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The impact of aging on cerebral vasomotor reactivity to carbon dioxide (1069.5)
Author(s) -
Riley Jonathan,
Tarumi Takashi,
Parker Rosemary,
Armstrong Kyle,
Tinajero Cynthia,
Zhang Rong
Publication year - 2014
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.28.1_supplement.1069.5
Subject(s) - medicine , hyperventilation , cerebral blood flow , anesthesia , vasomotor , cardiology
The objective of this study was to determine the age‐related differences in cerebral vasomotor reactivity (CVMR) to carbon dioxide. Methods: 92 healthy adults aged 23‐77 underwent measurements of cerebral blood flow velocity (CBFV) using transcranial Doppler, mean arterial pressure, and end‐tidal CO 2 (EtCO 2 ) during baseline, hyperventilation (HVT), and modified rebreathing (RB). CVMR was determined by the maximal gain between changes in normalized CBFV (CBFV%) and EtCO 2 using a 3rd order polynomial model and its derivative. Results: Lower CBFV and EtCO 2 were related to increasing age at baseline. HVT decreased EtCO 2 by 21±4 mmHg while RB increased by 19±3 mmHg. Increasing age was related to smaller hypocapnic but larger hypercapnic changes in CBFV% at the end of HVT and RB, respectively. The maximal gain between CBFV% and EtCO 2 did not differ by age. Advanced age was associated with greater differences in EtCO 2 between the baseline and the level at which the maximum gain in CBFV% occurred. Conclusions: These findings suggest that age‐related reductions in baseline CBFV and EtCO 2 may lead to a decrease in hypocapnic but an increase in hypercapnic CBFV response. The larger differences in EtCO 2 between baseline and the maximal gain of CBFV% with aging may lead to blunted response of CBF to given changes in arterial CO 2 at levels close to baseline. Grant Funding Source : Supported by National Institute on Aging