Visceral adiposity index (VAI) is predictive of an altered adipokine profile in patients with type 2 diabetes

Abstract

Aims: Although there is still no clear definition of "adipose tissue dysfunction" or ATD, the identification of a clinical marker of altered fat distribution and function may provide the needed tools for early identification of a condition of cardiometabolic risk. Our aim was to evaluate the correlations among various anthropometric indices [BMI, Waist Circumference (WC), Hip Circumference (HC), Waist/Hip ratio (WHR), Body Adiposity Index (BAI) and Visceral adiposity Index (VAI)] and several adipocytokines [Visfatin, Resistin, Leptin, Soluble leptin receptors (sOB-R), Adiponectin, Ghrelin, Adipsin, PAI-1, vascular endothelial growth factor (VEGF), Hepatocyte growth factor (HGF) TNF-α, hs-CRP, IL-6, IL-18] in patients with type 2 diabetes (DM2).

Materials and methods: Ninety-one DM2 patients (age: 65.25 ± 6.38 years; 42 men and 49 women) in stable treatment for the last six months with metformin in monotherapy (1.5-2 g/day) were cross-sectionally studied. Clinical, anthropometric, and metabolic parameters were evaluated. Serum adipocytokine levels were assayed with Luminex based kits.

Results: At the Pearson's correlation, among all the indices investigated, VAI showed a significant correlation with almost all adipocytokines analyzed [Visfatin, Resistin and hsCRP (all p<0.001); Adiponectin, sOb-R, IL-6, IL-18, HGF (all p<0.010); Ghrelin and VEGF (both p<0.05)]. Through a two-step cluster analysis, 55 patients were identified with the most altered adipocytokine profile (patients with ATD). At a ROC analysis, VAI showed the highest C-statistic [0.767 (95% CI 0.66-0.84)] of all the indices.

Conclusions: Our study suggests that the VAI, among the most common indexes of adiposity assessment, shows the best correlation with the best known adipocytokines and cardiometabolic risk serum markers. Although to date we are still far from clearly identifying an ATD, the VAI would be an easy tool for clearly mirroring a condition of cardiometabolic risk, in the absence of an overt metabolic syndrome.

Figure 1. Differences in serum levels of adipocytokines between Cluster 1 (DM2 patients without “adipose tissue dysfunction”) and Cluster 2 (DM2 patients with “hypothetical adipose tissue dysfunction”).

Figure 2. ROC Curves of the various anthropometric indices (BMI, WC, HC, WHR, BAI, VAI) for “hypothetical adipose tissue dysfunction” (Cluster 2).