Characterisation of liver fat in the UK biobank cohort

Abstract

Non-alcoholic fatty liver disease and the risk of progression to steatohepatitis, cirrhosis and hepatocellular carcinoma have been identified as major public health concerns. We have demonstrated the feasibility and potential value of measuring liver fat content by magnetic resonance imaging (MRI) in a large population in this study of 4,949 participants (aged 45-73 years) in the UK Biobank imaging enhancement. Despite requirements for only a single ( 3min) scan of each subject, liver fat was able to be measured as the MRI proton density fat fraction (PDFF) with an overall success rate of 96.4%. The overall hepatic fat distribution was centred between 1-2%, and was highly skewed towards higher fat content. The mean PDFF was 3.91%, and median 2.11%. Analysis of PDFF in conjunction with other data fields available from the UK Biobank Resource showed associations of increased liver fat with greater age, BMI, weight gain, high blood pressure and Type 2 diabetes. Subjects with BMI less than 25 kg/m 2 had a low risk (5%) of high liver fat (PDFF > 5.5%), whereas in the higher BMI population (>30 kg/m 2 ) the prevalence of high liver fat was approximately 1 in 3. These data suggest that population screening to identify people with high PDFF is possible and could be cost effective. MRI based PDFF is an effective method for this. Finally, although cross sectional, this study suggests the utility of the PDFF measurement within UK Biobank, particularly for applications to elucidating risk factors through associations with prospectively acquired data on clinical outcomes of liver diseases, including non-alcoholic fatty liver disease.

Multi‐parametric liver tissue characterization using MR fingerprinting: Simultaneous T1, T2, T2*, and fat fraction mapping

“…Liver values (mean [min, max]) measured in subjects C1.1‐11 with the proposed approach were 676 ms [607, 803] ms for water T 1 , 43.6 ms [35.9, 57.8] ms for water T 2 , 30.1 ms [17.9, 39] ms for T 2 *, and 2.56% [1.2, 5.3]% for FF. Corresponding mean values and range for muscle, spleen and subcutaneous fat are reported in Supporting Information Table in comparison to the conventional methods and literature values 34‐36 when available. Fat‐specific T 1 and T 2 are reported for the subcutaneous fat ROI.…”

Nonalcoholic fatty liver disease and chronic vascular complications of diabetes mellitus

“…population-based cohorts) and the diagnostic methodologies used for diagnosing NAFLD (imaging vs. biopsy), the prevalence of the disease has been found to be much greater in patients with T2DM than in the nondiabetic population, ranging from nearly 40% to 100% (as summarized in the Supplementary Table 1) [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] .…”

Genetics of 38 blood and urine biomarkers in the UK Biobank

“…We further tested multiple disease outcomes and liver fat percentage (LFP), a quantitative measure derived from costly MRI images of the liver obtained approximately 8 years after the initial assessment visit where the serum and urine samples used for our polygenic score calculation were collected 59 . Liver fat is driven by a combination of alcohol use and metabolic disorder 60 .…”