Clinical trial NCT01890876: Altitude, Exercise and Glucose Metabolism in Pre-diabetic Men
Official title: Altitude-dependent Effects of Concentric and Eccentric Exercise on Glucose Metabolism in Pre-diabetic Men
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Diabetes
Keywords: glucose tolerance, hypoxia, myokines, exercise
Lead sponsor: Universitaet Innsbruck
Sponsor class: OTHER
Collaborators: name: Medical University Innsbruck
First posted: 2013-07-02
Enrollment: 32
Sex: MALE
Minimum age (years): 50
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: Concentric (CE) and eccentric (EE) exercises may differently affect glucose metabolism which may be additionally modified when exercises are performed in hypoxia, e.g. at moderate (1500 - 2500 m) or high (2500 - 3500 m) altitudes. However, data on the effects of glucose metabolism due to CE and EE in hypoxia are scarce but would be of utmost importance considering the increasing number of persons suffering from impaired glucose tolerance or diabetes and the unique opportunities provided by the mountainous regions of the Alps to perform CE (e.g. uphill hiking) and EE (downhill hiking, downhill skiing) at altitude between 1500 - 3500 m. Metabolic responses to exercise may be largely mediated by interleukin 6 (IL-6), which is predominantly derived from the contracting limbs and may support the maintenance of metabolic homeostasis during exercise. In addition, IL-6 is elevated with acute and chronic altitude exposure at least partly mediated via adrenergic stimulation. Thus, the type of exercise as well as hypoxia may contribute to IL-6 elevations and differences in serum IL-6 concentrations might help to explain distinctions between responses of glucose metabolism to CE and EE at low and moderate to high altitude.

32 male subjects suffering from pre-diabetes will be randomly assigned to a downhill (EE) or uphill (CE) walking group performing 9 sessions at low altitude (860 - 1360 m) and 9 sessions at moderate to high altitude (2000 - 2500 m). Between normoxic and hypoxic condition will be a break of approximately 12 month. Measurements of glucose metabolism, IL-6 plasma concentration will be performed pre, mid (day 5) and post intervention. Moreover anthropometric, strength and exercise capacity characteristics will be performed pre and post intervention.

We hypothesize that EE in hypoxia is more effective in the modulation of glycemic control in pre-diabetic men than CE in hypoxia as well as EE and CE in normoxia. It is suggested that effects on glucose metabolism are associated with changes in plasma IL-6 concentrations. EE in hypoxia is expected to result in a more persistent rise of plasma IL-6 concentration than CE in hypoxia and in normoxia and to a more pronounced rise in plasma IL-6 than EE in normoxia.

Detailed description: Not desired.

Eligibility criteria: Inclusion Criteria:

* Pre-diabetes
* male
* age 50-65 years

Exclusion Criteria:

* smoking
* BMI \> 30 kg/m2
* diseases not compatible with intervention

Primary outcomes:
measure: Glucose tolerance
timeFrame: 18 months
Secondary outcomes:
measure: Myokines
timeFrame: 18 months
measure: Cardiovascular fitness
timeFrame: 18 months
Other outcomes:
Locations:
city: Innsbruck
country: Austria
facility: Department of Sport Science, Medical Section, University of Innsbruck
Study officials:
affiliation: department of sport science, medical section, university innsbruck
name: Martin Burtscher, Professor
role: PRINCIPAL_INVESTIGATOR
References:
citation: Drexel H, Saely CH, Langer P, Loruenser G, Marte T, Risch L, Hoefle G, Aczel S. Metabolic and anti-inflammatory benefits of eccentric endurance exercise - a pilot study. Eur J Clin Invest. 2008 Apr;38(4):218-26. doi: 10.1111/j.1365-2362.2008.01937.x.
citation: Duennwald T, Gatterer H, Groop PH, Burtscher M, Bernardi L. Effects of a single bout of interval hypoxia on cardiorespiratory control and blood glucose in patients with type 2 diabetes. Diabetes Care. 2013 Aug;36(8):2183-9. doi: 10.2337/dc12-2113. Epub 2013 Mar 27.
citation: Burtscher M, Gatterer H, Kunczicky H, Brandstatter E, Ulmer H. Supervised exercise in patients with impaired fasting glucose: impact on exercise capacity. Clin J Sport Med. 2009 Sep;19(5):394-8. doi: 10.1097/JSM.0b013e3181b8b6dc.
citation: Philippe M, Junker G, Gatterer H, Melmer A, Burtscher M. Acute effects of concentric and eccentric exercise matched for energy expenditure on glucose metabolism in healthy females: a randomized crossover trial. Springerplus. 2016 Aug 30;5(1):1455. doi: 10.1186/s40064-016-3062-z. eCollection 2016.