title: Comparative effects of carbohydrate versus fat restriction on serum levels of adipocytokines, markers of inflammation, and endothelial function among women with the metabolic syndrome: a randomized cross-over clinical trial.
abstract: OBJECTIVE
  Despite the efficacy of low-carbohydrate diets in the management of metabolic syndrome (MetS), it remains unknown if these favorable effects are mediated through changes in inflammation and endothelial dysfunction. We aimed to assess the effects of moderate substitution of dietary fats for carbohydrates on serum levels of adipocytokines, inflammatory indices, and biomarkers of endothelial function among women with the MetS.
  
  
  METHODS
  In a randomized cross-over clinical trial, 30 overweight or obese (BMI >25) women with the MetS were randomly allocated to follow either a high-carbohydrate (HC) (60-65% carbohydrates, 20-25% fats) diet or a moderately restricted carbohydrate (MRC) (43-47% carbohydrate, 36-40% fats) diet, each for 6 weeks. After a 2-week washout period, individuals were switched to the alternate diet for an additional 6 weeks. In a fasted state, markers of inflammation [high-sensitivity C-reactive protein (hs-CRP), high-sensitivity interleukin-6 (hs-IL-6), high-sensitivity tumor necrosis factor-α (hs-TNF-α), and serum amyloid A (SAA)], endothelial function [E-selectin, serum intercellular adhesion molecule 1 (sICAM-1), and serum vascular cell adhesion molecule 1 (sVCAM-1)], and adipocytokines (leptin and adiponectin) were measured in both study arms at baseline and after 6 weeks.
  
  
  RESULTS
  Consumption of an HC diet was associated with increased levels of SAA (3.27 ± 1.22 μg/ml) and decreased levels of adiponectin (-1.68 ± 2.30 ng/ml), while consumption of an MRC diet did not result in such unfavorable effects. Serum concentrations of leptin were reduced by the HC diet (p = 0.02), while they were not affected by the MRC diet. Changes in serum leptin levels were not significant between the two diets (p = 0.09). Serum concentrations of hs-CRP, hs-TNF-α, and IL-6 were not influenced by either diet. No significant differences between the two diets were found in terms of their effect on sICAM-1 and sVCAM-1 concentrations. Adherence to both diets resulted in a 9 ng/ml decrease in serum E-selectin levels (p < 0.05 for both).
  
  
  CONCLUSIONS
  Partial replacement of dietary carbohydrates by unsaturated fats prevents the increased levels of markers of systemic inflammation among women with the MetS.
authors.affiliation: Food Security Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Somayeh
authors.initials: S
authors.lastname: Rajaie
authors.forename: Leila
authors.initials: L
authors.lastname: Azadbakht
authors.forename: Parvaneh
authors.initials: P
authors.lastname: Saneei
authors.forename: Majid
authors.initials: M
authors.lastname: Khazaei
authors.forename: Ahmad
authors.initials: A
authors.lastname: Esmaillzadeh
mesh_terms: D054392:Adipokines / Q000097:blood*; D000328:Adult; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D001835:Body Weight; D002097:C-Reactive Protein / Q000378:metabolism; D018592:Cross-Over Studies; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D024821:Metabolic Syndrome / Q000097:blood / Q000178:diet therapy*; D008875:Middle Aged; D000685:Serum Amyloid A Protein / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000097:blood; D019010:Vascular Cell Adhesion Molecule-1 / Q000097:blood; D055815:Young Adult
chemical_list: D054392:Adipokines; D015415:Biomarkers; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D015850:Interleukin-6; D000685:Serum Amyloid A Protein; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D002097:C-Reactive Protein