Influence Of Remotely-Delivered Exercise On Glycemia In Women With Or At-Risk For Type 2 Diabetes

Exaggerated increases in blood glucose concentration following meals is a risk factor for the development of cardiovascular disease in women with or at risk for type 2 diabetes (T2D). Previous laboratory-based research has demonstrated that performing exercise after a meal can lower postprandial glycemic excursions; however, exercise is often performed at a pre-determined intensity with specialized exercise equipment, which may not reflect exercise performed at home. Whether unsupervised exercise performed following a meal at home can lower postprandial glycemia is not well characterized. PURPOSE: To investigate the effects of performing unsupervised exercise at a self-selected pace following dinner on postprandial glycemia in women with or at risk for T2D. METHODS: 65 women (age: 60 ± 6 yr, BMI: 32 ± 7 kg/m2) diagnosed with prediabetes, T2D, or a moderate-to-high Canadian Diabetes Risk score (≥21) were recruited across Ontario, Canada. Participants were mailed a continuous glucose monitor and activity tracker to measure blood glucose and heart rate. In a randomized and counterbalanced order, participants consumed a habitual dinner meal on 3 occasions (640 ± 273 kcal, 66 ± 35 g carbohydrate) and initiated the following interventions 30 min thereafter independently: no exercise (CTL), 15 min of video-guided bodyweight interval exercise (BWI; 8 x 1-min intervals, 1-min recovery) or 30 min of walking (WALK). Participants were instructed to walk at a moderate pace for WALK and complete as many repetitions as possible during the BWI exercise intervals. Mean ± standard deviation of heart rate during exercise and median (interquartile range) of 3 h glucose mean, peak and iAUC following dinner were calculated. RESULTS: At-home BWI and WALK elicited self-selected intensities of 76 ± 8% and 73 ± 7% HRmax, respectively. Compared to CTL, WALK reduced 3 h glucose mean (6.3 (1.2) vs. 6.9 (1.3) mmol/L, p = 0.002), peak (7.9 (1.9) vs. 8.3 (1.7) mmol/L, p = 0.029) and iAUC (106 (160) vs. 159 (174) mmol/L x 3 h, p = 0.044). 3 h glucose mean (6.7 (1.3) mmol/L), peak (8.0 (1.7) mmol/L) and iAUC (166 (175) mmol/L x 3 h) in BWI were not different from CTL. CONCLUSION: An unsupervised 30-minute walk performed at home after dinner reduced postprandial glycemia in women with or at risk for T2D. Supported by CCS and CIHR.