolites in skeletal muscle, stool, and serum; and analysis of the gut microbiota. Histone modifications in small intestinal epithelial cells were profiled using CUT&Tag. RESULTS: Compared with db/m mice, db/db mice had 22.4% lower grip strength and approximately five times the visceral fat weight (P < 0.0001). Serum cytokine arrays showed a 2.8-fold relative concentration of VEGF-A in db/db mice (P < 0.0001) and lower concentrations of several other cytokines. mRNA sequencing revealed downregulation of Myh expression in skeletal muscle, upregulation of lipid and glucose transporters, and downregulation of amino acid transporters in the small intestine of db/db/mice. The concentrations of saturated fatty acids in skeletal muscle were significantly higher, and the levels of essential amino acids were lower in db/db mice. Analysis of the gut microbiota, 16S rRNA sequencing, revealed lower levels of the phylum Bacteroidetes (59.7% vs. 44.9%) and higher levels of the phylum Firmicutes (20.9% vs. 31.4%) in db/db mice (P = 0.003). The integrated signal of histone modifications of lipid and glucose transporters was higher, while the integrated signal of histone modifications of amino acid transporters was lower in the db/db mice. CONCLUSIONS: The multi-omics approach provided insights into the epigenomic alterations in the small intestine, suggesting their involvement in the pathogenesis of inactivity-induced muscle atrophy in obese mice.

Association of Elevated Serum Branched-chain Amino Acid Levels With Longitudinal Skeletal Muscle Loss.

Context: Branched-chain amino acids (BCAA) are substrates for protein synthesis. Although their intake may contribute to an increase in skeletal muscle mass, elevated serum BCAA levels have been reported to be associated with insulin resistance, potentially resulting in decreased skeletal muscle mass. Objective: This study aimed to explore the association between elevated serum BCAA levels and longitudinal skeletal muscle loss. Design and Setting: A cohort analysis was conducted, in which serum amino acids were analyzed in healthy individuals who underwent a medical health checkup at Kameoka Municipal Hospital (HOZUGAWA study), Japan. Patients: Seventy-one participants (37 men and 34 women) underwent follow-up checkups after the baseline visit. The follow-up duration was 1.2 ± .4 years. Main Outcome Measures: The relationship between fasting baseline serum BCAA levels and lifestyle factors, body composition, blood test results, dietary history, and changes in skeletal muscle mass was evaluated. Results: In both men and women, serum BCAA levels were positively correlated with body weight, body mass index, skeletal muscle mass index (SMI), and serum triglycerides but inversely correlated with serum high-density lipoprotein cholesterol. In men, fasting serum BCAA levels were inversely associated with the rate of change in SMI (adjusted ß = -.529, P = .006), and elevated BCAA levels were independently associated with a longitudinal decrease in skeletal muscle mass (odds ratio: 1.740; 95% confidence interval: 1.023-2.960 per 50 nmol/mL serum BCAAs increase). Conclusion: Increased circulating BCAAs could be an indicator of skeletal muscle loss in men.

Changes in glycemic control and skeletal muscle mass indices after dapagliflozin treatment in individuals with type 1 diabetes mellitus.

AIMS/INTRODUCTION: Dapagliflozin is used for individuals with type 1 diabetes, although the effect of this medication on skeletal muscle mass is not well established. In addition, there are few studies examining the effects of good glycemic control on skeletal muscle mass in type 1 diabetes patients. We investigated changes in glycemic control and skeletal muscle mass with dapagliflozin in individuals with type 1 diabetes, and the association between these changes. MATERIALS AND METHODS: This was a post-hoc analysis of a multicenter, open-label, non-randomized, prospective, interventional study in individuals with type 1 diabetes. The participants received dapagliflozin at 5 mg/day for 4 weeks, and were reviewed before and after treatment. Weight- and height-corrected appendicular skeletal muscle mass (ASM) were calculated as indices of skeletal muscle mass using bioelectrical impedance analysis. RESULTS: A total of 36 individuals were included in the analysis. After the 4 weeks of dapagliflozin treatment, ASM/height2 decreased in the body mass index <23 group (P = 0.004). ASM / weight decreased in all men aged >60 years. The change in ASM / weight (%) was negatively correlated with the change in glycated hemoglobin (%;P = 0.023). The change in ASM / height2 (kg/m2 ) was also positively correlated with the change in time within the glucose range of 70-180 mg/dL (P = 0.036). CONCLUSION: Dapagliflozin treatment of individuals with type 1 diabetes, particularly non-obese individuals and older men, might result in loss of skeletal muscle mass. However, good glycemic control during treatment might prevent the onset and progression of sarcopenia.

Gut Microbiota Changes by an SGLT2 Inhibitor, Luseogliflozin, Alters Metabolites Compared with Those in a Low Carbohydrate Diet in db/db Mice.

In recent years, sarcopenic obesity has been considered central pathological factors in diabetes. This study aimed to compare the effect of luseogliflozin, a sodium-glucose co-transporter-2 inhibitor (SGLT2i), on sarcopenic obesity in comparison to that of a low-carbohydrate diet (LCD). Twenty-week-old male db/db mice were fed a normal diet (Ctrl), LCD, and normal diet with 0.01% w/w luseogliflozin (SGLT2i) for eight weeks. Skeletal muscle mass and grip strength decreased in the LCD group mice compared to those in the control group, while they increased in the SGLT2i group mice. The amino acid content in the liver, skeletal muscle, and serum were lower in the LCD group than those in the Ctrl group but increased in the SGLT2i group mice. Short-chain fatty acids in rectal feces were lower in the LCD group mice than those in the Ctrl group, whereas they were higher in the SGLT2i group mice. The abundance of Gammaproteobacteria, Enterobacteriaceae, Escherichia, Enterobacterales, and Bacteroides caccae species increased in the LCD group compared to the other two groups, whereas the abundance of Syntrophothermus lipocalidus, Syntrophomonadaceae family, Parabacteroidesdistasonis distasonis, and the genus Anaerotignum increased in the SGLT2i group. Luseogliflozin could prevent sarcopenic obesity by improving amino acid metabolism.

Inulin reduces visceral adipose tissue mass and improves glucose tolerance through altering gut metabolites.

AIM: Inulin, a soluble dietary fiber, is a source of energy for the host while the metabolites, such as short-chain fatty acids (SCFAs), produced in the gut through bacterial fermentation exerts the anti-obesity effect. In this study, we aimed to apply a metabolomics approach and clarify the role of this soluble dietary fiber on glucose and lipid metabolism under the calorie-matched condition. MATERIALS AND METHODS: Eight-week-old male C57BL/6J mice were fed a high-fat/high-sucrose based diet containing maltodextrin or inulin for 12 weeks through calorie-matched pair feeding. We evaluated glucose tolerance, and energy expenditure using indirect calorimetry, comprehensive metabolites in the content of jejunum, feces, and portal vein serum using gas chromatography-mass spectrometry, and histological changes in the adipose tissue. RESULTS: The inulin group exhibited reduced visceral adipose tissue and smaller size of visceral adipocyte. It also exhibited improved glucose tolerance and an increase in energy expenditure. Reflecting the results of fermentation, the metabolomics analysis revealed an increase in the succinic acid and SCFA contents in both feces and portal vein serum in the inulin group. CONCLUSIONS: Inulin altered the gut metabolites and reduced visceral adipose tissue, thereby resulting in improved glucose tolerance.

Effect of matcha consumption on gut microbiota in healthy Japanese individuals: study protocol for a double-blind crossover interventional study.

This study compares and clarifies the changes in intestinal flora resulting from the continuous consumption of two types of matcha. Healthy adults will consume two types of matcha tea for four weeks, and differences in the intestinal microflora before and after drinking will be compared. Gut microbiota will be identified using next-generation sequencing. Phylogenetic classification of the enterobacteria will be performed based on sequence similarities. The relative proportions of the classified enterobacteria to the total nucleotide sequences will be compared between the samples obtained from the two groups consuming different matcha. The continuous consumption of matcha may improve dysbiosis and prevent atherosclerosis. The effects may vary according to the type of matcha used. Trial registration: The study was registered with university hospital medical information network (UMIN) (UMIN000040303), and all participants gave their written informed consent. Registered 1 November 2020, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000045982.

Effects of probiotic Bifidobacterium bifidum G9-1 on the gastrointestinal symptoms of patients with type 2 diabetes mellitus treated with metformin: An open-label, single-arm, exploratory research trial.

AIMS/INTRODUCTION: Metformin is associated with the risk of gastrointestinal complications, and probiotic Bifidobacterium bifidum G9-1 (BBG9-1) can improve the symptoms of diarrhea. This study aimed to clarify the effects of probiotic BBG9-1 on the gastrointestinal symptoms of type 2 diabetes mellitus patients using metformin. MATERIALS AND METHODS: In this open-label single-arm exploratory study, 40 patients (mean age 64.0 ± 9.4 years) were given probiotic BBG9-1 for 10 weeks. Changes in the gastrointestinal symptom rating scale total score, which was the primary end-point, gastrointestinal symptom rating scale subscale scores, glycated hemoglobin levels and gut microbiota after the administration of probiotic BBG9-1 were evaluated by the Student's t-test. RESULTS: The gastrointestinal symptom rating scale total score significantly improved (from 2.02 ± 0.51 to 1.59 ± 0.43, change, -0.43 ± 0.49, P < 0.001). Furthermore, all gastrointestinal symptom rating scale subscale scores, including diarrhea (from 2.32 ± 1.14 to 1.89 ± 0.99, change, -0.42 ± 0.95, P = 0.007) and constipation (from 3.00 ± 1.16 to 2.20 ± 1.07, change, -0.80 ± 1.19, P < 0.001), scores also significantly improved. However, the glycated hemoglobin levels did not change (from 7.0 ± 0.7 to 7.0 ± 0.6%, change, 0.0 ± 0.4, P = 0.91). The relative abundance of the genus Sutterella decreased by the use of probiotic BBG9-1 (from 0.011 ± 0.009 to 0.008 ± 0.006, change, -0.003 ± 0.006, P = 0.002). CONCLUSIONS: Type 2 diabetes mellitus patients treated with metformin showed significant improvement in all gastrointestinal symptom rating scores after using probiotic BBG9-1 without changing the glucose control. This study showed the potential usefulness of probiotic BBG9-1 for improving gastrointestinal symptoms, including constipation and diarrhea, in type 2 diabetes mellitus patients treated with metformin.

Correlation between Liver Stiffness by Two-Dimensional Shear Wave Elastography and Waist Circumference in Japanese Local Citizens with Abdominal Obesity.

BACKGROUND: Various factors other than fibrosis could affect liver stiffness (LS), measured by two-dimensional shear wave elastography (2D-SWE). We aimed to clarify the factors affecting LS in local citizens. METHODS: We performed a cross-sectional study among local citizens of a health checkup program. Abdominal obesity was defined as waist circumference ≥85 cm for men and ≥90 cm for women. We evaluated the correlation between LS by 2D-SWE (Aplio 500) and waist circumference with linear regression analyses. We selected the following items as variables in the multivariate analysis: waist circumference, sex, hypertension, diabetes, diagnostic components of metabolic syndrome, γ-glutamyl transpeptidase, total bilirubin, NAFLD fibrosis score, and an indicator of a fatty liver, evaluated ultrasonographically. RESULTS: Overall, 345 individuals were included; 318 (181 men and 137 women; age, 63.4 years; waist circumference, 84.0 cm; LS, 5.79 kPa) were analyzed, 128 of whom had abdominal obesity and significantly higher LS than non-abdominally obese individuals. In the multivariate analysis, waist circumference was positively, independently, and significantly correlated with LS only in abdominally obese individuals. CONCLUSIONS: Liver stiffness by 2D-SWE could increase with increases in waist circumference in local citizens with abdominal obesity. Physicians should pay attention when assessing the LS of abdominally obese individuals.

Effect of probiotics, Bifidobacterium bifidum G9-1, on gastrointestinal symptoms in patients with type 2 diabetes mellitus: study protocol for open-label, single-arm, exploratory research trial (Big STAR study).

Metformin is associated with risks of gastrointestinal complications in patients with type 2 diabetes. In contrast, probiotic Bifidobacterium bifidum G9-1 (BBG9-1) could improve the symptoms of diarrhea caused by metformin in animal models. Thus, the primary outcome of this study will be the effect of the probiotic BBG9-1 on gastrointestinal symptoms, including diarrhea, in patients with type 2 diabetes who use metformin. This open-label, single-arm, and exploratory study will examine 40 patients with type 2 diabetes who use metformin and have symptoms of constipation or diarrhea. After the baseline examination (objective 1), patients will be administered probiotic BBG9-1 for 10 ± 2 weeks. Then, examinations will be performed (objective 2). The primary outcome will be changes in the symptoms of constipation or diarrhea from objective 1 to objective 2. Secondary outcomes will include changes in gut microbiota, and correlations between changes in fecal properties and biomarkers, including HbA1c level and body mass index. This is the first study to investigate the effect of probiotic BBG9-1 on the change in the symptom of constipation or diarrhea in patients with type 2 diabetes who use metformin.

Acute Bromide Intoxication in a Patient with Preserved Renal Function.

BACKGROUND Electrolyte imbalance is frequent in many situations, but severe hyperchloremia is markedly rare in the absence of renal impairment. We report a patient with preserved renal function who exhibited severe hyperchloremia and negative anion gap. CASE REPORT A 70-year-old female with preserved renal function presented with fatigue and impaired consciousness. Venous blood gas analysis was notable for a chloride level of 137 mEq/L and anion gap of -18.2 mEq/L. Careful history taking revealed that she had taken bromide-containing over-the-counter painkillers. Her symptoms and laboratory tests gradually improved after intravenous hydration and painkiller withdrawal. The serum level of bromide ions on admission was later found to be 4-times higher than that considered toxic. CONCLUSIONS It is important to recognize that hyperchloremia with a negative anion gap strongly suggests bromide intoxication, and that bromide intoxication can develop even in patients with preserved renal function. Careful history taking is essential to the diagnosis because some over-the-counter drugs that are widely available and a few prescription drugs contain bromides.

Association between Body Weight Gain from 20 Years of Age and Diabetic Nephropathy in Japanese Patients with Type 2 Diabetes.

BACKGROUND/AIMS: It has been reported that the body mass index shows a U-shaped association with death from cardiovascular disease (CVD) in the Asian population. The relationship between body weight (BW) gain from early adulthood and diabetic nephropathy remains to be elucidated in Japanese patients with type 2 diabetes. Our aim was to investigate the association between BW gain from early adulthood and diabetic nephropathy in Japanese patients with type 2 diabetes. METHODS: We assessed the BW of 471 consecutive patients with type 2 diabetes and calculated the change in BW from the age of 20 years to the lifetime maximum (ΔBWmax-20y). We then evaluated the relationship of ΔBWmax-20y with the degree of urinary albumin excretion (UAE), which is a useful marker for CVD. RESULTS: ΔBWmax-20y negatively correlated with the logarithm of UAE (r = -0.160, p = 0.002). Multiple regression analysis demonstrated that ΔBWmax-20y was independently correlated with the logarithm of UAE (ß =-0.112, p =0.034). CONCLUSIONS: BW gain from the age of 20 years is correlated with diabetic nephropathy in Japanese patients with type 2 diabetes.