Healthy
Conditions
Keywords
Beta-2 adrenergic agonist, Glucose homeostasis, Skeletal muscle, Human
Brief summary
The purpose of this study is to investigate the effect of two weeks clenbuterol/placebo supplementation on skeletal muscle glucose disposal in healthy male volunteers.
Interventions
Daily ingestion of clenbuterol hydrochloride capsules (40 microgram/day) for a total period of 14 days with a wash-out period of 4 weeks.
DRUGPlacebos
Daily ingestion of placebo capsules for a total period of 14 days with a wash-out period of 4 weeks.
Sponsors
Maastricht University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Intervention model description
Randomized, double-blinded, placebo-controlled, cross-over, single-center study
Eligibility
Sex/Gender
MALE
Age
18 Years to 30 Years
Healthy volunteers
Yes
Inclusion criteria
1. Caucasian; 2. Male sex; 3. Age: 18-30 4. BMI: 18-25 kg/m2; 5. Normal physical activity levels;
Exclusion criteria
1. Not meeting all inclusion criteria 2. Cardiovascular diseases (determined by means of questionnaires, heart rate/blood pressure measurements) 3. Respiratory diseases (including asthma, bronchitis and COPD); 4. Unstable body weight (weight gain or loss \> 5 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. Hb \< 8.4 mmol/L; 9. Epilepsy; 10. Smoking; 11. Renal and/or liver insufficiency; 12. Participation in another biomedical study within 1 month before the first study visit, possibly interfering with the study results; 13. Medication use known to hamper subject's safety during the study procedures; 14. Subjects who do not want to be informed about unexpected medical findings; 15. Subjects who do not want that their treating physician to be informed; 16. Inability to participate and/or complete the required measurements; 17. Participation in organised or structured physical exercise; 18. 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; 19. Hyperthyroidism
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Insulin-stimulated peripheral glucose disposal (Rd) | 2 weeks | Comparison between prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on insulin-stimulated peripheral glucose disposal (Rd) during the high-insulin infusion step during the two-step hyperinsulinemic-euglycemic clamp. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Skeletal muscle GLUT4 translocation | acute (4 hours) and long-term (2 weeks) | Comparison between acute (4h) and prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on skeletal muscle GLUT4 translocation as assessed by means of wide-field microscopy in skeletal muscle biopsies |
Other
| Measure | Time frame | Description |
|---|---|---|
| Heart rate | Acute (4 hours) and long-term (1 and 2 weeks) | Comparison between acute (4h) and prolonged (1 and 2 weeks) clenbuterol hydrochloride or placebo supplementation on heart rate as measured by means of an automated cuff. |
| Blood pressure | Acute (4 hours) and long-term (1 and 2 weeks) | Comparison between acute (4h) and prolonged (1 and 2 weeks) clenbuterol hydrochloride or placebo supplementation on blood pressure (systolic and diastolic) as measured by means of an automated cuff. |
| Insulin-mediated suppression of hepatic glucose production | 2 weeks | Comparison between prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on hepatic glucose production as assessed during the two-step hyperinsulinemic-euglycemic clamp. |
| Energy expenditure and substrate oxidation | Acute (4 hours) and long-term (2 weeks) | Comparison between acute (4h) and prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on energy expenditure and substrate oxidation as assessed by means of indirect calorimetry. |
| Body weight/composition | 2 weeks | Comparison between prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on body weight and composition as assessed by means of a Bodpod measurement. |
| Skeletal muscle glycogen | 2 weeks | Comparison between prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on skeletal muscle glycogen as assessed in muscle biopsies. |
| Skeletal muscle lipid content using wide-field microscopie | 2 weeks | Comparison between prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on skeletal muscle lipid content as assessed in muscle biopsies by wide-field microscopie. |
| Skeletal muscle gene expression | Acute (4 hours) and long-term (1 and 2 weeks) | Comparison between acute (4h) and prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on skeletal muscle gene expression of specific pathways as determined in muscle biopsies by means of RT-qPCR |
| Skeletal muscle protein expression using western blotting | Acute (4 hours) and long-term (1 and 2 weeks) | Comparison between acute (4h) and prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on skeletal muscle protein expression of specific pathways as determined in muscle biopsies as determined by means of Western Blotting |
| Sleeping energy expenditure and substrate oxidation | 2-weeks | Comparison between prolonged (2 weeks) clenbuterol hydrochloride or placebo supplementation on sleeping energy expenditure and substrate oxidation as assessed by means of a metabolic chamber (indirect calorimetry). |
| Plasma substrates | Acute (4 hours) and long-term (1 and 2 weeks) | Comparison between acute (4h) and prolonged (1 and 2 weeks) clenbuterol hydrochloride or placebo supplementation on plasma substrate concentrations, including insulin, glucose, free fatty acids and TAGs. |
Countries
Netherlands
Outcome results
None listed