Impact of Beta-Blocker Treatment and the Nutritional Status on Glycemic Response During Exercise in Type 2 Diabetic Patients

Background/Objective: More than 60% of type 2 diabetic individuals present with hypertension and have higher risk of cardiac complications. In addition to behavioural modifications, such as healthy food choices and regular physical activity, beta-blocker (BB) treatment may be considered in order to reduce morbidity and mortality especially following a cardiovascular event. However, this medication is generally associated with a deleterious impact on glucose metabolism. To assess the impact of a BB treatment on glucose response in type 2 diabetic patients exempt of cardiovascular complications. Methods: Six sedentary men, treated with diet and/or a hypoglycemic agent performed four exercise sessions at 60% of their VO2 peak, in the fasted state or 2 hours after a standardized breakfast, with and without BB (Atenolol 100 mg id for five consecutive days). Blood samples were assayed during the resting period, at 15-minutes intervals during the exercise session and the recovery period. Results: A reduction of blood glucose levels was observed following the exercise session performed in the postabsorptive state (41% and 37% reduction with and without BB treatment respectively; P < 0.01). One hour of exercise performed in the fasted state had minimal impact on glucose and insulin levels, with or without BB. BB treatment was not associated with increased baseline blood glucose or insulin levels in the fasted or the postabsorptive situation. Conclusion: These results suggest that the nutritional status has a more important impact on plasma glucose and insulin modulation than short-term use of BB per se.