title: The insulin-sensitizing effect of rosiglitazone in type 2 diabetes mellitus patients does not require improved in vivo muscle mitochondrial function.
abstract: OBJECTIVE
  Our objective was to investigate whether improved in vivo mitochondrial function in skeletal muscle and intramyocellular lipids (IMCLs) contribute to the insulin-sensitizing effect of rosiglitazone.
  
  
  METHODS
  Eight overweight type 2 diabetic patients (body mass index = 29.3 +/- 1.1 kg/m(2)) were treated with rosiglitazone for 8 wk. Before and after treatment, insulin sensitivity was determined by a hyperinsulinemic euglycemic clamp. Muscular mitochondrial function (half-time of phosphocreatine recovery after exercise) and IMCL content were measured by magnetic resonance spectroscopy.
  
  
  RESULTS
  Insulin sensitivity improved after rosiglitazone (glucose infusion rate: 19.9 +/- 2.8 to 24.8 +/- 2.1 micromol/kg.min; P < 0.05). In vivo mitochondrial function (phosphocreatine recovery half-time: 23.8 +/- 3.5 to 20.0 +/- 1.7 sec; P = 0.23) and IMCL content (0.93 +/- 0.18% to 1.37 +/- 0.40%; P = 0.34) did not change. Interestingly, the changes in PCr half-time correlated/tended to correlate with changes in fasting insulin (R(2) = 0.50; P = 0.05) and glucose (R(2) = 0.43; P = 0.08) levels. Changes in PCr half-time did not correlate with changes in glucose infusion rate (R(2) = 0.08; P = 0.49).
  
  
  CONCLUSIONS
  The rosiglitazone-enhanced insulin sensitivity does not require improved muscular mitochondrial function.
authors.affiliation: Department of Radiology, Maastricht University Hospital, Maastricht, The Netherlands. v.schrauwen@hb.unimaas.nl
authors.forename: Vera B
authors.initials: VB
authors.lastname: Schrauwen-Hinderling
authors.forename: Marco
authors.initials: M
authors.lastname: Mensink
authors.forename: Matthijs K C
authors.initials: MK
authors.lastname: Hesselink
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Sels
authors.forename: M Eline
authors.initials: ME
authors.lastname: Kooi
authors.forename: Patrick
authors.initials: P
authors.lastname: Schrauwen
mesh_terms: D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000378:metabolism; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D008931:Mitochondria, Muscle / Q000187:drug effects* / Q000502:physiology; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D007004:Hypoglycemic Agents; D045162:Thiazolidinediones; D000077154:Rosiglitazone