title: Reduction in liver fat by dietary MUFA in type 2 diabetes is helped by enhanced hepatic fat oxidation.
abstract: The aim of this work was to investigate hepatic lipid metabolic processes possibly involved in the reduction of liver fat content (LF) observed in patients with type 2 diabetes after an isoenergetic diet enriched in monounsaturated fatty acids (MUFAs).
  
  
  
  This is an ancillary analysis of a published study. In a parallel-group design, 30 men and eight women, aged 35-70 years, with type 2 diabetes and whose blood glucose was controlled satisfactorily (HbA1c< 7.5% [58 mmol/mol]) by diet or diet plus metformin, were randomised by MINIM software to follow either a high-carbohydrate/high-fibre/low-glycaemic index diet (CHO/fibre diet, n = 20) or a high-MUFA diet (MUFA diet, n = 18) for 8 weeks. The assigned diets were known for the participants and blinded for people doing measurements. Before and after intervention, LF was measured by1H-MRS (primary outcome) and indirect indices of de novo lipogenesis (DNL) (serum triacylglycerol palmitic:linoleic acid ratio), stearoyl-CoA desaturase activity (SCD-1) (serum triacylglycerol palmitoleic:palmitic acid ratio) and hepatic β-oxidation of fatty acids (β-hydroxybutyrate plasma concentrations) were measured.
  
  
  
  LF was reduced by 30% after the MUFA diet, as already reported. Postprandial β-hydroxybutyrate incremental AUC (iAUC) was significantly less suppressed after the MUFA diet (n = 16) (-2504 ± 4488 μmol/l × 360 min vs baseline -9021 ± 6489 μmol/l × 360 min) while it was unchanged after the CHO/fibre diet (n = 17) (-8168 ± 9827 μmol/l × 360 min vs baseline -7206 ± 10,005 μmol/l × 360 min, p = 0.962) (mean ± SD, p = 0.043). In the participants assigned to the MUFA diet, the change in postprandial β-hydroxybutyrate iAUC was inversely associated with the change in LF (r = -0.642, p = 0.010). DNL and SCD-1 indirect indices did not change significantly after either of the dietary interventions.
  
  
  
  Postprandial hepatic oxidation of fatty acids is a metabolic process possibly involved in the reduction of LF by a MUFA-rich diet in patients with type 2 diabetes.
  
  
  
  ClinicalTrials.gov NCT01025856 FUNDING : The study was funded by Ministero Istruzione Università e Ricerca and Italian Minister of Health.
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Lutgarda
authors.initials: L
authors.lastname: Bozzetto
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Costabile
authors.affiliation: Institute of Biostructures and Bioimaging, National Research Council, Naples, Italy.
authors.forename: Delia
authors.initials: D
authors.lastname: Luongo
authors.affiliation: Department of Chemical Science, Federico II University, Naples, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Naviglio
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Cicala
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Piantadosi
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Lidia
authors.initials: L
authors.lastname: Patti
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Cipriano
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University, Via Pansini 5, 80131, Naples, Italy. annuzzi@unina.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Annuzzi
authors.affiliation: Department of Clinical Medicine and Surgery, Federico II University, Via Pansini 5, 80131, Naples, Italy.
authors.forename: Angela A
authors.initials: AA
authors.lastname: Rivellese
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000178:diet therapy* / Q000378:metabolism*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D050155:Lipogenesis / Q000502:physiology; D008099:Liver / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D019518:Postprandial Period; D013230:Stearoyl-CoA Desaturase / Q000378:metabolism
chemical_list: D001786:Blood Glucose; D005229:Fatty Acids, Monounsaturated; C523776:SCD1 protein, human; D013230:Stearoyl-CoA Desaturase
keywords: De novo lipogenesis; Diet; Liver fat; Monounsaturated fatty acids; Stearoyl-coenzyme A desaturase-1 activity; Type 2 Diabetes; β-Hydroxybutyrate; β-Oxidation