Ultrasound and MRI abdominal fat distribution and its associations with metabolic conditions in adults with abdominal obesity

AIMS: To evaluate the accuracy of abdominal fat distribution of subcutaneous (SAT) and visceral adipose tissue (VAT) assessed by ultrasound (US) compared to magnetic resonance imaging (MRI), as the gold standard technique. Additionally, to assess the association between abdominal fat distribution measured by US and metabolic conditions in adults with abdominal obesity. MATERIALS AND METHODS: A cross-sectional study (ClinicalTrials.gov: NCT05882149) included 113 individuals (65.5% women) with waist circumference ≥102 cm for men and ≥88 cm for women. VAT and SAT were measured by both US and MRI. Diagnostic performance was evaluated using ROC curve analysis. RESULTS: Participants were (mean ± SD) 52.8 ± 10.9 years old. VAT thickness measured by US showed a strong correlation with MRI (r = 0.82). For prediabetes, US-measured VAT thickness showed fair diagnostic accuracy in women (AUC = 0.71) with a proposed cut-off of 5.87 cm. For metabolic syndrome, US-measured VAT thickness showed poor diagnostic accuracy in women (AUC = 0.69), with a proposed cut-off of 4.83 cm. Also, VAT/SAT ratio (thickness) measured by US showed fair diagnostic accuracy for prediabetes in women (AUC = 0.72), with a proposed cut-off of 3.04, and poor diagnostic accuracy for metabolic syndrome in women (AUC = 0.69), with a proposed cut-off of 2.52. CONCLUSIONS: Ultrasound represents a useful screening tool for VAT thickness evaluation with an easy translation to clinical practice. Particularly, VAT thickness and VAT/SAT ratio (thickness) are positively associated with prediabetes and metabolic syndrome, especially in women.