SPINA (structure parameter inference approach) is a cybernetic method for advanced interpretation of laboratory results. It allows for calculating constant structure parameters of endocrine feedback control systems in vivo from hormone or metabolite concentrations that have been obtained from serum or plasma specimens. The method is based on mathematical and cybernetic modelling of processing structures. First successful implementations apply to evaluation of thyroid function (SPINA Thyr) and insulin-glucose homeostasis (SPINA Carb). The methodology allows for calculating the thyroid's maximum secretory capacity (GT or SPINA-GT) and the sum activity of peripheral 5'-deiodinases (GD or SPINA-GD) from levels of TSH, (F)T4 and (F)T3 that have been determined once only. A similar method delivers estimates for beta cell function (SPINA-GBeta) and insulin receptor gain (SPINA-GR) from fasting insulin and glucose concentrations. The functions provided deliver calculated structure parameters of thyroid and insulin-glucose homeostasis in statistical environments based on the statistical language S (e.g. the R® platform).

{"references": ["Dietrich JW, Landgrafe-Mende G, Wiora E, Chatzitomaris A, Klein HH, Midgley JE, Hoermann R. Calculated Parameters of Thyroid Homeostasis: Emerging Tools for Differential Diagnosis and Clinical Research. Front Endocrinol (Lausanne). 2016 Jun 9;7:57. doi: 10.3389/fendo.2016.00057. PMID: 27375554; PMCID: PMC4899439.", "Dietrich JW, Dasgupta R, Anoop S, Jebasingh F, Kurian ME, Inbakumari M, Boehm BO, Thomas N. SPINA Carb: a simple mathematical model supporting fast in-vivo estimation of insulin sensitivity and beta cell function. Sci Rep. 2022 Oct 21;12(1):17659. doi: 10.1038/s41598-022-22531-3. PMID: 36271244; PMCID: PMC9587026."]}