title: Effects of adding exercise to a 16-week very low-calorie diet in obese, insulin-dependent type 2 diabetes mellitus patients.
abstract: BACKGROUND
  Reduction of 50% excess body weight, using a very low-calorie diet (VLCD; 450 kcal/d) improves insulin sensitivity in obese type 2 diabetes mellitus patients.
  
  
  OBJECTIVE
  The objective of the study was to evaluate whether adding exercise to the VLCD has additional benefits.
  
  
  METHODS
  This was a randomized intervention study.
  
  
  METHODS
  The study was conducted at a clinical research center in an academic medical center.
  
  
  METHODS
  Twenty-seven obese [body mass index 37.2 ± 0.9 kg/m(2) (mean ± sem)] insulin-treated type 2 diabetes mellitus patients.
  
  
  METHODS
  Patients followed a 16-wk VLCD. Thirteen of them simultaneously participated in an exercise program (E) consisting of 1-h, in-hospital training and four 30-min training sessions on a cycloergometer weekly.
  
  
  METHODS
  Insulin resistance was measured by a hyperinsulinemic euglycemic clamp. Insulin signaling, mitochondrial DNA (mtDNA) content, and intramyocellular lipid content was measured in skeletal muscle biopsies.
  
  
  RESULTS
  Baseline characteristics were identical in both groups. Substantial weight loss occurred (-23.7 ± 1.7 kg VLCD-only vs. -27.2 ± 1.9 kg VLCD+E, P = NS within groups). The exercise group lost more fat mass. Insulin-stimulated glucose disposal increased similarly in both study groups [15.0 ± 0.9 to 39.2 ± 4.7 μmol/min(-1) · kg lean body mass (LBM(-1)) VLCD-only vs. 17.0 ± 1.0 to 37.5 ± 3.5 μmol/min(-1) · kg LBM(-1) in VLCD+E], as did phosphorylation of the phosphatidylinositol 3-kinase-protein kinase B/AKT insulin signaling pathway. In contrast, skeletal muscle mtDNA content increased only in the VLCD+E group (1211 ± 185 to 2288 ± 358, arbitrary units, P = 0.016 vs. 1397 ± 240 to 1196 ± 179, P = NS, VLCD-only group). Maximum aerobic capacity also only increased significantly in the VLCD+E group (+6.6 ± 1.7 ml/min(-1) · kg LBM(-1) vs. +0.7 ± 1.5 ml/min(-1) · kg LBM(-1) VLCD-only, P = 0.017).
  
  
  CONCLUSIONS
  Addition of exercise to a 16-wk VLCD induces more fat loss. Exercise augments maximum aerobic capacity and skeletal muscle mtDNA content. These changes are, however, not reflected in a higher insulin-stimulated glucose disposal rate.
authors.affiliation: Department of Endocrinology and Metabolism, Leiden University Medical Center, 2300 RC Leiden, The Netherlands. m.snel@lumc.nl
authors.forename: Marieke
authors.initials: M
authors.lastname: Snel
authors.forename: Amalia
authors.initials: A
authors.lastname: Gastaldelli
authors.forename: D Margriet
authors.initials: DM
authors.lastname: Ouwens
authors.forename: Matthijs K C
authors.initials: MK
authors.lastname: Hesselink
authors.forename: Gert
authors.initials: G
authors.lastname: Schaart
authors.forename: Emma
authors.initials: E
authors.lastname: Buzzigoli
authors.forename: Marijke
authors.initials: M
authors.lastname: Frölich
authors.forename: Johannes A
authors.initials: JA
authors.lastname: Romijn
authors.forename: Hanno
authors.initials: H
authors.lastname: Pijl
authors.forename: A Edo
authors.initials: AE
authors.lastname: Meinders
authors.forename: Ingrid M
authors.initials: IM
authors.lastname: Jazet
mesh_terms: D031204:Caloric Restriction; D002153:Calorimetry, Indirect; D003131:Combined Modality Therapy; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000178:diet therapy / Q000628:therapy*; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000178:diet therapy / Q000628:therapy*; D013997:Time Factors
chemical_list: D007004:Hypoglycemic Agents; D007328:Insulin