title: Correlation Between the Cerebral Oxyhaemoglobin Signal and Physiological Signals During Cycling Exercise: A Near-Infrared Spectroscopy Study.
abstract: Near-infrared spectroscopy (NIRS) is a widely used noninvasive method for measuring human brain activation based on the cerebral haemodynamic response. However, systemic changes can influence the signal's parameters. Our study aimed to investigate the relationships between NIRS signals and skin blood flow (SBF) or blood pressure during dynamic movement. Nine healthy volunteers (mean age, 21.3 ± 0.7 years; 6 women) participated in this study. The oxyhaemoglobin (O2Hb) signal, SBF, and mean arterial pressure (MAP) were measured while the volunteers performed multi-step incremental exercise on a bicycle ergometer, at workloads corresponding to 30, 50, and 70 % of peak oxygen consumption (VO2peak) for 5 min. The Pearson's correlation coefficients for the O2Hb signal and SBF at 50 and 70 % VO2peak were 0.877 (P < 0.01) and -0.707 (P < 0.01), respectively. The correlation coefficients for O2Hb and MAP during warm-up, 30 % VO2peak, and 50 % VO2peak were 0.725 (P < 0.01), 0.472 (P < 0.01), and 0.939 (P < 0.01), respectively. Changes in the state of the cardiovascular system influenced O2Hb signals positively during low and moderate-intensity exercise, whereas a negative relationship was observed during high-intensity exercise. These results suggest that the relationship between the O2Hb signal and systemic changes is affected by exercise intensity.
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan. tsubaki@nuhw.ac.jp.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Tsubaki
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Haruna
authors.initials: H
authors.lastname: Takai
authors.affiliation: Kobe City Medical Center General Hospital, 2-2-1 Minatojimaminamimachi, Chuo-ku, Kobe-city, Hyogo, 650-0047, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Oyanagi
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Kojima
authors.affiliation: Niigata Rehabilitation Hospital, 761 Kizaki, Kita-ku, Niigata-shi, Niigata, 950-3304, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Tokunaga
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Miyaguchi
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sugawara
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sato
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tamaki
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Onishi
mesh_terms: D062186:Arterial Pressure; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D001921:Brain / Q000378:metabolism*; D015444:Exercise / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption; D010108:Oxyhemoglobins / Q000378:metabolism*; D012039:Regional Blood Flow; D012867:Skin / Q000098:blood supply*; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010108:Oxyhemoglobins; D010100:Oxygen
keywords: Mean arterial pressure; Multistep incremental exercise; Near-infrared spectroscopy; Oxyhaemoglobin; Skin blood flow