Home About us Contact
|
Home About us Contact | ||
|
|
||
Plasma Insulin Concentrations (plasma + insulin_concentration)
Selected AbstractsEffects of castration on insulin levels and glucose tolerance in the mouse differ from those in manTHE PROSTATE, Issue 15 2010Takamitsu Inoue Abstract BACKGROUND Plasma insulin concentration is increased in prostate cancer patients during androgen deprivation therapy (ADT) and hyperinsulinemia has been associated with aggressive prostate cancer behavior. To investigate the possible role of castration-induced hyperinsulinemia as a mechanism that may attenuate the beneficial effects of ADT in patients with prostate cancer, a murine model would be useful. We therefore investigated long-term metabolic effects of castration in several mouse models. METHODS We studied the long-term influence of castration on energy intake, body weight, glucose tolerance, plasma-insulin, plasma insulin-like growth factor-1 (IGF-1), plasma adiponectin, and plasma leptin in C57BL/6, Swiss nu/nu, and CB17 scid mice receiving various diets. In each case, mice were randomized to have either bilateral orchiectomy or a sham operation. RESULTS Energy intake, body weight, blood glucose levels in glucose tolerance test, plasma insulin, plasma IGF-1, and plasma leptin level in all had a trend to be decreased in castrated as compared to sham operated mice. Plasma adiponectin level was increased in the castrated mice. CONCLUSIONS The effects of castration on glucose, insulin, and related markers in several mouse models studied does not coincide with clinical observations; further studies in this area will require clinical research and/or the use of alternate models such as the dog. Prostate 70: 1628,1635, 2010. © 2010 Wiley-Liss, Inc. [source] Clustering of cardiovascular risk factors in type 2 diabetes mellitus: prognostic significance and trackingDIABETES OBESITY & METABOLISM, Issue 1 2001J. Kaukua Summary Aim Little attention has been paid to the prognostic significance and tracking effect of risk factor clusters characteristic of type 2 diabetes mellitus. We studied the clustering of eight cardiovascular risk factors (smoking, high body mass index, elevated systolic blood pressure, high serum, low density lipoprotein (LDL) cholesterol, high serum LDL triglycerides, low serum, high density lipoprotein (HDL) cholesterol, high fasting blood glucose and high plasma insulin concentration) and their effect on the prognosis and the tracking effect. Methods This study is a population-based prospective follow-up of newly diagnosed type 2 diabetic subjects (n = 133, aged 45,64 years) in Eastern Finland. The following end points were used: all-cause mortality, cardiovascular mortality, and incidences of first myocardial infarction and first stroke. Furthermore, we studied the ,tracking effect' of the risk factor clusters during the 10-year follow-up period. Results When the clustering of risk factors typical of type 2 diabetes mellitus was taken into account, all-cause mortality increased from 28.6% to 50.0% (p <,0.05) and cardiovascular disease mortality increased from 14.3% to 50.0% (p <,0.01) depending on the number of risk factors present. The incidence of first myocardial infarction increased from 0% to 40.0% (p <,0.05) as the number of risk factors increased from 0 to 5. In survivors, the proportion of individuals with no risk factors decreased and the proportion on individuals with three to four risk factors increased during the 10-year follow-up period despite the high mortality among the group with many risk factors. Conclusions The risk factor clusters among type 2 diabetic subjects are of great predictive value and when not aggressively treated, show a relentless increase despite selective mortality. [source] Effects of dietary protein level and cold exposure on tissue responsiveness and sensitivity to insulin in sheepJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 11-12 2001H. Sano The effects of dietary crude protein (CP) level and cold exposure on tissue responsiveness and sensitivity to insulin were studied in sheep. Nine rams were assigned to one of three isoenergetic diets which contained 70, 100, and 140% of CP for maintenance. They were exposed from a thermoneutral environment (20 °C) to a cold environment (0 °C) for 7 days. A hyperinsulinemic euglycemic clamp approach was applied for the determination of tissue responsiveness to insulin (the maximal glucose infusion rate, GIRmax) and tissue sensitivity to insulin (the plasma insulin concentration at half maximal glucose infusion rate, ED50). Dietary CP level influenced digestibilities of dry matter and CP (P=0.002 and P=0.001, respectively), and cold exposure decreased (P=0.01) CP digestibility. The GIRmax and ED50 tended to be influenced (P=0.08) by dietary CP level. The GIRmax was enhanced (P=0.0001) during cold exposure. Significant interactions between diet and environment were found for the GIRmax (P=0.04), but not for ED50 (P=0.07). It is concluded that in sheep dietary CP level can modify insulin action in response to cold exposure. [source] Influence of Sirolimus on Cyclosporine-Induced Pancreas Islet Dysfunction in RatsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 9 2009H. K. Song This study was performed to investigate the effect of sirolimus (SRL) on cyclosporine (CsA)-induced pancreatic islet dysfunction in rats. Three separate studies were performed. First, diabetogenic effect of SRL was evaluated with three different doses (0.15, 0.3 and 0.6 mg/kg). Second, rats were treated with SRL (0.3 mg/kg) with or without CsA (15 mg/kg) for 4 weeks. Third, rats were treated with CsA for 4 weeks, and then switched to SRL for 4 weeks. The effect of SRL on CsA-induced pancreatic islet dysfunction was evaluated by an intraperitoneal glucose tolerance test, plasma insulin concentration, HbA1c level, HOMA-R index, immunohistochemistry of insulin and pancreatic beta islet cell mass. The SRL treatment increased blood glucose concentration in a dose-dependent manner. The combined treatment with SRL and CsA increased blood glucose concentration, Hemoglobin A1c (HbA1c) level, HOMA-R [fasting insulin (mU/mL) x fasting glucose (mmol/L)]/22.5] index and decreased plasma insulin concentration, immunoreactivity of insulin and pancreatic beta islet cell mass compared with rats treated with CsA. CsA withdrawal for 4 weeks improved pancreatic beta-cell function and structure. However, conversion from CsA to SRL further increased blood glucose levels compared with the rats converted from vehicle to SRL. The results of our study demonstrate that SRL is diabetogenic and aggravates CsA-induced pancreatic islet dysfunction. [source] Diet in late pregnancy and glucose-insulin metabolism of the offspring 40 years laterBJOG : AN INTERNATIONAL JOURNAL OF OBSTETRICS & GYNAECOLOGY, Issue 7 2000A. W. Shiell Statistician Objective To determine how diets of women in pregnancy influence the glucose-insulin metabolism of their offspring in adult life. Design A follow up study of men and women born during 1948,1954 whose mothers had taken part in a survey of diet in late pregnancy. Setting Aberdeen, Scotland. Population One hundred and sixty-eight men and women born in the Aberdeen Maternity Hospital. Main outcome measure Plasma glucose and insulin concentrations, fasting and after a standard oral glucose challenge. Results The offspring of women who had high intakes of fat and protein in late pregnancy had a reduced plasma insulin increment between fasting and 30 min with a 7.0% decrease in increment (P= 0.007) per 10 g increase in protein intake and a 4.9% decrease (P= 0.002) per 10 g increase in fat intake. This was independent of the mother's body mass index or weight gain in pregnancy. A low maternal body mass index in early or late pregnancy was associated with a raised fasting plasma insulin concentration with a decrease of 2.4% (P= 0.05) per 1 kg/m2 increase of maternal body mass. Conclusion High intakes of protein and fat during pregnancy may impair development of the fetal pancreatic beta cells and lead to insulin deficiency in the offspring. The offspring of thin mothers tend to be insulin resistant. [source] The glucose lowering effect of an oral insulin (Capsulin) during an isoglycaemic clamp study in persons with type 2 diabetesDIABETES OBESITY & METABOLISM, Issue 1 2010S. D. Luzio Aim: Randomized, open, single-centre, two-way crossover study comparing the pharmacokinetic (PK) and pharmacodynamic (PD) properties of subcutaneous (sc) regular human insulin (Actrapid) and oral insulin in a capsule form (Capsulin). Methods: Sixteen persons (12 males) with type 2 diabetes on oral hypoglycaemic agents (OHAs) participated. Mean (s.d.) age 60.2 (5.5) years, BMI 28.3 (3.4) kg/m2, haemoglobin A1c (HbA1c) 7.4% (1.1). Two 6-h isoglycaemic glucose clamp studies were conducted 11 days apart. All subjects received in random order 12U sc Actrapid on one clamp study day and either 150U or 300U Capsulin (Cap) on the other day. Glucose infusion rates (GIRs), plasma insulin and C-peptide concentrations were determined throughout each 6-h isoglycaemic clamp. Between the clamp study days, all patients received 150U Capsulin twice daily, dropping all their standard OHAs apart from metformin. Self-monitored blood glucose (SMBG) levels were taken four times a day between the clamp study days. Results: Administration of either Actrapid or Capsulin (150 and 300U) increased GIRs reaching a maximum values at approximately 280,330 min. Overall values for maximum GIR values were higher for Actrapid than either dose of Capsulin (p < 0.05). The significantly greater systemic insulin concentrations following Actrapid were reflected in the AUC0,6 h (910 ± 270 vs. 472 ± 245 pmol h/L; 950 ± 446 vs. 433 ± 218 pmol h/L; both p < 0.05 for Actrapid vs. 150U Capsulin and 300U Capsulin respectively). No difference was observed between 150U and 300U Capsulin. During the repeat-dosing period, good safety and tolerability were observed with Capsulin, and SMBG levels remained stable. At the poststudy visit, significant falls in HbA1c, weight and triglycerides were observed. Conclusions: Administration of the oral insulin Capsulin preparation demonstrated a significant hypoglycaemic action over a period of 6 h associated with only a small increase in circulating plasma insulin concentrations. [source] Combination therapy using metformin or thiazolidinediones and insulin in the treatment of diabetes mellitusDIABETES OBESITY & METABOLISM, Issue 6 2005Suzanne M. Strowig The biguanide, metformin, sensitizes the liver to the effect of insulin, suppressing hepatic glucose output. Thiazolidinediones such as rosiglitazone and pioglitazone enhance insulin-mediated glucose disposal, leading to reduced plasma insulin concentrations. These classes of drugs may also have varying beneficial effects on features of insulin resistance such as lipid levels, blood pressure and body weight. Metformin in combination with insulin has been shown to significantly improve blood glucose levels while lowering total daily insulin dose and body weight. The thiazolidinediones in combination with insulin have also been effective in lowering blood glucose levels and total daily insulin dose. Triple combination therapy using insulin, metformin and a thiazolidinedione improves glycaemic control to a greater degree than dual therapy using insulin and metformin or insulin and a thiazolidinedione. There is insufficient evidence to recommend the use of metformin or thiazolidinediones in type 1 diabetic patients. Although these agents are largely well tolerated, some subjects experience significant gastrointestinal problems while using metformin. Metformin is associated with a low risk of lactic acidosis, but should not be used in patients with elevated serum creatinine or those being treated for congestive heart failure. The thiazolidinediones are associated with an increase in body weight, although this can be avoided with careful lifestyle management. Thiazolidinediones may also lead to oedema and are associated with a low incidence of hepatocellular injury. Thiazolidinediones are contraindicated in patients with underlying heart disease who are at risk of congestive heart failure and in patients who have abnormal hepatic function. The desired blood glucose-lowering effect and adverse event profiles of these agents should be considered when recommending these agents to diabetic patients. The potential for metformin or the thiazolidinediones to impact long-term cardiovascular outcomes remains under investigation. [source] Role for the Pineal and Melatonin in Glucose Homeostasis: Pinealectomy Increases Night-Time Glucose ConcentrationsJOURNAL OF NEUROENDOCRINOLOGY, Issue 12 2001S. E. La Fleur Abstract The effects of melatonin on glucose metabolism are far from understood. In rats, the biological clock generates a 24-h rhythm in plasma glucose concentrations, with declining concentrations in the dark period. We hypothesized that, in the rat, melatonin enhances the dark signal of the biological clock, decreasing glucose concentrations in the dark period. We measured 24-h rhythms of plasma concentrations of glucose and insulin in pinealectomized rats fed ad libitum and subjected to a scheduled feeding regimen with six meals equally distributed over the light/dark cycle and compared them with previous data of intact rats. Pinealectomy dampened the amplitude of the 24-h rhythm in plasma glucose concentrations in rats fed ad libitum, and abolished it completely in rats subjected to the scheduled feeding regimen, while plasma insulin concentrations did not change under both conditions. Pinealectomy abolished the nocturnal decline in plasma glucose concentrations irrespective of whether rats were fed ad libitum or subjected to the scheduled feeding regimen. Melatonin replacement restored 24-h mean plasma glucose concentrations in pinealectomized rats that were subjected to the scheduled feeding regimen but, interestingly, it did not restore the 24-h rhythm. Melatonin treatment also resulted in higher meal-induced insulin responses, probably mediated via an increased sensitivity of the ,-cells. Taken together, our data demonstrate that the pineal hormone, melatonin, influences both glucose metabolism and insulin secretion from the pancreatic ,-cell. The present study also demonstrates that removal of the pineal gland cannot be compensated by mimicking plasma melatonin concentrations only. [source] Corni fructus as the major herb of Die-Huang-Wan for lowering plasma glucose in Wistar ratsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 11 2004Shorong-Shii Liou Die-Huang-Wan is a mixture of six herbs used to lower plasma glucose by increasing insulin secretion in normal rats. Die-Huang-Wan contains the herbs dioscorea (Dioscoreae rhizoma), cornus (Corni fructus), alisma (Rhizoma alismatis), holelen (Poria), rehmannia (Rehmanniae radix) and tree peony bark (Moutan radicis cortex). The present study was designed to clarify the major herb contributing to the plasma glucose-lowering action of Die-Huang-Wan in rats. A decrease in plasma glucose was not observed in Wistar rats treated with the cornus-deleted formula of Die-Huang-Wan; however, the action was retained in the other herb-deleted formulas containing cornus. In normal rats, the decrease in plasma glucose and increase in plasma insulin concentrations were dependent on the dose of cornus and were similar to those produced by Die-Huang-Wan. Treatment of Wistar rats with each of the other five herbs separately did not result in a decrease in plasma glucose. Moreover, the increase in plasma insulin or reduction in plasma glucose resulting from cornus treatment was blocked by atropine or 4-diphenylacetoxy-N-methylpiperidine methiodide mustard, indicating mediation of muscarinic M3 receptors similar to that caused by Die-Huang-Wan. These results suggest that cornus is the major contributor to the plasma glucose-lowering action in Die-Huang-Wan in normal rats. [source] Hypoglycaemic effect of Calamintha officinalis Moench. in normal and streptozotocin-induced diabetic ratsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 6 2004A. Lemhadri The purpose of this study was to investigate the effects of a water extract from the aerial parts of Calamintha officinalis Moench., after either a single dose or daily oral administration for 15 days, on plasma blood glucose concentrations and basal insulin levels in normal and streptozotocin-induced diabetic rats (STZ diabetic rats). The results clearly demonstrated the hypoglycaemic effect of this plant extract in both normal and STZ diabetic rats. In addition, no changes were observed in basal plasma insulin concentrations after treatment with this plant in normal or STZ diabetic rats, indicating that the underlying mechanism of the plant's pharmacological action seems to be independent of insulin secretion. We conclude that the aqueous C. officinalis extract exhibits a significant hypoglycaemic effect in normal and STZ diabetic rats without affecting basal plasma insulin concentrations, and supports, therefore, its traditional use by the Moroccan population. [source] Inflammatory change of fatty liver induced by intraportal low-dose lipopolysaccharide infusion deteriorates pancreatic insulin secretion in fructose-induced insulin-resistant ratsLIVER INTERNATIONAL, Issue 8 2008Po-Shiuan Hsieh Abstract Background: This study tested whether subacute inflammatory change of fatty liver induced by portal endotoxaemia is detrimental to pancreatic insulin secretion in fructose-fed rats (FFRs) with fatty liver. Methods: Rats were randomly assigned into two groups with a regular or fructose-enriched diet for 8 weeks. Rats, after fructose feeding for 4 weeks, were further divided into three subgroups: on fructose diet alone, on fructose diet combined with intraportal saline or lipopolysaccharide (LPS) infusion (n=8 per group) for the next 4 weeks. In another set of experiments, the liver and pancreatic tissues were obtained for histological examination in these four groups. Pancreatic insulin secretion was evaluated by in vivo hyperglycaemic clamp study. Results: Fasting plasma insulin concentrations and homoeostasis model assessment-insulin resistance, an insulin resistance score, were significantly increased in FFRs but failed to change in rats with LPS treatment. The 4-week intraportal LPS infusion significantly increased circulating aspartate transaminase, alanine transaminase and C-reactive protein levels but did not alter endotoxin levels in FFRs. The increased white blood cell count was also noted in rats after intraportal LPS infusion for 2 and 4 weeks. The attenuated first-phase and second-phase insulin responses in FFRs shown in hyperglycaemic clamp were further deteriorated in those with intraportal LPS infusion. Increased histopathological scores of liver and pancreas shown in FFRs were further increased in those combined with portal endotoxaemia. Conclusion: This study demonstrates that the chronic subacute inflammatory change of fatty liver induced by mild portal endotoxaemia could deteriorate insulin secretion in a rodent model of metabolic syndrome and fatty liver. [source] Acanthosis nigricans is a reliable cutaneous marker of insulin resistance in obese Japanese childrenPEDIATRICS INTERNATIONAL, Issue 6 2003Hajime Yamazaki AbstractBackground:,Acanthosis nigricans (AN) is a skin condition characterized by darkening and thickening of skin with formation of irregular folds, usually limited to a few specific areas of the body. Recently, AN has been reported to be linked to hyperinsulinemia and obesity. The aim of the present study was to determine whether or not the presence of AN in obese Japanese children is a reliable cutaneous marker. Methods:,The authors analyzed the clinical characteristics of 439 obese Japanese children (260 boys, 179 girls; mean age 10.1 years; mean percentage overweight 51.9%), who had visited Tsuruoka City Shonai Hospital in 1990,2000. Eighty-two of the 439 children were examined using an oral glucose tolerance test (OGTT). Of these children, the authors retrospectively studied 16 subjects: eight with AN and eight without AN (age range: 10.8,13.9 years; percentage overweight range: 54.3,97.0%). They were age and percentage obesity-matched males with normal glucose tolerance during OGTT. Females with normal glucose tolerance during OGTT were excluded from the 16 subjects because the number was too small and children with impaired glucose tolerance or type 2 diabetes during OGTT were also excluded because of glucose toxicity. Eighty-two children including the 16 subjects were analyzed at their first visit for the presence or absence of AN on the posterior of the neck, and for characteristics including age, birthweight, body height, bodyweight, percentage overweight, blood pressure, liver function markers serum lipid concentrations, fasting plasma glucose concentrations and insulin concentrations shown by the results of OGTT. Results:,(1) Children with AN showed significantly more glucose intolerance including impaired glucose tolerance and type 2 diabetes compared with those children without AN, and fasting plasma insulin concentrations were most significantly correlated with the presence of AN. (2) Insulin resistance based on fasting plasma insulin concentrations was seen in significantly more children with AN than in children without AN, even in age and percentage obesity-matched subjects with normal glucose tolerance during OGTT. Conclusions:, Acanthosis nigricans could be a reliable cutaneous marker of insulin resistance in obese Japanese children. [source] | ||||||||||