Ultrasound derived fat fraction indicates reduction of liver fat content after lifestyle modification in obese patients.

BackgroundSteatosis hepatis is of outstanding clinical importance. The aim of this study was to apply the new parametric method "Ultrasound Derived Fat Fraction" (UDFF) to monitor changes of liver fat in obese patients undergoing weight loss measures.MethodsIn 53 obese patients BMI, absolute body fat, waist circumference and UDFF were measured before and after a three-month weight loss intervention. UDFF measurements were performed using a Siemens ultrasound system (DAX, 1.0-3.5 Mz). We analysed the correlation of change in BMI (≥-1 vs < -1), body fat (≥-2 kg vs < -2 kg) and waist circumference (≥-10 cm vs < -10 cm) with the change in UDFF (≥-30% vs < -30%) (significance level: p < 0.0167).ResultsAt baseline, mean BMI was 39.2 (range: 29.8-63.6), body fat 51.3 kg (range: 29.9-111.7), waist circumference 120.2 cm (range: 95-164) and UDFF 26% (range: 7-41%). 54.7% of patients lost at least 2 kg of body fat. These patients were significantly more likely to have a reduction in UDFF of at least 30% (≥2 kg fat: 58.6% vs. < 2 kg fat: 20.8%; p = 0.011). For BMI and waist circumference changes no significant correlation with UDFF was observed.ConclusionThis study underlines that UDFF could be a promising, non-invasive tool to monitor changes in liver fat.