Volume 51: 379-385, 2002


The Relationship Between the IGF-I System and Its Binding Proteins and Microvascular Reactivity in Type 1 Diabetes Mellitus


M. KRŠEK, M. PRÁZNÝ, J. ŠKRHA, V. JUSTOVÁ, Z. LACINOVÁ, T. HAAS

Third Department of Internal Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic


Received November 21, 2001
Accepted January 22, 2002


Summary
The system of IGF-I and its binding proteins may be involved in the pathogenesis of vascular damage in Type 1 diabetes. The aim of this study was to analyze the relationship between this system and the microvascular reactivity in Type 1 diabetes as measured by laser-Doppler flowmetry. Twenty-two Type 1 diabetic patients (13 women and 9 men) with microangiopathy and fifteen healthy subjects (8 women and 7 men) were examined clinically, underwent laser-Doppler flowmetry and intima-media thickness measurements. Fasting serum levels of IGF-I, free IGF-I, IGFBPs and lipids were examined. The microvascular reactivity was impaired in Type 1 diabetic patients. Maximal perfusion during post-occlusive reactive hyperemia (PORHmax) and during thermal hyperemia (THmax) was significantly decreased in Type 1 diabetes (p<0.01). Percentage perfusion increase in both tests (PORH and TH) was lower in Type 1 diabetes mellitus (p<0.01) and the reaction after heating was slower in diabetic patients (THmax/t) (p<0.01). We did not find any significant dependence of microvascular reactivity on the parameters of IGF-I or its binding proteins. We conclude that the microvascular reactivity is impaired in Type 1 diabetes mellitus, but this impairment is not clearly dependent on the activity of the IGF-I system. It is probably only a complementary pathogenic factor.


Key words
IGF-I · IGFBP-1 · Microangiopathy · IDDM · Laser-Doppler flowmetry


Reprint requests
M. Kršek, M.D., Ph.D., Third Department of Internal Medicine, First Faculty of Medicine, Charles University, U nemocnice 1, 128 08 Prague 2, Czech Republic. Fax: 00420 224919780. E-mail:
mkrse@lf1.cuni.cz


PHYSIOLOGICAL RESEARCH
© 2002 by the Institute of Physiology, Czech Academy of Sciences

ISSN 0862 - 8408

Issue 4