Medicine:SPINA-GBeta
| SPINA-GBeta | |
|---|---|
| Medical diagnostics | |
| Reference range | 0.64–3.73 pmol/s |
| Calculator | https://doi.org/10.5281/zenodo.7479856 |
| Purpose | Medical diagnosis, research |
| Test of | Pancreatic beta cell function |
SPINA-GBeta is a calculated biomarker for pancreatic beta cell function.[1][lower-alpha 1] It represents the maximum amount of insulin that beta cells can produce per time-unit (e.g. in one second).
How to determine GBeta
The index is derived from a mathematical model of insulin-glucose homeostasis.[2] For diagnostic purposes, it is calculated from fasting insulin and glucose concentrations with:
[math]\displaystyle{ {\widehat{G}}_{\beta }=\frac{[I](\infty )({D}_{\beta }+\left[G\right](\infty ))}{{G}_{3}[G](\infty )} }[/math].[1]
[I](∞): Fasting Insulin plasma concentration (μU/mL)
[G](∞): Fasting blood glucose concentration (mg/dL)
Dβ: EC50 for glucose at beta cells (7 mmol/L)
G3: Parameter for pharmacokinetics (58,8 s/L)
Clinical significance
Validity
SPINA-GBeta significantly correlates with the M value in glucose clamp studies and (better than HOMA-Beta) with the two-hour value in oral glucose tolerance testing (OGTT), glucose rise in OGTT, subscapular skinfold, truncal fat content and the HbA1c fraction.[1]
It has the additional advantage that it circumvents the HOMA-blind zone, which renders the calculation of HOMA-Beta impossible if the fasting glucose concentration is 3.5 mmol/L (63 mg/dL) or below.[3] Unlike HOMA-Beta, SPINA-Beta can be sensibly calculated in the whole range of measurements.[1]
Reliability
In repeated measurements, SPINA-GBeta had higher retest reliability than HOMA-Beta, a measurement for beta cell function from the homeostasis model assessment.[1][4]
Clinical utility
In the FAST study, an observational case-control sequencing study including 300 persons from Germany, SPINA-GBeta differed more clearly between subjects with and without diabetes than the corresponding HOMA-Beta index.[4]
Other uses
Together with the reconstructed insulin receptor gain (SPINA-GR), SPINA-GBeta provides the foundation for the definition of a fasting based disposition index of insulin-glucose homeostasis (SPINA-DI).[4]
Pathophysiological implications
In several populations, SPINA-GBeta correlated with the area under the glucose curve and 2-hour concentrations of glucose, insulin and proinsulin in oral glucose tolerance testing, concentrations of free fatty acids, ghrelin and adiponectin, and the HbA1c fraction.[4]
See also
- SPINA-GR
- SPINA-GD
- SPINA-GT
- Homeostatic model assessment
- QUICKI
Notes
- ↑ SPINA is an acronym for "structure parameter inference approach".
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Dietrich, JW; Dasgupta, R; Anoop, S; Jebasingh, F; Kurian, ME; Inbakumari, M; Boehm, BO; Thomas, N (21 October 2022). "SPINA Carb: a simple mathematical model supporting fast in-vivo estimation of insulin sensitivity and beta cell function.". Scientific Reports 12 (1): 17659. doi:10.1038/s41598-022-22531-3. PMID 36271244. Bibcode: 2022NatSR..1217659D.
- ↑ Dietrich, Johannes W.; Böhm, Bernhard (27 August 2015). "Die MiMe-NoCoDI-Plattform: Ein Ansatz für die Modellierung biologischer Regelkreise". GMDS 2015; 60. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik: Biometrie und Epidemiologie e.V. (GMDS). doi:10.3205/15gmds058.
- ↑ Cersosimo, E; Solis-Herrera, C; Trautmann, ME; Malloy, J; Triplitt, CL (January 2014). "Assessment of pancreatic β-cell function: review of methods and clinical applications.". Current Diabetes Reviews 10 (1): 2–42. doi:10.2174/1573399810666140214093600. PMID 24524730.
- ↑ 4.0 4.1 4.2 4.3 Dietrich, Johannes W.; Abood, Assjana; Dasgupta, Riddhi; Anoop, Shajith; Jebasingh, Felix K.; Spurgeon, R.; Thomas, Nihal; Boehm, Bernhard O. (2 January 2024). "A novel simple disposition index ( SPINA‐DI ) from fasting insulin and glucose concentration as a robust measure of carbohydrate homeostasis". Journal of Diabetes. doi:10.1111/1753-0407.13525. PMID 38169110.
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