Postprandial Samples Research Articles

Comparative Metabolomics Elucidates Postprandial Metabolic Modifications in Plasma of Obese Individuals with Metabolic Syndrome

Although higher intakes of dairy milk are associated with a lower risk of metabolic syndrome (MetS), the underlying protective mechanism remains unclear. This study investigated the dynamic metabolic profile shift following the ingestion of low-fat milk or an isocaloric volume of rice milk in obese individuals with metabolic syndrome (MetS). In a randomized, double-blind, crossover study, postprandial plasma samples ( n = 266) were collected from 19 MetS participants. Plasma samples were analyzed by a targeted metabolomics platform which specifically detects 117 metabolites from 25 metabolic pathways. The comprehensive time-course metabolic profiling in MetS participants indicated that the postprandial metabolic profiles distinguish low-fat milk and rice milk consumption in a time-dependent manner. Metabolic biomarkers, such as orotate, leucine/isoleucine and adenine, showed significantly different trends in the two test beverages. Bayesian statistics identified 12 metabolites associated with clinical characteristics of postprandial vascular endothelial function, such as flow-mediated dilation (FMD), postprandial plasma markers of oxidative stress and NO status. Furthermore, metabolic pathway analysis based on these metabolite data indicated the potential utility of metabolomics to provide mechanistic insights of dietary interventions to regulate postprandial metabolic excursions.

Simple Screening for Glucose Intolerance Based on Myoinositol Levels in Self-Collected Urine Samples at Home

Background: Urinary myoinositol (UMI) is a molecule with a structure similar to D-glucose. In the presence of hyperglycemia, reabsorption of MI in the renal tubules is inhibited by urinary glucose (UG), resulting in high concentrations of MI excreted into the urine. Unlike UG, UMI is highly stable at room temperature (RT) for over a week. Therefore, we conducted a study to establish a simple screening method for glucose intolerance (GI) based on UMI levels in self-collected pre- and postprandial urine samples at home. Methods: First, to diagnose GI, we performed a 75gOGTT at the hospital in 115 volunteers without a past history of diabetes (DM). Within a week, each volunteer collected urine samples before and 2h after consuming the test meal (500kcal, energy bar) at home, and these samples were shipped to a single laboratory at RT. UMI was measured using an enzymatic method. Results: To assess the usefulness of UMI for screening GI (IGT+DM), we performed statistical analyses using receiver-operating characteristic (ROC) curve. It revealed that the area under the curve of ROC (AUCROC) for 2h-postprandial UMI/creatinine (Cr) was 0.74 for diagnostic accuracy of GI (IGT+DM). The optimal cut-off was 27 mg/gCr with a sensitivity of 60%, and a specificity of 81%. For diagnostic accuracy of DM, AUCROC for 2h-postprandial UMI/Cr was 0.83, with a sensitivity of 80%, and a specificity of 74% at the cut-off value of 27 mg/gCr. Conclusions: UMI measurement of urine samples self-collected at home may be a non-invasive, inexpensive, and valuable screening method for GI. This strategy may be suitable for subjects in area with limited access to medical care including developing countries, and could be the first step towards further medical examinations such as blood glucose (OGTT when required), and HbA1c. Disclosure M. Takakado: None. Y. Takata: None. R. Kawamura: None. H. Osawa: None.

Abstract 179: CETP Facilitates SAA Exchange Between Lipoproteins

Serum amyloid A (SAA) is a family of acute phase reactants that are elevated in chronic inflammatory conditions such as obesity and diabetes. SAA promotes atherosclerosis in mice. Although SAA is generally thought to be exclusively an HDL apolipoprotein, we and others have detected SAA on apoB-containing lipoproteins in obese/diabetic mice and humans. The goal of this study was to investigate mechanisms underlying SAA exchange between lipoprotein fractions. Obese humans with or without metabolic syndrome or type 2 diabetes were recruited. Plasma samples were collected fasting and hourly for 8h after consumption of a high fat drink. Whereas SAA was found predominantly on HDL in fasting samples, in diabetic subjects SAA shifted from HDL to VLDL and LDL in post prandial samples. Postprandial LDL and VLDL containing SAA had increased proteoglycan binding compared to fasting LDL and VLDL from the same subject. We previously reported that HDLs remodeled by CETP release lipid-free SAA. To determine if CETP facilitates SAA exchange between particles, HDL-containing SAA was incubated with SAA-free VLDL in the presence of increasing amounts of CETP. Even in the absence of CETP, 16±3% of HDL-associated SAA shifted to VLDL; in samples with CETP, 19-28% of total SAA was found on VLDL and up to 17% was lipid-poor/lipid-free. To investigate whether CETP promotes SAA exchange in vivo, SAA-deficient mice that lack CETP were injected with HDL containing SAA and then bled at 1, 3, 6 and 24 hours. Essentially all SAA was found on HDL at each time point. In contrast, in SAA-deficient mice expressing CETP by adenoviral vector, approximately 50% and 20% of SAA was associated with the VLDL and LDL fractions, respectively, 1h after injection of HDL-containing SAA. Thus, increased CETP activity in diabetes may promote the transfer of SAA from HDL to apoB-containing lipoproteins, leading to increased retention in the vasculature.

Chronic pharyngitis and the association with pepsin detection and reflux disease

Background: Pepsin is a biomarker for reflux disease and a major etiological factor in laryngopharyngeal reflux (LPR). Do chronic pharyngitis patients have significant concentrations of pepsin present in saliva samples indicating the presence of reflux disease? Methods: Thirty-two patients with chronic pharyngitis symptoms and laryngoscopy findings from the reflux finding score (RFS), indicating chronic pharyngitis, were recruited from an Ear, Nose and Throat (ENT) department. A total of 96 patient saliva samples were analysed for the presence of pepsin. Reflux questionnaires assessed the symptoms of reflux [reflux symptom index (RSI), RFS, and reflux disease questionnaire (RDQ)] and, the non-invasive reflux diagnostic device Peptest TM was used to determine the concentration of pepsin present in the patient’s saliva samples. Peptest TM uses lateral flow technology and contains two unique human anti-pepsin monoclonal antibodies fully validated and sensitive for the detection of pepsin in saliva. Results: In total, 78% of chronic pharyngitis patients had medium to high concentrations of pepsin (>75 ng/mL) in their saliva samples. In chronic pharyngitis patients 81% were found to have a positive pepsin concentration in post-prandial samples, compared to the control, where 32% were found to have a positive pepsin concentration. Conclusions: A correlation was shown between the presence of pepsin and the presence of chronic pharyngitis. 78% of chronic pharyngitis patients were shown to have medium to high concentrations of pepsin in their saliva samples and 81% had a positive pepsin concentration in post-prandial samples. Peptest TM demonstrated good diagnostic potential and as a non-invasive, rapid and easy to use test, it will play an important role as a first line reflux diagnostic.

Modulatory Effects of Breed, Feeding Status, and Diet on Adipogenic, Lipogenic, and Lipolytic Gene Expression in Growing Iberian and Duroc Pigs.

Meat quality depends on tissue composition which is in turn influenced by different factors, such as diet, genotype, age, or sex. We evaluated the effects of breed, 24 h fasting, and dietary energy source (HO: oleic acid versus CH: carbohydrates) on the expression of candidate genes involved in adipogenesis, lipogenesis, and lipolysis in the adipose tissue from Iberian and Duroc growing pigs. The Iberian pigs showed greater feed intake, backfat thickness, and saturated fatty acids (SFA) content in the subcutaneous fat, whereas the Duroc pigs had greater ham weight and polyunsaturated fatty acids (PUFA) content. In both breeds, the diet induced changes in the fatty acid (FA) composition of subcutaneous fat samples. The HO group had higher monounsaturated fatty acids (MUFA) and oleic acid, and lower SFA than the CH group. Regarding gene expression, breed and feeding status (fasting versus postprandial) had significant effects on gene expression, with quantitative interactions between them, while diet showed negligible effects. In general, adipogenic and lipogenic genes were upregulated in the Iberian pigs and in postprandial samples. In contrast, the expression of lipolytic genes showed complex interaction effects. Our results agree with the phenotypic differences between the Iberian and Duroc breeds and with the inhibition of lipogenesis by fasting. Quantitative interactions between breed and feeding status effects were observed, which indicates a different response to fasting of the two breeds, with the obese Iberian breed showing a more stable expression of lipogenic genes. These results highlight the complexity of lipid metabolism regulation, especially in relation to lipolysis processes.

The diagnostic value of pepsin detection in saliva for gastro-esophageal reflux disease: a preliminary study from China

BackgroundNone of current diagnostic methods has been proven to be a reliable tool for gastro-esophageal reflux disease (GERD). Pepsin in saliva has been proposed as a promising diagnostic biomarker for gastro-esophageal reflux. We aimed to determine the diagnostic value of salivary pepsin detection for GERD.MethodsTwo hundred and fifty patients with symptoms suggestive of GERD and 35 asymptomatic healthy volunteers provided saliva on morning waking, after lunch and dinner for pepsin determination using the Peptest lateral flow device. All patients underwent 24-h multichannel intraluminal impedance pH (24-h MII-pH) monitoring and upper gastrointestinal endoscopy. Based on 24-h MII-pH and endoscopy study, patients were defined as GERD (abnormal MII-pH results and/or reflux esophagitis) and non-GERD otherwise.ResultsPatients with GERD had a higher prevalence of pepsin in saliva and higher pepsin concentration than patients with non-GERD and healthy controls (P < 0.001 for all). The pepsin test had a sensitivity of 73% and a specificity of 88.3% for diagnosing GERD using the optimal cut-off value of 76 ng/mL. Postprandial saliva samples collected when the symptoms occurred had a more powerful ability to identify GERD.ConclusionsSalivary pepsin test had moderate diagnostic value for GERD. It may be a promising tool to replace the use of currently invasive tools with advantages of non-invasive, easy to perform and cost effective.Trial registrationChiCTR-DDD-16009506 (date of registration: October 20, 2016).

Estimation of Chicken Intake by Adults Using Metabolomics-Derived Markers

Improved assessment of meat intake with the use of metabolomics-derived markers can provide objective data and could be helpful in clarifying proposed associations between meat intake and health. The objective of this study was to identify novel markers of chicken intake using a metabolomics approach and use markers to determine intake in an independent cohort. Ten participants [age: 62 y; body mass index (in kg/m2): 28.25] in the NutriTech food intake study consumed increasing amounts of chicken, from 88 to 290 g/d, in a 3-wk span. Urine and blood samples were analyzed by nuclear magnetic resonance and mass spectrometry, respectively. A multivariate data analysis was performed to identify markers associated with chicken intake. A calibration curve was built based on dose-response association using NutriTech data. A Bland-Altman analysis evaluated the agreement between reported and calculated chicken intake in a National Adult Nutrition Survey cohort. Multivariate data analysis of postprandial and fasting urine samples collected in participants in the NutriTech study revealed good discrimination between high (290 g/d) and low (88 g/d) chicken intakes. Urinary metabolite profiles showed differences in metabolite levels between low and high chicken intakes. Examining metabolite profiles revealed that guanidoacetate increased from 1.47 to 3.66 mmol/L following increasing chicken intakes from 88 to 290 g/d (P < 0.01). Using a calibration curve developed from the NutriTech study, chicken intake was calculated through the use of data from the National Adult Nutrition Survey, in which consumers of chicken had a higher guanidoacetate excretion (0.70 mmol/L) than did nonconsumers (0.47 mmol/L; P < 0.01). A Bland-Altman analysis revealed good agreement between reported and calculated intakes, with a bias of -30.2 g/d. Plasma metabolite analysis demonstrated that 3-methylhistidine was a more suitable indicator of chicken intake than 1-methylhistidine. Guanidoacetate was successfully identified and confirmed as a marker of chicken intake, and its measurement in fasting urine samples could be used to determine chicken intake in a free-living population. This trial was registered at clinicaltrials.gov as NCT01684917.

Short-Term Supplementation of a Moderate Carbohydrate Diet with Psyllium Reduces Fasting Plasma Insulin and Tumor Necrosis Factor-α in Patients with Type 2 Diabetes Mellitus

ABSTRACTThe purpose of this study was to compare effects of a moderate carbohydrate diet supplemented with psyllium with those of a lower carbohydrate diet supplemented with placebo powder on glycemic control in patients with type 2 diabetes (T2D). In an open randomized controlled trial, 37 patients with T2D with body mass index (BMI) 25–35 kg/m2 received either a low-energy, moderate carbohydrate diet plus 7 grams of psyllium powder (MoCyllium group) or a low-energy, lower carbohydrate diet plus placebo powder (LoCarb group) for 2 weeks. Fasting and 2-hour postprandial plasma glucose, insulin, and tumor necrosis factor-α (TNF-α) as well as the homeostasis model assessment of insulin resistance (HOMA-IR) were determined at the beginning and end of the 2-week period. Postprandial samples were obtained after ingestion of a standardized breakfast meal in both groups. Body weight change did not differ between the two groups. There was no significant intervention effect on fasting plasma glucose. Fasting plasma insulin and TNF-α significantly decreased from baseline in the MoCyllium group (p = .01). The differences of absolute change of insulin and TNF-α between the groups were statistically significant (p = .002 and p = .017, respectively). Insulin sensitivity, evaluated by HOMA-IR, increased significantly in the MoCyllium group (p = .016), and comparison of absolute change between the groups showed a trend toward statistical significance. No statistical differences were detected among postprandial glucose, insulin, and TNF-α concentrations. The finding supports the concept that in diabetic patients with cultural preferences to a higher carbohydrate diet, an increase in soluble fiber intake should be encouraged.

Metabolic profiles from two different breakfast meals characterized by 1H NMR-based metabolomics

It is challenging to measure dietary exposure with techniques that are both accurate and applicable to free-living individuals. We performed a cross-over intervention, with 24 healthy individuals, to capture the acute metabolic response of a cereal breakfast (CB) and an egg and ham breakfast (EHB). Fasting and postprandial urine samples were analyzed using 1H nuclear magnetic resonance (NMR) spectroscopy and multivariate data analysis. Metabolic profiles were distinguished in relation to ingestion of either CB or EHB. Phosphocreatine/creatine and citrate were identified at higher concentrations after consumption of EHB. Beverage consumption (i.e., tea or coffee) could clearly be seen in the data. 2-furoylglycine and 5-hydroxymethyl-2-furoic acid – potential biomarkers for coffee consumption were identified at higher concentrations in coffee drinkers. Thus 1H NMR urine metabolomics is applicable in the characterization of acute metabolic fingerprints from meal consumption and in the identification of metabolites that may serve as potential biomarkers.

Metabolic Profiling Reveals Differences in Plasma Concentrations of Arabinose and Xylose after Consumption of Fiber-Rich Pasta and Wheat Bread with Differential Rates of Systemic Appearance of Exogenous Glucose in Healthy Men

BackgroundThe consumption of products rich in cereal fiber and with a low glycemic index is implicated in a lower risk of metabolic diseases. Previously, we showed that the consumption of fiber-rich pasta compared with bread resulted in a lower rate of appearance of exogenous glucose and a lower glucose clearance rate quantified with a dual-isotope technique, which was in accordance with a lower insulin and glucose-dependent insulinotropic polypeptide response. ObjectiveTo gain more insight into the acute metabolic consequences of the consumption of products resulting in differential glucose kinetics, postprandial metabolic profiles were determined. MethodsIn a crossover study, 9 healthy men [mean ± SEM age: 21 ± 0.5 y; mean ± SEM body mass index (kg/m2): 22 ± 0.5] consumed wheat bread (132 g) and fresh pasta (119 g uncooked) enriched with wheat bran (10%) meals. A total of 134 different metabolites in postprandial plasma samples (at −5, 30, 60, 90, 120, and 180 min) were quantified by using a gas chromatography–mass spectrometry–based metabolomics approach (secondary outcomes). Two-factor ANOVA and advanced multivariate statistical analysis (partial least squares) were applied to detect differences between both food products. ResultsForty-two different postprandial metabolite profiles were identified, primarily representing pathways related to protein and energy metabolism, which were on average 8% and 7% lower after the men consumed pasta rather than bread, whereas concentrations of arabinose and xylose were 58% and 53% higher, respectively. Arabinose and xylose are derived from arabinoxylans, which are important components of wheat bran. The higher bioavailability of arabinose and xylose after pasta intake coincided with a lower rate of appearance of glucose and amino acids. We speculate that this higher bioavailability is due to higher degradation of arabinoxylans by small intestinal microbiota, facilitated by the higher viscosity of arabinoxylans after pasta intake than after bread intake. ConclusionsThis study suggests that wheat bran, depending on the method of processing, can increase the viscosity of the meal bolus in the small intestine and interfere with macronutrient absorption in healthy men, thereby influencing postprandial glucose and insulin responses. This trial was registered at www.controlled-trials.com as ISRCTN42106325.

Homogeneous Assays for LDL-C and HDL-C are Reliable in Both the Postprandial and Fasting State.

Aim: Most epidemiological and clinical studies calculated low-density lipoprotein-cholesterol (LDL-C) by Friedewald's formula which cannot be used in the postprandial samples. Although the homogeneous assays with poor analytical performance were withdrawn from the market, it remained unclear whether the currently available reagents for LDL-C and high-density lipoprotein-cholesterol (HDL-C) are as accurate for postprandial samples as for fasting samples.Methods: Fresh blood samples were collected from 59 non-diseased and 109 diseased subjects. Postprandial samples constituted 72.9% and 39.4% of these samples. LDL-C and HDL-C concentrations were measured using the homogeneous assays of four manufacturers (Denka Seiken, Wako, Kyowa Medex, and Sekisui Medical). Simultaneously, LDL-C and HDL-C concentrations were determined using the reference measurement procedures (RMPs) of the Centers for Disease Control and Prevention (CDC). Total errors were calculated using a routine method (TEcom) and via error component analysis (TEeca).Results: All homogeneous assays for LDL-C and HDL-C met the National Cholesterol Education Program (NCEP) requirements in terms of coefficient of variation, and TEcom in both non-diseased and diseased subjects. LDL-C and HDL-C values measured by the homogeneous assays were in good agreement with those measured by the RMPs in both fasting and postprandial samples. The TEcom and TEeca values of the postprandial samples were similar to those of fasting samples, although the TEeca values were up to 4.4-fold greater than the TEcom values.Conclusions: In both non-diseased and diseased subjects, the homogeneous assays for LDL-C and HDL-C of four manufacturers are as accurate for postprandial samples as for fasting samples.

Does Time of Sampling or Food Intake Alter Thyroid Function Test?

Context:A common question from most patients or laboratories is whether blood sample for thyroid-stimulating hormone (TSH) and free T4 (fT4) needs to be collected in a fasting state and whether time of the day when sample is collected matters.Aims:The aim of the study was to study the impact of the time of day and food intake on levels of TSH and fT4.Settings and Design:Cross-sectional prospective data collection.Subjects and Methods:We prospectively collected data from 52 volunteers who were not known to have any thyroid disorder and were not on any thyroid-related medication. Blood samples for TSH and fT4 were collected on day 1 at 8 am and 10 am with the patient remaining in the fasting state till the collection of the second sample at 10 am. On day 2, samples were collected at 8 am (fasting state) and at 10 am (2 h postprandial state). In 22 volunteers from the group, the tests were performed in three common assay techniques including chemiluminescent assays (chemiluminescent immunoassay [CLIA] and chemiluminescent microparticle immunoassay [CMIA]) and enzyme-linked fluorescence assay.Results:The mean (standard deviation) and median (interquartile range) TSH during the extended fast on day 1 were 2.26 ± 1.23 and 2.19 (1.21–3.18), which was significantly lower than the fasting TSH performed on day 1 (P < 0.001). Similarly, the values of TSH 2 h postmeal on day 2 of the testing (mean 1.93 ± 1.12; median 1.64 [1.06–2.86]) were significantly lower than TSH performed in the fasting state on day 2 (P < 0.001). The mean fT4 value was 1.01 ± 0.15 with median of 0.99 (0.91–1.11) in the fasting state and there was no significant difference between the fT4 values performed during fasting, extended fasting, and postmeal state. Among the volunteers in whom the test was performed in the three different assay techniques, the TSH was not statistically different either in the fasting (P = 0.801), extended fasting (P = 0.955), and postprandial samples (P = 0.989). The fT4 values did not vary significantly when done by the same assay method. However, the fT4 levels varied significantly (P < 0.001) when done by another assay method.Conclusions:We conclude stating that the timing of the test affects TSH values and this should be factored in making decisions in diagnosis of subclinical hypothyroidism.

Salivary concentration of N-acylethanolamines upon food mastication and after meal consumption: Influence of food dietary fiber

The primary objective of this study was to evaluate the impact of the amount and type of food dietary fiber on salivary concentrations of N-acylethanolamines (NAEs) and glucose upon food mastication and in the post-prandial phase.Three types of biscuits enriched with 3% barley β-glucan (βGB) or whole-wheat bran (WWBB) or without dietary fiber (control, CB) were developed. A crossover randomized human study was carried out by collecting saliva samples from eighteen healthy and fasting participants in a resting condition, upon mastication of parafilm and one of the three biscuits. Subsequently, the amount of biscuits consumed in an ad-libitum breakfast was measured and post-prandial saliva samples, blood glucose, appetite, and food liking were collected over the following 2h.Salivary concentration of oleoylethanolamide (OEA) and linoleoylethanolamide (LEA) significantly increased during all biscuits mastication compared to food-free conditions, with OEA increasing more (~138 folds) than LEA (~7 folds). Subjects consumed always 75g of biscuits at breakfast. Salivary OEA peaked at 15min and returned to baseline concentration at 60min after consumption of all types of biscuits whereas LEA peaked only after WWBB. Fifteen minutes after βGB consumption all NAE levels were significantly lower than those after WWBB. No difference of biscuit type on post prandial blood glucose was recorded.Results demonstrated that NAEs were released in saliva during biscuit mastication, independently from dietary fiber composition. The type of dietary fiber could influence the persistence of NAEs in saliva over 30min after consumption. Future studies will clarify the mechanisms behind these findings and the role of salivary NAEs in food liking and appetite cues after food consumption.

Brief Communication: Discordant ability of the triglyceride to apolipoprotein B ratio to predict triglyceride-rich lipoprotein particle size in normal-weight and obese men.

The atherogenicity of triglyceride-rich lipoproteins (TRLs) is dependent of their particle size as it determines their metabolic fate. Since TRL possess a single apolipoprotein B (Apo B) molecule per particle, the triglyceride (TG)/Apo B ratio has been used as a convenient method to estimate TRL size. The aim of this study was to validate this approach by correlating the serum TG/Apo B ratio, and the TRL particle size measured by dynamic light scattering (DLS). Twenty-four male volunteers (12 normal-weight and 12 obese individuals) received a high-fat meal. Preprandial (0 h) and postprandial (2 and 4 h) serum samples were collected after meal ingestion, and TRLs were isolated. Serum TG and Apo B levels were quantified, and the TG/Apo B ratio was plotted against TRL particle size measured by DLS for correlation. A strong association between TRL particle size and serum TG/Apo B ratio for normal-weight subjects (P ≤ 0.001) was observed but not for obese subjects (P = 0.6116). TG/Apo B ratio correlates with particle size in healthy normal-weight males but not in obese individuals. Whether this ratio is useful to estimate TRL size in females and in other dyslipidemic patients should be subject of future investigations.

Key Role for the 12-Hydroxy Group in the Negative Ion Fragmentation of Unconjugated C24 Bile Acids.

Host-gut microbial interactions contribute to human health and disease states and an important manifestation resulting from this cometabolism is a vast diversity of bile acids (BAs). There is increasing interest in using BAs as biomarkers to assess the health status of individuals and, therefore, an increased need for their accurate separation and identification. In this study, the negative ion fragmentation behaviors of C24 BAs were investigated by UPLC-ESI-QTOF-MS. The step-by-step fragmentation analysis revealed a distinct fragmentation mechanism for the unconjugated BAs containing a 12-hydroxyl group. The unconjugated BAs lacking 12-hydroxylation fragmented via dehydration and dehydrogenation. In contrast, the 12-hydroxylated ones, such as deoxycholic acid (DCA) and cholic acid (CA), employed dissociation routes including dehydration, loss of carbon monoxide or carbon dioxide, and dehydrogenation. All fragmentations of the 12-hydroxylated unconjugated BAs, characterized by means of stable isotope labeled standards, were associated with the rotation of the carboxylate side chain and the subsequent rearrangements accompanied by proton transfer between 12-hydroxyl and 24-carboxyl groups. Compared to DCA, CA underwent further cleavages of the steroid skeleton. Accordingly, the effects of stereochemistry on the fragmentation pattern of CA were investigated using its stereoisomers. Based on the knowledge gained from the fragmentation analysis, a novel BA, 3β,7β,12α-trihydroxy-5β-cholanic acid, was identified in the postprandial urine samples of patients with nonalcoholic steatohepatitis. The analyses used in this study may contribute to a better understanding of the chemical diversity of BAs and the molecular basis of human liver diseases that involve BA synthesis, transport, and metabolism.

Characterization and quantification of oxyntomodulin in human and rat plasma using high-resolution accurate mass LC-MS.

A thorough understanding of the biological role of oxyntomodulin (OXM) has been limited by the availability of sensitive and specific analytical tools for reliable in vivo characterization. Here, we utilized immunoaffinity capture coupled with high-resolution accurate mass LC-MS detection to quantify OXM and its primary catabolites. Quantification of intact OXM 1-37 in human and rat plasma occurred in pre- and post-prandial samples. Profiles for the major catabolites were observed allowing kinetic differences to be assessed between species. A validated assay in human and rat plasma was obtained for OXM 1-37 and its catabolites, 3-37 and 4-37. The value of full scan high-resolution accurate mass detection without selected reaction monitoring for low-abundance peptide quantification was also demonstrated.

Long-Term Ursodeoxycholic Acid Therapy Does Not Alter Lithocholic Acid Levels in Patients with Cystic Fibrosis with Associated Liver Disease

To evaluate the fasting and postprandial serum bile acid composition in patients with cystic fibrosis-associated liver disease (CFLD) after chronic administration of ursodeoxycholic acid (UDCA) (20mg/kg/day). The aim was to specifically focus on the extent of biotransformation of UDCA to its hepatotoxic metabolite, lithocholic acid, because of recent concerns regarding the safety of long-term, high-dose UDCA treatment for CFLD. Twenty patients with CFLD (median age 16years, range: 2.4-35.0) prescribed UDCA therapy for at least 2years were studied. Total and individual serum bile acids were measured by stable-isotope dilution mass spectrometry, in fasting and 2-hour postprandial samples taken during chronic UDCA (20mg/kg/day) administration. During chronic UDCA administration (median duration 8years, IQR: 6-16), UDCA became the predominant serum bile acid in all patients (median, IQR: 3.17, 1.25-5.56μmol/L) and chenodeoxycholic acid concentrations were greater than cholic acid (1.86, 1.00-4.70μmol/L vs 0.40, 0.24-2.71μmol/L). The secondary bile acids, deoxycholate and lithocholate, were present in very low concentrations in fasted serum (<0.05μmol/L). After UDCA administration, 2-hour postprandial concentrations of both UDCA and chenodeoxycholic acid significantly increased (P<.01), but no significant changes in serum lithocholic acid concentrations were observed. These data do not support recent suggestions that enhanced biotransformation of UDCA to the hepatotoxic secondary bile acid lithocholic occurs when patients with CFLD are treated with relatively high doses of UDCA.

Salivary Amylase as Potential Biochemical Marker in Diabetes Mellitus

Abstract Introduction: Diabetes mellitus has emerged as a major global health problem. Diagnosing and monitoring diabetes is the best way for its prevention, thus reducing the burden of disease. As saliva is easily available and accessible when compared with serum, salivary biomarkers have gained importance in recent years and, therefore, can be helpful in diagnosing the disease. Aims: The purpose of this study was to estimate the salivary amylase level in patients with types I and II diabetes mellitus and to correlate these findings with those of nondiabetic individuals in order to ascertain its value as a biochemical indicator for diagnosing and monitoring the patients. Materials and methods: Three groups of patients were selected for the present study. Group A: 20 nondiabetic, healthy individuals; group B: 20 type I diabetes mellitus patients; group C: 20 type II diabetes mellitus patients. Fasting and postprandial unstimulated saliva samples were collected and subjected for analysis of salivary amylase. Estimation of salivary amylase was determined by direct substrate method. Results: The mean fasting salivary amylase level for types I and II diabetic and nondiabetic individuals was 245.60, 239.10, and 149 U/dL respectively, whereas the mean postprandial salivary amylase was 257.35, 246.15, and 154.2 U/dL respectively. The mean value of variables was compared using Student's t test and one-way analysis of variance test. Conclusion: The mean salivary amylase level was significantly increased in both types I and II diabetic individuals as compared with healthy nondiabetic subjects (p &lt; 0.05). However, there was no significant difference in the mean of types I and II diabetic patients.

A Male with Extreme Subcutaneous Insulin Resistance: A Case Report.

Though insulin has no upper limit in dosage, we do not encounter very high dose requirements too often. The reported case is the first in Bangladesh to require more than 1000 international units (IU) of subcutaneous insulin per day. A 44-year old male diabetic patient from Bangladesh presented with unusually uncontrolled diabetes mellitus due to extreme insulin resistance. Despite dramatic increase in insulin step by step up to 1110 IU of concomitant short and intermediate acting insulin per day by subcutaneous route, his blood glucose remained over 12 mmol/L persistently, in all the fasting, pre-prandial, postprandial and random samples. He was also treated with several oral hypoglycemic agents including metformin, vildagliptin, glimepiride, pioglitazone and miglitol along with insulin but blood glucose levels remained almost unchanged. However, intravenous infusion of insulin over 4 hours caused a plummet in the glucose level. His blood test for insulin autoantibody was negative. This paper provides a scope to review literatures on extreme subcutaneous insulin resistance and its management. It also reveals the limitations of management due to lack of facilities in an underdeveloped country, which hinders proper exploration to many medical issues.

Associations between whole peripheral blood fatty acids and DNA methylation in humans.

Fatty acids (FA) modify DNA methylation in vitro, but limited information is available on whether corresponding associations exist in vivo and reflect any short-term effect of the diet. Associations between global DNA methylation and FAs were sought in blood from lactating infants (LI; n = 49) and adult males (AMM; n = 12) equally distributed across the three conventional BMI classes. AMM provided multiple samples at 2-hour intervals during 8 hours after either a single Western diet-representative meal (post-prandial samples) or no meal (fasting samples). Lipid/glucose profile, HDAC4 promoter and PDK4 5’UTR methylation were determined in AMM. Multiple regression analysis revealed that global (in LI) and both global and PDK4-specific DNA methylation (in AMM) were positively associated with eicosapentaenoic and arachidonic acid. HDAC4 methylation was inversely associated with arachidonic acid post-prandially in AMM. Global DNA methylation did not show any defined within-day pattern that would suggest a short-term response to the diet. Nonetheless, global DNA methylation was higher in normal weight subjects both post-prandially and in fasting and coincided with higher polyunsaturated relative to monounsaturated and saturated FAs. We show for the first time strong associations of DNA methylation with specific FAs in two human cohorts of distinct age, diet and postnatal development stage.