GLUCOSE TOLERANCE AND IMMUNOREACTIVE INSULIN IN PATIENTS WITH PHEOCHROMOCYTOMA: THE EFFECT OF α-RECEPTOR BLOCKING AGENTS

1971 ◽  
Vol 66 (2) ◽  
pp. 368-378 ◽  
Author(s):  
Ruth Illig ◽  
W. H. Ziegler

ABSTRACT Blood glucose, plasma insulin, free fatty acids and urinary noradrenaline were investigated in 5 patients with noradrenaline producing pheochromocytoma (4 adenomas, 1 metastatic tumour) and in 3 control subjects. Oral glucose tolerance tests were performed before therapy, during treatment with the α-receptor blocking agent phenoxybenzamine, and in 4 patients after surgical removal of the tumour. In the untreated pheochromocytoma patients, glucose curves were pathologically high; insulin secretion was low in relation to blood glucose levels or almost completely suppressed depending on the plasma noradrenaline concentrations. During phenoxybenzamine treatment glucose curves remained abnormal; insulin concentrations increased both in patients and control subjects. Six to 26 days after operation, glucose curves and insulin secretion became normal. Fractionated urine collections revealed a fall in noradrenaline excretion after oral glucose load. The urinary excretion of noradrenaline increased when α-receptor blockade was effective. The increased release of insulin under α-receptor blockade in patients and control subjects suggests that noradrenaline plays a role in the regulation of insulin secretion in normal conditions as well as in patients with pheochromocytoma.

Endocrine ◽  
2003 ◽  
Vol 22 (2) ◽  
pp. 177-180
Author(s):  
Erika Hubina ◽  
László Kovács ◽  
Zoltán Görömbey ◽  
István Szabolcs ◽  
Sándor Czirják ◽  
...  

2004 ◽  
Vol 287 (2) ◽  
pp. E241-E246 ◽  
Author(s):  
David A. Ehrmann ◽  
Elena Breda ◽  
Matthew C. Corcoran ◽  
Melissa K. Cavaghan ◽  
Jacqueline Imperial ◽  
...  

Deterioration in glucose tolerance occurs rapidly in women with polycystic ovary syndrone (PCOS), suggesting that pancreatic β-cell dysfunction may supervene early. To determine whether the compensatory insulin secretory response to an increase in insulin resistance induced by the glucocorticoid dexamethasone differs in women with PCOS and control subjects, we studied 10 PCOS and 6 control subjects with normal glucose tolerance. An oral glucose tolerance test (OGTT) and a graded glucose infusion protocol were performed at baseline and after subjects took 2.0 mg of dexamethasone orally. Basal (Φb), static (Φs), dynamic (Φd), and global (Φ) indexes of β-cell sensitivity to glucose were derived. Insulin sensitivity (Si) was calculated using the minimal model; a disposition index (DI) was calculated as the product of Si and Φ. PCOS and control subjects had nearly identical fasting and 2-h glucose levels at baseline. Φb was higher, although not significantly so, in the PCOS subjects. The Φd, Φs, and Φ indexes were 28, 19, and 20% higher, respectively, in PCOS subjects. The DI was significantly lower in PCOS (30.01 ± 5.33 vs. 59.24 ± 7.59) at baseline. After dexamethasone, control subjects averaged a 9% increase (to 131 ± 12 mg/dl) in 2-h glucose levels; women with PCOS had a significantly greater 26% increase to 155 ± 6 mg/dl. The C-peptide-to-glucose ratios on OGTT increased by 44% in control subjects and by only 15% in PCOS subjects. The accelerated deterioration in glucose tolerance in PCOS may result, in part, from a relative attenuation in the response of the β-cell to the demand placed on it by factors exacerbating insulin resistance.


1999 ◽  
pp. 609-618 ◽  
Author(s):  
M Vaxillaire ◽  
ME Pueyo ◽  
K Clement ◽  
J Fiet ◽  
J Timsit ◽  
...  

OBJECTIVE: To evaluate insulin secretion and sensitivity in affected (diabetes mellitus or impaired glucose tolerance; n=7) and in unaffected (normal glucose tolerance; n=3) carriers of hepatocyte nuclear factor-1alpha (maturity-onset diabetes of the young-3 (MODY3)) gene mutations. METHODS: Insulin secretion was assessed by an i.v. glucose tolerance test (IVGTT), hyperglycemic clamp and arginine test, and insulin sensitivity by an euglycemic hyperinsulinemic clamp. Results were compared with those of diabetic MODY2 (glucokinase-deficient) and control subjects. RESULTS: The amount of insulin secreted during an IVGTT was decreased in affected MODY3 subjects (46+/-24 (s.d.) pmol/kg body weight (BW)) as compared with values in MODY2 (120+/-49pmol/kg BW) and control (173+/-37pmol/kg BW; P=0.0004) subjects. The amount of insulin secreted during a 10mmol/l glucose clamp was decreased in affected MODY3 subjects (171+/-78pmol/kg BW) and MODY2 subjects (302+/-104pmol/kg BW) as compared with control subjects (770+/-199pmol/kg BW; P=0.0001). Insulin secretion in response to arginine was decreased in affected MODY3 subjects. Milder and heterogeneous defects were observed in the unaffected MODY3 subjects; the amount of insulin secreted during the hyperglycemic clamp was 40-79% of that of controls. The response to arginine was abnormally delayed. Insulin sensitivity was decreased in diabetic but not in non-diabetic MODY3 subjects. CONCLUSIONS: Beta-cell dysfunction in response to glucose and arginine is observed in affected and unaffected MODY3 subjects. The MODY3 and MODY2 subtypes present different insulin secretion profiles. Secondary insulin resistance might contribute to the chronic hyperglycemia of MODY3 patients and modulate their glucose tolerance.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Yancui Sun ◽  
Yanqiu Zhu ◽  
Lu Zhang ◽  
Yan Lu ◽  
Yan Liu ◽  
...  

The study aims to explore the relationship between plasma insulin secretion and arterial stiffness in nondiabetic essential hypertensive patients. A total of 730 nondiabetic essential hypertensive patients registered between January 2016 and October 2020 were enrolled. A two-hour oral glucose tolerance test (OGTT) was performed to detect the levels of C-peptide and blood glucose at 0 hours and 2 hours, as well as the difference between C-peptide (Δ C-peptide) and blood glucose (Δ blood glucose) over the same period. Patients were divided into two groups: the normal glucose tolerance (NGT) group (n = 322) and the impaired glucose tolerance (IGT) group (n = 408). A multiple linear regression analysis was used to evaluate the association between brachial-ankle pulse wave velocity (baPWV) and the other factors. 0 h C-peptide, 2 h C-peptide, and Δ C-peptide were found to be higher in the IGT group. baPWV was positively linear correlated with 2 h C-peptide (r = 0.086, p = 0.020 ) and Δ C-peptide (r = 0.115, p = 0.002 ). baPWV remained independently associated with 0 h C-peptide, 2 h C-peptide, and Δ C-peptide, after adjusting by age, gender, smoking, body mass index (BMI), high-density lipoprotein (HDL), cholesterol, systolic blood pressure (SBP), and triglycerides (TG). Our data shows that higher endogenous insulin secretion might play an important role in the progression of arterial stiffness in nondiabetic essential hypertensive patients.


2018 ◽  
Vol 5 (7) ◽  
pp. 2440-2454
Author(s):  
D. A. Omoboyowa ◽  
F. O. Afolabi ◽  
T. C. Aribigbola

Background: The anti-hyperglycemic potential of methanol stem bark extract of Anacardium occidentale (MSBEAO) was investigated using an alloxan-induced diabetic rat model. Alloxan administration induces the generation of free radicals which can affect antioxidant status resulting in the disruption of the β-cells of the pancreas. Therefore, this study examines the antioxidant potential of the plant extract and the ameliorating effect on the pancreas of alloxan-induced diabetic rats. Methods: Diabetes was induced by intraperitoneal injection of 150 mg/kg body weight of alloxan monohydrate. MSBEAO, at a concentration of 100 or 200 mg/kg b.w. was orally administered to alloxan-induced diabetic rats and normal rats. The hypoglycemic effect, oral glucose tolerance test, and biochemical assay of alloxan-induced diabetic rats were assayed using standard procedures. Results: Preliminary phytochemical screening of the extract revealed the presence of alkaloids, tannins, saponins, terpenoids, carbohydrates, and phenols at moderate concentrations. The lethality dose (LD50) of the plant extract was found to be equal to or less than 5000 mg/kg b.w. The hypoglycemic effect of the extract on the non-diabetic rats revealed a significant (p<0.05) decrease in the blood glucose concentration of animals administered with 1 g/kg b.w. of the extract, compared to normal control rats administered with normal saline. In the oral glucose tolerance test, the methanol extract exerted the highest response, similar to glibenclamide after 15 and 30 minutes of administration, compared to the control rats. The methanol extract yielded the highest blood glucose lowering effects after 9 days of treatment (p<0.05), compared to diabetic rats administered with normal saline and 0.3 mg/kg b.w. of glibenclamide. Administration of the extract at 200 mg/kg b.w. showed improved pancreas architecture and regeneration of the β-cells, compared with the pancreas of animals in the other groups. Conclusion: The results of this study suggest that MSBEAO is a potentially effective agent for the management of diabetes which might result from the antioxidant-generating capacity of the stem bark.


2012 ◽  
Vol 19 (04) ◽  
pp. 462-468
Author(s):  
M. IKRAM ◽  
SYED HAIDER HASAN ALAM ◽  
SHAFQAT MUKHTAR ◽  
M. Saeed

Introduction: Gestational diabetes mellitus is common disorder in pregnancy. It is associated with adverse pregnancy outcome. There is no consensus regarding the optimal approach to screening of gestational diabetes mellitus. The present study has tried toobserve the value of fasting blood glucose in screening of gestational diabetes. Objective: To determine the frequency of patients in whomfasting blood glucose and 100gm glucose tolerance show agreement for screening of gestational diabetes mellitus at 24 -28 wks. Studydesign: Comparative cross sectional study. Settings: The study was conducted at Gynecology and Obstetrics department Shaikh ZayedFederal Post Graduate Institute Lahore. Duration of study with dates: 6 months from 12Nov 2010 to 11 May 2011. Material and method: Thestudy included 135 booked patients with positive family history of diabetes mellitus. All patients underwent fasting blood glucose at 24-28 weeksof gestation, regardless of results of fasting blood glucose on next visit they underwent 100g oral glucose tolerance test (OGTT). The agreementbetween fasting blood glucose and 100g oral glucose tolerance test was calculated in frequency and percentages. Results: The mean age ofwomen in studied population was 27.15±3.70.Out of 135 patients 86.7 %( 117) showed agreement between results of fasting blood glucose and100g OGTT while 13.31 %( 18) showed no agreement between both of the tests. Conclusions: Fasting blood glucose is a good screeningoption for gestational diabetes mellitus along with positive history. It provides a simple, cheap and more practical test for screening of gestationaldiabetes mellitus. However diagnostic confirmation with 100g OGTT should be done.


2022 ◽  
Author(s):  
Marta Garaulet ◽  
Jesus Lopez-Minguez ◽  
Hassan S Dashti ◽  
Céline Vetter ◽  
Antonio Miguel Hernández-Martínez ◽  
...  

<strong>Objective: </strong>We tested whether the concurrence of food intake and elevated concentration of endogenous melatonin, as occurs in late eating, results in impaired glucose control, in particular in carriers of the type 2 diabetes-associated G allele in the melatonin-receptor-1-b gene (<i>MTNR1B</i>).<strong> </strong> <p><strong>Research Design and Methods:</strong> In a Spanish natural late eating population, a randomized, cross-over study design was performed, following an 8-h fast. Each participant <strong>(n=845) </strong>underwent two evening 2-h 75g oral glucose tolerance tests (OGTT): an early condition scheduled 4 hours prior to habitual bedtime <strong>(“early dinner-timing”)</strong>, and a late condition scheduled 1 hour prior to habitual bedtime <strong>(“late dinner-timing”)</strong>, simulating an early and a late dinner timing, respectively.<strong> </strong>Differences in postprandial glucose and insulin responses were determined using incremental area under the curve (AUC) calculated by the trapezoidal method between <strong>early and late dinner-timing.</strong><strong></strong></p> <p><strong>Results:</strong> <strong>Melatonin serum levels were </strong>3.5-fold <strong>higher in the late <i>vs. </i>early condition, with late dinner-timing resulting in </strong>6.7% <strong>lower insulin</strong> <strong>area-under-the-curve (AUC) and </strong>8.3%<strong> higher glucose</strong> <strong>AUC. In the late condition<i> MTNR1B</i> G-allele carriers had lower glucose tolerance than non-carriers. Genotype differences in glucose tolerance were attributed to reductions in </strong>β-cell <strong>function (<i>P<sub>int</sub></i><sub> </sub>AUCgluc=0.009, <i>P<sub>int</sub></i><sub> </sub>CIR=0.022, <i>P<sub>int </sub></i>DI=0.018).</strong></p> <p><strong>Conclusions:</strong> <strong>Concurrently high endogenous melatonin and carbohydrate intake, as typical for late eating, impair glucose tolerance, especially in <i>MTNR1B</i> G-risk-allele carriers<i>, </i>attributable to insulin secretion defects.</strong></p>


1995 ◽  
Vol 88 (3) ◽  
pp. 301-306 ◽  
Author(s):  
Lorraine A. Nolte ◽  
Samy M. Abdel-Halim ◽  
Iva K. Martin ◽  
Amel Guenifi ◽  
Juleen R. Zierath ◽  
...  

1. The effect of glucose intolerance on insulin-stimulated glucose transport in isolated skeletal muscles was investigated in male F, hybrids of spontaneously diabetic GK (Goto—Kakizaki) and control Wistar rats at 1 and 2 months of age. 2. Hybrid rats are characterized by markedly impaired glucose-induced insulin secretion. The area under the blood glucose curve was significantly higher following an intraperitoneal glucose injection (2 g/kg) in hybrid rats in both age groups than in the control rats (P < 0.001). In 2-month-old hybrid rats the incremental area under the insulin curve during the intraperitoneal glucose tolerance test was not different from that of control rats. Serum cholesterol, triacylglycerol or plasma free fatty acid levels did not differ between the groups. Fasting and post-prandial plasma glucose concentrations were elevated in 2-month-old hybrid rats compared with control rats (54%, P < 0.05, and 27%, P < 0.05, respectively), but were not differerent in 1-month-old rats. Plasma insulin did not differ between the hybrid and control rats in the fasting or post-prandial state at either age studied. 3. The insulin dose—response curves for 3-O-methylglucose transport did not differ between 1-month-old hybrid and control rats for either the soleus or epitrochlearis muscle. The insulin dose—response curve for the epitrochlearis, but not for the soleus, muscle from 2-month-old hybrid rats was shifted to the right compared with the curve from the control animals (P < 0.05). 4. In conclusion, the hybrid rat is a non-obese, non-hyperinsulinaemic animal model, which at a young age is characterized by impaired insulin secretion and moderate glucose intolerance. In this glucose-intolerant rat model, mild peripheral insulin resistance gradually develops, as reflected by the decreased insulin-induced glucose transport in the fast-twitch epitrochlearis muscle. It is suggested that the elevated blood glucose per se may have contributed to the slight decrease in peripheral insulin action.


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