Obese Human Beta-2-adrenergic Stimulation and Muscle Glucose Uptake

Targeting the Beta-2-adrenergic Pathway to Improve Skeletal Muscle Glucose Uptake in Obese Humans

The purpose of this study is to investigate the effect of four weeks clenbuterol/placebo supplementation on skeletal muscle glucose disposal in overweight/obese male and (postmenopausal) female volunteers.

Inclusion Criteria:

1. Caucasian;
2. Male or (postmenopausal; defined as 1 year after the last cycle) female;
3. Age between 40-70 years;
4. BMI: 27-35 kg/m2;

Exclusion Criteria:

1. Not meeting all inclusion criteria

2. Cardiovascular disease (determined by means of questionnaires, heart rate/blood pressure measurements and an ECG)

3. Respiratory diseases (including asthma, bronchitis and COPD);

4. Unstable body weight (weight gain or loss > 3 kg in the last three months);

5. Intention to lose or gain body weight (e.g. with caloric restriction or physical activity)

6. Excessive alcohol and/or drug abuse;

7. Hypokalaemia;

8. Hyperthyroidism

9. Anaemia;

10. Epilepsy;

11. Smoking;

12. Renal and/or liver insufficiency;

13. Diagnosed with type 1 or type 2 diabetes mellitus;

14. Any contra-indications to MRI scanning. These contra-indications include patients with:

    1. Electronic implants such as pacemakers, defibrillators or neurostimulators
    2. Central nervous system aneurysm clip
    3. Some hearing aids (such as cochlear implant) and artificial (heart) valves which are contraindicated for MRI/MRS
    4. Iron containing corpora aliena in the eye or brains
    5. Claustrophobia

15. Participation in another biomedical study within 1 month before the first study visit, possibly interfering with the study results;

16. Medication use known to hamper subject's safety during the study procedures;

17. Subjects who do not want to be informed about unexpected medical findings;

18. Subjects who do not want that their treating physician to be informed;

19. Inability to participate and/or complete the required measurements;

20. Participation in organised or structured physical exercise (>2h per week);

21. Any condition, disease or abnormal laboratory test result that, in the opinion of the Investigator, would interfere with the study outcome, affect trial participation or put the subject at undue risk;