IGF-1 response to arm exercise with eccentric and concentric muscle contractions in resistance-trained athletes with left ventricular hypertrophy

• Published in: International journal of sports medicine Vol. 34; no. 2; p. 116
• Main Authors: Żebrowska, A, Waśkiewicz, Z, Zając, A, Gąsior, Z, Galbo, H, Langfort, J
• Format: Journal Article
• Language: English
• Published: Germany 01.02.2013
• Subjects: Arm - physiology; Athletes; Biomarkers - blood; Case-Control Studies; Exercise Test; Human Growth Hormone - blood; Humans; Hydrocortisone - blood; Hypertrophy, Left Ventricular - blood; Hypertrophy, Left Ventricular - diagnostic imaging; Hypertrophy, Left Ventricular - etiology; Insulin - blood; Insulin-Like Growth Factor Binding Protein 3 - blood; Insulin-Like Growth Factor I - metabolism; Male; Muscle Contraction - physiology; Resistance Training; Testosterone - blood; Ultrasonography; Young Adult
• ISSN: 1439-3964
• DOI: 10.1055/s-0032-1321720

The study aimed at evaluating changes in plasma levels of insulin-like growth factor 1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), testosterone, growth hormone (GH), cortisol, and insulin in resistance-trained male athletes with (n=9) and without (n=9) left ventricular hypertrophy (LVH) in response to eccentric (ECC) and concentric (CON) arm exercise. 10 age-matched healthy non-trained subjects served as controls. M-mode and 2D Doppler echocardiography were used to estimate LV mass.Resting IGF-1 concentration was higher in LVH athletes compared to controls (52 ± 5 nM vs. 46 ± 7 nM, p<0.05). ECC exercise resulted in higher (p<0.05) serum IGF-1 concentrations in athletes with LVH (70 ± 11 nM, n=9) compared to those without LVH (62 ± 10 nM, n=9), and to untrained controls (54 ± 6 nM). Both CON and ECC exercise resulted in higher serum IGFBP-3 levels in LVH athletes compared to controls (242 ± 57 and 274 ± 58, athletes, vs. 215 ± 63 and 244 ± 67, controls, nM, p<0.05). In ECC exercise, GH concentrations were lower in LVH than in non-LVH athletes (4.7 ± 2.1 vs. 6.1 ± 1.8 ng  mL(-1), p<0.05). No differences in other hormones were found between groups. In conclusion, LVH is accompanied by elevated resting serum IGF-1 and enhanced response to eccentric arm exercise. These findings suggest a role of IGF-1, possibly released from contracting muscle, in stimulating LV hypertrophy in resistance training.