Insulin Sensitivity from Meal Tolerance Tests in Normal Subjects: A Minimal Model Index

• Published in: The journal of clinical endocrinology and metabolism Vol. 85; no. 11; pp. 4396 - 4402
• Main Authors: Caumo, Andrea, Bergman, Richard N., Cobelli, Claudio
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Oxford University Press 01.11.2000; Endocrine Society
• Subjects: Area Under Curve; Biological and medical sciences; Blood Glucose - drug effects; Blood Glucose - metabolism; Dietary Carbohydrates; Eating - physiology; Endocrinology; Female; Glucose; Glucose tolerance; Glucose Tolerance Test; Humans; Insulin - pharmacology; Insulin resistance; Investigative techniques, diagnostic techniques (general aspects); Male; Mathematics; Medical sciences; Middle Aged; Models, Biological; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Population studies; Reference Values; Regression Analysis; Sensitivity analysis; Endocrinopathy; Human; Mathematical formula; Target tissue resistance; Pancreatic hormone; Meal; Adult; Glucose tolerance test; Diagnosis; Measurement method; Insulin
• ISSN: 0021-972X; 1945-7197
• DOI: 10.1210/jcem.85.11.6982

In this report a new approach is introduced that allows estimation of insulin sensitivity (SI) from orally ingested glucose during an oral glucose tolerance test (OGTT) or a meal glucose tolerance test (MGTT) in normal subjects. The method hinges on the classic minimal model of glucose kinetics that is coupled with an equation describing the rate of appearance of glucose into the circulation after oral glucose ingestion. The model provides an estimate of SI in a given individual based on simple area under the curve type of calculations. To prove the reliability of the new approach, MGTT studies performed in 10 normal subjects were analyzed and the SI index from the MGTT was compared with the SI index obtained in the same subjects from an insulin-modified, frequently sampled iv glucose test (FSIGT). SI from the MGTT was 13.6 ± 3.9 × 10−4 dL/kg·min/μU·mL and was strongly correlated to the SI from the FSIGT (rs = 0.89; P < 0.01). In conclusion, this study shows that in normal subjects the minimal model can be applied to a MGTT/OGTT to derive an index of insulin sensitivity that is in good agreement with the one estimated from the FSIGT. Due to its simplicity, this method has potential for use in population studies, but further investigation is required to ascertain its applicability to subjects with severe insulin resistance and impaired secretory function.