Original Article (Clinical Investigation) Enhanced Prediction of Renal Function Decline by Replacing Waist Circumference With “a Body Shape Index (Absi)” in Diagnosing Metabolic Syndrome: A Retrospective Cohort Study in Japan

Abstract Background: Abdominal obesity as a risk factor for diagnosing metabolic syndrome (MetS) is conventionally evaluated using waist circumference (WC), although WC does not necessarily reflect visceral adiposity. We aimed to examine whether replacing WC with “A Body Shape Index (ABSI)”, an abdominal obesity index, in MetS diagnosis is useful for predicting renal function decline (RFD). Methods: A retrospective cohort study was conducted in 5438 Japanese urban residents (median age 48 years) who participated in a public health screening program for 4 consecutive years. Systemic arterial stiffness was assessed by cardio-ankle vascular index (CAVI), and high CAVI was defined as CAVI ≥ 9.0. The predictability of the occurrence of RFD (eGFR < 60 mL/min/1.73m 2 ) by replacing high WC with high ABSI (ABSI ≥ 0.080) was examined using three sets of MetS diagnostic criteria: Japanese, International Diabetes Federation (IDF) and National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII). Results: In Japanese and NCEP-ATPIII criteria, MetS diagnosed using ABSI (ABSI-MetS) was associated with significantly higher age-adjusted CAVI compared to non-MetS, whereas MetS diagnosed using WC (WC-MetS) showed no association. Kaplan-Meier analysis of the rate of new-onset RFD over 4 years (total 8.7%) showed remarkable higher rate in subjects with ABSIMetS than in those without (log-rank test p <0.001), but almost no difference between subjects with and without WC-MetS ( p = 0.014-0.617). In Cox analysis including gender, high CAVI and low-density lipoprotein‒cholesterol ≥140 mg/dL as confounders, only ABSI-MetS diagnosed by Japanese criteria contributed independently to the occurrence of RFD (HR = 1.41, p = 0.011). High CAVI was also an independent contributor to the occurrence of RFD. In a subanalysis, ABSI-MetS diagnosed by Japanese criteria contributed significantly to the occurrence of RFD regardless of age or gender, while WC-MetS by Japanese criteria contributed significantly only in older women. Conclusion: In this study, replacing WC with ABSI in MetS diagnostic criteria more efficiently predicted subjects at risk of RFD and arterial stiffening. Further studies are needed to confirm whether MetS diagnosed using ABSI also predicts CVD.