A Comparison of Neuromuscular Recruitment in Trained and Untrained Adults

ConditionsHealthy Insulin Resistance

Trial statusRecruiting

Trial phaseNot listed

Trial typeObservational

Biological sexAll

Age60-85

SponsorMayo Clinic

About this trial

The objective of the study is to use neurological techniques to obtain quantitative measurements of nervous system control of skeletal muscle activity in adults aged 60-85 who are either long-term resistance exercisers or who are untrained.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Participant must have a BMI between 18.5 and 38

Participant be aged between 60 and 85

Regularly exercises at least 5 days a week a minimum of 30 minutes per day.

Engages in less than 2 days of exercise less than 30 minutes each day.

Disqualifiers

Surgical History - Gastric surgery, pacemaker placement, weight loss surgery, metabolic and obstetric surgery.

Smokers will be excluded from the study.

Medications: Insulins, common diabetic drugs, anti-hyperglycemic drugs, beta blockers cardiac selective, beta-blockers noncardiac selective, oral steroids, opioids anti-depressants, and hormones

Conidiations and Diagnosis: Disorder of coronary artery, hepatic failure, gastroparesis, disorder of the adrenal gland, drug related disorders, substance abuse, malignant neoplastic disease, psychotic disorders, disorder of skeletal muscle, finding of brain, chronic kidney disease, renal failure syndrome, disorder of pulmonary circulation, cerebrovascular disease, neuro developmental disorder, disorder of immune function, disorder of central nervous system.

Trial population

A total of 80 participants will be equally divided into resistance-trained and untrained groups. Participants will be matched for age, sex, and BMI. Participants are to have a fasting blood sugar under 140 mg/dL. Untrained men and women will have a hip to waist ratio of \>0.85 in women or \>80cm and \>0.90 in men or \>94cm. Participants will be from the Rochester Minnesota area aged 60-85 with a BMI 30-38.

Trial design

Design model

Case-control

Time perspective

Prospective

Treatments tested in this trial

Neuromuscular Test
Diagnostic test
To measure neuromuscular connectivity, Transcranial Magnetic Stimulation (TMS) will be used to stimulate regions of the cerebral cortex known to control specific muscles. Electromyography (EMG) activity will then be measured from the following muscle groups: deltoid, biceps, extensor digitorum communis, abductor pollicis brevis, abductor digiti minimi, and first dorsal interosseous muscle.
DEXA
Diagnostic test
The DEXA test uses X-rays to measure how many grams of calcium and other bone minerals are packed into a segment of bone. The test also measures the amount of fat-free mass, and fat mass.
Mixed Meal Tolerance Test
Diagnostic test
Fasting blood will be collected for glucose, insulin, and c-peptide. Participants will be provided with a milkshake with a fixed amount of protein, carbohydrates, and fat. Glucose, insulin, and c-peptide will be measured at multiple time points (every 10 minutes) until four hours after consumption (50% Fat, 30% Carbohydrate HO, 20% Protein). Approximately 70mls of blood will be drawn during this time
Strength Test
Diagnostic test
Knee extensor strength will be tested by gradually increasing the workload on a pneumatic Keiser knee extension machine. The test will begin with a warm-up of 4-5 reps with one leg at 30-50 psi. Then the participant will increase the workload at self-selected intervals ranging from 5-20psi until a maximum effort is achieved. If a rep is failed, then the workload will be reduced by 5psi until a successful rep is performed or a workload is reached in which a successful rep had been previously achieved. Handgrip strength will be tested using a handheld dynamometer (Baseline® standard hydraulic hand dynamometer). The test is performed with the participant seated with the elbow unsupported and flexed at 90 degrees, forearm neutral, wrist held between 0-15 degrees of ulnar deviation (Horowitz, 1997). Maximum grip is the average of three 3-5 second trials.

Treatment groups

80 Participants

are divided into 2 treatment groups

Group A: Highly resistance-trained4 interventions

Group B: Untrained4 interventions

Trial outcomes

Primary outcomes

Electromyography (EMG) response following Transcranial Magnetic Stimulation (TMS)

To assess connectivity between the nervous system and skeletal muscle, we will use transcranial magnetic stimulation (TMS) coupled with electromyography (EMG). TMS uses a magnetic field to carry a short-lasting electrical current pulse into the brain where it stimulates neurons, particularly in superficial regions of cerebral cortex, and neural activities can be measured at different levels along the motor pathways (predominantly the CST). When combined with EMG, this approach will allow us to quantify changes in muscular activity after stimulating the CST and other descending tracts and to assess the neuromuscular connectivity. EMG assess the health of muscles and the nerve cells that control them (motor neurons). EMG results can reveal nerve dysfunction, muscle dysfunction or problems with nerve-to-muscle signal transmission. Motor neurons transmit electrical signals that cause muscles to contract. Electrodes will then translate signals into graphs, sounds or numerical values.

Time frame

21 days

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Mayo Clinic

Lead sponsor

National Institute on Aging (NIA)

Collaborator

Source ClinicalTrials.gov

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