M. Deuschle et al., ENDURANCE TRAINING AND ITS EFFECT UPON THE ACTIVITY OF THE GH-IGFS SYSTEM IN THE ELDERLY, International journal of sports medicine, 19(4), 1998, pp. 250-254
There is an age-associated decline in the activity of the GH-ICFs syst
em. However, so far, it has not been studied, whether this decline in
somatotrophic activity might be preventable by intensive exercising. W
e studied 11 elderly male (50-78 years) marathon runners and 10 age-ma
tched male (52-73 years) sedentary controls to evaluate plasma concent
rations of GH, total and free IGF-I and IGF-II and of IGF-binding prot
ein-1 (IGFBP-1), IGFBP-2, IGFBP-3 and insulin. When comparing the two
groups (runners vs controls) no differences were found in GH (1.0 +/-
1.2 vs 1.3 +/- 1.3 mu g/l [mean +/- SD]), IGF-1 (115 +/- 23 vs 113 +/-
21 mu g/l), IGF-II (961 +/- 192 vs 864 +/- 125 mu g/l), free IGF-1 (2
27 +/- 80 vs 318 +/- 146 ng/l), free IGF-II (563 +/- 249 vs 492 +/- 10
8 ng/l), IGFBP-3 (2403 +/- 515 vs 2307 +/- 326 mu g/l) or insulin (26
+/- 13 vs 27 +/- 18 mU/l). However, IGFBP-1 (4.44 +/- 2.61 vs 2.28 +/-
0.93 mu g/l) and IGFBP-2 (493 +/- 143 vs 340 +/- 186 mu g/l) were fou
nd to be significantly increased in marathon runners. In conclusion, o
ur findings do not support the hypothesis that the age-associated decl
ine in GH, IGF-1 and IGFBP-3 may be preventable by intensive endurance
training. However, marathon running affects the regulation of the GH-
ICFs system activity at the level of IGFBP-1 and -B9-2.