Effect of Chronic Ethanol Consumption on Exogenous Glucose Metabolism in Rats Using [1-13C], [2-13C], and [3-13C]glucose Breath Tests.

The C3 carbon of glucose molecules becomes the C1 carbon of pyruvate molecules during glycolysis, and the C1 and C2 carbons of glucose molecules are metabolized in the tricarboxylic acid (TCA) cycle. Utilizing this position-dependent metabolism of C atoms in glucose molecules, [1-13C], [2-13C], and [3-13C]glucose breath tests are used to evaluate glucose metabolism. However, the effects of chronic ethanol consumption remain incompletely understood. Therefore, we evaluated glucose metabolism in ethanol-fed rats using [1-13C], [2-13C], and [3-13C]glucose breath tests. Ethanol-fed (ERs) and control rats (CRs) (n = 8 each) were used in this study, and ERs were prepared by replacing drinking water with a 16% ethanol solution. We administered 100 mg/kg of [1-13C], [2-13C], or [3-13C]glucose to rats and collected expired air (at 10-min intervals for 180 min). We compared the 13CO2 levels (Δ13CO2, ‰) of breath measured by IR isotope ratio spectrometry and area under the curve (AUC) values of the 13CO2 levels-time curve between ERs and CRs. 13CO2 levels and AUCs after administration of [1-13C]glucose and [2-13C]glucose were lower in ERs than in CRs. Conversely, the AUC for the [3-13C]glucose breath test showed no significant differences between ERs and CRs, although 13CO2 levels during the 110-120 min interval were significantly high in ERs. These findings indicate that chronic ethanol consumption diminishes glucose oxidation without concomitantly reducing glycolysis. Our study demonstrates the utility of 13C-labeled glucose breath tests as noninvasive and repeatable methods for evaluating glucose metabolism in various subjects, including those with alcoholism or diabetes.

Preparation of [1'-13 C]citric acid as a probe in a breath test to evaluate tricarboxylic acid cycle flux.

[1'-13 C]Citric acid (1) was efficiently prepared from dimethyl 1,3-acetonedicarboxylate in two steps as a probe for a breath test. The synthetic method was selected because of the yield and reproducibility. Compound 1 was orally administrated to rats, and the time course of the increase of 13 CO2 /12 CO2 ratios (Δ13 CO2 ) in their breath was successfully followed, indicating the metabolism of 1. Thus, the 13 C-breath test using 1 is a promising method to evaluate tricarboxylic acid (TCA) cycle flux.

Evaluation of the One-Hour ¹³C-Propionate Breath Test in 49 Patients from a Single Center in Japan to Detect Vitamin B12 Deficiency.

BACKGROUND Given the unavailability of reliable biomarkers for vitamin B12 (VB12) deficiency in clinical settings, the usefulness of the ¹³C-propionate breath test (PBT), utilizing VB12 as a coenzyme of methylmalonyl-CoA in propionate metabolism, as a diagnostic modality for VB12 deficiency has been studied. However, a collection time of 2 h reduces its convenience. Hence, we evaluated the effectiveness of 1-h PBT for detecting VB12 deficiency in 49 patients with suspected VB12 deficiency. MATERIAL AND METHODS We collected 100-200 mL breath gas every 10 min until 1 h after the administration of 1 g of ¹³C-propionate from 49 patients (31 men, 18 women; median age, 70 years) with clinically suspected VB12 deficiency and calculated the ¹³CO2 recovered in the breath per hour as the recovery rate (RR [%dose/h]) from ¹³CO2/¹²CO2 using infrared isotope spectrometry. We compared the RRs between groups: (1) with serum VB12 levels ≥145 pg/mL and <145 pg/mL, (2) with mean corpuscular volume ≤100 fL and >100 fL, and 3) pre- and post-VB12 supplementation. RESULTS The RRs peaked within 30 min. The RRs at 20 min (RR20) and 30 min (RR30) were significantly lower in macrocytotic patients (41.28 vs 50.07, p=0.026 and 37.82 vs 43.93, P=0.003). The RR30 was higher in the supplemented patients (41.93 vs 32.84, P=0.024). There was no significant difference in RRs between the patients with normal and low serum VB12 levels. CONCLUSIONS The 1-h PBT can be a diagnostic modality for VB12 deficiency because 1 h is a sufficient collection time.

Alteration of Breath Hydrogen and Methane in Ethanol-Fed Rats.

Chronic alcohol consumption can cause dysbiosis, but it is difficult to determine the effect of alcohol on the structure and activity of gastrointestinal tract microbiota. We therefore designed a noninvasive hydrogen breath test (HBT) to investigate the alteration in the chemical profile of gut microbiota in ethanol-fed rats. Thirteen F344/DuCri rats were fed on a commercial mash food with 16% ethanol solution drinking fluid from 4 weeks of age. HBTs were carried out on six 8-week-old and seven 24-week-old ethanol-fed rats. As controls, HBTs were carried out on sixteen 8-week-old, six 24-week-old, and five 48-week-old male rats. Six 24-week- old male rats were examined twice at 1-week intervals. HBTs were performed after fasting for 24 hr. Rats were orally administrated 4 mL/kg of 65% lactulose solution and housed in an animal chamber. The expired air was collected in a breath-sampling bag at 10-min intervals for 180 min. The hydrogen (H2) and methane (CH4) levels in the breath sample were measured using a breath analyzer and were expressed.as parts- per million (ppm). Elevated H2 and CH4 levels were more frequent in male rats. Maximal values of H2 and CH4 were highest in 8-week- old rats, followed by 48-week-old and 24-week-old rats. No ethanol-fed rat exhaled more than 2 ppm of H2 or CH4 until 180 min after the oral administration of lactulose, unlike the controls. This alteration was more obvious than that of aging or gender differentiation. We conclude that there is a close association between chronic ethanol consumption and H2 and CH4 production. An asymptomatic heavy drinker might have dysbiosis that involves gut microbiota with lower fermentation performance.

Role of infected grandmothers in transmission of Helicobacter pylori to children in a Japanese rural town.

AIM: Although the prevalence of Helicobacter pylori (H. pylori) increases with age and the main period of acquisition is childhood, the route of transmission of H. pylori infection remains unclear. This study aims to evaluate the relationship between prevalence of children and grandparents. METHODS: A total of 838 consecutive children who attended the Urita clinic and whose blood was taken for work up were enrolled in the present study. They were 449 boys and 389 girls, with a mean age of 12.4 years. H. pylori serology of their family members who were living together in one house was picked up to analyse intra-familial clustering of H. pylori infection. The family members of these children consisted of 448 fathers, 597 mothers, 205 grandfathers, 361 grandmothers and 589 siblings. RESULTS: The seropositive rates of mothers, grandmother and siblings in seropositive children were significantly higher than those in seronegative children. H. pylori infection in mothers and grandmothers was a marked risk factor for infection in the index children. Larger family size was not a risk factor for H. pylori infection. In contrast, having an infected father or grandfather was not an independent predictor for children infection. CONCLUSIONS: Our data demonstrate that not only mother-to-child transmission but also grandmother-to-child transmission is an important mechanism for the spread of H. pylori in a three-generation household.

Effects of ethanol and sex on propionate metabolism evaluated via a faster 13C-propionate breath test in rats.

BACKGROUND: Alcoholism is regarded as a risk factor for vitamin B12 (VB12) deficiency. Because VB12 serves as a coenzyme of methylmalonyl-CoA mutase, a key enzyme in propionate metabolism, the 13C-propionate breath test (PBT) has been studied as a non-invasive diagnostic modality for VB12 deficiency. However, the conventional PBT requires 2 h, which is inconvenient in clinical practice. We hypothesized that a faster PBT can be used to evaluate propionate metabolism and is more easily adaptable for clinical practice. AIM: To evaluate a faster PBT for assessing the effects of long-term ethanol consumption on propionate metabolism in ethanol-fed rats (ERs). METHODS: ERs were obtained by replacing standard drinking water (for control rats, CRs) with 16% ethanol solution in descendants of F344/DuCrj rats. Faster PBT was performed by administering 13C-propionate aqueous solution to male and female ERs and CRs by inserting a metal tubule from the mouth to the stomach; exhaled gas was collected in a bag to measure its 13CO2/12CO2 isotope ratio via infrared isotope spectrometry. Serum VB12 and alanine transaminase (ALT) levels were measured via chemiluminescence immunoassay and the lactate dehydrogenase-ultraviolet method, respectively. We evaluated statistical differences in mean body weight, change in 13CO2 (Δ13CO2‰), peak Δ13CO2‰, and serum VB12 and ALT, between males and females and between ERs and CRs using the t-test and Mann-Whitney U test for normally and non-normally distributed variables, respectively. RESULTS: Males weighed significantly more than females (P < 0.001); CRs weighed significantly more than ERs (P < 0.008). Δ13CO2 reached a peak (Cmax) at 20 min and 30 min in females and males, respectively, decreasing after 20-30 min without rebound in all groups. Males had significantly higher Cmax and Δ13CO2 at 15-45 min than females (P < 0.05; for all pairs). Propionate metabolism was enhanced in male ERs relative to male CRs, whereas metabolism did not differ markedly between ERs and CRs for females. Males had higher serum VB12 levels than females, without prominent differences between the ER and CR groups. Male CRs had notably higher ALT levels than male ERs. Thus, chronic ethanol consumption may trigger fatty acid production via intestinal bacteria and changes in gut microbiome composition. CONCLUSION: Faster PBT shows that 16% ethanol consumption promotes propionate metabolism without inducing liver injury. This PBT may be used clinically to evaluate gut flora status.

The Relationship between Serum Insulin-Like Growth Factor-1 Levels and Body Composition Changes after Sleeve Gastrectomy.

INTRODUCTION: We previously reported that preoperative serum insulin-like growth factor-1 (IGF-1) is a predictor of total weight loss percentage (%TWL) after laparoscopic sleeve gastrectomy (LSG). IGF-1 may suppress muscle loss after surgery. IGF-1 almost accurately reflects the growth hormone (GH) secretion status, and GH has lipolytic effects. Therefore, IGF-1 may influence both the maintenance of skeletal muscle and the reduction of adipose tissue after LSG. The identification of the relationship between preoperative serum IGF-1 and body composition changes after LSG can help in understanding the pathophysiology of obesity. METHODS: We retrospectively reviewed 72 patients with obesity who underwent LSG and were followed up for 12 months. We analyzed the relationship between preoperative serum IGF-1 levels and body composition changes after LSG. A multiple regression model was used. RESULTS: LSG led to a significant reduction in body weight. Both body fat mass and skeletal muscle mass decreased after LSG. Preoperative serum IGF-1 levels significantly correlated with %TWL, changes in skeletal muscle mass, and body fat mass after LSG. The multiple regression model showed that preoperative serum IGF-1 levels were related to decreased body fat mass and maintaining skeletal muscle mass after LSG. DISCUSSION/CONCLUSION: Preoperative IGF-1 measurement helps predict not only successful weight loss but also decreases body fat mass and maintains skeletal muscle mass after LSG.

Decreased Triglyceride and Increased Serum Lipoprotein Lipase Levels Are Correlated to Increased High-Density Lipoprotein-Cholesterol Levels after Laparoscopic Sleeve Gastrectomy.

INTRODUCTION: Laparoscopic sleeve gastrectomy (LSG) significantly increases high-density lipoprotein cholesterol (HDL-C) and lipoprotein lipase (LPL) in pre-heparin serum (pre-heparin LPL levels). LPL is a regulator of serum triglyceride (TG) and HDL-C production; this may be the mechanism for HDL-C increase after LSG. This study aimed to elucidate the mechanism of increase in HDL-C levels by examining the relationship between changes in serum HDL-C levels and LPL after LSG. METHODS: We retrospectively reviewed 104 obese patients, who underwent LSG and were followed up for 12 months. We analyzed the relationship between changes in serum HDL-C levels and various clinical parameters after LSG. RESULTS: A significant decrease was observed in the patients' BMI and serum TG levels after LSG. Conversely, HDL-C levels and pre-heparin LPL levels were significantly increased after LSG. Simple linear regression showed that changes in HDL-C levels were significantly correlated with total weight loss percentage, change in TG levels, abdominal fat areas, and pre-heparin LPL levels. Additionally, the multiple regression model revealed that a decrease in TG levels and an increase in pre-heparin LPL levels were correlated with increased HDL-C levels after LSG. DISCUSSION/CONCLUSION: These results show that a decrease in TG levels and an increase in LPL are mechanisms for increased HDL-C levels after LSG.

High presepsin concentrations in bile and its marked elevation in biliary tract diseases: A retrospective analysis.

BACKGROUND: Presepsin is a diagnostic and prognostic biomarker of both bacterial infection and sepsis; however, elevated presepsin levels have also been observed without sepsis. We conducted several analyses to evaluate the clinical laboratory parameters affecting presepsin levels. METHOD: We analyzed the association between sequential organ failure assessment (SOFA) scores and plasma presepsin levels and then analyzed clinical laboratory parameters in 567 patients with univariate and multivariate regression analysis and analysis of covariance (ANCOVA). We also determined presepsin in the bile of 11 patients and examined the presepsin immunostaining in liver. RESULTS: Spearman's rank correlation analysis with loge change revealed that presepsin levels were closely associated with loge-transformed SOFA score (ρ = 0.541), alkaline phosphatase (ALP); (ρ = 0.454) and gamma-glutamyl transferase; (ρ = 0.505). Multivariate regression analysis revealed that loge-transformed SOFA score (ß-coefficient = 0.316), ALP level (ß-coefficient = 0.380), and creatinine level (ß-coefficient = 0.290) independently and significantly affected loge presepsin levels. ANCOVA revealed that presepsin levels were significantly higher in patients with hepatobiliary disease. Patients who presented with dilatation of the bile ducts and elevated ALP levels or total bilirubin levels exhibited high presepsin levels in the bile. Presepsin production in liver Kupffer cells was also confirmed by immunostaining. CONCLUSION: Presepsin levels is correlated with the elevation of biliary enzymes in patients without renal dysfunction or sepsis. Additionally, presepsin exists with high concentrations in the bile and is positive in Kupffer cells.

13C-glucose breath tests: a non-invasive method for detecting early clinical manifestations of exogenous glucose metabolism in type 2 diabetic patients.

AIMS: 13C-glucose breath tests are reported as an alternative non-invasive method to evaluate glucose metabolism. However, the metabolic results differ based on the site of the carbon atom in the glucose. The aim of this study was to evaluate changes in the metabolism of carbon atoms contained in glucose in patients with diabetes using [1, 2, 3-13C]glucose breath tests. METHODS: Sixteen healthy participants and 20 diabetic patients were enrolled in the study. Three types of breath tests, [1-13C], [2-13C], and [3-13C]glucose breath tests, were performed after an overnight fast. Breath samples were taken at baseline and at 10-min intervals over 150 min, and 13CO2 excretion curves were expressed using non-dispersive infrared isotope spectrometry. RESULTS: 13CO2 levels increased more rapidly, and the peak value of 13CO2 (Cmax) was highest after the administration of [3-13C]glucose followed by [2-13C] and [1-13C]glucose in controls. Delayed 13CO2 excretion and a low area under the curve through 150 min (AUC150) were obtained in diabetic patients. The group with severe diabetes had a significantly lower Cmax and AUC150 in the [1-13C]glucose breath test. CONCLUSIONS: The [1-13C]glucose breath test, which has been used to evaluate glucose metabolism, is suitable for patients with late-stage diabetes, whereas the [2-13C]glucose breath test is ideal in the early stages. Although the [3-13C]glucose breath test is theoretically useful for evaluating the uptake of glucose and the anaerobic glycolysis system, it can be used in practice to distinguish reduced uptake from impaired oxidation of glucose in combination with the other two tests.

Investigation of Metabolism of Exogenous Glucose at the Early Stage and Onset of Diabetes Mellitus in Otsuka Long-Evans Tokushima Fatty Rats Using [1, 2, 3-13C]Glucose Breath Tests.

This study aimed to evaluate changes in glucose metabolism at the early stage and onset of diabetes in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Specifically, after the oral administration of [1, 2, 3-13C]glucose, the levels of exhaled 13CO2, which most likely originated from pyruvate decarboxylation and tricarboxylic acid, were measured. Eight OLETF rats and eight control rats (Long-Evans Tokushima Otsuka [LETO]) were administered 13C-glucose. Three types of 13C-glucose breath tests were performed thrice in each period at 2-week intervals. [3-13C]glucose results in a 13C isotope at position 1 in the pyruvate molecule, which provides 13CO2. The 13C at carbons 1 and 2 of glucose is converted to 13C at carbons 2 and 1 of acetate, respectively, which produce 13CO2. Based on metabolic differences of the labeled sites, glucose metabolism was evaluated using the results of three breath tests. The increase in 13CO2 excretion in OLETF rats was delayed in all three breath tests compared to that in control rats, suggesting that OLETF rats had a lower glucose metabolism than control rats. In addition, overall glucose metabolism increased with age in both groups. The utilization of [2-13C]glucose was suppressed in OLETF rats at 6-12 weeks of age, but they showed higher [3-13C]glucose oxidation than control rats at 22-25 weeks of age. In the [1-13C]glucose breath test, no significant differences in the area under the curve until 180 minutes (AUC180) were observed between OLETF and LETO rats of any age. Glucose metabolism kinetics were different between the age groups and two groups of rats; however, these differences were not significant based on the overall AUC180 of [1-13C]glucose. We conclude that breath 13CO2 excretion is reduced in OLETF rats at the primary stage of prediabetes, indicating differences in glucose oxidation kinetics between OLETF and LETO rats.