title: Serum fatty acid composition and insulin resistance are independently associated with liver fat markers in elderly men.
abstract: OBJECTIVE
  To investigate the relationships of serum fatty acid (FA) composition and estimated desaturase activities with the liver fat marker alanine aminotransferase (ALT).
  
  
  METHODS
  546 Swedish elderly men of a population-based cohort participated in this cross-sectional study. FA composition was assessed in serum cholesterol esters to determine dietary fat quality (e.g. linoleic) and desaturation products (e.g. dihomo-gamma-linolenic acid). Desaturase indices, including stearoyl coenzymeA desaturase-1 (SCD-1), were calculated by FA product-to-precursor ratios.
  
  
  RESULTS
  In linear regression analyses adjusting for lifestyle, abdominal obesity and insulin sensitivity, the dietary biomarker linoleic acid (n-6), but not n-3 FAs, was inversely related to ALT. Desaturation products including palmitoleic, oleic, gamma-linolenic and dihomo-gamma-linolenic acids, and Delta6-desaturase and SCD-1 indices were directly related to ALT (all p<0.05). After further adjustment for factors previously linked to fatty liver (i.e. serum lipids, adiponectin concentrations), SCD-1 index (p=0.004) and insulin resistance (p<0.0001) were independent determinants of ALT activity, whereas waist circumference, triglycerides, non-esterified FA and adiponectin were not.
  
  
  CONCLUSIONS
  A low dietary intake of linoleic acid and elevated SCD-1 index may contribute to higher ALT activity in elderly men, even independently of obesity and insulin resistance.
authors.affiliation: Department of Public Health and Caring Sciences/Clinical Nutrition and Metabolism, Uppsala University, Uppsala Science Park, 75185 Uppsala, Sweden. helena.petersson@pubcare.uu.se <helena.petersson@pubcare.uu.se>
authors.forename: Helena
authors.initials: H
authors.lastname: Petersson
authors.forename: Johan
authors.initials: J
authors.lastname: Arnlöv
authors.forename: Björn
authors.initials: B
authors.lastname: Zethelius
authors.forename: Ulf
authors.initials: U
authors.lastname: Risérus
mesh_terms: D000368:Aged; D000375:Aging / Q000097:blood*; D015992:Body Mass Index; D004041:Dietary Fats / Q000097:blood; D005227:Fatty Acids / Q000097:blood*; D005234:Fatty Liver / Q000097:blood* / Q000503:physiopathology; D015200:Fluoroimmunoassay; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008019:Life Style; D008297:Male; D056128:Obesity, Abdominal / Q000097:blood / Q000503:physiopathology; D012044:Regression Analysis; D013230:Stearoyl-CoA Desaturase / Q000097:blood*; D013548:Sweden
chemical_list: D004041:Dietary Fats; D005227:Fatty Acids; D013230:Stearoyl-CoA Desaturase