Objective: To examine the effect of a 4-month progressive strength training program on muscle and fat mass assessed by computed tomography (CT) in type 2 diabetes mellitus (T2DM) patients, and to assess the relationships of changes in muscle cross-section area (CSA) with glycaemic control.
Methods: Twenty adults (mean age +/- SE: 56.4 +/- 0.9 a) with T2DM participated in a supervised strength training program for 4 months 3 days/week. Muscle and fat areas of the quadriceps muscle were estimated by CT volumetry before and immediately after the training. Glycaemic (HbA1c) and anthropometric (BMI, skinfolds) measurements were assessed at 0 and 4 months, respectively.
Results: After strength training, muscle strength increased significantly in all measured muscle groups. Quadriceps size (CSA of the muscle) was increased by 2.4% (from 7.99 +/- 0.3 cm(3) to 8.18 +/- 0.3 cm(3), p = 0.003) for the right extremity, 3.9% (from 8.1 +/- 0.4 cm(3) to 8.41 +/- 0.5 cm(3), p = 0.04) for the left side. Fat tissue CSA reduced from 0.66 +/- 0.1 cm(3) to 0.56 +/- 0.12 cm(3) for the right leg (15.3% reduction) and from 0.58 +/- 0.12 cm(3) to 0.37 +/- 0.13 cm(3) for the left leg (35.8% reduction), resulting in a mean fat CSA reduction of 24.8%. Fat mass assessed by skin folds was significantly reduced and lean body mass was significantly increased. The change in muscle CSA was not correlated with the changes in HbA1c or muscle strength.
Conclusions: Strength training significantly improves both muscle mass and the muscle to fat ratio in T2DM. However, changes in muscle observed with computed tomography were not related to changes observed in HbA1c with training.