Abstract

In this Minireview we describe how, in the process of finding the appropriate diagnostic cutoffs for several traditional biochemical predictors of insulin resistance, we found that the product of the fasting insulin value (I0) times the glucose value at 60 min of the OGTT (G60) predicted insulin resistance. Moreover, it did so more efficiently than the traditional predictors of insulin resistance (HOMA, the QUICKI, and the ISI-OL). The new predictor was labelled as the I0*G60. Its area under the ROC curve against the Steady State Plasma Glucose (SSPG) value of the Pancreatic Suppression Test was 0.867, higher than the respective value of the ISI-OL (0.835), the best performing of the traditional biochemical predictors of insulin resistance. The sensitivity rose from 0.811 (ISI-OL) to 0.865 (I0*G60). The cutoff for the new predictor suggesting insulin resistance was > 428.2 mMol/L*pMol/L (> 1,110 mg/dL*mU/L). The ROC Curve analysis-defined cutoff against the SSPG of the traditional predictors improved notoriously the sensitivity of these tests when compared with the commonly used cutoffs. The HOMA and the QUICKI had similar diagnostic performances. The ISI-OL and the I0*G60 had a strong non-linear mathematical relationship (r > 0.9). A simple OGTT with 3 glucose values (0-60-120 min) and a single insulin value (0 min) would allow the proper categorization of a patient, both in terms of glucose tolerance and insulin sensitivity status. The I0*G60 is simple to perform, inexpensive, and easily calculable.

Keywords: Insulin Resistance; Biochemical Predictors of Insulin Resistance; I0*G60; Matsuda-DeFronzo’s ISI Composite; HOMA

References

1. Contreras PH., et al. “A simple and improved predictor of insulin resistance extracted from the oral glucose tolerance test: the I0*G60”. Journal of the Endocrine Society 3.8 (2019): 1154-1166. 
2. Cheal KL., et al. “Relationship to insulin resistance of the adult treatment panel III diagnostic criteria for identification of the metabolic syndrome”. Diabetes 53.5 (2004): 1195-1200. 
3. Alberti KGMM., et al. “Metabolic syndrome-a new world-wide definition. A Consensus Statement from the International Diabetes Federation”. Diabetic Medicine 23 (2006): 469-480. 
4. Grundy SM., et al. “Diagnosis and Management of the Metabolic Syndrome. An American Heart Association/National Heart, Lung, and Blood Institute Scientific Statement”. Circulation 112 (2005): 2735-2752. 
5. Matthews DR., et al. “Homeostasis model assessment: insulin resistance and b-cell function from fasting glucose and insulin in man”. Diabetologia 7 (1985): 412-419. 
6. Matsuda M and DeFronzo RA. “Insulin sensitivity indices obtained from oral glucose tolerance testing: comparison with the euglycemic insulin clamp”. Diabetes Care 22.9 (1999):1462-1470. 
7. Pei D., et al. “Evaluation of octreotide to assess insulin mediated glucose disposal by the insulin suppression test”. Diabetologia 37.8 (1994): 843-845. 
8. Shen S-W., et al. “Comparison of impedance to insulin-mediated glucose uptake in normal subjects and in subjects with latent diabetes”. Journal of Clinical Investigation 49.12 (1970): 2151-2160. 
9. DeFronzo RA., et al. “Glucose clamp technique: a method for quantifying insulin secretion and resistance”. American Journal of Physiology 237.2 (1979): E214-E223. 
10. Kim MK., et al. “Hyperinsulinemia in individuals with obesity: role of insulin clearance”. Obesity (Silver Spring) 23.12 (2015): 2430-243. 
11. Vigil P., et al. “Evidence of subpopulations with different levels of insulin resistance in women with polycystic ovary syndrome”. Hum Reproduction 22.11 (2007): 2974-2980. 
12. Contreras PH and Vigil P. “Long-term testosterone administration on insulin sensitivity in older men with low or low-normal testosterone levels”. Journal of Clinical Endocrinology and Metabolism 104.3 (2019): 678-679. 
13. Greenfield MS., et al. “Assessment of insulin resistance with the insulin suppression test and the euglycemic clamp”. Diabetes 30.5 (1981): 387-392. 
14. Knowles JW., et al. “Measurement of insulin-mediated glucose uptake: direct comparison of the modified insulin suppression test and the euglycemic, hyperinsulinemic clamp”. Metabolism 62.4 (2013): 548-553. 
15. Ferrannini E and Mari A. “How to measure insulin sensitivity”. Journal of Hypertension 16.7 (1998): 895-906. 
16. Abdul-Ghani MA., et al. “What is the best predictor of future type 2 diabetes?” Diabetes Care 30.6 (2007): 1544-1548. 
17. Abbasi F., et al. “Plasma glucose concentration 60 min post oral glucose load and risk of type 2 diabetes and cardiovascular disease: Pathophysiological implications”. Diabetes and Vascular Disease Research 16.4 (2019): 337-343.