Revised waist circumference cut-off points for the criteria of abdominal obesity in the Spanish population: Multicenter nationwide Spanish population based study

Aims: To investigate the optimal waist circumference (WC) cut-off points in the general Spanish-population and its relationships with insulin resistance (IR) and metabolic syndrome (MS) due to the disparity of values WC in the different regional areas. Methods: A multicenter nationwide Spanish population based study on 3844 unrelated subjects, aged 35-74 years. Receiver operating characteristic (ROC) curve was analysed to identify the optimal WC cut-off points for detecting metabolic abnormalities related to the MS. Results: The prevalence of MS, International Diabetes Federation (IDF) criteria: 29.1%/33.1% in males/females (P =.004), Adult Treatment Panel III (ATPIII) criteria: 23.5%/30.9% males/females (P <.001). Optimal WC cut-off to obtain the maximal sensitivity and specificity for detecting two or more of the other metabolic abnormalities associated with MS or IR was 94.5/89.5 cm in males/females. According to these cut-off points, the prevalence of abdominal-obesity was 57.2%/61.3% in males/females, P =.011 and prevalence of MS was similar in both genders (males/females: 27.9%/28.9%, P =.527). The Spearman correlation coefficient relating WC to HOMA IR was 0.395. IR was similarly prevalent in males/females 24.1%/21.7% (P <.088). Prevalence of IR was 43% in subjects with MS by IDF criteria. Conclusions: The new WC cut-off points found in our population were 94.5/89.5 cm for males/females. For males, the cut-off points were lower than those defined by ATPIII but similar to IDF criteria. For females these cut-off points were higher than those proposed by ATPIII/IDF criteria.