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Alterations in endothelial function and fractional O 2 extraction in long‐term cancer survivors treated with chemotherapy and radiation
Author(s) -
Ade Carl,
Brown Michael,
Caldwell Jacob,
Didier Kaylin,
Reiter Landon,
Ederer Austin
Publication year - 2015
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.29.1_supplement.675.25
Subject(s) - medicine , arterial stiffness , brachial artery , radiation therapy , cardiology , cancer , nuclear medicine , urology , blood pressure
Chemotherapy and radiation cancer therapeutics increase arterial stiffness and decrease aerobic exercise capacity. During exercise, the profile of microvascular fractional O 2 extraction measured via near‐infrared spectroscopy (NIRS) derived muscle deoxygenation (Δdeoxy‐[Hb+Mb]) provides information on the dynamic matching of O 2 delivery‐to‐O 2 utilization. We tested the hypothesis that cancer survivors would have an altered profile of Δdeoxy‐[Hb+Mb] during exercise that would be related to decreases in endothelial function. To date, 2 cancer survivors (CS) and 1 healthy control (HC) completed a brachial artery flow‐mediated dilation test (FMD) and ramp exercise test on a cycle ergometer. During exercise Δdeoxy‐[Hb+Mb] of the vastus lateralis and rectus femoris was measured, normalized from baseline (0%) to the gas exchange threshold (GET) (100%). The power output at GET (PO GET ) was lower in CS compared to HC. CS had a smaller shear rate normalized FMD compared to HC (1.07 × 10 ‐5 vs. 3.54 × 10 ‐5 %Δ/s ‐1 s, respectively). Both groups displayed a linear increase in %Δdeoxy‐[Hb+Mb]. The %Δdeoxy‐[Hb+Mb] slope of the vastus lateralis was greater in CS compared to HC when plotted as a function of PO GET (2.04 vs. 0.80 % W ‐1 , respectively) and %PO GET (1.84 vs. 1.17 % %W ‐1 , respectively). A greater %Δdeoxy‐[Hb+Mb] slope of the rectus femoris was also observed in CS compared to HC (1.29 vs. 0.74 % W ‐1 and 1.17 vs. 1.09 % %W ‐1 , respectively). In conclusion, the greater reliance on fractional O 2 extraction in CS during exercise suggests an impaired matching of O 2 delivery‐to‐O 2 utilization relationship during exercise compared to HC, which may be the result of decreased endothelial function.