Ed. Lehmann et al., RETROSPECTIVE VALIDATION OF A PHYSIOLOGICAL MODEL OF GLUCOSE-INSULIN INTERACTION IN TYPE-1 DIABETES-MELLITUS, Medical engineering & physics, 16(3), 1994, pp. 193-202
We have previously described a physiological model of glucose-insulin
interaction in insulin-dependent (type 7) diabetes mellitus which has
been developed for patient and medical staff education about diabetes
mellitus, as well as possibly for clinical use. The model attempts to
reflect the underlying (patho)physiology of insulin action and carbohy
drate absorption in quantitative terms such as insulin sensitivity, vo
lume of glucose and insulin distribution and maximal gastric emptying.
The model's predictions also allow a 24 h simulation of patient blood
glucose profiles to be generated. Advice is provided by a qualitative
knowledge based system which suggests what the next step in improving
glycaemic control might be for a given patient, e.g. 'increase before
breakfast long-acting insulin by 2 units' Validation work performed o
n a previous version of the knowledge based system has demonstrated th
at it can provide qualitative advice comparable to that of a clinician
. Furthermore, bench testing of the predictive accuracy of the model h
as yielded encouraging results. We therefore set out to perform a prel
iminary retrospective medical validation of the physiological model wi
ng data collected by 30 insulin-dependent diabetic patients attending
diabetes out-patient clinics at various centres throughout Europe.We f
ound that the physiological model could only be parameterized for data
from 24 (80%) of the 30 patients in the study. Comparison of observed
and predicted blood glucose data from these 24 patients over a period
of 5-6 days following parameter estimation revealed a mean (+/- SD) r
oot mean square deviation between measured and simulated blood glucose
values of 1.93 +/- 0.86 mmoll(-1). The implications of these results
are discussed.