Seventy-seven Italian elite athletes (42 M, 35 F, mean age±SE: 24.4±0.7 yr, age range: 17-47 yr) of different sport disciplines (sprinters, triathletes, middle-distance runners, road-walkers, cyclists, rowing athletes, skiers, roller hockey players, swimmers) were sampled on-the-field (before a training session) for the determination of basal GH, IGF-I, C-terminal cross-linked telopeptide of type I collagen (ICTP) and amino-terminal propeptide of type III procollagen (PIIINP) levels, two GH-dependent peripheral markers of bone and collagen turnover, respectively. Basal GH concentrations were significantly higher (p< 0.001) in female (5.8±1.0 ng/ml) vs male athletes (1.8±0.5 ng/ml), with a large spread of values in either gender. Mean GH levels of athletes were significantly higher than those recorded in age-matched sedentary controls (females: 2.5±0.5 ng/ml, p<0.001; males: 0.5±0.2 ng/ml, p<0.05). Among female athletes, 7/35 had basal GH values higher than the upper limit of control values (>9.5 ng/ml), while among males 7/42 had values higher than the upper limit of male sedentary controls (>3.6 ng/ml). No significant differences in basal GH concentrations were found between females taking oral contraceptives (OC) and those who did not receive this treatment (5.0±2.1 vs 6.0±1.2 ng/ml). IGF-I levels (236.4±7.8 ng/ml) were in the normal range for age in all athletes (except for 1 athlete with slightly increased levels), no significant correlation being found between GH and IGF-I levels (R2=0.0393). Mean ICTP (4.6±0.2 ng/ml) and PIIINP (4.4±0.1 ng/ml) concentrations of elite athletes were not significantly different from those recorded in age and matched healthy sedentary subjects; 4 athletes showed increased PIIINP levels and 2 had increased ICTP levels. ICTP and PIIINP levels were positively correlated with chronological age (p<0.001), a positive correlation being also found between the two markers (p<0.001). On the contrary, no significant correlation was found between basal GH/IGF-I levels and ICTP/PIIINP levels. In conclusion, the present study demonstrates that: 1) elite athletes (particularly females), which have frequently increased basal GH on-the-field, have actually normal IGF-I levels; 2) ICTP and PIIINP levels of athletes are similar to those recorded in healthy sedentary, being significantly higher in younger subjects of both groups; 3) the presence of increased basal GH levels, being associated with normal IGF-I, ICTP and PIIINP levels, is probably the result of a transient GH peak in this study group. Further additional studies are requested to verify the possible use of these peripheral GH-dependent markers for detecting exogenous chronic administration of recombinant GH in athletes.
Elite volunteer athletes of different sport disciplines may have elevated baseline GH levels divorced from unaltered levels of both IGF-I and GH-dependent bone and collagen markers: a study on the field / A. Sartorio, N. Marazzi, F. Agosti, G. Faglia, C. Corradini, E. De Palo, S.G. Cella, A.E. Rigamonti, E.E. Muller. - In: JOURNAL OF ENDOCRINOLOGICAL INVESTIGATION. - ISSN 0391-4097. - 27:5(2004), pp. 410-415.
|Titolo:||Elite volunteer athletes of different sport disciplines may have elevated baseline GH levels divorced from unaltered levels of both IGF-I and GH-dependent bone and collagen markers: a study on the field|
RIGAMONTI, ANTONELLO EMILIO (Penultimo)
MULLER, EUGENIO (Ultimo)
|Parole Chiave:||Bone turnover; Collagen synthesis; Elite athletes; GH|
|Settore Scientifico Disciplinare:||Settore MED/33 - Malattie Apparato Locomotore|
Settore BIO/14 - Farmacologia
|Data di pubblicazione:||2004|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/BF03345283|
|Appare nelle tipologie:||01 - Articolo su periodico|