Use of Glutamine for Recovery Muscle Strength

After an Anterior Cruciate Ligament Reconstruction by surgery, the most important muscle of the knee, called quadriceps femoral, loses strength in more than 60% of cases, which if not corrected can progress to osteoarthritis in up to 80% of patients, compromising their quality of life.

The main treatment for loss of muscle strength in these patients is rehabilitation which includes strength and endurance exercises.However, in some cases, amino acids such as Glutamine (Gln) have been employed as an aid to recover muscle strength, but the evidence on this topic is not consistent and is inconclusive. Therefore, the main purpose of this study is to investigate if the oral complementation with Glutamine in combination with strength and resistance training can improve the muscle strength of the quadriceps femoral in patients with anterior cruciate ligament reconstruction compared with those receiving a placebo after six weeks of intervention.

The study design is a randomized, double-blind and controlled trial. A total of 50 adult men will be recruited from medical departments of the National Institute of Rehabilitation in Mexico City.

Patients: Fifty men 20 to 50 years old, between 15 to 19 weeks after surgical reconstruction of anterior cruciate ligament and moderate loss of muscle strength of knee (assessment with computerized dynamometer), will be recruited from the Sport Rehabilitation department, and the treatment will be carried out in the Sport Medicine area, both of the National Institute of Rehabilitation in Mexico City. Patients with diabetes, obesity, hypertension, kidney or liver diseases or with glucocorticoid treatment, and athletes will not be included.

Intervention: The sample will be randomized in two groups. At the beginning and at the end of the training session, the experimental group will receive 10 grams of glutamine, and the control group will receive 10 grams of placebo (maltodextrin), both dissolved in 120 milliliters of water and all participants will not be aware of the supplement content.

Both groups will participate in the same standardized resistance training program, to ensure progression (or regression if necessary) to all training components and adherence to the intervention, each participant will do the training program in a therapeutic gym of Sport Medicine area three times per week, during 6 weeks of follow-up. One training session consists of 20 minutes of warm-up, 40 to 60 minutes of aerobic and anaerobic exercises and 15 minutes of cooling down. The exercises of the lower part of the body consist in 3 sets of 10 repetitions for healthy knees, and 12 repetitions for knees with anterior cruciate ligament reconstruction in a modular leg press, leg curl and leg extension machine.

All participants, irrespective of the supplement that they receive, will be closely monitored by a physician specialist in Sport Medicine and a nutritionist, who will give a dietary program to standardize protein consumption. Status nutritional will be assessed according to Body Mass Index \[(BMI) 19.9-24.9, 25-29.9\].

Muscle strength will be measured by a computer dynamometer. The reliability of the dynamometry will be evaluated by Intraclass Correlation Coefficient (ICC). Thigh circumference will be measured by a anthropometric technique (Nutritionists certified by the International Society for the Advance of Kinanthropometry in level one, will carry out the measurement). Fasting glucose, lipid profile and liver function test will be carried out in the clinical laboratory of National Institute of Rehabilitation. The measurements are going to be held twice; before the first training session, and 6 weeks after.

For each participant the study duration will start in the first training session until 6 weeks after. Endpoints assessments will be performed at baseline (2 days before starting the training program) and after 6 weeks of follow-up (2 days after the last training session). Data will be collected by study investigators blinded to the allocation of the participants.

Comparison: The control group will receive maltodextrin powder (placebo) dissolved in 120 milliliters of water. The placebo will be inside gray envelopes, in the same manner that the glutamine was administered.

Outcomes: The main outcome is to change the strength of quadriceps femoris (assessment by isokinetic dynamometer).

Eligibility Criteria:
Inclusion Criteria:

* Patients between 15 to 19 weeks after surgical reconstruction of anterior cruciate ligament
* Moderate loss of muscle strength of knee (assessment with computerized dynamometer)
* Perform the training sessions in the hospital
* No athletes
* Index Body Mass: 20 - 30 kg/m²
* Without consumption of supplements based on amino acids in the last 6 months
* To sign informed consent letter

Exclusion Criteria:

* Diabetes mellitus I or 2
* Liver and renal diseases
* Dyslipidemia
* Glucocorticoid consumption
* Active cancer
* Glutamine allergy or intolerance
* Planning to lose weight/go on special diet