The relationship between the IGF-I system and its binding proteins and microvascular reactivity in Type 1 diabetes mellitus.
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) (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.
Krsek
M
M
Third Department of Internal Medicine, First Faculty of Medicine, Charles University, Prague, Czech Republic. mkrsek@lf1.cuni.cz
Prázný
M
M
Skrha
J
J
Justová
V
V
Lacinová
Z
Z
Haas
T
T
D001775:Blood Circulation; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D005260:Female; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D012016:Reference Values
D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I