Type 1 diabetes: dealing with physical activity

For patients with type 1 diabetes (T1D) using multiple insulin injections (MII), there are currently no guidelines for insulin dose adjustments in the event of physical activity (PA) and no simple algorithms that can be applied directly. Thus, the objective of this study was to assess the relevance of simple algorithms based on assessments of PA intensity by T1D patients themselves.

This 4-month observational study was conducted in 35 patients using the Diabeo software system. Algorithms for insulin dose adjustments aimed to reduce the insulin dose of the meal closest to PA by 30 and 50% for moderate and intense PA, respectively. A 50% reduction plus extra carbohydrates was proposed for intense PA of long duration. These algorithms were entered into the Diabeo system.

The mean blood glucose (BG) profile in the event of PA (n = 151 triple BG values) was compared with that when no PA was performed (n = 3606). The initial mean FBG values were similar in both groups (7.58 ± 2.70 mmol/L vs. 7.80 ± 3.49 mmol/L; P = 0.36), whereas there was a slight, but significant, increase in 2-hours postprandial BG (PPBG) values related to PA, with a return to similar values before the next meal. The incidence of mild hypoglycaemia was similar, whether PA was undertaken or not, for the 2-hour PPBG and the next fasting/premeal glucose values.

This appears to be a pragmatic and efficient method for T1D patients using MII to adjust insulin doses in the event of PA that only requires an assessment of PA intensity by the patients themselves to anticipate the magnitude of the reduction in insulin doses.