Effects of adding exercise to a 16-week very low-calorie diet in obese, insulin-dependent type 2 diabetes mellitus patients.

Abstract

CONTEXT:

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.

DESIGN:

This was a randomized intervention study.

SETTING:

The study was conducted at a clinical research center in an academic medical center.

SUBJECTS:

Twenty-seven obese [body mass index 37.2 ± 0.9 kg/m(2) (mean ± sem)] insulin-treated type 2 diabetes mellitus patients.

INTERVENTION:

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.

OUTCOME MEASURES:

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).

CONCLUSION:

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: Marieke Snel, Amalia Gastaldelli, D Margriet Ouwens, Matthijs K C Hesselink, Gert Schaart, Emma Buzzigoli, Marijke Frölich, Johannes A Romijn, Hanno Pijl, A Edo Meinders, Ingrid M Jazet
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 97 Issue 7 Pg. 2512-20 (Jul 2012) ISSN: 1945-7197 [Electronic] United States
• PMID: 22569236 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Hypoglycemic Agents
• Insulin

Topics

• Caloric Restriction
• Calorimetry, Indirect
• Combined Modality Therapy
• Diabetes Mellitus, Type 2 (complications, diet therapy, therapy)
• Exercise (physiology)
• Exercise Therapy
• Female
• Glucose Clamp Technique
• Glucose Tolerance Test
• Humans
• Hypoglycemic Agents (therapeutic use)
• Insulin (therapeutic use)
• Male
• Middle Aged
• Obesity (complications, diet therapy, therapy)
• Time Factors