title: Improved insulin sensitivity after exercise training is linked to reduced plasma C14:0 ceramide in obesity and type 2 diabetes.
abstract: OBJECTIVE
  To assess the effect of exercise training on insulin sensitivity and plasma ceramides in obesity and type 2 diabetes (T2D).
  
  
  METHODS
  Twenty-four adults with obesity and normal glucose tolerance (NGT, n = 14) or diabetes (n = 10) were studied before and after a 12-week supervised exercise-training program (5 days/week, 1 h/day, 80-85% of maximum heart rate). Changes in body composition were assessed using hydrostatic weighing and computed tomography. Peripheral tissue insulin sensitivity was assessed by a 40 mU/m(2) /min hyperinsulinemic euglycemic clamp. Plasma ceramides (C14:0, C16:0, C18:0, C18:1, C20:0, C24:0, and C24:1) were quantified using electrospray ionization tandem mass spectrometry after separation with HPLC.
  
  
  RESULTS
  Plasma ceramides were similar for the subjects with obesity and NGT and the subjects with diabetes, despite differences in glucose tolerance. Exercise significantly reduced body weight and adiposity and increased peripheral insulin sensitivity in both groups (P < 0.05). In addition, plasma C14:0, C16:0, C18:1, and C24:0 ceramide levels were reduced in all subjects following the intervention (P < 0.05). Decreases in total (r = -0.51, P = 0.02) and C14:0 (r = -0.56, P = 0.009) ceramide were negatively correlated with the increase in insulin sensitivity.
  
  
  CONCLUSIONS
  Ceramides are linked to exercise training-induced improvements in insulin sensitivity, and plasma C14:0 ceramide may provide a specific target for investigating lipid-related insulin resistance in obesity and T2D.
authors.affiliation: Department of Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Takhar
authors.initials: T
authors.lastname: Kasumov
authors.affiliation: Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Thomas P J
authors.initials: TP
authors.lastname: Solomon
authors.affiliation: Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Calvin
authors.initials: C
authors.lastname: Hwang
authors.affiliation: Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Hazel
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Jacob M
authors.initials: JM
authors.lastname: Haus
authors.affiliation: Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA.|Center for Cardiovascular Diagnostics and Prevention, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: Renliang
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology & Hepatology, Cleveland Clinic, Cleveland, Ohio, USA.|Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio, USA.|Department of Nutrition, Case Western Reserve, University School of Medicine, Cleveland, Ohio, USA.|Metabolic Translational Research Center, Endocrine and Metabolism Institute, Cleveland Clinic, Cleveland, Ohio, USA.
authors.forename: John P
authors.initials: JP
authors.lastname: Kirwan
mesh_terms: D000328:Adult; D001823:Body Composition; D001835:Body Weight; D002518:Ceramides / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000628:therapy*; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000628:therapy*; D010807:Physical Endurance / Q000502:physiology
chemical_list: D002518:Ceramides