IL6 and postmenopausal osteoporosis: When circulating IGFBP-3 and IL-6 levels of 3.65 μg/ml and 0.205 IU/ml (Youden index 46.37 and 34.78) were taken as cut-off values, the sensitivity and specificity of their assay in the diagnosis of postmenopausal osteoporosis were 89.12% and 57.25% and 80.25% and 54.53%, respectively.