XIV National Congress SISMES

PURPOSE Sedentary lifestyle and unbalanced nutrition could develop insulin resistance in breast cancer survivors (BCS). In contrast, aerobic exercise could improve glycemic control. The interaction between aerobic exercise and glucose homeostasis still needs to be investigated in BCS. This study aims to evaluate the effect of a 12-week aerobic exercise training program on 24h glycemic control in BCS. METHODS Sixteen BCS women (ClinicalTrials.gov NCT04818359) without diabetes were randomized into a control (CG, n=8) and intervention (IG, n=8) group. Both groups received lifestyle guidelines on physical activity and Mediterranean diet. The IG also followed a 12-week supervised aerobic exercise training program with incremental intensity (40-70% of heart rate reserve) and duration (20-60 min) for 3 days/week. The 24h glycemic variability index (i.e., % time >140 mg/dL obtained by using a flash glucose monitoring device) and caloric intake (retrieved from a food diary) were evaluated for 14 days at the beginning and at the end of the study. Cardiorespiratory fitness (V̇O2max), anthropometric and body composition parameters (e.g., BMI and % body fat), and metabolic markers (HOMA-IR and fasting glucose and insulin) were evaluated before and after intervention. The difference between groups over time was evaluated using a two-way mixed ANOVA for the 24h glycemic variability index and a two-way RM-MANOVA for the other secondary variables. RESULTS After the intervention, the 24h glycemic variability index revealed that the time spent in a hyperglycemic state (glucose >140 mg/dL) increased significantly (p=0.015) in CG (5.0±4.5 to 11.6±12.0) compared to IG (10.9±12.7 to 11.0±10.4). The caloric intake increased in both CG (+19%; p=0.068) and IG (+28.1%, p=0.028). Fasted insulin level decreased in both CG (−34.9%; p=0.006) and IG (−18.5%; p=0.051), and HOMA-IR decreased by −34.2% in CG (p=0.012) and by −17.6% (p=0.060) in IG. The V̇O2max increased significantly in IG (+16.4%; p=0.017) and non-significantly in CG (+2.2%; p=0.638). Anthropometric, body composition parameters and fasting glucose did not change in both groups. CONCLUSIONS The IG showed a higher control of the glycemic variability and less time spent in hyperglycemia than the CG after the intervention. However, insulin and HOMA-IR of IG were only slightly modified, highlighting the importance of the combined effect of exercise and caloric intake, which increased in IA and might have mitigated the exercise effect.