Issue of Waist Circumference for the Diagnosis of Metabolic Syndrome Regarding Arterial Stiffness: Possible Utility of a Body Shape Index in Middle-Aged Nonobese Japanese Urban Residents Receiving Health Screening

Abstract

Introduction: Abdominal obesity as a risk factor for diagnosing metabolic syndrome (MetS) is evaluated using waist circumference (WC), although WC does not necessarily reflect visceral adiposity. This cross-sectional study aimed to clarify whether replacing WC with "A Body Shape Index (ABSI)," an abdominal obesity index, in MetS diagnosis detects individuals with arterial stiffening assessed by cardio-ankle vascular index (CAVI).

Methods: A retrospective cross-sectional study was conducted in 46,872 Japanese urban residents (median age 40 years) who underwent health screening. Exclusion criteria were current treatments and a past history of cardiovascular disease (CVD). The Japanese, International Diabetes Federation, and NCEP-ATPIII criteria were used to diagnose MetS. High CAVI was defined as CAVI ≥9.0.

Results: CAVI correlated positively with ABSI (β = 0.127), but negatively with WC (β = -0.186), independent of age, sex, systolic blood pressure, fasting plasma glucose, and high-density lipoprotein--cholesterol. Receiver operating characteristic (ROC) analysis showed that ABSI had a stronger contribution to high CAVI (area under the ROC curve [AUC] = 0.730) than WC (AUC = 0.595) and body mass index (AUC = 0.520). ABSI ≥0.080 was defined as abdominal obesity based on the results of ROC analysis for high CAVI and estimated glomerular filtration rate <60 mL/min/1.73 m2. Logistic regression analysis revealed that replacing high WC with ABSI ≥0.080 in MetS diagnosis enhanced the detection of subjects with high CAVI.

Discussion/conclusion: Use of ABSI can detect subjects with arterial stiffening, which may lead to efficient stratification of CVD risk. Further studies are needed to confirm whether MetS diagnosis using ABSI predicts CVD morbidity and mortality.

Keywords: A body shape index; Cardio-ankle vascular index; Cardiovascular disease; Metabolic syndrome; Visceral adiposity; Waist circumference.

Fig. 1

Discriminatory powers of 3 body adiposity indices for high CAVI (≥9.0). Curves represent ROC analyses for discriminating the probability of high CAVI (≥9.0). CAVI, cardio-ankle vascular index; ROC, receiver operating-characteristics; WC, weight circumference; BMI, body mass index.

Fig. 2

Differences in age-adjusted CAVI according to different MetS diagnostic criteria using WC (WC-MetS) or using ABSI (ABSI-MetS) as the visceral obesity index. WC-MetS (a) and ABSI-MetS (b) diagnosed by Japanese criteria. WC-MetS (c) and ABSI-MetS (d) diagnosed by IDF criteria. WC-MetS (e) and ABSI-MetS (f) diagnosed by NCEP-ATPIII criteria. Data are presented as mean ± SD. One-way ANOVA followed by Bonferroni multiple comparison tests were used for statistical analysis. CAVI, cardio-ankle vascular index; ROC, receiver operating characteristics; MetS, metabolic syndrome; ABSI, a body shape index; ANOVA, analysis of variance; IDF, International Diabetes Federation; NCEP-ATPIII, National Cholesterol Education Program-Adult Treatment Panel III; WC, weight circumference.