Validation of a Novel Visceral Adiposity Prediction Tool and Comparison to Existing Adiposity Indices

Abstract

Background/objectives: Visceral adiposity measured by computed tomography (CT) as intra-abdominal fat area (IAFA) predicts metabolic diseases. Measuring IAFA by CT, however, is not practical. We developed a new index (Visceral Adiposity Estimate – VAE) for IAFA estimation, and validated its performance. Subjects/methods: We recorded age, BMI, waist circumference (WC), fasting lipids, glucose, and smoking status for 622 participants in the Japanese-American Community Diabetes Study (JACDS). IAFA was measured with a single CT slice at the umbilicus. We used stepwise linear regression and regressed IAFA on commonly available laboratory and demographic variables in sex-stratified models. We termed this estimate the VAE. For men, variables included were age, WC, HDL, and glucose; for women, age, BMI, WC, HDL, LDL, and glucose. We compared area under receiver-operating characteristic curves (AUROC) between VAE, the Visceral Adiposity Index (VAI: a measure incorporating BMI, WC, triglycerides, and HDL), and WC for IAFA dichotomized at the median and 75 th percentile. Results were validated in 1645 Japanese participants in the Ohtori Study. Results: Participant characteristics were: JACDS, mean age 53.7, 55% male; Ohtori, mean age 50.4, 63% male. In JACDS, VAE predicted above-median IAFA (men: AUROC = 0.88; women: AUROC = 0.94) better than VAI and WC for men (VAI AUROC = 0.74, p < 0.001; WC AUROC = 0.81, p < 0.001) and women (VAI AUROC = 0.79, p < 0.001; WC AUROC = 0.88, p = 0.001). At the 75 th percentile, VAE predicted IAFA (men: AUROC = 0.88; women: AUROC = 0.93) better than VAI and WC for men (VAI AUROC = 0.74, p < 0.001; WC AUROC = 0.84, p = 0.004) and women (VAI AUROC = 0.78, p < 0.001; WC AUROC = 0.88, p = 0.030). Results were similar for Ohtori. Conclusions: VAE predicted IAFA better than VAI or WC in derivation and validation datasets of Japanese-American and Japanese populations.