Proposed Cutoff Level of Waist Circumference in Japanese Men: Evaluation by Homeostasis Model Assessment of Insulin Resistance Levels

Abstract

Objective The aim of this study is to propose the cutoff level of waist circumference (WC) on the basis of homeostasis model assessment of insulin resistance (HOMA-IR) levels in order to diagnose metabolic syndrome (MetS). Methods We examined a total of 798 non-diabetic men (40-65 years of age) by using a receiver operating characteristic (ROC) curve to determine the cutoff level that yielded the maximum sensitivity plus specificity. According to the criteria proposed by the International Diabetes Federation (IDF), and the Japanese Society of Internal Medicine (JSIM), subjects with ! 2 metabolic components other than abdominal obesity, were considered to have MetS.Results The overall prevalence rates of IDF-and JSIM-MetS were 17.4% (n=139) and 15.5% (n=124), respectively. The median levels of WC and HOMA-IR were 83.1 [interquartile range (IQR): 78.5-88.4] cm and 0.84 (IQR: 0.61-1.19), respectively. HOMA-IR was highly correlated with each metabolic parameter (each p< 0.05), and in addition, multiple linear regression analysis of HOMA-IR (adjusted R 2 =0.459) showed that WC level was the strongest independent predictors of HOMA-IR level (F=141.1, p<0.05). According to ROC curve analysis, the cutoff level of HOMA-IR for predicting IDF-and JSIM-MetS was 0.92 for both (sensitivity: 79.9% and 78.2%, specificity: 64.9% and 63.6%). Based on the HOMA-IR level, the proposed WC cutoff level was 82.7 cm (sensitivity: 75.4%, specificity: 63.8%). Conclusion This study suggests that WC level should be more strictly managed than current criteria, for preventing the development of MetS in non-diabetic middle-aged Japanese men.

Anthropometric parameters and their associations with cardio-metabolic risk in Chinese working population

“…All these findings suggested the WC and WHR criteria for central obesity in men may be too cautiously high. In accord to this, based on HOMA-IR level correlating to metabolic parameters among Japanese subjects, Kamezaki F et al demonstrated that WC cutoff level should be reduced and more strictly managed [ 28 ].…”

Association of seasonal variation in the prevalence of metabolic syndrome with insulin resistance

“…In this study, MetS was defined according to the criteria proposed by six major world organizations including the International Diabetes Federation (IDF) and the joint committee of eight Japanese medical societies including the Japanese Society of Internal Medicine (JSIM). 4,5,20,21 The IDF criteria are as follows: subjects with three or more of the following components are considered to have IDF-MetS: (1) elevated WC defined as WC X85 cm according to the JSIM criteria; (2) elevated TG defined as TG X150 mg per 100 ml or selfreported consumption of lipid-lowering medications; (3) reduced HDL cholesterol defined as HDL cholesterol o40 mg per 100 ml; (4) elevated BP defined as BP X130/85 mm Hg or self-reported consumption of antihypertensive drugs; (5) elevated glucose defined as having a fasting glucose level of X100 mg per 100 ml. The sole criterion for JSIM diagnosis is abdominal obesity defined as a WC of X85 cm.…”

Silymarin Induces Insulin Resistance through an Increase of Phosphatase and Tensin Homolog in Wistar Rats

“…To the best of our knowledge, this is the first study to show that silymarin may induce insulin resistance. In this report, we demonstrated the presence of insulin resistance using HOMA-IR as described previously [32] while the values were different with that in clinics [28], [29]. In addition, the effective dose in rats was not the same as that used in clinics; oral dose of silymarin in human subjects was 420–1680 mg/day [33], [34] whereas the dose for cancer-resistance was 13000 mg/day [35].…”

“…Insulin resistance was characterized using the HOMA-IR and hyperinsulinemic-euglycemic clamping. HOMA-IR is widely used clinically to identify the presence of insulin resistance [27]–[29], and hyperinsulinemic-euglycemic clamping is reported as a reliable tool in research for the estimation of insulin resistance in animals [30], [31]. To the best of our knowledge, this is the first study to show that silymarin may induce insulin resistance.…”