Purpose: This study aimed to evaluate the clinical validity of three different obesity criteria and to access the cut-off values of body mass index (BMI) and waist circumference (WC) to diagnose glucose intolerance.
Methods: We analyzed 11,579 participants (6,678 men, 4,901 women) from 15,278 individuals who had undergone a worksite annual health check-up in 2013, excluding those with missing values, on diabetes medication, and aged <20 years or ≥60 years. The diagnostic validity of three cut-off values as criteria was evaluated: a BMI ≥25, a WC ≥85 cm (men) and ≥90 cm (women) using the Japan Society for the Study of Obesity (JASSO) criterion, and a WC ≥90 cm (men) and ≥80 cm (women) (WHO criterion). For each age and sex strata, we compared the ratio of obese and non-obese participants with glucose intolerance, and determined the BMI and WC cut-off values using receiver operating characteristic (ROC) curves corresponding to 126 mg/dL, 110 mg/dL, and 100 mg/dL FBS levels, and 6.5%, 6.0%, and 5.6% HbA1c levels, respectively.
Results: In men, the prevalence and odds ratios of glucose intolerance were similar for BMI and WHO WC criteria, but in women, those values were inconsistent for all three. In ROC analysis, BMI cut-off values corresponding to each of the three FBS and HbA1c levels were 24.5–25.7 (area under the curve [AUC] 0.63–0.71), and 21.3–25.0 (AUC 0.62–0.86) in men and women. WC cut-off values were 80.9–89.2 (AUC 0.66–0.74), and 76.9–85.0 (AUC 0.63–0.88) in men and women. BMI and WC cut-off values tended to reduce as glucose levels reduced, but only the BMI in men settled to a value of approximately 25.
Conclusion: In this population, the cut-off values in women were lower than the present JASSO WC criterion, necessitating further investigation of this criterion.
