title: Two methods for determining plasma IL-6 in humans at rest and following exercise.
abstract: We compared two methods to determine IL-6 at rest and following exercise. On two occasions, plasma IL-6 was determined in 10 men and 13 women before and immediately following 90 min of cycling at 65% V(O)(2max) using a cytometric bead array (CBA) and an ELISA. The CBA detected IL-6 in 63% of pre-exercise samples and 84% of post-exercise samples; the ELISA detected IL-6 in all samples. In samples with detectable IL-6, resting values were comparable between the CBA and ELISA (2.3 +/- 1.0 and 2.4 +/- 1.2 pg/mL, respectively; p = 0.99); the IL-6 response to exercise was underestimated (p = 0.0003) by the CBA by ~45%, compared with the ELISA. CBA- and ELISA-determined IL-6 values were moderately correlated (r = 0.66, p < 0.0001), but exhibited poor agreement (mean bias +/- 1SD = -1.4 +/- 2.1 pg/mL). The CBA provided concordant IL-6 concentrations at rest, when detected, but underestimated exercise-induced increases in IL-6 versus the ELISA method.
authors.affiliation: Children's Exercise and Nutrition Centre, McMaster University, Chedoke Hospital, Evel Bldg, Sanatorium Road, Hamilton, ON, L8N 3Z5, Canada. timmonbw@mcmaster.ca
authors.forename: Brian W
authors.initials: BW
authors.lastname: Timmons
authors.forename: Mazen J
authors.initials: MJ
authors.lastname: Hamadeh
authors.forename: Mark A
authors.initials: MA
authors.lastname: Tarnopolsky
mesh_terms: D000328:Adult; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D015444:Exercise / Q000502:physiology*; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance; D012146:Rest / Q000502:physiology*
chemical_list: D015850:Interleukin-6
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