Ectopic adipose tissue: association of obesity phenotypes with integral metabolic indices of obesity

Abstract

Aim. To study the relationship and predictive value of integral metabolic indices of obesity in the identification of ectopic obesity.Material and methods. The study included 326 patients (146 men and 180 women, mean age 61±9 years). Anthropometric data, degree of obesity, body mass index (BMI), waist circumference (WC), sagittal abdominal diameter (SAD), body obesity index (BAI), visceral obesity index (VAI), lipid accumulation index (LAP), triglycerides-glucose index (TyG) was assessed. Perivascular adipose tissue (PVAT) volume, pericardial adipose tissue (PAT) volume and thickness of perirenal fat tissue (PRF) were assessed with CT.Results. Patients were divided into groups: with isolated ectopic obesity (iEO) (n=17); with isolated abdominal obesity (iAO) (n=74); with EO variants: pericardial (PCO) (n=31), perivascular (PVO) (n=22) or perirenal (PRO) (n=33) with AO; with mixed ectopic obesity and AO (mEO+AO) (n=117), and patients without obesity (n=32). Significantly higher BMI, WC, SAD, and BAI indices were found in individuals with PCO+AO, PRO+AO and mEO+AO. The highest values of LAP were found in groups: PCO+AO, PVO+AO, PRO+AO. There was a correlation between ectopic fat depots and WC (r=0,62 for PAT, r=0,55 for PVAT and r=0,39 for PRF, p=0,01) and SAD (0,429, 0,329 and 0,435, respectively, p=0,01). Correlation was established between PAT, PRF and LAP (0,425 and 0,319, respectively, p=0,01). The highest AUC values>0,8 had models of WC and SAD in identification of PCO (0,801 and 0,801, respectively) and PRO (0,826 and 0,826, respectively). For PCO, the cut-off point of WC was 100,5 cm (specificity 72,9%, sensitivity 70,2%, p=0,000), SAD — 25 cm (specificity 73%, sensitivity 70,2%, p=0,000). For PRO, the cut-off of WC was 101 cm (specificity 71,4%, sensitivity 72,7%, p=0,000), SAD — 25 cm (specificity 71,4%, sensitivity 72,7%, p=0,000).Conclusion. Еctopic fat depots are related to the risk of metabolic disorders. Potential informative value of simple and accessible integral metabolic indices was established. WC>100,5 cm, SAD>25 cm may indicate to the presence of PCO; WC>101 cm, SAD>25 cm — to the presence of PRO.