title: Effects of insulin therapy on myocardial lipid content and cardiac geometry in patients with type-2 diabetes mellitus.
abstract: OBJECTIVE
  Recent evidence suggests a link between myocardial steatosis and diabetic cardiomyopathy. Insulin, as a lipogenic and growth-promoting hormone, might stimulate intramyocardial lipid (MYCL) deposition and hypertrophy. Therefore, the aim of the present study was to investigate the short-term effects of insulin therapy (IT) on myocardial lipid content and morphology in patients with T2DM.
  
  
  METHODS
  Eighteen patients with T2DM were recruited (age 56 ± 2 years; HbA1c: 10.5 ± 0.4%). In 10 patients with insufficient glucose control under oral medication IT was initiated due to secondary failure of oral glucose lowering therapy (IT-group), while 8 individuals did not require additional insulin substitution (OT-group). In order to assess MYCL and intrahepatic lipid (IHLC) content as well as cardiac geometry and function magnetic resonance spectroscopy (MRS) and imaging (MRI) examinations were performed at baseline (IT and OT) and 10 days after initiation of IT. Follow up measurements took place 181 ± 49 days after IT.
  
  
  RESULTS
  Interestingly, basal MYCLs were 50% lower in IT- compared to OT-group (0.41 ± 0.12 vs. 0.80 ± 0.11% of water signal; p = 0.034). After 10 days of IT, an acute 80%-rise in MYCL (p = 0.008) was observed, while IHLC did not change. Likewise, myocardial mass (+13%; p = 0.004), wall thickness in end-diastole (+13%; p = 0.030) and concentricity, an index of cardiac remodeling, increased (+28%; p = 0.026). In the long-term MYCL returned to baseline, while IHCL significantly decreased (-31%; p = 0.000). No acute changes in systolic left ventricular function were observed.
  
  
  CONCLUSIONS
  The initiation of IT in patients with T2DM was followed by an acute rise in MYCL concentration and myocardial mass.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
authors.forename: Drazenka
authors.initials: D
authors.lastname: Jankovic
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Winhofer
authors.forename: Miriam
authors.initials: M
authors.lastname: Promintzer-Schifferl
authors.forename: Evelyne
authors.initials: E
authors.lastname: Wohlschläger-Krenn
authors.forename: Christian Heinz
authors.initials: CH
authors.lastname: Anderwald
authors.forename: Peter
authors.initials: P
authors.lastname: Wolf
authors.forename: Thomas
authors.initials: T
authors.lastname: Scherer
authors.forename: Gert
authors.initials: G
authors.lastname: Reiter
authors.forename: Siegfried
authors.initials: S
authors.lastname: Trattnig
authors.forename: Anton
authors.initials: A
authors.lastname: Luger
authors.forename: Michael
authors.initials: M
authors.lastname: Krebs
authors.forename: Martin
authors.initials: M
authors.lastname: Krssak
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D006321:Heart / Q000503:physiopathology*; D006801:Humans; D007328:Insulin / Q000627:therapeutic use*; D050356:Lipid Metabolism; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*
chemical_list: D007328:Insulin