title: Regional cerebral hemodynamic response to incremental exercise is blunted in poorly controlled patients with uncomplicated type 1 diabetes.
abstract: OBJECTIVE
  Cerebral vasoreactivity to pharmacologically induced hypercapnia is impaired in poorly controlled patients with type 1 diabetes but otherwise free from microangiopathy. However, whether this response is also compromised during exercise, a daily-life physiological condition challenging regional cerebral hemodynamics, is unknown. We aimed to investigate prefrontal cortex hemodynamics during incremental maximal exercise in patients with uncomplicated type 1 diabetes, taking into account long-term glycemic control as well as exercise- and diabetes-influenced vasoactive stimuli.
  
  
  METHODS
  Two groups of patients (type 1 diabetes with adequate glycemic control [T1D-A], n = 8, HbA1c 6.8 ± 0.7% [51 ± 7.7 mmol/mol]; type 1 diabetes with inadequate glycemic control [T1D-I], n = 10, HbA1c 9.0 ± 0.7% [75 ± 7.7 mmol/mol]) were compared with 18 healthy control subjects (CON-A and CON-I) matched for physical activity and body composition. Throughout exercise, near-infrared spectroscopy allowed investigation of changes in oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), and total hemoglobin (THb) in the prefrontal cortex. Venous and arterialized capillary blood was sampled during exercise to assess for factors that may alter prefrontal cortex hemodynamics and oxygenation.
  
  
  RESULTS
  No differences were observed between T1D-A and CON-A, but VO2max was impaired (P < 0.05) and cerebral blood volume (THb) increase blunted (P < 0.05) in T1D-I compared with CON-I. Nonetheless, O2Hb appeared unaltered in T1D-I probably partly due to blunting of simultaneous neuronal oxygen extraction (i.e., a lower HHb increase; P < 0.05). There were no intergroup differences in arterial oxygen content, Paco2, pH, [K(+)], and free insulin levels.
  
  
  CONCLUSIONS
  Maximal exercise highlights subtle disorders of both hemodynamics and neuronal oxygenation in the prefrontal cortex of poorly controlled patients with type 1 diabetes. These findings may warn clinicians of brain endothelial dysfunction occurring even before overt microangiopathy during exercise.
authors: University of Lille, URePSSS, "Physical Activity, Muscle, Health" Research Team, Lille, France.
authors: Semah
authors: S
authors: Tagougui
authors: Department of Diabetology, Lille University Hospital, EA 4489, Lille, France.
authors: Pierre
authors: P
authors: Fontaine
authors: School of Kinesiology and Health Science, Faculty of Health, York University, Toronto, ON, Canada.
authors: Erwan
authors: E
authors: Leclair
authors: University of Lille, URePSSS, "Physical Activity, Muscle, Health" Research Team, Lille, France.
authors: Julien
authors: J
authors: Aucouturier
authors: Department of Physiology, EA 2689 and IFR 22, Lille, France.
authors: Régis
authors: R
authors: Matran
authors: University of Lille, URePSSS, "Physical Activity, Muscle, Health" Research Team, Lille, France.
authors: Kahina
authors: K
authors: Oussaidene
authors: Regional Hospital Centre of Roubaix, Roubaix, France.
authors: Aurélien
authors: A
authors: Descatoire
authors: University Paris Sud-University of Orléans, EA 4532 CIAMS, Orléans, France.
authors: Fabrice
authors: F
authors: Prieur
authors: University of Lille, URePSSS, "Physical Activity, Muscle, Health" Research Team, Lille, France.
authors: Patrick
authors: P
authors: Mucci
authors: Department of Diabetology, Lille University Hospital, EA 4489, Lille, France.
authors: Anne
authors: A
authors: Vambergue
authors: University of Lille, URePSSS, "Physical Activity, Muscle, Health" Research Team, Lille, France.
authors: Georges
authors: G
authors: Baquet
authors: University of Lille, URePSSS, "Physical Activity, Muscle, Health" Research Team, Lille, France elsa.heyman@univ-lille2.fr.
authors: Elsa
authors: E
authors: Heyman
mesh_terms: D000328:Adult; D000368:Aged; D001810:Blood Volume / Q000502:physiology; D001921:Brain / Q000378:metabolism; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology; D003922:Diabetes Mellitus, Type 1 / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption / Q000502:physiology; D010108:Oxyhemoglobins / Q000378:metabolism; D017397:Prefrontal Cortex / Q000502:physiology*; D019265:Spectroscopy, Near-Infrared; D014664:Vasodilation / Q000502:physiology
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen