Plasma Insulin Determinations Research Articles

Cholesterol 7α-Hydroxylase Gene-204A/C Polymorphism in Normal and Gestational Diabetic Pregnancies

To investigate the cholesterol 7α-hydroxylase gene ( CYP7A1)-204A/C single nucleotide polymorphism and its relationship with the blood lipid levels of pregnant women with gestational diabetes mellitus (GDM) and normal pregnant women. The genotype and allele frequencies of CYP7A1-204A/C gene polymorphism of 1037 normal pregnant women, the normal controls, and 627 pregnant women with GDM were examined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and blood glucose (Glu) were measured by enzymatic assay. Chemiluminescence determination of plasma insulin (Ins) was conducted. Apolipoproteins A1 (apoA1) and B (apoB) were measured by the turbidimetric immunoassay. Allele frequencies of A and C at the CYP7A1-204A/C polymorphic locus were 0.586 and 0.414, respectively, in the GDM group and 0.557 and 0.443, respectively in the control group. The distribution of genotype frequencies in both groups showed conformity with the Hardy-Weinberg principle. There was no significant difference in allele and genotype frequencies between the GDM group and the control group. In the control group, carriers of the genotype AA were associated with significantly higher concentrations of apoA1 and lower levels of Ins and homeostatic model assessment of insulin resistance (HOMA-IR) compared with those with genotype CC (all P<0.05). In the non-obese subgroup of the control subjects, carriers of the genotype CC were associated with significantly higher plasma TG or apoA1 levels compared with those with genotype AA ( P<0.05). In the GDM group, carriers with genotype AA of CYP7A1-204A/C polymorphism had elevated levels of gestational weight gain (GWG) compared with those with genotype CC ( P<0.05). These results suggest that 204A/C polymorphism in the CYP7A1 gene is not associated with GDM, but may be closely associated with gestational weight gain in pregnant women with GDM. Variants in this locus are strongly associated with plasma apoA1, Ins, and HOMA-IR levels in the controls and elevated plasma TG levels in non-obese controls.

MON-184 Hypoglycemia During Mixed Meal Tolerance Testing and Early Glucose Dysregulation in Cystic Fibrosis

Post-prandial and oral glucose tolerance test (OGTT)-related hypoglycemia is common in cystic fibrosis (CF). The mechanisms underlying this “reactive” hypoglycemia are unclear. We hypothesized that late hypoglycemia would be associated with higher peak plasma glucose, impaired early-phase insulin secretion compared to PI-NGT, and augmentation of late insulin secretion. To understand these relationships, we performed standardized mixed-meal tolerance tests (MMTT) with timed blood sampling for determination of plasma glucose, insulin and C-peptide in non-diabetic adolescents and young adults with pancreatic insufficient CF (PI-CF). Glucose tolerance was defined by OGTT as: normal (NGT; 1-hour glucose <155 and 2-hour glucose <140mg/dL, n=13), or abnormal (AGT; 1-hour glucose ≥155 or 2-hour glucose ≥140 mg/dL and <200 mg/dL, n=21). Hypoglycemia was defined as plasma glucose <70mg/dL during MMTT and used to assign subjects to exposure groups for analysis. Insulin secretory rates (ISRs) were derived by parametric deconvolution of C-peptide kinetics using a two-compartment model. Glucose and ISR incremental areas under curve (Glc-AUC; ISR-AUC) were calculated. Peak plasma glucose and ISR-AUCinterval were compared between hypoglycemia groups [hypo(+) vs hypo(-)] using Student’s t-test and Mann Whitney U Tests, respectively. Linear regression was performed to explore whether ISR AUC was different in hypo(+) vs hypo(-) after adjustment for Glc-AUC. 34 subjects with PI-CF were evaluated. Participants were 50% female, aged 25±8.7 years, with FEV-1 % predicted 81±19, HbA1c 5.5±0.4%, and BMI z-score 0.17±1. Hypoglycemia occurred in 9 subjects (2 NGT, 7 AGT) at 163±30 min following the start of the meal. No group differences in gender, age, lung function, HbA1c, or BMI z-score were found. Peak plasma glucose was higher in hypo(+) vs hypo(-) (215±21 vs 168±33 mg/dL, p=0.0004). Moreover, early-phase ISR-AUC15-45 min was lower in hypo(+) vs hypo(-) PI-NGT (609±190 vs 1313±850 µU/mL, p=0.03), including the 2 NGT-hypo(+): 430mg/dL and 548mg/dL, respectively. ISR-AUC120-180 min was not different in hypo(+) than hypo(-) PI-AGT (2528 ±1723 vs 2219±1072 µU/mL, p=0.85); however, glc-AUC120-180 min was lower in hypo(+) than hypo(-) PI-AGT (-785±1288mg·min/dL vs 750±1115 mg·min/dL, p=0.015). After adjusting for glc-AUC over this interval, hypo(+) tended to have higher late insulin secretion than hypo(-) PI-AGT (p=0.089). Meal-related hypoglycemia in CF is common and not only seen following the glucose load of an OGTT. Hypoglycemia is associated with early glucose dysregulation (higher peak plasma glucose), loss of early-phase insulin secretion (lower ISR AUC15-45 min), and possible late compensatory hyperinsulinemia (higher ISR AUC120-180 min relative to glucose). Whether hypoglycemia may predict progression to CFRD in individuals with PI-CF requires further study.

Determination of human insulin in dog plasma by a selective liquid chromatography-tandem mass spectrometry method: Application to a pharmacokinetic study

A simple, sensitive and selective LC-MS/MS method for quantitative analysis of human insulin was developed and validated in dog plasma. Insulin glargine was used as the internal standard. After a simple step of solid-phase extraction, the chromatographic separation of human insulin was achieved by using InertSustain Bio C18 column with a mobile phase of acetonitrile containing 1% formic acid (A)—water containing 1% formic acid (B). The detection was performed by positive ion electrospray ionization in multiple-reaction monitoring (MRM) mode. Good linearity was observed in the concentration range of 1–1000 μIU/mL (r2 > 0.99), and the lower limit of quantification was 1 μIU/mL (equal to 38.46 pg/mL). The intra- and inter-day precision (expressed as relative standard deviation, RSD) of human insulin were ≤12.1% and ≤13.0%, respectively, and the accuracy (expressed as relative error, RE) was in the range of −7.23–11.9%. The recovery and matrix effect were both within acceptable limits. This method was successfully applied for the pharmacokinetic study of human insulin in dogs after subcutaneous administration.

Aptamer@Au-o-phenylenediamine modified pencil graphite electrode: A new selective electrochemical impedance biosensor for the determination of insulin

In this work, a poly-orthophenylene diamine substrate is decorated with gold nanoparticles (GNPs) and then with single-stranded DNA (ss-DNA) aptamer immobilized on the surface of a pencil graphite electrode (PGE) for the detection and determination of plasma insulin. In this procedure, a polymer layer is formed on the surface of the graphite electrode using anodic oxidation of orthophenylene diamine monomers. The parameters affecting the biosensor sensitivity including the potential applied to form the polymer layer, incubation time, concentration of immobilized ss-DNA, and the presence of MgCl2 (as salt) are evaluated. Electrochemical impedance spectroscopy and cyclic voltammetry are then used to characterize the biosensor. The biosensor is employed under optimal conditions to obtain figures of merit, which reveal a linear range and a limit of detection of 1.0–1000.0nmolL−1 and 0.27nmolL−1, respectively. Finally, the aptasensor is employed for the determination of insulin in real plasma and urine samples to verify its performance and effectiveness.

Antibodies against glutamic acid decarboxylase and indices of insulin resistance and insulin secretion in nondiabetic adults: a cross-sectional study.

BackgroundAutoimmunity against insulin-producing beta cells from pancreatic islets is a common phenomenon in type 1 diabetes and latent autoimmune diabetes in adults. Some reports have also related beta-cell autoimmunity to insulin resistance (IR) in type 2 diabetes. However, the extent to which autoimmunity against components of beta cells is present and relates to IR and insulin secretion in nondiabetic adults is uncertain.AimTo explore the association between antibodies against glutamic acid decarboxylase (GADA), a major antigen from beta cells, and indices of whole-body IR and beta-cell capacity/insulin secretion in adults who do not have diabetes.MethodsWe studied 81 adults of both sexes aged 30–70, without known diabetes or any autoimmune disease. Participants underwent an oral glucose tolerance test (OGTT) with determination of plasma glucose and insulin at 0, 30, 60, 90, and 120 minutes. From these results we calculated indices of insulin resistance (homeostasis model assessment of insulin resistance [HOMA-IR] and incremental area under the insulin curve [iAUCins]) and insulin secretion (corrected insulin response at 30 minutes and HOMA beta-cell%). GADAs were measured in fasting plasma using immunoenzymatic methods.ResultsWe found an overall prevalence of GADA positivity of 21.3%, without differences by sex and no correlation with age. GADA titers did not change monotonically across quartiles of any of the IR or insulin secretion indices studies. GADA did not correlate linearly with fasting IR expressed as HOMA-IR (Spearman’s r=−0.18, p=0.10) or postabsorptive IR expressed as iAUCins (r=−0.15, p=0.18), but did show a trend toward a negative correlation with insulin secretory capacity expressed by the HOMA-beta cell% index (r=−0.20, p=0.07). Hemoglobin A1c, body mass index, and waist circumference were not associated with GADA titers.ConclusionGADA positivity is frequent and likely related to impaired beta-cell function among adults without known diabetes.

Determinants of glomerular filtration rate following bariatric surgery in individuals with severe, otherwise uncomplicated, obesity: an observational, prospective study.

Obesity-induced nephropathy is an established clinical entity arising from a "maladaptive" response to lipid accumulation at the nephron level. Bariatric surgery positively affects renal function, reducing or increasing glomerular filtration rate (GFR) in subjects with hyperfiltration and renal impairment, respectively. The effect of this surgery in patients with normal estimated GFR (eGFR) is less clear. A complete clinical and biochemical assessment of 135 severely obese, otherwise healthy subjects, was obtained before Roux-en-Y gastric bypass (RYGB). All subjects underwent an OGTT with plasma glucose and insulin determinations. Follow-up data were recorded at 6, 12, 24 and 48months after intervention. Baseline eGFR was 98.2±13.6ml/min/1.73m2; hyperfiltration (>120ml/min/1.73m2) was present in 7% of the cohort. No eGFR variation over the follow-up emerged, except at the last visit (-3.6±1.4ml/min/1.73m2 at month 48, p=0.01 vs baseline). In the univariate analysis, the renal performance at 48months was inversely related to baseline eGFR (r=-0.17, p=0.04) and plasma triglycerides (r=-0.04, p=0.05). Fasting and OGTT-derived variables did not impact eGFR. By multiple regression analysis, eGFR time course was independently predicted only by baseline eGFR (p=0.03). Interestingly, patients having a baseline eGFR >100ml/min/1.73m2 (median value) showed, after 48months, an average loss of -8.3±2.2ml/min/1.73m2, while those with eGFR <100 exhibited a slight increase (+1.8±2.3ml/min/1.73m2, p<0.01). Long-term data confirm the safety of RYGB on renal function. Interestingly, a subtle hyperfiltration, i.e., occurring in high-normal range of eGFR, is attenuated by surgical procedure. Lastly, high serum triglycerides may track an unfavorable renal outcome.

Posttransplantation diabetes mellitus in patients after kidney transplantation - Incidence and risk factors

Transplantation (NTX) associated ischemia-reperfusion-mechanisms and the predisposition for insulin resistance are discussed as causes of a posttransplantation diabetes mellitus (PTDM). Furthermore, immunosuppressants can have a damaging effect on insulin secretion. 55 metabolically healthy patients with an endstage renal disease (age 52 ± 14 years, body mass index 27 ± 5 kg / m(2), blood pressure 137 ± 15/82 ± 11 mmHg) were included in a prospectively cohort study. These patients were transplanted between 2009 and 2011 (82 % of the NTX patients). Baseline examination was performed before NTX. Within the 2nd week as well as 6 and 12 months after transplantation an oral glucose tolerance test (oGGT), 3 and 9 months after NTX a glucagon test took place. In these connections the determination of plasma glucose, C-peptide and insulin was performed. Study endpoints were: graft failure, impaired glucose tolerance (iGT), PTDM, patient's death. Over a follow-up-period of 1 year post NTX iGT / PTDM occurred in 31 % and graft failure in 13 %. In comparison with the healthy control group patients with iGT / PTDM were older (59 ± 8 vs. 48 ± 14ys, p = 0.001), overweight (BMI 29 ± 4 vs. 26 ± 5 kg / m(2), p = 0.038), showed an indication of an insulin resistance before NTX (HOMA 4.0 ± 2.9 vs. 2.4 ± 1.4, p = 0.013; C-peptide 10.1 ± 5.2 vs. 7.1 ± 3.6 ng / ml, p = 0.014; insulin 14.6 ± 9.4 vs. 10.6 ± 5.5mU / l, p = 0.045) and higher HbA1c levels (5.6 ± 0.5 vs. 5.4 ± 0.4 %, p = 0.032). Age (p = 0.001), fasting plasma glucose (p = 0.042), the glucose levels of oGTT immediately after transplantation were shown as prognostically relevant (fasting glucose: p = 0.027; 1 h: p = 0.014; 2 h: p = 0.002). An isolated defective secretion as a result of a toxic damage to the β-cells by immunosuppressants couldn't be shown in any of the patients with iGT / PTDM. 4 % of the patients died in the first year after NTX. In 31 % a disorder of glucose metabolism was found as a frequent complication after NTX. The HOMA index was found to be a meaningful marker for an existing insulin resistance. The fasting glucose before and an oGTT in the first weeks after NTX showed itself as clinically valid laboratory parameters for a risk assessment.

Population pharmacokinetic modeling of glibenclamide in poorly controlled South African type 2 diabetic subjects.

AimThe aim of this study was to describe the pharmacokinetics (PK) of glibenclamide in poorly controlled South African type 2 diabetic subjects using noncompartmental and model-based methods.MethodsA total of 24 subjects with type 2 diabetes were administered increasing doses (0 mg/d, 2.5 mg/d, 5 mg/d, 10 mg/d, and 20 mg/d) of glibenclamide daily at 2-week intervals. Plasma glibenclamide, glucose, and insulin determinations were performed. Blood sampling times were 0 minute, 30 minutes, 60 minutes, 90 minutes, and 120 minutes (post breakfast sampling) and 240 minutes, 270 minutes, 300 minutes, 330 minutes, 360 minutes, and 420 minutes (post lunch sampling) on days 14, 28, 42, 56, and 70 for doses of 0 mg, 2.5 mg, 5.0 mg, 10 mg, and 20 mg, respectively. Blood sampling was performed after the steady state was reached. A total of 24 individuals in the data set contributed to a total of 841 observation records. The PK was analyzed using noncompartmental analysis methods, which were implemented in WinNonLin®, and population PK analysis using NONMEM®. Glibenclamide concentration data were log transformed prior to fitting.ResultsA two-compartmental disposition model was selected after evaluating one-, two-, and three-compartmental models to describe the time course of glibenclamide plasma concentration data. The one-compartment model adequately described the data; however, the two-compartment model provided a better fit. The three-compartment model failed to achieve successful convergence. A more complex model, to account for enterohepatic recirculation that was observed in the data, was unsuccessful.ConclusionIn South African diabetic subjects, glibenclamide demonstrates linear PK and was best described by a two-compartmental model. Except for the absorption rate constant, the other PK parameters reported in this study are comparable to those reported in the scientific literature. The study is limited by the small study sample size and inclusion of poorly controlled type 2 diabetic subjects.

Effect of long-term olanzapine treatment on meal-induced insulin sensitization and on gastrointestinal peptides in female Sprague-Dawley rats.

Meal-induced insulin sensitization (MIS), an endogenous adaptive mechanism is activated post-prandially. Reduced MIS leads to diabetes, but its activation improves insulin sensitivity. MIS is preserved to single olanzapine administration, therefore we aimed to investigate the chronic effect of olanzapine on fasted-state insulin sensitivity and on MIS in female Sprague-Dawley rats. Daily food and water intake, stool and urine production and body weight were determined. The MIS was characterized by a rapid insulin sensitivity test. Fasting hepatic and peripheral insulin sensitivity were determined by a hyperinsulinaemic euglycaemic glucose clamping supplemented with radiotracer technique. Fasted and post-prandial blood samples were obtained for plasma insulin, leptin, ghrelin, amylin, GLP-1, GIP, PYY and PP determination. Adiposity was characterized by weighing intra-abdominal and inguinal fat pads. Olanzapine caused hepatic insulin resistance and a reduced metabolic clearance rate of insulin, but the MIS retained its function. Body weight and adiposity were enhanced, but olanzapine failed to increase food intake. Fasting insulin and leptin were elevated and the post-prandial reduction in ghrelin level was inhibited by olanzapine.The MIS remained functionally intact after long-term olanzapine treatment. Altered insulin, leptin and ghrelin levels indicate olanzapine-induced metabolic derangements. Pharmacological activation of MIS could potentially be exploited to treat or prevent olanzapine-induced insulin resistance.

A supported liquid membrane for microextraction of insulin, and its determination with a pencil graphite electrode modified with RuO2-graphene oxide

A new method for the microextraction and electrochemical determination of insulin is presented based on the following steps: (1) extraction of insulin from an aqueous phase (the donor phase) at pH 8.0 into a sodium dodecyl sulfate (SDS) supported liquid membrane phase to form an insulin-dodecyl sulfate complex, (2) re-extraction of insulin into a small volume of an acceptor phase at pH 3.0 (leading to preconcentration), and (3) detection by differential pulse voltammetry (DPV) using a new kind of electrode. The effects of the pH values of the donor and acceptor phases, SDS concentration, percentage of organic solvent, extraction time and ionic strength on the microextraction were optimized. A pencil graphite electrode modified with graphene oxide and ruthenium dioxide was used as an electrochemical sensor. The DPV responses to the concentration of insulin was linear in the range 0.0008–0.020 and 0.02–1.00 μmol L−1, with a detection limit of 24 pmol L−1. The technique was successfully applied to the determination of insulin in human urine and plasma.

Efficacy of different doses of ulinastatin for prevention of insulin resistance in patients undergoing partialhepatectomy

Objective To evaluate the efficacy of different doses of ulinastatin for prevention of insulin resistance in the patients undergoing partial hepatectomy. Methods Sixty patients of both sexes, aged 33-71 yr, weighing 44-70 kg, of ASA physical status Ⅰor Ⅱ, scheduled for electivepartial hepatectomy, were randomly assigned into 3 groups(n=20 each)using a random number table: control group(group C), low dose of ulinastatin group(group UL)and high dose of ulinastatin group(group UH). Before induction of anesthesia and at the beginning of operation, ulinastatin 2 500 U/kg and 5 000 U/kg(in 20 ml of normal saline)were injected intravenously in UL and UH groups, respectively.The equal volume of normalsaline was given instead of ulinastatin in group C. Before skin incision, before removal of the liver, after removal of the liver, and after closure of the abdominal cavity, blood samples were taken from the right internal jugular vein for determination of plasma glucose, insulin and glucagon concentrations.Insulin sensitivity index was calculated. Results Compared with group C, insulin sensitivity index was significantly increased, and the plasma glucose and insulin concentrations were decreased in UL and UH groups. Conclusion Ulinastatin 2 500 U/kg injected intravenously before induction of anesthesia and at beginning of operation can effectively prevent insulin resistance in the patients undergoing partial hepatectomy. Key words: Trypsin inhibitors; Insulin resistance; Hepatectomy

Вплив імуномодуляторів природного походження на вміст інсуліну у крові курчат-бройлерів за умов стресу

The results of determination of protein fractions content insulin and protein concentrations in plasma of broiler chickens, which further added to the feed of natural origin biologically active substances is given. As an antistressors and immunomodulators in pre-slaughter period biologically active substances of spleen extract were obtained with and without ultrasound application. Aerosol introduction of spleen extract to the broiler chickens feed increases the insulin concentration in broiler chickens blood compared to control.

Thermogenic Effect of Glucose in Hypothyroid Subjects

The importance of thyroid hormone, catecholamines, and insulin in modification of the thermogenic effect of glucose (TEG) was examined in 34 healthy and 32 hypothyroid subjects. We calculated the energy expenditure at rest and during oral glucose tolerance test. Blood samples for determinations of glucose, plasma insulin, adrenaline (A), and noradrenaline (NA) were collected. It was found that TEG was lower in hypothyroid than in control group (19.68 ± 3.90 versus 55.40 ± 7.32 kJ, resp., P < 0.0004). Mean values of glucose and insulin areas under the curve were higher in women with hypothyroidism than in control group (286.79 ± 23.65 versus 188.41 ± 15.84 mmol/L·min, P < 0.003 and 7563.27 ± 863.65 versus 4987.72 ± 583.88 mU/L·min, P < 0.03 resp.). Maximal levels of catecholamines after glucose ingestion were higher in hypothyroid patients than in control subjects (Amax—0.69 ± 0.08 versus 0.30 ± 0.07 nmol/L, P < 0.0001, and NAmax—6.42 ± 0.86 versus 2.54 ± 0.30 nmol/L, P < 0.0002). It can be concluded that in hypothyroidism TEG and glucose tolerance are decreased while the adrenergic response to glucose administration is enhanced. Presumably, these changes are related to decreased insulin sensitivity and responsiveness to catecholamine action.

THERAPEUTIC EFFECTS OF VOLATILE OILS AND ALCOHOLIC AQUEOUS EXTRACTS OF BASIL AND THYME LEAVES ON DIABETIC RATS

The objective of this work to study the therapeutic effect of volatile oils and alcoholic aqueous extracts of basil and thyme leaves in blood glucose and lipid profile of alloxan- induced in diabetic rats. volatile oils were extracted by hydrodistilation and alcoholic aqueous extracts which had been obtained by using methanol. In the experiment animals, fifty rats were divided into ten groups (n=5). Rats were injected (i.p) with alloxan- monohydrate (100mg/kg b.w.).Animals showing fasting blood glucose higher than 300mg/dl were selected and used as diabetic rats. volatile oils and alcoholic aqueous extracts of basil and thyme were administered at dose levels of 200 and 300 mg/kg body weight orally. Scavenging effect on DPPH radicals were determined .Hypoglycemic and hypolipidemic effects of the extracts were evaluated by the determination of blood glucose, plasma insulin, total cholesterol, triglyceride, LDL-cholesterol, ALT, AST, creatinine, uric acid and bilirubin. Also, evaluated some blood antioxidant parameters by the determination of MDA, SOD and GSH. The results showed high scavenging activity with a concentration of 1000 ug/mg where alcoholic aqueous extracts of basil leaves were the best ones (96.97 ±0.58), followed by BHT (95.9 ±3.18) then by alcoholic aqueous extracts of thyme leaves (94.2 ± 58).The results revealed that the group treated with volatile oils and alcoholic aqueous extracts of basil and thyme exhibited high levels of insulin in comparing with diabetic control (4.8Uu/ml). The rats group treated with basil oil(200mg),thyme oil (200mg) and basil oil(300mg)significant increase P< 0.01of plasma insulin (9.01Uu/ml),( 9.4 Uu/ml) and (9.51Uu/ml) respectively. The results showed that the diabetic rats receiving volatile oils and alcoholic aqueous extracts of basil and thyme had significantly lower levels of serum total cholesterol, triglyceride and LDL-cholesterol levels than those of diabetic control group. All treated groups showed significant increase in superoxide dismutase compared with diabetic control group.

Oxidative stress and inflammation in obesity after taurine supplementation: a double-blind, placebo-controlled study

Some researchers found decreased levels of plasma taurine in obese subjects and animals, and reduced expression of an important enzyme of taurine synthesis. These evidences, coupled with the metabolic imbalance of obesity and the possible anti-inflammatory and antioxidant effects of taurine, highlighted the use of taurine as a supplement in obesity treatment. The aim of the present study was to investigate whether taurine supplementation, associated with nutritional counseling, modulates oxidative stress, inflammatory response, and glucose homeostasis in obese women. A randomized double-blind placebo-controlled study was conducted with 16 women with obesity diagnosis and 8 women in the normal weight range. The obese volunteers were matched by age and body mass index and randomly assigned to either the placebo (3 g/day starch flour) or taurine (3 g/day taurine) group. The study lasted 8 weeks, and the experimental protocol included nutritional assessment and determination of plasma sulfur amino acids, insulin, and adiponectin, serum glycemia, and markers of inflammatory response and oxidative stress. Plasma taurine levels were significantly decreased (41%) in the obese volunteers. Both the placebo and taurine groups showed significant reduction in weight (3%), with no differences between groups. Different from placebo, taurine-supplemented group showed significant increase in plasma taurine (97%) and adiponectin (12%) and significant reduction in the inflammatory marker hs-C-reactive protein (29%) and in the lipid peroxidation marker thiobarbituric acid reactive substances (TBARS) (20%). Eight weeks of taurine supplementation associated with nutritional counseling is able to increase adiponectin levels and to decrease markers of inflammation (high-sensitivity C-reactive protein) and lipid peroxidation (TBARS) in obese women.

The effects of overstocking Holstein dairy cattle during the dry period on cortisol secretion and energy metabolism

The objective was to determine whether overstocking during the dry period could alter physiological parameters in dairy cattle associated with cortisol secretion and energy metabolism. Four groups of 10 late-gestation, nonlactating Holstein cows (6 multiparous cows and 4 heifers per group) were exposed to both a control [1 lying stall/cow and 0.67m of linear feed bunk (FB) space/cow] and an overstocked (1 stall/2 cows and 0.34m of FB space/cow) stocking density treatment in a replicated crossover design with 14-d treatment periods. On d 1, 3, 5, 7, 9, and 11 of each 14-d treatment period, blood and fecal samples were collected from each cow for the determination of plasma nonesterified fatty acids (NEFA), glucose, insulin, and fecal cortisol metabolite (11,17-dioxoandrostane; 11,17-DOA) concentrations. Glucose and ACTH challenges were conducted on d 13 and 14, respectively, of each treatment period. Dry matter intake per cow was greater during the overstocked period than during the control period (15.9 vs. 14.9±0.5kg/d). Plasma NEFA and glucose concentrations were greater (0.11 vs. 0.09±0.006mEq/L and 65.3 vs. 64.2±1.1mg/dL, respectively) and 11,17-DOA concentration tended to be greater (891 vs. 792±86ng/g of fecal dry matter) during the overstocked period than during the control period. Insulin concentration was the same during the overstocked (29.0±2.1μIU/mL) and control (31.2±2.1μIU/mL) periods. Overstocking was associated with slightly slower glucose clearance from circulation as evidenced by a greater area under the curve estimate for the glucose response curves (2,882 vs. 2,657±165mg/dL × 180min) but a more attenuated insulin response (insulin area under the curve = 5,258 vs. 6,692±1,104μIU/mL × 180min for the overstocked and control periods, respectively). Changes in tissue glucose uptake may be mediated by changes in pancreatic insulin secretion or peripheral tissue responses to insulin. The role of glucocorticoids in mediating these changes in energy metabolism is still unclear because stocking density treatment was not associated with changes in adrenal secretion of cortisol following ACTH stimulation.

Crosslinking with transglutaminase does not change metabolic effects of sodium caseinate in model beverage in healthy young individuals

BackgroundPostprandial metabolic and appetitive responses of proteins are dependent on protein source and processing technique prior to ingestion. Studies on the postprandial effects of enzymatic crosslinking of milk proteins are sparse. Our aim was to study the effect of transglutaminase (TG)-induced crosslinking of sodium caseinate on postprandial metabolic and appetite responses. Whey protein was included as reference protein.MethodsThirteen healthy individuals (23.3 ± 1.1 y, BMI 21.7 ± 0.4 kg/m2) participated in a single-blind crossover design experiment in which the subjects consumed three different isovolumic (500 g) pourable beverages containing either sodium caseinate (Cas, 29 g), TG-treated sodium caseinate (Cas-TG, 29 g) or whey protein (Wh, 30 g) in a randomized order. Blood samples were collected at baseline and for 4 h postprandially for the determination of plasma glucose, insulin and amino acid (AA) concentrations. Gastric emptying (GE) was measured using the 13 C-breath test method. Appetite was assessed using visual analogue scales.ResultsAll examined postprandial responses were comparable with Cas and Cas-TG. The protein type used in the beverages was reflected as differences in plasma AA concentrations between Wh and Cas, but there were no differences in plasma glucose or insulin responses. A tendency for faster GE rate after Wh was detected. Appetite ratings or subsequent energy intake did not differ among the protein beverages.ConclusionsOur results indicate that the metabolic responses of enzymatically crosslinked and native sodium caseinate in a liquid matrix are comparable, suggesting similar digestion and absorption rates and first pass metabolism despite the structural modification of Cas-TG.

Determination of Insulin in Humans with Insulin-Dependent Diabetes Mellitus Patients by HPLC with Diode Array Detection

A simple and reliable high-performance liquid chromatographic method with diode array detection has been developed and validated for the determination of insulin in human plasma. A good chromatographic separation was achieved on a C18 column with a mobile phase consisting of acetonitrile and 0.2M sodium sulfate (pH 2.4), 25:75 (v/v). Its flow rate was 1.2 mL/min. Calibration curve was linear within the concentration range of 0.15-25 µg/mL. Intra-day and inter-day relative standard deviations for insulin in human plasma were less than 6.3 and 8.5%, respectively. The limits of detection and quantification of insulin were 0.10 and 0.15 µg/mL, respectively. Also, this assay was applied to determine the pharmacokinetic parameters of insulin in eight insulin-dependent diabetes mellitus patients after subcutaneous injection of 25 IU of Actrapid HM.

Estrous and ovarian responses following the administration of different insulin doses following progestagen-cloprostenol treatment in mated does during the dry season

Thirty-nine nulliparous and cyclic free-ranging Anglo-nubian goats were synchronized using 60mg MAP intravaginal sponges for 10days and 50μg cloprostenol treatment, 48h before sponge removal (SR). Goats were allocated to 3 groups with 13 animals in each group. The treatment groups, Insulin 0.14 and Insulin 0.20 were treated subcutaneously, for 3 consecutive days – beginning 48h before SR, with 0.14IU/kg BW/day or 0.2IU/kg BW/day of a long-acting insulin, respectively. The Control group received a 0.5ml saline solution (s.c.). The goats were monitored for the occurrence of estrus and mated at the onset of estrus and 24h later. Transrectal ultrasonography was used to monitor the ovarian follicular dynamics, ovulation rate and diagnose pregnancy. Blood samples were collected from 48h before SR to the 12th day of pregnancy for plasma insulin determinations. Insulin administration exhibited an increase (p<0.05) in animals with plasma insulineamia. Insulin treated goats recorded a higher (p<0.05) ovulation rate, when compared to saline control treated goats (1.7±0.23 vs 1.0±0.21). Nulliparous does from the Insulin 0.14 group recorded large follicles at 0, 12 and 18h of the estrous period (p<0.05), a more efficient synchronization of ovulation (p<0.05) and larger size CLs (p<0.05). It was concluded that administration in insulin induced a positive effect on ovarian response in nulliparous goats. Furthermore, in these animals the reproductive performance appeared to be independent of the increase of insulin dosage.

The prevalence and clinical characteristics of glucose metabolism disorders in patients with liver cirrhosis. A prospective study

Aims. To define the prevalence and clinical characteristics of glucose metabolism disorders (GMD) in patients with compensated liver cirrhosis (LC).Material and methods. Fasting plasma glucose (FPG) levels were measured to 130 patients with clinically stable LC. Oral glucose tolerance tests (OGTT) and fasting plasma insulin determinations were performed to patients with normal FPG. Insulin resistance (IR) was calculated with HOMA2-IR index. GMD were classified according to FPG and OGTT tests results and to the chronologic relation between diagnosis of diabetes mellitus (DM) and LC as follows: type-2 DM (T2DM), hepatogenous diabetes (HD) and impaired glucose tolerance. Patients from all groups were compared.Results. The prevalence of GMD were as follows: T2DM in 25 patients (19.2%, 95% CI 12.5-25.9), HD in 28 (21.5%, 95% CI 14.5-28.5) and IGT in 36 (38.5%, 95% CI 30.1-46.7). The total of patients with GMD was 79.2% (95% CI 72.3-86.1). In 41% of cases GMD were subclinical and 48.7% of patients had IR. Patients with T2DM had a higher number of variables with significant differences compared with the other groups (more marked compared to the patients without GMD). The only differences between the patients with T2DM and HD were hypercreatininemia: 1.14 ± 0.53 vs. 0.84 ± 0.22 mg/dL (p = 0.005) and family history of DM: 8 (32%) vs. 2 (7%) (p = 0.02).Conclusion. Almost 80% of patients with compensated LC had GMD. Half of them were subclinical. The patients with T2DM had marked clinical differences compared to patients from the other groups, particularly renal impairment.