title: Association of aerobic fitness level with exercise-induced hypoglycaemia in Type 1 diabetes.
abstract: To determine the impact of physical fitness level on hypoglycaemia risk during exercise in people with Type 1 diabetes.
  
  
  
  A total of 44 patients [34 adults (aged 22-70 years) and 10 adolescents (aged 12-18 years)] with Type 1 diabetes, treated with insulin pump therapy, underwent a standardized exercise session. Cardiorespiratory fitness (maximum oxygen uptake) was measured and classified, based on established norms for age and sex, into either poor (< 25th percentile) or good fitness level (> 25th percentile). Plasma glucose levels were measured every 10 min, each patient performed physical activity at 60% maximum oxygen uptake either on a treadmill for 1 h or on a bicycle for 30 min. Frequency of hypoglycaemia (plasma glucose < 4 mmol/l) and decline in plasma glucose levels during exercise were assessed.
  
  
  
  In all, 23 patients had a good exercise fitness level. Hypoglycaemic events occurred in 17/23 patients (74.0%) in the good fitness level group compared with 8/21 patients (38.0%) in the poor fitness level group (P = 0.02). Both groups had similar pre-exercise plasma glucose levels. The plasma glucose values during exercise in the good fitness level group compared with the poor fitness level group were: plasma glucose nadir 3.9 ± 1.6 vs 5.5 ± 2.4 mmol/l (P = 0.01) and plasma glucose change -4.6 ± 3.4 vs. -2.1 ± 3.1 mmol/l (P = 0.01). The correlation between the plasma glucose nadir and maximum oxygen uptake was r = -0.38 (P = 0.01).
  
  
  
  Patients with good fitness level seem to be more prone to hypoglycaemia during exercise. This could be the result of better insulin sensitivity and the fact that they tend to exercise at greater work thresholds. These results are a step toward a better understanding of the association between physical fitness and exercise-induced hypoglycaemia.
authors.affiliation: Department of Pediatric Endocrinology, Montreal Children's Hospital, McGill University Health Centre, Montréal, Québec, Canada.|Department of General Pediatrics, Division of General Pediatrics, King Saud University, King Khalid University Hospital, Riyadh, Saudi Arabia.
authors.forename: R A
authors.initials: RA
authors.lastname: Al Khalifah
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Suppère
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada.|Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Haidar
authors.affiliation: Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada.|Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec, Canada.|Nutrition Department, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada.|Montreal Diabetes Research Center, Montréal, Québec, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Rabasa-Lhoret
authors.affiliation: Centre de Recherche CHUM, Saint-Denis, Montréal, Québec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Ladouceur
authors.affiliation: Department of Pediatric Endocrinology, Montreal Children's Hospital, McGill University Health Centre, Montréal, Québec, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Legault
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000503:physiopathology; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000209:etiology*; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007328:Insulin / Q000008:administration & dosage; D007332:Insulin Infusion Systems; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D007328:Insulin