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Gastroenterology Research and Practice
Volume 2013, Article ID 498296, 8 pages
http://dx.doi.org/10.1155/2013/498296
Research Article

Insulin Resistance Increases MRI-Estimated Pancreatic Fat in Nonalcoholic Fatty Liver Disease and Normal Controls

1Division of Internal Medicine, Department of Medicine, University of California at San Diego, UC San Diego Health System, 9500 Gilman Drive, MC 0063, La Jolla, CA 92093, USA
2Department of Pathology, University of California at San Diego, UC San Diego Health System, 9500 Gilman Drive, MC 0063, La Jolla, CA 92093, USA
3Division of Gastroenterology, Department of Pediatrics, University of California at San Diego, UC San Diego Health System, 9500 Gilman Drive, MC 0063, La Jolla, CA 92093, USA
4Division of Gastroenterology, Department of Medicine, University of California at San Diego, UC San Diego Health System, 9500 Gilman Drive, MC 0063, La Jolla, CA 92093, USA
5Division of Epidemiology, Department of Family and Preventive Medicine, University of California at San Diego, UC San Diego Health System, 9500 Gilman Drive, MC 0063, La Jolla, CA 92093, USA
6Liver Imaging Group, Department of Radiology, University of California at San Diego, UC San Diego Health System, 9500 Gilman Drive, MC 0063, La Jolla, CA 92093, USA

Received 4 September 2013; Accepted 7 October 2013

Academic Editor: Gyorgy Baffy

Copyright © 2013 Niraj S. Patel et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background. Ectopic fat deposition in the pancreas and its relationship with hepatic steatosis and insulin resistance have not been compared between patients with nonalcoholic fatty liver disease (NAFLD) and healthy controls. Aim. Using a novel magnetic resonance imaging (MRI) based biomarker, the proton-density-fat-fraction (MRI-PDFF), we compared pancreatic fat content in patients with biopsy-proven NAFLD to healthy controls and determined whether it is associated with insulin resistance and liver fat content. Methods. This nested case-control study was derived from two prospective studies including 43 patients with biopsy-proven NAFLD and 49 healthy controls who underwent biochemical testing and MRI. Results. Compared to healthy controls, patients with NAFLD had significantly higher pancreatic MRI-PDFF (3.6% versus 8.5%, value <0.001), and these results remained consistent in multivariable-adjusted models including age, sex, body mass index, and diabetes ( value =0.03). We found a strong correlation between hepatic and pancreatic MRI-PDFF (Spearman correlation, = 0.57, value <0.001). Participants with increased insulin resistance determined by homeostatic-model-of-insulin-resistance (HOMA-IR) greater than 2.5 had higher pancreatic (7.3% versus 4.5%, value =0.015) and liver (13.5% versus 4.0%, value <0.001) MRI-PDFF. Conclusion. Patients with NAFLD have greater pancreatic fat than normal controls. Insulin resistance is associated with liver and pancreatic fat accumulation.