scholarly journals Improved Insulin Sensitivity during Pioglitazone Treatment Is Associated with Changes in IGF-I and Cortisol Secretion in Type 2 Diabetes and Impaired Glucose Tolerance

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Lisa Arnetz ◽  
Neda Rajamand Ekberg ◽  
Charlotte Höybye ◽  
Kerstin Brismar ◽  
Michael Alvarsson

Background. Hypercortisolism and type 2 diabetes (T2D) share clinical characteristics. We examined pioglitazone's effects on the GH-IGF-I and HPA axes in men with varying glucose intolerance. Methods. 10 men with T2D and 10 with IGT received pioglitazone 30–45 mg for 12 weeks. OGTT with microdialysis in subcutaneous adipose tissue and 1 μg ACTH-stimulation test were performed before and after. Glucose, insulin, IGF-I, IGFBP1, and interstitial measurements were analyzed during the OGTT. Insulin sensitivity was estimated using HOMA-IR. Results. HOMA-IR improved in both groups. IGF-I was initially lower in T2D subjects () and increased during treatment ( to SD; ); no change was seen in IGT ( SD before and during treatment). Fasting glycerol decreased in T2D (), indicating reduced lipolysis. Fasting cortisol decreased in T2D ( to  nmol/L; ) but increased in IGT ( to  nmol/L; ). Peak cortisol was lower in T2D during treatment ( to , versus to  nmol/L in IGT; ). Conclusions. Pioglitazone improved adipose tissue and liver insulin sensitivity in both groups. This may explain increased IGF-I in T2D. Pioglitazone affected cortisol levels in both groups but differently, suggesting different mechanisms for improving insulin sensitivity between T2D and IGT.

2021 ◽  
Author(s):  
Yury Orlando Nunez Lopez ◽  
Anna Casu ◽  
Zuzana Kovacova ◽  
Alejandra M Petrilli ◽  
Olga Sideleva ◽  
...  

Pioglitazone, a PPARγ agonist, is used to treat type 2 diabetes (T2D). PPARγ is highly expressed in adipose tissue (AT), however the effects of pioglitazone to improve insulin sensitivity are also evident in other tissues. We hypothesized that pioglitazone modifies the cargo of circulating AT-derived extracellular vesicles (EVs) to alter interorgan crosstalk. We tested this in a 3-month trial in which 24 subjects with T2D who were well-controlled with diet/exercise or metformin were randomized to treatment with either pioglitazone 45 mg/day or placebo (NCT00656864). Levels of 42 adipocyte-derived EV-miRNAs were measured in plasma EVs. Levels of 5 miRNAs (i.e., miR-7-5p, miR-20a-5p, miR-92a-3p, miR-195-5p, and miR-374b-5p) were significantly downregulated in EVs in response to pioglitazone treatment relative to placebo. However, the opposite occurred for miR-195-5p in subcutaneous AT from the same participants. Changes in miRNA expression in EVs and AT correlated with changes in suppression of lipolysis and improved insulin sensitivity, among others. DICER was downregulated and exosomal miRNA sorting-related genes YBX1 and hnRNPA2B1 displayed a trend toward downregulation in AT. Furthermore, analysis of EV-miRNA targeted genes identified a network of overtargeted transcripts that changed in a coordinated manner in AT. Collectively, our results suggest that some beneficial pharmacologic effects of PIO are mediated by adipose-specific miRNA regulation and exosomal/EV trafficking.


2020 ◽  
Author(s):  
Ada Admin ◽  
Marie Louise Johansen ◽  
Jaime Ibarrola ◽  
Amaya Fernández-Celis ◽  
Morten Schou ◽  
...  

Activation of the mineralocorticoid receptor (MR) may promote dysfunctional adipose tissue in patients with type 2 diabetes, where increased pericellular fibrosis has emerged as a major contributor. The knowledge of the association between the MR, fibrosis and the effects of an MR antagonist (MRA) in human adipocytes remains very limited. The present sub-study including 30 participants was prespecified as part of the Mineralocorticoid Receptor Antagonist in type 2 Diabetes (MIRAD) trial, randomizing patients to either high dose eplerenone or placebo for 26 weeks. In adipose tissue biopsies, changes in fibrosis were evaluated by immunohistological examinations and by the expression of mRNA and protein markers of fibrosis. Treatment with an MRA reduced pericellular fibrosis, synthesis of the major subunits of collagen type I and VI, and the profibrotic factor α-smooth muscle actin, as compared to placebo in subcutaneous adipose tissue. Furthermore, we found decreased expression of the MR and downstream molecules neutrophil gelatinase–associated lipocalin, galectin-3, and lipocalin-like prostaglandin D2 synthase with an MRA. In conclusions, we present original data demonstrating reduced fibrosis in adipose tissue with inhibition of the MR, which could be a potential therapeutic approach to prevent the extracellular matrix remodeling of adipose tissue in type 2 diabetes.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xinlei Wang ◽  
Xiaoqin Zhao ◽  
Yunjuan Gu ◽  
Xiaohui Zhu ◽  
Tong Yin ◽  
...  

In China, most normal BMI (body mass index of ≥18.5 to <25 kg/m2) adults with type 2 diabetes (T2DM) exhibit visceral adiposity. This study compared the effects of exenatide and humalog Mix25 on normal BMI patients with T2DM and visceral adiposity. A total of 95 patients were randomized to receive either exenatide or humalog Mix25 treatment for 24 weeks. Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were quantified by magnetic resonance imaging (MRI) and liver fat content (LFC) by liver proton magnetic resonance spectroscopy (1H MRS). Each patient’s weight, waist circumference, BMI, blood glucose, insulin sensitivity, pancreatic β-cell function, and fibroblast growth factor 21 (FGF-21) levels were measured. Data from 81 patients who completed the study (40 and 41 in the exenatide and humalog Mix25 groups, respectively) were analysed. The change in 2 h plasma blood glucose was greater in the exenatide group (P=0.039). HOMA-IR and MBCI improved significantly after exenatide therapy (P<0.01, P=0.045). VAT and LFC decreased in both groups (P<0.01 for all) but to a greater extent in the exenatide group, while SAT only decreased with exenatide therapy (P<0.01). FGF-21 levels declined more in the exenatide group (P<0.01), but were positively correlated with VAT in the entire cohort before (r=0.244, P=0.043) and after (r=0.290, P=0.016) the intervention. The effects of exenatide on glycaemic metabolism, insulin resistance, pancreatic β-cell function, and fat deposition support its administration to normal BMI patients with T2DM and visceral adiposity.


2003 ◽  
Vol 284 (2) ◽  
pp. E443-E448 ◽  
Author(s):  
A. S. Lihn ◽  
T. Østergård ◽  
B. Nyholm ◽  
S. B. Pedersen ◽  
B. Richelsen ◽  
...  

Adiponectin is suggested to be an important mediator of insulin resistance. Therefore, we investigated the association between adiponectin and insulin sensitivity in 22 healthy first-degree relatives (FDR) to type 2 diabetic patients and 13 matched control subjects. Subcutaneous adipose tissue biopsies were taken before and after a hyperinsulinemic euglycemic clamp. FDR subjects were insulin resistant, as indicated by a reduced Mvalue (4.44 vs. 6.09 mg · kg−1· min−1, P < 0.05). Adiponectin mRNA expression was 45% lower in adipose tissue from FDR compared with controls ( P < 0.01), whereas serum adiponectin was similar in the two groups (6.4 vs. 6.6 μg/ml, not significant). Insulin infusion reduced circulating levels of adiponectin moderately (11–13%) but significantly in both groups ( P < 0.05). In the control group, adiponectin mRNA levels were negatively correlated with fasting insulin ( P < 0.05) and positively correlated with insulin sensitivity ( P < 0.05). In contrast, these associations were not found in the FDR group. In conclusion, FDR have reduced adiponectin mRNA in subcutaneous adipose tissue but normal levels of circulating adiponectin. Adiponectin mRNA levels are positively correlated with insulin sensitivity in control subjects but not in FDR. These findings indicate dysregulation of adiponectin gene expression in FDR.


Endocrinology ◽  
2009 ◽  
Vol 150 (4) ◽  
pp. 1670-1679 ◽  
Author(s):  
Michael M. Swarbrick ◽  
Peter J. Havel ◽  
Arthur A. Levin ◽  
Andrew A. Bremer ◽  
Kimber L. Stanhope ◽  
...  

Protein tyrosine phosphatase (PTP)-1B antagonizes insulin signaling and is a potential therapeutic target for insulin resistance associated with obesity and type 2 diabetes. To date, studies of PTP-1B have been limited by the availability of specific antagonists; however, treatment of rodents with antisense oligonucleotides (ASOs) directed against PTP-1B improves insulin sensitivity, inhibits lipogenic gene expression, and reduces triglyceride accumulation in liver and adipose tissue. Here we investigated ASO-mediated PTP-1B inhibition in primates. First, PTP-1B ASO (ISIS 113715) dose-dependently inhibited PTP-1B mRNA and protein expression in cultured monkey hepatocytes. Subcutaneous administration of ISIS 113715 reduced PTP-1B mRNA expression in liver and adipose tissue of normal-weight monkeys by 40–50% and improved insulin sensitivity during an iv glucose tolerance test (IVGTT). In obese, insulin-resistant rhesus monkeys, treatment with 20 mg/kg ISIS 113715 for 4 wk reduced fasting concentrations of insulin and glucose and reduced insulin responses during an IVGTT. In these animals, adiponectin concentrations were also increased by 70%, most of which was an increase of high-molecular-weight oligomers. These effects were not observed in monkeys on a lower, dose-escalation regimen (1–10 mg/kg over 9 wk). Overall, the increase of adiponectin concentrations during ISIS 113715 treatment was correlated with the lowering of insulin responses during IVGTT (r = −0.47, P = 0.042). These results indicate that inhibition of PTP-1B with ASOs such as ISIS 113715 may be a viable approach for the treatment and prevention of obesity-associated insulin resistance and type 2 diabetes because they potently increase adiponectin concentrations in addition to improving insulin sensitivity.


2011 ◽  
Vol 50 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Soumaya Kouidhi ◽  
Rym Berrhouma ◽  
Kamel Rouissi ◽  
Slim Jarboui ◽  
Marie-Stéphanie Clerget-Froidevaux ◽  
...  

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