Impact of beta-blocker treatment and nutritional status on glycemic response during exercise in patients with type 2 diabetes.
OBJECTIVE
Most individuals with type 2 diabetes are affected by hypertension and thus have higher risk of cardiac complications. In addition to behavioural modifications, such as healthy food choices and regular physical activity, beta-blocker treatment may be considered to reduce morbidity and mortality, especially after a cardiovascular event. However, this medication is generally associated with a deleterious impact on glucose metabolism. The objective of the study was to assess the impact of beta-blocker treatment on glucose response during exercise in patients with type 2 diabetes, free of cardiovascular complications.


METHODS
Ten sedentary men, treated with diet and/or hypoglycemic agents have performed four exercise sessions at 60% of their V O2peak, in the fasted state or 2 hours following a standardized breakfast, with and without beta-blockers (atenolol 100 mg id for five consecutive days). Blood samples were drawn during the resting period, at 15-min intervals during the exercise session and during the recovery period.


RESULTS
A reduction of blood glucose levels was observed following the exercise session in the postprandial state (48% and 44% reduction with and without beta-blockers respectively; P < 0.001). One hour of exercise performed in the fasted state had a minimal impact on glucose and insulin levels, whether with or without beta-blockers. beta-blocker treatment was not associated with increased baseline blood glucose or insulin levels in the fasted or the postprandial situation.


CONCLUSIONS
Dietary status has a more important impact on plasma glucose and insulin modulation than short-term use of beta-blockers.
Centre de recherche de l'Hôpital Laval, Institut universitaire de cardiologie et de pneumologie del'Université Laval, Québec, Canada.
Annie
A
Ferland
Patrice
P
Brassard
Sara
S
Croteau
Simone
S
Lemieux
Jean
J
Bergeron
Stéphanie
S
Lacroix
Lison
L
Fournier
Paul
P
Poirier
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000328:Adult; D001262:Atenolol / Q000627:therapeutic use; D001786:Blood Glucose / Q000032:analysis*; D001835:Body Weight / Q000187:drug effects; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000178:diet therapy* / Q000188:drug therapy*; D004032:Diet; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D019518:Postprandial Period / Q000187:drug effects; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D001786:Blood Glucose; D007004:Hypoglycemic Agents; D001262:Atenolol