Journal of Applied Physiology, Vol 80, Issue 1 240-244, Copyright © 1996 by American Physiological Society

ARTICLES

Changes in insulin action and GLUT-4 with 6 days of inactivity in endurance runners

M. D. Vukovich, P. J. Arciero, W. M. Kohrt, S. B. Racette, P. A. Hansen and J. O. Holloszy
Section of Applied Physiology, Washington University Medical School, St. Louis, Missouri 63110, USA.

The purpose of this investigation was to determine whether decreased insulin action after 6 days of inactivity in endurance-trained runners was associated with a decrease in skeletal muscle glucose transporter protein levels (GLUT-4) in the gastrocnemius muscle. Seven endurance runners (5 men and 2 women) volunteered to participate in this investigation. All subjects had normal glucose tolerance as determined by the National Diabetes Data Group guidelines. Each individual completed two hyperinsulinemic euglycemic clamps at insulin infusion rates of 15 (LO) and 40 (HI) mU.m-2.min-1, one approximately 18 h after a training bout and the second after 6 days of inactivity (IA). Muscle biopsies for the measurement of GLUT-4 were obtained from the gastrocnemius before each clamp. Glucose disposal rates during the last 30 min of each insulin infusion were significantly reduced after 6 days of IA, averaging 6.45 +/- 1.04 mg.kg fat-free mass (FFM)-1.min-1 before and 4.55 +/- 0.56 mg.kg FFM-1.min-1 after detraining for the LO insulin infusion rate and 13.77 +/- 0.88 mg.kg FFM-1.min-1 before and 11.81 +/- 0.60 mg.kg FFM-1.min-1 after detraining for the HI insulin infusion rate (both P < 0.05), despite the fact that plasma insulin was higher in the inactive state (LO, 19.2 +/- 0.9 microU/ml before and 23.4 +/- 1.5 microU/ml after detraining; HI, 56.0 +/- 2.0 microU/ml before and 61.6 +/- 1.6 microU/ml after detraining; P < 0.05)). Calculated insulin clearance was greater in the trained than in the inactive state (P < 0.03). Muscle GLUT-4 transporter protein after 6 days of IA was reduced by 17.5 +/- 5.4% (P < 0.02). These results demonstrate that 6 days of IA reduces insulin action in endurance-trained runners and suggest that a reduction in muscle GLUT-4 transporter level plays a role in the decrease in glucose disposal rates.

This article has been cited by other articles:

				G. Kacerovsky-Bielesz, M. Chmelik, C. Ling, R. Pokan, J. Szendroedi, M. Farukuoye, M. Kacerovsky, A. I. Schmid, S. Gruber, M. Wolzt, et al. Short-Term Exercise Training Does Not Stimulate Skeletal Muscle ATP Synthesis in Relatives of Humans With Type 2 Diabetes Diabetes, June 1, 2009; 58(6): 1333 - 1341. [Abstract] [Full Text] [PDF]

				K. A. Burgomaster, N. M. Cermak, S. M. Phillips, C. R. Benton, A. Bonen, and M. J. Gibala Divergent response of metabolite transport proteins in human skeletal muscle after sprint interval training and detraining Am J Physiol Regulatory Integrative Comp Physiol, May 1, 2007; 292(5): R1970 - R1976. [Abstract] [Full Text] [PDF]

				F. W. Booth and S. J. Lees Fundamental questions about genes, inactivity, and chronic diseases Physiol Genomics, January 17, 2007; 28(2): 146 - 157. [Abstract] [Full Text] [PDF]

				C. K. Roberts and R. J. Barnard Effects of exercise and diet on chronic disease J Appl Physiol, January 1, 2005; 98(1): 3 - 30. [Abstract] [Full Text] [PDF]

				G. N. Kraniou, D. Cameron-Smith, and M. Hargreaves Effect of short-term training on GLUT-4 mRNA and protein expression in human skeletal muscle Exp Physiol, September 1, 2004; 89(5): 559 - 563. [Abstract] [Full Text] [PDF]

				S. M. Phillips, B. G. Stewart, D. J. Mahoney, A. L. Hicks, N. McCartney, J. E. Tang, S. B. Wilkinson, D. Armstrong, and M. A. Tarnopolsky Body-weight-support treadmill training improves blood glucose regulation in persons with incomplete spinal cord injury J Appl Physiol, August 1, 2004; 97(2): 716 - 724. [Abstract] [Full Text] [PDF]

				S. R. Stannard and N. A. Johnson Insulin resistance and elevated triglyceride in muscle: more important for survival than 'thrifty' genes? J. Physiol., February 1, 2004; 554(3): 595 - 607. [Abstract] [Full Text] [PDF]

				K. R. Short, J. L. Vittone, M. L. Bigelow, D. N. Proctor, R. A. Rizza, J. M. Coenen-Schimke, and K. S. Nair Impact of Aerobic Exercise Training on Age-Related Changes in Insulin Sensitivity and Muscle Oxidative Capacity Diabetes, August 1, 2003; 52(8): 1888 - 1896. [Abstract] [Full Text] [PDF]

				F. W Booth, M. V Chakravarthy, and E. E Spangenburg Exercise and gene expression: physiological regulation of the human genome through physical activity J. Physiol., September 1, 2002; 543(2): 399 - 411. [Abstract] [Full Text] [PDF]

				G. L. Dohm Exercise Effects on Muscle Insulin Signaling and Action: Invited Review: Regulation of skeletal muscle GLUT-4 expression by exercise J Appl Physiol, August 1, 2002; 93(2): 782 - 787. [Abstract] [Full Text] [PDF]

				F. W. Booth, M. V. Chakravarthy, S. E. Gordon, and E. E. Spangenburg Waging war on physical inactivity: using modern molecular ammunition against an ancient enemy J Appl Physiol, July 1, 2002; 93(1): 3 - 30. [Abstract] [Full Text] [PDF]

				B. O.'t Eijnde, B. Ursø, E.A. Richter, P.L. Greenhaff, and P. Hespel Effect of Oral Creatine Supplementation on Human Muscle GLUT4 Protein Content After Immobilization Diabetes, January 1, 2001; 50(1): 18 - 23. [Abstract] [Full Text]

				I. Tabata, Y. Suzuki, T. Fukunaga, T. Yokozeki, H. Akima, and K. Funato Resistance training affects GLUT-4 content in skeletal muscle of humans after 19 days of head-down bed rest J Appl Physiol, March 1, 1999; 86(3): 909 - 914. [Abstract] [Full Text] [PDF]

				P. J. Arciero, D. L. Smith, and J. Calles-Escandon Effects of short-term inactivity on glucose tolerance, energy expenditure, and blood flow in trained subjects J Appl Physiol, April 1, 1998; 84(4): 1365 - 1373. [Abstract] [Full Text] [PDF]

				H. H. Host, P. A. Hansen, L. A. Nolte, M. M. Chen, and J. O. Holloszy Rapid reversal of adaptive increases in muscle GLUT-4 and glucose transport capacity after training cessation J Appl Physiol, March 1, 1998; 84(3): 798 - 802. [Abstract] [Full Text] [PDF]