Adverse Metabolic Response to Regular Exercise: Is It a Rare or Common Occurrence?

et al. (2012) Adverse Metabolic Response to Regular Exercise: Is It a Rare or Common Occurrence? PLoS ONE 7(5): e37887. doi:10.1371/journal.pone.0037887 Adverse Metabolic Response to Regular Exercise: Is It a Rare or Common Occurrence? Claude Bouchard 0 1 Steven N. Blair 0 1 Timothy S. Church 0 1 Conrad P. Earnest 0 1 James M. Hagberg 0 1 Keijo Ha kkinen 0 1 Nathan T. Jenkins 0 1 Laura Karavirta 0 1 William E. Kraus 0 1 Arthur S. Leon 0 1 D. C. Rao 0 1 Mark A. Sarzynski 0 1 James S. Skinner 0 1 Cris A. Slentz 0 1 Tuomo Rankinen 0 1 Shengxu Li, Tulane School of Public Health and Tropical Medicine, United States of America 0 Current address: Department of Biomedical Sciences, University of Missouri , Columbia, Missouri , United States of America 1 1 Human Genomics Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America, 2 Departments of Exercise Science and Epidemiology/Biostatistics, University of South Carolina, Columbia, South Carolina, United States of America, 3 Preventive Medicine Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America, 4 Department of Kinesiology, University of Maryland, College Park, Maryland, United States of America, 5 Department of Biology of Physical Activity, University of Jyva skyla , Jyva skyla , Finland, 6 Department of Medicine, Duke University Medical Center , Durham , North Carolina, United States of America, 7 School of Kinesiology, University of Minnesota , Minneapolis , Minnesota, United States of America, 8 Division of Biostatistics, Washington University School of Medicine , St. Louis , Missouri, United States of America, 9 Professor Emeritus of Kinesiology, Indiana University , Bloomington, Indiana , United States of America Background: Individuals differ in the response to regular exercise. Whether there are people who experience adverse changes in cardiovascular and diabetes risk factors has never been addressed. Methodology/Principal Findings: An adverse response is defined as an exercise-induced change that worsens a risk factor beyond measurement error and expected day-to-day variation. Sixty subjects were measured three times over a period of three weeks, and variation in resting systolic blood pressure (SBP) and in fasting plasma HDL-cholesterol (HDL-C), triglycerides (TG), and insulin (FI) was quantified. The technical error (TE) defined as the within-subject standard deviation derived from these measurements was computed. An adverse response for a given risk factor was defined as a change that was at least two TEs away from no change but in an adverse direction. Thus an adverse response was recorded if an increase reached 10 mm Hg or more for SBP, 0.42 mmol/L or more for TG, or 24 pmol/L or more for FI or if a decrease reached 0.12 mmol/L or more for HDL-C. Completers from six exercise studies were used in the present analysis: Whites (N = 473) and Blacks (N = 250) from the HERITAGE Family Study; Whites and Blacks from DREW (N = 326), from INFLAME (N = 70), and from STRRIDE (N = 303); and Whites from a University of Maryland cohort (N = 160) and from a University of Jyvaskyla study (N = 105), for a total of 1,687 men and women. Using the above definitions, 126 subjects (8.4%) had an adverse change in FI. Numbers of adverse responders reached 12.2% for SBP, 10.4% for TG, and 13.3% for HDL-C. About 7% of participants experienced adverse responses in two or more risk factors. Conclusions/Significance: Adverse responses to regular exercise in cardiovascular and diabetes risk factors occur. Identifying the predictors of such unwarranted responses and how to prevent them will provide the foundation for personalized exercise prescription. - Competing Interests: C. Bouchard is a member of the Science Advisory Board of Pathway Genomics. This does not alter the authors adherence to all the PLoS ONE policies on sharing data and materials. Introduction Physical activity level and cardiorespiratory fitness are strongly and inversely associated with the risk of cardiovascular-, metabolic-, and aging-related morbidities, as well as premature mortality [1]. To alleviate the health burden associated with sedentary behavior and poor fitness, public health recommendations are that adults be physically active at a moderate intensity for 150 minutes per week or at a vigorous intensity for 75 minutes per week [2]. However, there is considerable interindividual variability in the ability to improve ones cardiorespiratory fitness and cardiometabolic and diabetes risk factor profile in response to regular exercise. This clear finding of the HERITAGE Family Study has been replicated [3,4,5,6]. A fundamental question is whether there are individuals who experience one or several adverse responses (ARs) in terms of exercise-induced changes in common risk factors. This issue is addressed herein based on data from six exercise intervention studies, with a focus on exercise-induced changes in Body weight, kg Fasting insulin*, pmol/L HDL-C, mmol/L Triglycerides, mmol/L Systolic BP, mm Hg Mean SD (at first test) 13.219.8 (12) ICC = intraclass correlation computed from the within-subject variance compared to the overall measurement variance. TE = technical error defined by the within-subject standard deviation calculated from repeated measurements. It includes a combination of measurement error plus dayto-day variation. CV = Coefficients of variation is expressed as a percentage and is derived from the technical error and the measurement mean. *Note on insulin: The values reported here are from the repeated measurements obtained at baseline (N = 779) and after (N = 624) the exercise program in HERITAGE (Information S1). The TE used for this report is shown in parentheses. To convert pmol/L of insulin to mU/L, divide by 6.945. To convert mmol/L of HDL-C to mg/dL, divide by 0.02586. To convert mmol/L of triglycerides to mg/dl, divide by 0.01129. doi:10.1371/journal.pone.0037887.t001 resting systolic blood pressure (SBP), fasting insulin (FI), HDLcholesterol (HDL-C), and triglycerides (TG). The studies used for this purpose are: HERITAGE Family Study (HERITAGE), DREW, INFLAME, STRRIDE, University of Maryland Gene Exercise Research Study (MARYLAND), and University of Jyvaskyla study (JYVASKYLA). Data on a maximum of 1687 adults from six studies were available for analysis. These studies will be briefly described, followed by the definition of AR and the statistical procedures employed. More information on each study is available in Information S1. HERITAGE (Health, Risk Factors, Exercise Training And Genetics) Family Study The sample, study design, and exercise training protocol of HERITAGE have been described elsewhere [7]. Briefly, 473 adults from 99 families of Caucasian descent and 250 Blacks from 105 families or sibships completed the 20-week endurance training program. Parents were 65 years of age or less while offspring ranged in age from 17 to 41 (...truncated)