COMPARISON BETWEEN REAL AND ESTIMATED CARBOHYDRATE SUPPLEMENTS IN TYPE 1 DIABETIC PATIENTS DURING 1-H RUNS

Introduction Physical activity helps maintaining a better metabolic control and enhances self-esteem in patients with type 1 diabetes (T1DM). Voluntary exercise is, however, limited by the risk of exercise-induced hypoglycemia (i.e. <3.9 mmol/L; Dubé et al., 2006), which is usually minimized by the ingestion of a carbohydrates supplement (CHO-s), even after reduction of the insulin dose (Grimm, 2004). The recently proposed ECRES algorithm (Francescato et al., 2011) estimates, on a patient and situation specific basis, the CHO-s required to keep a safe glycemia. The real CHO-s during the Telethon 2013 24x1 hour Marathon run were compared with the CHO-s estimated by ECRES. Methods Nineteen T1DM patients were studied (8F; 9 with insulin pump; 36±10 yrs, 68±11 kg, HbA1c 7.5±0.9%), with continuous medical assistance during the event. Patient’s usual therapy and any specific adjustment, glycemia before, at the middle, and at the end, and heart rate during the run were recorded. ECRES algorithm was adjusted on patient’s specific data and the estimated amounts of CHO-s were compared to the real ones. Results Patients run on average 10.4±2.8 km, showing an average heart rate of 157±21 bpm. Glycemia at the start ranged from 4.5 to 20.6 mmol/L (average 10.5±4.3 mmol/L); in 8/19 cases glycemia was > 10 mmol/L. Glycemia decreased significantly (p<0.01) to 7.4±3.1 mmol/L at the end of the runs. At the middle of the run, 3 patients showed a moderate hypoglycemia (>3.3 mmol/L) quickly compensated consuming a few sugar drops, and 1 patient showed a glycemia of 2 mmol/L that was difficult to be fully compensated by the end of the run. In 3 patients glycemia increased by the end of the run. Average consumed CHO-s amounted to 42±42 g. The CHO-s estimated by the ECRES algorithm were significantly related to the actual values (R=0.65, n=19, p<0.005) and would allow 63% of patients to conclude their 1-h run with glycemia in the optimal range. Discussion Results show that patients frequently prefer minimizing the risk of exercise-induced hypoglycemia with a very high glycemia at the start of the activity. The ECRES algorithm would have suggested appropriate amounts in a high percentage of cases also for the challenging physical activity constituted by the 24x1-h Marathon. This suggests that the ECRES algorithm can indeed become a useful tool for T1DM patients to help them keeping more constant glycemic levels on each exercise occasion. References Dubé MC, Valois P, et al. (2006). Diabetes Res Clin Pract, 72: 20-26 Francescato MP, Geat M, et al. (2011). Med Sci Sports Exerc, 43: 2-11 Grimm JJ, Ybarra J, et al. (2004). Diabetes Metab, 30: 465–70