Cut-off values for waist circumference in Turkish population: Is there a threshold to predict insulin resistance?

Objectives: To identify the cut-off values for waist circumference (WC) that may best predict cardiometabolic risk associated with insulin resistance in adult Turkish men and women.

Study Design: A total of 1,039 non-diabetic subjects (592 females, 447 males; mean age 40.2+/-12.8 years) aged = or >18 years were enrolled. Insulin resistance was assessed with homeostasis model assessment of insulin resistance (HOMA-IR). The subjects were classified into quantiles based on the WC values and quantiles were compared with respect to the HOMA-IR levels. Receiver operating characteristic (ROC) analysis was used to identify the WC cut-off value that would best predict insulin resistance.

Results: HOMA-IR values increased in parallel with increasing WC quantiles for both genders (p=0.001). The cut-off values for WC that showed the highest sensitivity and specificity to predict insulin resistance were 93 cm for men (91.6% and 51%, respectively) and 83 cm for women (91.1% and 34.8%, respectively).

Conclusion: Our results demonstrate that the cut-off values for WC that would best predict cardiometabolic risk associated with insulin resistance are 93 cm for men and 83 cm for women in Turkish adults. However, our findings also raise the question as to whether it is indeed necessary to define a WC cut-off value for the prediction of insulin resistance, because, regardless of the cut-off WC value taken into account, insulin resistance will be overlooked in a significant number of individuals with a WC below this cut-off value.