Liver fat is superior to visceral and pancreatic fat as a risk biomarker of impaired glucose regulation in overweight/obese subjects.

Abstract

To investigate the distribution of abdominal fat, particularly ectopic fat accumulation, in relation to glucose metabolism in overweight/obese patients. This study included 257 overweight/obese subjects with body mass index ≥23 kg/m2 . All the subjects underwent an oral glucose tolerance test. Magnetic resonance imaging-proton density fat fraction was used to measure fat accumulation in the liver, pancreas and abdomen. Impaired glucose regulation (IGR) was defined as the presence of prediabetes or diabetes. Liver fat content (LFC) and visceral adipose tissue (VAT) were higher in overweight/obese subjects with diabetes than in those with normal glucose tolerance (NGT). No significant differences were observed in the pancreas fat content and subcutaneous fat area between subjects with NGT and IGR. LFC was an independent risk factor of IGR (odds ratio=1.824 per standard deviation unit, 95% CI 1.242-2.679, p=.002). Compared with the lowest tertile of LFC, the multivariate-adjusted odds ratio for the prevalence of IGR in the highest tertile was 2.842 (95% CI 1.205-6.704). However, no association was observed between the VAT per standard deviation increment and tertiles after adjusting for multiple factors. For discordant visceral and liver fat phenotypes, the high LFC-low VAT and high LFC-high VAT groups had a higher prevalence of IGR than the low LFC-low VAT group. However, there was no difference in the prevalence of IGR between the low LFC-low VAT and low LFC-high VAT groups. Compared with visceral and pancreatic fat content, LFC is a superior risk biomarker for IGR in overweight/obese subjects.