Background
The model-based dynamic insulin sensitivity and secretion test (DISST) uses fasting glucose ( G 0 ) as the basal glucose ( G B ) concentration when assessing insulin sensitivity ( SI ). However, this model was developed in a healthy, normoglycaemic cohort. We sought to determine the suitability the DISST model has for individuals with established type 2 diabetes (T2D).
Methods
14 participants with established T2D were recruited to take part in a dietary intervention study. Insulin-modified intravenous glucose tolerance tests (IM-IVGTT) were undertaken at week 0, 12 and 24 and were used with DISST model to identify G B . A total of 36 tests were conducted across 12 participants throughout the study. Measured G 0 and identified G B values were compared using a Kolmogorov-Smirnov (KS) and signed rank (RS) test for the cohort.
Results
There were significant differences between the G 0 and identified G B values in this cohort (p rs and p ks < 0.0001), although both values were well correlated ( R = 0.70). The residual plot demonstrates that the modified model captures the behaviour of the participants more accurately than the original model.
Conclusions
This analysis has shown that G B is an important variable for modelling the glycaemic behaviour in T2D. These findings suggest that the original DISST model, while appropriate for normoglycaemic cohorts, needs to model basal glucose level as a variable for assessing individuals with established T2D.