Alveolar gas exchange and tissue deoxygenation during exercise in type 1 diabetes patients and healthy controls

We used near-infrared spectroscopy to investigate whether leg and arm skeletal muscle and cerebral deoxygenation differ during incremental cycling exercise in men with type 1 diabetes (T1D, n = 10, mean ± SD age 33 ± 7 years) and healthy control men (matched by age, anthrometry, and self-reported physical activity, CON, n = 10, 32 ± 7 years) to seek an explanation for lower aerobic capacity (V˙O2peak) often reported in T1D. T1D had lower V˙O2peak (35 ± 4 ml kg−1 min−1 vs. 43 ± 8 ml kg−1 min−1, P < 0.01) and peak work rate (219 ± 33 W vs. 290 ± 44 W, P < 0.001) than CON. Leg muscle deoxygenation (↑ [deoxyhemoglobin]; ↓ tissue saturation index) was greater in T1D than CON at a given absolute submaximal work rate, but not at peak exercise, while arm muscle and cerebral deoxygenation were similar. Thus, in T1D compared with CON, faster leg muscle deoxygenation suggests limited circulatory ability to increase O2 delivery as a plausible explanation for lower V˙O2peak and earlier fatigue in T1D.

► Muscle and cerebral oxygenation during exercise in type 1 diabetes patients (T1D) and controls.
► Enhanced deoxygenation in active muscle in T1D at a given work rate.
► Similar cerebral and inactive muscle oxygenation in T1D and controls.
► Reduced maximal O2 uptake in T1D at a similar self-reported physical activity than controls.