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Normal cardiac autonomic regulation during submaximal, but not maximal, cycle ergometry exercise in persons with Down syndrome
Author(s) -
Baynard Tracy,
Goulopoulou Styliani,
Figueroa Arutor,
Collier Scott R,
Pitetti Kenneth H,
Fernhall Bo
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1108.6
Subject(s) - heart rate , medicine , heart rate variability , cardiology , cycle ergometer , blood pressure , cardiac cycle , exercise physiology , endocrinology
Objective To compare heart rate variability (HRV) responses to submaximal cycle ergometry exercise between persons with and without DS when matched for heart rate (HR) changes to that stressor. METHODS Persons with and without DS (n=9/grp; 28 yrs) were matched for HR responses during a 6 min cycle ergometry task (avg cycle HR‐baseline HR) performed at 50% of body weight in Watts. HRV was assessed in the frequency domain (total power, low frequency (LF) and high frequency HF)). Blood pressure was obtained using finger photoplethysmography. RESULTS The mean change in HR was 29 ± 10 bpm. Both groups exhibited similar responses to the cycle exercise, with no differences between groups in any of the HRV measures. Systolic blood pressure was different between groups (p<0.05), but changed similarly with exercise. Peak aerobic capacity (DS vs. Control: 24.2 vs. 36.7 mL/kg/min), HR (167 vs. 189 bpm), and catecholamine levels (epinephrine: 55 vs. 314 pg/mL) were lower with maximal exercise in those with DS vs. controls (p<0.05). CONCLUSIONS While persons with DS exhibit attenuated work capacity and peak HR, it appears that a subset of individuals do have normal cardiac autonomic regulation at submaximal exercise loads. Supported in part by an American Heart Association Grant‐in‐AidDS ControlsRest Cycle Rest CycleSystolic BP (mm Hg)* 110 ± 7 137 ± 20 136 ± 21 159 ± 26 Total power (ms 2 ) 2175 ± 495 774 ± 146 3233 ± 526 555 ± 155 Low Frequency (ms 2 ) 972 ± 284 127 ± 46 1678 ± 284 163 ± 45 High Frequency (ms 2 ) 252 ± 105 73 ± 27 343 ± 106 49 ± 27