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
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