Improved Insulin Sensitivity during Pioglitazone Treatment Is Associated with Changes in IGF-I and Cortisol Secretion in Type 2 Diabetes and Impaired Glucose Tolerance. (15th January 2012)

• Record Type: Journal Article
• Authors: Arnetz, Lisa; Rajamand Ekberg, Neda; Höybye, Charlotte; Brismar, Kerstin; Alvarsson, Michael
• Other Names: Anderwald C. Academic Editor.; Escobar-Jimenez F. Academic Editor.; Furlanetto T. W. Academic Editor.; Morosini P. Academic Editor.; Tamemoto H. Academic Editor.
• Is Part Of: ISRN endocrinology. Volume 2013(2013)
• Publication Date: 2012-01-15
• Subjects: Endocrinology -- Periodicals; Endocrine System Diseases; Endocrinology; Endocrinology; Electronic journals; Periodical; Fulltext; Internet Resources; Periodicals; Periodicals; 616.4
• DOI: 10.1155/2013/148497
• Languages: English
• ISSNs: 2090-4630

Abstract

Abstract : 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 μ g 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 (P = 0.004 ) and increased during treatment (− 1.4 ± 0.5 to − 0.5 ± 0.4 SD; P = 0.007 ); no change was seen in IGT (0.4 ± 39 SD before and during treatment). Fasting glycerol decreased in T2D (P = 0.038 ), indicating reduced lipolysis. Fasting cortisol decreased in T2D (400 ± 30 to 312 ± 25 nmol/L; P = 0.041 ) but increased in IGT (402 ± 21 to 461 ± 35 nmol/L; P = 0.044 ). Peak cortisol was lower in T2D during treatment (599 ± 32 to 511 ± 43, versus 643 ± 0.3 to 713 ± 37 nmol/L in IGT; P = 0.007 ). 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.