Bio-medical Ontologies Maintenance and Change Management

The Minimal Model of Glucose Disappearance in
Type I Diabetes
Margarita Fernandez 1 , Minaya Villasana 2 ,andDanStreja 3
1 Depto. de Cómputo Científico y Estadística, USB, AP 89000; Caracas 1080-A; Venezuela
margarita@cesma.usb.ve
2 Depto. de Cómputo Científico y Estadística, USB, AP 89000; Caracas 1080-A; Venezuela
mvillasa@usb.ve
3 David Geffen School of Medicine, UCLA, Los Angeles, USA
dstreja@ucla.edu
Summary. In this chapter we evaluate the ability of the minimal model of glucose
disappearance to describe experimental data collected from 9 diabetic patients controlled
subcutaneously by an insulin pump. Two versions of the minimal model are
used: the nonlinear classic minimal model developed by Bergman et al. (MM) and
the linear approximation proposed by Fernandez et al. (LMM). All data windows
(n = 13) show residuals that are correlated for both the LMM and MM (p-value
< 0.01). The results also show that both the LMM and MM provide an equivalent
goodness of fit with R 2 values that are statistically equivalent (p-value > 0.05). This
study confirms that the minimal model of glucose disappearance, either the classic
or linear version, is unable to describe the observed experimental data possibly as
a result of the physiological constraints imposed by the minimal model approach
on the system dynamics, together with possible errors derived from the unmeasured
insulin dynamics. Further testing on more complex models should be performed.
1 Introduction
The aim of the present study has been to evaluate if the minimal model of glucose
disappearance is able to describe the experimental data collected from 9 diabetic
patients being controlled subcutaneously by an insulin pump.
On previous research the authors have shown the inability of the simple two compartmental
model known as the minimal model [3] to follow these experimental data
[14]. This model was included in the study to describe the dynamics of glucose, and
two input models were also supplied [14]:
• An interstitial insulin absorption model proposed by Shichiri et al. [18] to account
for the dynamics of insulin supplied subcutaneously by the insulin pump.
• A model published by Radziuk et al. [17] to describe the rate of appearance of
the external glucose following ingestion.
In this respect, the chosen input models have been identified by the authors as
possible sources of error and further work has been proposed to improve the results
A.S. Sidhu et al. (Eds.): Biomedical Data and Applications, SCI 224, pp. 295–315.
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