Regular moderate intensity physical activity and blood concentrations of endogenous anabolic hormones and thyroid hormones in aging men

Background: Physical activity has been reported to affect endocrine function in elderly men. Objectives: To establish an association between regular moderate physical activity and endogenous anabolic hormone levels in healthy aging men. Participants Twenty four middle-aged (57.4 +/- 4.7 years) and 23 elderly (68.3 +/- 2.6 years) physically active men who in the past 10 years had been regularly bicycling during leisure time were compared with 24 middle-aged (57.9 +/- 4.0 years) and 24 elderly (67.2 +/- 1.7 years) sedentary men. Groups did not differ for body composition. Measurements: Serum dehydroepiandrosterone sulfate (DHEAS), insulin-like growth factor-I (IGF-I). fi ee testosterone (FT). and thyroid hormone levels were assessed. Results: In general, elderly men had lower IGF-I (P < 0.001). DHEAS (P = 0.013), and triodothyronine levels (P < 0.001) than their middle-aged counterparts. Independently of age, however, physically active men had on average higher IGF-I (P = 0.031), DHEAS (P = 0.001). and triodothyronine serum levels (P < 0.001) than sedentary men. FT and thyroid stimulating hormone (TSH) serum concentrations did not differ across age groups, but physically active men had lower TSH values than sedentary men (P = 0.021). Conclusions: Our results suggest that, in aging men, regular moderate physical activity is associated with higher levels of IGF-I and DHEAS levels and with thyroid function alterations. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.