title: A randomised controlled trial of increasing fruit and vegetable intake and how this influences the carotenoid concentration and activities of PON-1 and LCAT in HDL from subjects with type 2 diabetes.
abstract: BACKGROUND
  High density lipoproteins (HDL) have many cardioprotective roles; however, in subjects with type 2 diabetes (T2D) these cardioprotective properties are diminished. Conversely, increased fruit and vegetable (F&V) intake may reduce cardiovascular disease risk, although direct trial evidence of a mechanism by which this occurs in subjects with T2D is lacking. Therefore, the aim of this study was to examine if increased F&V consumption influenced the carotenoid content and enzymes associated with the antioxidant properties of HDL in subjects with T2D.
  
  
  METHODS
  Eighty obese subjects with T2D were randomised to a 1- or ≥6-portion/day F&V diet for 8-weeks. Fasting serum was collected pre- and post-intervention. HDL was subfractionated into HDL2 and HDL3 by rapid ultracentrifugation. Carotenoids were measured in serum, HDL2 and HDL3 by high performance liquid chromatography. The activity of paraoxonase-1 (PON-1) was measured in serum, HDL2 and HDL3 by a spectrophotometric assay, while the activity of lecithin cholesterol acyltransferase (LCAT) was measured in serum, HDL2 and HDL3 by a fluorometric assay.
  
  
  RESULTS
  In the ≥6- vs. 1-portion post-intervention comparisons, carotenoids increased in serum, HDL2 and particularly HDL3, (α-carotene, p = 0.008; β-cryptoxanthin, p = 0.042; lutein, p = 0.012; lycopene, p = 0.016), as did the activities of PON-1 and LCAT in HDL3 (p = 0.006 and 0.044, respectively).
  
  
  CONCLUSIONS
  To our knowledge, this is the first study in subjects with T2D to demonstrate that increased F&V intake augmented the carotenoid content and influenced enzymes associated with the antioxidant properties of HDL. We suggest that these changes would enhance the cardioprotective properties of this lipoprotein.
  
  
  BACKGROUND
  ISRCTN21676269.
authors.forename: Jane-Ann
authors.initials: JA
authors.lastname: Daniels
authors.forename: Ciara
authors.initials: C
authors.lastname: Mulligan
authors.forename: David
authors.initials: D
authors.lastname: McCance
authors.forename: Jayne V
authors.initials: JV
authors.lastname: Woodside
authors.forename: Christopher
authors.initials: C
authors.lastname: Patterson
authors.forename: Ian S
authors.initials: IS
authors.lastname: Young
authors.affiliation: Centre for Public Health, Queen's University Belfast, Pathology Building, Grosvenor Road, Belfast BT12 6BJ, UK. j.mceneny@qub.ac.uk.
authors.forename: Jane
authors.initials: J
authors.lastname: McEneny
mesh_terms: D000328:Adult; D000368:Aged; D043303:Aryldialkylphosphatase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002338:Carotenoids / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000178:diet therapy; D005260:Female; D005638:Fruit; D006801:Humans; D008297:Male; D008875:Middle Aged; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000097:blood*; D014675:Vegetables
chemical_list: D015415:Biomarkers; D008076:Cholesterol, HDL; D002338:Carotenoids; D007862:Phosphatidylcholine-Sterol O-Acyltransferase; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human