Associations between cardiorespiratory responses to exercise and the C34T AMPD1 gene polymorphism in the HERITAGE Family study

1 Pennington Biomedical Research Center, Human Genomics Laboratory, Baton Rouge, Louisiana 70808 2 Laval Hospital Research Center and Division of Kinesiology, Laval University, Sainte-Foy G1K 7P4, Quebec, Canada 3 Laboratory of Physiological Hygiene and Exercise Science, Division of Kinesiology, University of Minnesota, Minneapolis, Minnesota 55455 4 Department of Kinesiology, Indiana University, Bloomington, Indiana 46405 5 Department of Health and Kinesiology, Texas A & M University, College Station, Texas 77843-4243 6 Division of Biostatistics, and Departments of Genetics and Psychiatry, Washington University School of Medicine, St. Louis, Missouri 63110-1093 The associations of the C34T polymorphism of the adenosine monophosphate deaminase 1 ( AMPD1 ) gene with cardiorespiratory phenotypes were tested during cycling exercise at absolute and relative power outputs progressing to exhaustion before and after endurance training for 20 wk in the HERITAGE Family Study cohort ( n = 779). Since no blacks were mutant homozygotes (TT), only whites were considered for analysis (400 normal homozygotes, CC; 97 heterozygotes, CT; and 6 TT). For sedentary state, cycling at the absolute power output of 50 W resulted in a higher rating of perceived exertion in TT ( P < 0.0001). At the relative intensity of 60% of O 2 max , stroke volume was lower in TT ( P < 0.05). Maximal values for power output, systolic blood pressure, heart rate, CO 2 , and respiratory exchange ratio were lower in TT ( P < 0.05). The cardiorespiratory training response at 50 W and at 60% of O 2 max was similar across C34T-AMPD1 genotypes. However, the maximal values for ventilation, O 2 , and CO 2 during exercise increased less in TT ( P < 0.01). The results indicate that subjects with the TT genotype at the C34T AMPD1 gene have diminished exercise capacity and cardiorespiratory responses to exercise in the sedentary state. Furthermore, the training response of ventilatory phenotypes during maximal exercise is more limited in TT. adenosine; human muscle; myoadenylate deaminase