Can laboratory based research regarding type 1 diabetes and exercise be applied into the real-life environment?

Abstract

The aim of this study was to determine whether results from laboratory based research examining glycaemic control during and after exercise can be applied to a real-life (non-laboratory) environment. A comparative study of individuals with type 1 diabetes (n = 9) using basal bolus analogue insulin regimens was undertaken. Glycaemic control before and after two 40-minute runs at 70% VO2 max, in both laboratory and real-life environments, was measured across 10 time-points during and up to 12 hours after exercise. Insulin was adjusted in all participants following a self-management algorithm. Pooled mean glucose concentrations at each time-point were compared. There was no statistically significant difference (F[1, 8] = 1.489, p = 0.257) in overall mean glucose concentrations between environments. Similarly, the exercise environment or time-point of measurement had no statistically significant effect on mean glucose concentration (F[9, 72] = 0.499, p = 0.871). However, during exercise, episodes of both hypoglycaemia (<4.0 mmol/L) and hyperglycaemia (>9.0 mmol/L) were more frequent in the laboratory environment than in the real-life environment: 5 vs 1 and 25 vs 19 episodes, respectively; the frequency of acceptable concentrations (4.0-9.0 mmol/L) was greater in the real-life environment (24 vs 34). In the 8-12 hours after exercise, hypoglycaemia occurred more frequently in the real-life environment (3 vs 8) with hyperglycaemia occurring more frequently in the laboratory environment (22 vs 14); again, there were slightly increased acceptable concentrations in the real-life environment (29 vs 33). The exercise environment does not appear to affect overall mean blood glucose concentrations. However, it may affect the timing and frequency of hypoglycaemia and hyperglycaemia.