Response.

Abstract

Dear Editor-in-Chief, Smart et al. (1) expressed concern we made no conclusions about the antihypertensive benefits of isometric resistance training (IRT) in the American College of Sports Medicine pronouncement on the role of physical activity (PA) to prevent and treat hypertension (2). At the time of publication of the pronouncement, there were two meta-analyses on this topic (3,4); we included Carlson et al. (3) which led Smart et al. to believe that we missed Inder et al. (4). The American College of Sports Medicine pronouncement (2) on PA and hypertension contained seminal portions of the 2018 Physical Activity Guidelines Advisory Committee Scientific Report (5). In the 2018 Physical Activity Guidelines Advisory Committee Scientific Report, we performed a comprehensive search of the literature from 2006, the publication of the first Report, until February 2018. We also conducted a methodological study quality assessment of potentially qualifying reviews and graded the evidence. The magnitude of the blood pressure (BP) response to PA is strongly and positively related to resting BP so that we reported our findings separately among adults with normal BP, prehypertension, and hypertension rather than combining them. Of the two potentially qualifying meta-analyses on IRT and hypertension (3,4), we retained Carlson et al. (3) for the following reasons. There was significant overlap between the two meta-analyses. Inder et al. (4) reported the systolic BP (SBP), diastolic BP (DBP), and mean arterial (MAP) BP reductions among the combined sample, and only reported the MAP reductions among adults with hypertension versus normal BP, stating no significance was found for SBP and DBP (data not reported). Carlson et al. (3) reported the SBP, DBP, and MAP reductions among the combined sample and adults with hypertension versus normal BP, all of which were statistically significant. The overall methodological study quality rating was higher for Carlson et al. (3) than Inder et al. (4). Carlson et al. (3) did not disclose the resting BP of the 61 adults with hypertension in the sample, all of whom were on medication, so that it was not possible to comment on regression to the mean as they may or may not have been controlled. After thoughtful consideration, we were unable to make any conclusions about the antihypertensive benefits of IRT. At the time of the publication of the pronouncement, we were aware of the statement (not the endorsement) of the American Heart Association/American College of Cardiology that the meta-analyses of Cornelissen and Smart (6), Carlson et al. (3), and Inder et al. (4) suggested IRT resulted in substantial lowering of BP (7). The Exercise and Sport Science Australia position stand (8) now recommends IRT for the management of hypertension based on these same reviews, and the Canadian hypertension guidelines state that the use of resistance exercise that includes handgrip isometric exercise is safe (9). However, until a large, well-designed randomized controlled trial is done among adults with hypertension comparing IRT (the alternative) to aerobic exercise training (the recommended standard), any conclusions that can be made about the use of IRT in the treatment of hypertension should be made with caution. Linda S. Pescatello Department of Kinesiology University of Connecticut Storrs, CT David M. Buchner Department of Kinesiology and Community Health University of Illinois at Urbana Champaign Champaign, IL John M. Jakicic Department of Health and Physical Activity University of Pittsburgh Pittsburgh, PA Ken E. Powell Centers for Disease Control and Prevention Atlanta, GA (Retired) William E. Kraus Department and School of Medicine Duke University Durham, NC Bonny Bloodgood Sheppard ICF Next Fairfax, VA Wayne W. Campbell Departments of Nutrition Science Purdue University West Lafayette, IN Sondra Dietz ICF Next Fairfax, VA Loretta DiPietro Department of Exercise and Nutrition Sciences and Milken Institute of Public Health The George Washington University Washington, DC Stephanie M. George National Institute of Arthritis Musculoskeletal and Skin Diseases National Institutes of Health Bethesda, MD Anne McTiernan Fred Hutchinson Cancer Research Center Schools of Medicine and Public Health University of Washington Seattle, WA Russell R. Pate Department of Exercise Science and School of Public Health University of South Carolina Columbia, SC Katrina L. Piercy Office of Disease Prevention and Health Promotion US Department of Health and Human Services Rockville, MD