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Impaired hypoxic exercise vasodilation in older adults
Author(s) -
Evans Trent Douglas,
Blain Gregory,
Limberg Jacqueline,
Kiefer Adam,
Sebranek Josh,
Proctor Lester,
Schrage William
Publication year - 2010
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.24.1_supplement.619.11
Subject(s) - medicine , forearm , hypoxia (environmental) , vasodilation , blood pressure , cardiology , blood flow , brachial artery , endocrinology , surgery , oxygen , chemistry , organic chemistry
Research suggests exercise blood flow may be impaired in older adults. We hypothesized that forearm blood flow would be impaired during exercise in older subjects (64±3 years, n=10) compared to young controls (27±2 years, n=18), and that any impairment would be exaggerated under hypoxic conditions. We measured forearm blood flow (FBF, Doppler Ultrasound), blood pressure (BP, Finapress), and Hb saturation (pulse oximeter) while subjects performed dynamic forearm exercise (8 kg, 20 contractions/min) for 4 minutes in normoxic (~98% SaO 2 ) and hypoxic (80% SaO 2 ) conditions. BP was greater in older subjects than young controls (p<0.05), therefore FBF measures were normalized for perfusion pressure (FVC=FBF/BP). FVC was similar between groups at rest and steady‐state exercise in normoxia and hypoxia (p>0.05). FVC did not increase in either group from normoxia to hypoxia at rest (p>0.05). During hypoxic exercise, young subjects increased FVC from normoxic levels (p<0.05); older subjects did not (p>0.05). These preliminary results suggest that forearm exercise vasodilation is preserved in older adults under normoxic conditions, but impairments may exist when responding to hypoxia during exercise. Support: AFAR A08235 , AHA 0815622G, APS UGSRF, NIH HL091397