In adolescents with type 1 diabetes, one study reported reduction in forearm blood flow after local exercise (rhythmic handgrip) despite the absence of any otherwise clinically detectable vascular disorders (33).
To our knowledge, arterial O2 transport capacity has never been investigated during exercise in patients with type 1 diabetes and with different levels of HbA1c.
Several in vitro studies suggest possibly increased O2Hb affinity (i.e., a leftward shift of the O2 dissociation curve) and/or decreased sensitivity of hemoglobin to the allosteric effect of organic phosphates as a result of hemoglobin glycation at a degree corresponding to HbA1c levels in patients with poor glycemic control (i.e., 8%) (10,25,26,36).