Is there a need to measure preand post-capillary blood glucose following a cardiac exercise class?

Exercise training is associated with positive health outcomes in people with cardiovascular disease (CVD) and type 2 diabetes mellitus (T2DM). However, fear of hypoglycaemia is a potential barrier to participants attending a cardiac exercise class. Therefore, we assessed the capillary blood glucose (CBG) responses to the Imperial NHS Trust cardiac exercise class. Forty patients (median age 66 years, interquartile range [IQR] 57-74 years) with CVD and T2DM treated with insulin and/or sulfonylureas completed a cardiac exercise class. CBG was measured immediately before and after the exercise class. Subgroup analysis assessed CBG levels in patients who had consumed food <2 and ≥2 hours and had taken their insulin and/or sulfonylureas <4 and ≥4 hours before the exercise class. Overall, post-exercise CBG had significantly decreased (-3.0 mmol/L, p≤0.0001). Subgroup analyses demonstrated significant reductions in CBG in both food consumption groups (<2 hours -2.9 mmol/L, p≤0.0001, and ≥2 hours -3.1 mmol/L, p≤0.0001) and medication groups (<4 hours -3.4 mmol/L, p≤0.0002, and ≥4 hours -2.7 mmol/L, p≤0.0001). However, there were no significant differences in CBG between the food consumption groups and the medication groups, respectively (p=0.7 and p=0.3). Cardiac exercise classes resulted in significant reductions in CBG levels. However, the timing of food consumption or medication intake did not influence the magnitude of CBG decline after the cardiac exercise class.