Influence of type 2 diabetes on muscle deoxygenation during ramp incremental cycle exercise

Norita Gildea, Joel Rocha, Adam McDermott, Donal O'Shea, Simon Green, Mikel Egaña*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)
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We tested the hypothesis that type 2 diabetes (T2D) alters the profile of muscle fractional oxygen (O2) extraction (near-infrared spectroscopy) during incremental cycle exercise. Seventeen middle-aged individuals with uncomplicated T2D and 17 controls performed an upright ramp test to exhaustion. The rate of muscle deoxygenation (i.e. deoxygenated haemoglobin and myoglobin concentration, Δ[HHb+Mb]) profiles of the vastus lateralis muscle were normalised to 100% of the response, plotted against % power output (PO) and fitted with a double linear regression model. Peak oxygen uptake was significantly (P < 0.05) reduced in individuals with T2D. The %Δ[HHb+Mb]/%PO slope of the first linear segment of the double linear regression function was significantly (P < 0.05) steeper in T2D than controls (1.81±0.61 vs 1.35±0.43). Both groups displayed a near-plateau in Δ[HHb+Mb] at an exercise intensity (%PO) not different amongst them. Such findings suggest that a reduced O2 delivery to active muscles is an important underlying cause of exercise intolerance during a maximum graded test in middle-aged individuals with T2D.

Original languageEnglish
Article number103258
Number of pages7
JournalRespiratory Physiology and Neurobiology
Early online date23 Jul 2019
Publication statusPublished - 1 Nov 2019


  • Near-infrared spectroscopy
  • Oxygen extraction
  • Cycling
  • Exercise tolerance
  • Type 2 diabetes


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