Table 2.
Calculated cut-off values for fasting indices based on receiver operating characteristic curve and Youden’s index analyses using the euglycemic hyperinsulinemic clamp (M index) as the reference for diagnosing insulin resistance
| Variable | Cut-off values to predict IR | AUC | Sn% (95 % CI) | Sp% (95 % CI |
|---|---|---|---|---|
| Insulin sensitivity: | ||||
| 1/Insulin (mL/µIU) | < 0.11 | 0.94 (0.88–0.99) | 91 (77–97) | 85 (66–94) |
| RISQI ([µIU/ml]−0.5) | < 0.32 | 0.94 (0.88–0.99) | 91 (77–97) | 85 (66–94) |
| QUICKI | < 0.33 | 0.93 (0.87–0.99) | 85 (70–94) | 85 (67–94) |
| β-cell response: | ||||
| FI (µIU/mL) | > 9.5 | 0.94 (0.88–0.99) | 91 (77–97) | 85 (66–94) |
| MIRG ([µIUins]2 /[10•L• mggluc]) | > 4.4 | 0.93 (0.87–0.99) | 88 (73–95) | 85 (66–93) |
| HOMA-β | > 147 | 0.94 (0.88–0.99) | 79 (63–90) | 96 (81–100) |
RISQI reciprocal of the square root of insulin; QUICKI quantitative insulin sensitivity check index; FI fasting insulin concentration; MIRG modified insulin-to-glucose ration; HOMA-β homeostatic model assessment of β-cell function; AUC area under the curve; Sn sensitivity; Sp specificity; CI confidence interval