title: Impact of obesity and Down syndrome on peak heart rate and aerobic capacity in youth and adults.
abstract: Individuals with Down syndrome (DS) exhibit reduced aerobic capacity with reduced peak heart rate (HRpeak). This condition is often coexistent with higher level of obesity compared to individuals without DS. The purpose of this study is to investigate the effects of obesity and Down syndrome (DS) on peak heart rate (HRpeak) and peak oxygen consumption (VO2peak) in children and adults both with and without intellectual disabilities (ID)s. VO2peakand HRpeakfrom individualized treadmill tests on 654 individuals were analyzed. Body mass index was used to categorize individuals' weight status using standard cut-offs. DS groups had the lowest HRpeak(167bpm±14, p<0.05) compared to individuals with (183bpm±12) without ID (187bpm±12). Obesity did not affect HRpeakamong adults and children with DS. VO2peakwas lower among individuals with DS (25.2mL/kg/min±6.3, p<0.05) when compared individuals with (37.0mL/kg/min±10.5) and without ID (36.1mL/kg/min±10.4). Obese adults with DS had lower VO2peak(24.3mL/kg/min±6.9, p=0.001) compared to the normal weight (26.7±7.1mL/kg/min) and overweight groups (27.0mL/kg/min±6.1) with DS. Conversely, in children, obesity level did not impact VO2peakin individuals with DS. Our results suggest that DS attenuates both VO2peakand HRpeak, regardless of obesity status and age group. However, obesity was associated with lower VO2peakin all adults, but not in children with DS.
authors.affiliation: Integrative Physiology Laboratory, Department of Kinesiology and Nutrition University of Illinois at Chicago, Chicago, IL 60612, United States. Electronic address: swee3@uic.edu.
authors.forename: Sang Ouk
authors.initials: SO
authors.lastname: Wee
authors.affiliation: Department of Physical Therapy, Wichita State University, Wichita, KS 67260-0210, United States. Electronic address: ken.pitetti@wichita.edu.
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Pitetti
authors.affiliation: Department of Integrative Physiology and Anatomy at the University of North Texas Health Science Center (Fort Worth, Texas 76107), United States. Electronic address: Styliani.Goulopoulou@unthsc.edu.
authors.forename: Styliani
authors.initials: S
authors.lastname: Goulopoulou
authors.affiliation: Department of Health, Leisure, and Exercise Science, Appalachian State University, Boone, NC 28608, United States. Electronic address: colliersr@appstate.edu.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Collier
authors.affiliation: School of Psychology, Education and Sports Sciences, University Ramon Llull, Barcelona, Spain. Electronic address: miriamelisagb@blanquerna.url.edu.
authors.forename: Myriam
authors.initials: M
authors.lastname: Guerra
authors.affiliation: Integrative Physiology Laboratory, Department of Kinesiology and Nutrition University of Illinois at Chicago, Chicago, IL 60612, United States. Electronic address: tbaynard@uic.edu.
authors.forename: Tracy
authors.initials: T
authors.lastname: Baynard
keywords: Down syndrome; Obesity; Peak heart rate; Peak oxygen consumption