Optimal Waist Circumference Cutoff Value Reflecting Insulin Resistance as a Diagnostic Criterion of Metabolic Syndrome in a Nondiabetic Korean Population Aged 40 Years and Over: The Chungju Metabolic Disease Cohort (CMC) Study

Abstract

PurposeWe aimed at determining the cutoff value of waist circumference with respect to its ability to reflect insulin resistance in a Korean population.Materials and MethodsA total of 8,817 subjects aged 40 years and over were analyzed. Insulin resistant individuals were defined as those who had the highest quartile value of the homeostasis model assessment of insulin resistance (HOMA-IR) in a non-diabetic population. Receiver operating characteristic (ROC) curve analysis and multiple logistic regression analysis were applied.ResultsThe cutoff value of waist circumference reflecting insulin resistance from the ROC analysis was 84.4 cm for men and 80.6 cm for women. Sensitivity and specificity were 70.0% and 54.2% in men and 71.1% and 59.3% in women, respectively. After being controlled for other covariates, the odds ratio for the risk of insulin resistance using < 70 cm of waist circumference as a reference increased significantly in the category of 85.0-89.9 cm for men and 80.0-84.9 cm for women. In addition, statistically significant associations were consistently observed over the category of 85.0-89.9 cm for men and 80.0-84.9 cm for women.ConclusionThe optimal cutoff value for waist circumference reflecting insulin resistance is considered to be 85 cm for men and 80 cm for women, suggesting that the Asian criterion of abdominal obesity (90 cm for men and 80 cm for women) as a component of metabolic syndrome (MetS) might not be applicable for middle-aged to older men in Korea.

Cut off values for abdominal obesity as a criterion of metabolic syndrome in an ethnic Kyrgyz population (Central Asian region)

“…In an ethnic Korean population, the borderline WC ranges from 85 to 90 cm in men and from 80 to 85 cm in women [30-32]. The borderline WC values of 99.5 cm for men and 94.3 cm were found for Iranians aged 19-65 years [33].…”

Measurement of Waist Circumference

“…These cutoff values have been adopted by the modified NCEP ATP III (7) and the IDF (8), which means that the criteria for WC association with metabolic disease in Asian populations are based on the proportion of cases identified rather than on the performance of WC in predicting risk. A number of different cutoff values for WC have been proposed based on correlations to visceral adiposity, disease identification, or disease prediction (10,11,18), and all are different.…”

Relationship between Waist Circumferences Measured at the Umbilical Level and Midway between the Ribs and Iliac Crest

“…In older and younger males, the presently estimated MWC RIbased cut-off values were not always in keeping with the current WC cut-off value in the IDF criteria for males; however, they fully agreed with recent proposals based on cross-sectional designs that the WC cutoff value for males in the IDF criteria should be revised to 85 cm, repeatedly reported in Korea 17) , Japan 5,10) , China 18) and Hong Kong 19) . Notably, the latest cohort study mentioned above also supports this revision 16) . In contrast, the MWC RI-based cut-off value in younger females was inconsistent with the current WC cut-off value in females in the IDF criteria; however, this was not surprising considering the generation difference in UWC RI-based cut-off values in females 11) .…”

“…Since subjects suffering from significant diseases other than MetS, regular smokers, as well as excessive drinkers were excluded in advance, the present conditions for selecting healthy subjects were thought to be comparable with those for setting the normal RIs of laboratory data described in document C28-A2 of the National Committee for Clinical Laboratory Standards: NCCLS 15) . In older females, the MWC RI-based cut-off value was mostly identical to the WC cut-off value in the IDF criteria for females, of which validity was confirmed by a recent cohort study targeting the development of insulin resistance for a non-diabetic Korean population aged 40 years and over 16) . In older and younger males, the presently estimated MWC RIbased cut-off values were not always in keeping with the current WC cut-off value in the IDF criteria for males; however, they fully agreed with recent proposals based on cross-sectional designs that the WC cutoff value for males in the IDF criteria should be revised to 85 cm, repeatedly reported in Korea 17) , Japan 5,10) , China 18) and Hong Kong 19) .…”