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JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
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Research
article
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SERUM IGF-I AND HORMONAL RESPONSES TO INCREMENTAL EXERCISE IN ATHLETES WITH AND WITHOUT LEFT VENTRICULAR HYPERTROPHY |
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Aleksandra Zebrowska1  ,
Zbigniew Gasior2 and Józef Langfort11,3 |
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1Department of Physiology, Academy of Physical Education, Katowice, Poland 2Department of Cardiology, Silesian University School of Medicine, Katowice, Poland 3Laboratory of Experimental Pharmacology, Polish Academy of Science, Warsaw, Poland. |
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© Journal of Sports Science and Medicine (2009) 8, 67 - 76 Search Google Scholar for Citing Articles |
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| ABSTRACT | |||
| We investigated the response of insulin-like growth factor (IGF-
I), insulin-like growth factor binding protein-3 (IGFBP-3) and some hormones,
i.e., testosterone (T), growth hormone (GH), cortisol (C), and insulin (I),
to maximal exercise in road cyclists with and without diagnosed left ventricular
hypertrophy. M-mode and two-dimensional Doppler echocardiography was performed
in 30 professional male endurance athletes and a group of 14 healthy untrained
subjects using a Hewlett-Packard Image Point HX ultrasound system with standard
imaging transducers. Echocardiography and an incremental physical exercise
test were performed during the competitive season. Venous blood samples
were drawn before and immediately after the maximal cycling exercise test
for determination of somatomedin and hormonal concentrations. The basal
concentration of IGF-I was statistically higher (p < 0.05) in athletes
with left ventricular muscle hypertrophy (LVH) when compared to athletes
with a normal upper limit of the left ventricular wall (LVN) (p < 0.05)
and to the control group (CG) (p < 0.01). The IGF-I level increased significantly
at maximal intensity of incremental exercise in CG (p < 0.01), LVN (p
< 0.05) and LVH (p < 0.05) compared to respective values at rest.
Long-term endurance training induced an increase in resting (p < 0.01)
and post-exercise (p < 0.05) IGF-I/IGFBP-3 ratio in athletes with LVH
compared to LVN. The testosterone (T) level was lower in LVH at rest compared
to LVN and CG groups (p < 0.05). These results indicate that resting
serum IGF-I concentration were higher in trained subjects with LVH compared
to athletes without LVH. Serum IGF- I/IGFBP-3 elevation at rest and after
exercise might suggest that IGF-I act as a potent stimulant of left ventricular
hypertrophy in chronically trained endurance athletes.
Key words: Echocardiography, heart, somatomedins, anabolic hormones, endurance training. |
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