title: Ectopic fat accumulation in the pancreas and its clinical relevance: A systematic review, meta-analysis, and meta-regression.
abstract: OBJECTIVE
  Growing evidence suggests that individuals with excessive fat in the pancreas are at an increased risk of chronic metabolic disorders. The aim was to systematically review studies on non-alcoholic fatty pancreas disease (NAFPD) with a view to determine its prevalence, associations with metabolic co-morbidities, and to suggest normal pancreatic fat percentage threshold.
  
  
  METHODS
  Three electronic databases (MEDLINE, Scopus, and Embase) were queried. Studies in humans were eligible for inclusion if they provided data on NAFPD and/or pancreatic fat percentage. Where possible, data were pooled using random-effects meta-analysis and the effect of covariates analysed using meta-regression.
  
  
  RESULTS
  Pooling data on pancreatic fat percentage from nine studies (1209 healthy individuals who underwent magnetic resonance imaging), yielded the weighted mean and weighted standard deviation of 4.48% and 0.87%, respectively. Pooling data on NAFPD from eleven studies (12,675 individuals), yielded the pooled prevalence of 33% (95% confidence interval, 24% - 41%). Meta-regression analysis showed that the prevalence of NAFPD was independent of age and sex. The presence of NAFPD was associated with a significantly increased risk of arterial hypertension (risk ratio 1.67; 95% confidence interval, 1.32-2.10; p<0.0001), diabetes mellitus (risk ratio 2.08; 95% confidence interval, 1.44-3.00; p=0.0001), and metabolic syndrome (risk ratio 2.37; 95% confidence interval, 2.07-2.71; p<0.0001).
  
  
  CONCLUSIONS
  The findings indicate that NAFPD is a frequent clinical entity, associated with significantly increased risk of metabolic syndrome and its components. The normal pancreatic fat cut-off point of 6.2% may be recommended for use in future prospective studies.
authors.affiliation: Department of Surgery, University of Auckland, Auckland, New Zealand.
authors.forename: Ruma G
authors.initials: RG
authors.lastname: Singh
authors.affiliation: Department of Surgery, University of Auckland, Auckland, New Zealand.
authors.forename: Harry D
authors.initials: HD
authors.lastname: Yoon
authors.affiliation: Department of Surgery, University of Auckland, Auckland, New Zealand.
authors.forename: Landy M
authors.initials: LM
authors.lastname: Wu
authors.affiliation: Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
authors.affiliation: Department of Surgery, University of Auckland, Auckland, New Zealand.
authors.forename: Lindsay D
authors.initials: LD
authors.lastname: Plank
authors.affiliation: Department of Surgery, University of Auckland, Auckland, New Zealand. Electronic address: max.petrov@gmail.com.
authors.forename: Maxim S
authors.initials: MS
authors.lastname: Petrov
mesh_terms: D000818:Animals; D005223:Fats / Q000378:metabolism*; D006801:Humans; D050356:Lipid Metabolism / Q000235:genetics*; D008659:Metabolic Diseases / Q000150:complications / Q000453:epidemiology / Q000235:genetics; D010179:Pancreas / Q000378:metabolism* / Q000473:pathology; D010182:Pancreatic Diseases / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D015995:Prevalence
chemical_list: D005223:Fats
keywords: Diabetes mellitus; Ectopic fat; Metabolic disorders; Non-alcoholic fatty pancreas disease