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DISTq: An Iterative Analysis of Glucose Data for Low-Cost, Real-Time and Accurate Estimation of Insulin Sensitivity.

Docherty PD, Chase JG, Lotz T, Hann CE, Shaw GM, Berkeley JE, Mann JI, McAuley K - Open Med Inform J (2009)

Bottom Line: The gap between these tests presents an opportunity for new approaches.Correlations of the resulting SI values was R=0.91.This estimate has enough resolution for SI prediction and monitoring of response to therapy.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, University of Canterbury, New Zealand.

ABSTRACT
Insulin sensitivity (SI) estimation has numerous uses in medical and clinical situations. However, highresolution tests that are useful for clinical diagnosis and monitoring are often too intensive, long and costly for regular use. Simpler tests that mitigate these issues are not accurate enough for many clinical diagnostic or monitoring scenarios. The gap between these tests presents an opportunity for new approaches. The quick dynamic insulin sensitivity test (DISTq) utilises the model-based DIST test protocol and a series of population estimates to eliminate the need for insulin or C-peptide assays to enable a high resolution, low-intensity, real-time evaluation of SI. The method predicts patient specific insulin responses to the DIST test protocol with enough accuracy to yield a useful clinical insulin sensitivity metric for monitoring of diabetes therapy. The DISTq method replicated the findings of the fully sampled DIST test without the use of insulin or C-peptide assays. Correlations of the resulting SI values was R=0.91. The method was also compared to the euglycaemic hyperinsulinaemic clamp (EIC) in an in-silico Monte-Carlo analysis and showed a good ability to re-evaluate SI(EIC) (R=0.89), compared to the fully sampled DIST (R=0.98) Population-derived parameter estimates using a-posteriori population-based functions derived from DIST test data enables the simulation of insulin profiles that are sufficiently accurate to estimate SI to a relatively high precision. Thus, costly insulin and C-peptide assays are not necessary to obtain an accurate, but inexpensive, real-time estimate of insulin sensitivity. This estimate has enough resolution for SI prediction and monitoring of response to therapy. In borderline cases, re-evaluation of stored (frozen) blood samples for insulin and C-peptide would enable greater accuracy where necessary, enabling a hierarchy of tests in an economical fashion.

No MeSH data available.


Related in: MedlinePlus

The physiological compartmental model used to match the DIST test data (symbols are fully defined in the Methods section).
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Figure 1: The physiological compartmental model used to match the DIST test data (symbols are fully defined in the Methods section).

Mentions: The dynamic insulin sensitivity test (DIST) is a recently developed low-dose, short-protocol test similar to the IM-IVGTT [17, 24]. The subject’s response to a relatively low dose (5-20g) IV glucose bolus followed by a low dose (0.5-2U) IV insulin bolus is monitored with samples assayed for glucose, insulin and C-peptide. These concentrations are used to identify model-based parameters for SI, endogenous insulin secretion (Uen) and liver clearance (nL) by solving the physiological model shown in Fig. (1). The model is a compartmental pharmaco-kinetic (PK) and pharmacodynamic (PD) model representing the physiological pathways and interactions between insulin, C-peptide and glucose in the human body [25]. Prior modelling studies have shown the SI value from the model can be highly correlated to the insulin sensitivity metric (ISI) from the EIC (R=0.99) [17], and a clinical validation study is ongoing with initial correlations of R≈0.78. Note that the DIST differs from the IM-IVGTT by measuring every 5-10 minutes and using significantly lower insulin and glucose doses.


DISTq: An Iterative Analysis of Glucose Data for Low-Cost, Real-Time and Accurate Estimation of Insulin Sensitivity.

Docherty PD, Chase JG, Lotz T, Hann CE, Shaw GM, Berkeley JE, Mann JI, McAuley K - Open Med Inform J (2009)

The physiological compartmental model used to match the DIST test data (symbols are fully defined in the Methods section).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2812840&req=5

Figure 1: The physiological compartmental model used to match the DIST test data (symbols are fully defined in the Methods section).
Mentions: The dynamic insulin sensitivity test (DIST) is a recently developed low-dose, short-protocol test similar to the IM-IVGTT [17, 24]. The subject’s response to a relatively low dose (5-20g) IV glucose bolus followed by a low dose (0.5-2U) IV insulin bolus is monitored with samples assayed for glucose, insulin and C-peptide. These concentrations are used to identify model-based parameters for SI, endogenous insulin secretion (Uen) and liver clearance (nL) by solving the physiological model shown in Fig. (1). The model is a compartmental pharmaco-kinetic (PK) and pharmacodynamic (PD) model representing the physiological pathways and interactions between insulin, C-peptide and glucose in the human body [25]. Prior modelling studies have shown the SI value from the model can be highly correlated to the insulin sensitivity metric (ISI) from the EIC (R=0.99) [17], and a clinical validation study is ongoing with initial correlations of R≈0.78. Note that the DIST differs from the IM-IVGTT by measuring every 5-10 minutes and using significantly lower insulin and glucose doses.

Bottom Line: The gap between these tests presents an opportunity for new approaches.Correlations of the resulting SI values was R=0.91.This estimate has enough resolution for SI prediction and monitoring of response to therapy.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering, University of Canterbury, New Zealand.

ABSTRACT
Insulin sensitivity (SI) estimation has numerous uses in medical and clinical situations. However, highresolution tests that are useful for clinical diagnosis and monitoring are often too intensive, long and costly for regular use. Simpler tests that mitigate these issues are not accurate enough for many clinical diagnostic or monitoring scenarios. The gap between these tests presents an opportunity for new approaches. The quick dynamic insulin sensitivity test (DISTq) utilises the model-based DIST test protocol and a series of population estimates to eliminate the need for insulin or C-peptide assays to enable a high resolution, low-intensity, real-time evaluation of SI. The method predicts patient specific insulin responses to the DIST test protocol with enough accuracy to yield a useful clinical insulin sensitivity metric for monitoring of diabetes therapy. The DISTq method replicated the findings of the fully sampled DIST test without the use of insulin or C-peptide assays. Correlations of the resulting SI values was R=0.91. The method was also compared to the euglycaemic hyperinsulinaemic clamp (EIC) in an in-silico Monte-Carlo analysis and showed a good ability to re-evaluate SI(EIC) (R=0.89), compared to the fully sampled DIST (R=0.98) Population-derived parameter estimates using a-posteriori population-based functions derived from DIST test data enables the simulation of insulin profiles that are sufficiently accurate to estimate SI to a relatively high precision. Thus, costly insulin and C-peptide assays are not necessary to obtain an accurate, but inexpensive, real-time estimate of insulin sensitivity. This estimate has enough resolution for SI prediction and monitoring of response to therapy. In borderline cases, re-evaluation of stored (frozen) blood samples for insulin and C-peptide would enable greater accuracy where necessary, enabling a hierarchy of tests in an economical fashion.

No MeSH data available.


Related in: MedlinePlus