Age and Insulin Resistance (AGIR)

University of Lausanne (UNIL)

Status

Enrolling

Conditions

Aging

Physical Inactivity

Obesity

Treatments

Behavioral: Physical activity

Study type

Interventional

Funder types

Other

Identifiers

NCT01224886

Protocol 188/10 (Other Identifier)

AGIR

Details and patient eligibility

About

Insulin resistance is a crucial factor for the development of type 2 diabetes and a major health problem for older adults. It is the principal mechanism by which obesity is considered to increase the risk for type 2 diabetes and is a key feature of the metabolic syndrome. The elevated prevalence of obesity and type 2 diabetes in the older population has important consequences on the morbidity and mortality as well as on the economic burden on society. Controversy currently exists as to whether or not aging contributes to insulin resistance. Many potential factors confound the association between aging and insulin resistance, including obesity and physical inactivity.

Ectopic lipid depositions, defined as an excess accumulation of triglycerides in non adipose tissues such as in the liver (intrahepatic lipids) and within the muscle fibers (intramyocellular lipids), are positively associated with obesity and insulin resistance. Furthermore, the accumulation of intracellular lipids is often cited as being a key determinant in the underlying mechanisms of insulin resistance. In addition of playing an important role in obesity and type 2 diabetes, these ectopic fat depositions are also observed in common conditions such as aging and physical inactivity.

The intervention trial will test in skeletal muscle, liver and heart of sedentary obese volunteers, normal weight volunteers and masters athletes, the overall hypotheses that exercise improvement of fat oxidation capacity and/or decrease of damaging fat metabolites is a primary factor that predicts the improvement in insulin resistance.

Enrollment

150 estimated patients

Sex

All

Ages

60 to 80 years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

Age 60-80
Sedentary or highly trained
BMI 18-40
Non-Smoker
Normal glucose tolerance or impaired glucose tolerance
Willingness to comply with the protocol

Exclusion criteria

Contraindication to moderate exercise or clinical conditions precluding from joining an exercise program, such as clinically significant cardiovascular disease, peripheral vascular disease, uncontrolled hypertension, neurological or orthopedic disease
Recent weight loss or weight gain
Known diabetes
Known drugs to affect glucose homeostasis such as nicotinic acid, glucocorticoids
Severe anemia or lipid disturbances, hepatic or renal disease
Recent history of cancer
Hypothyroidism
Recent hormone replacement therapy
Known allergy to lidocaine or other local anesthetic
Positive stress test
Active alcohol or substance abuse