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Effect of Acetazolamide on Postural Control in Lowlanders Older Than 40 Years at Altitude

Phase 4
Completed
Conditions
Altitude Hypoxia
Interventions
Drug: Placebo oral capsule
Registration Number
NCT03536429
Lead Sponsor
University of Zurich
Brief Summary

Randomized, placebo controlled trial evaluating the effect of acetazolamide on postural control in lowlanders older than 40 years travelling from 760 m to 3'100 m.

Detailed Description

This is a randomized, placebo-controlled, double-blind parallel trial evaluating the effect of preventive acetazolamide intake on the postural control in lowlanders older than 40 years travelling to altitude. Participants living in the Bishkek area, Kyrgyzstan (760m), will be transferred by car within 4h to the Tuja Ashu high altitude clinic (3'100 m), and stay there for 2 days. Acetazolamide 375mg/day (or placebo), will be administered before departure at 760 m and during the stay at altitude. Outcomes will be assessed during the stay at 3'100 m.

An interim analysis will be carried out when 80 participants will have completed the study or after the first year. The Peto's method will be used and the trial will be stopped when pre-specified futility boundaries were crossed.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
99
Inclusion Criteria
  • Healthy men and women, age 40-75 yrs, without any disease and need of medication.
  • Born, raised and currently living at low altitude (<800m).
  • Written informed consent.
  • Kyrgyz ethnicity
Exclusion Criteria
  • Any active respiratory, cardiovascular or other disease requiring regular treatment or being otherwise relevant for tolerance of hypoxia or altitude exposure.
  • Any condition that may interfere with protocol compliance including current heavy smoking (>20 cigarettes per day or >20 pack-years with active smoking during the last 10 years), regular use of alcohol.
  • Allergy to acetazolamide and other sulfonamides.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
ACETAZOLAMIDE oral capsuleACETAZOLAMIDE oral capsuleAcetazolamide 375mg/day (capsule @125 mg: 1 in the morning, 2 in the evening), orally. Medication starts 24 hours before ascent to 3'100m until the morning after the second night at 3'100m
PLACEBO oral capsulePlacebo oral capsulePlacebo (capsules identically looking as acetazolamide capsules: 1 in the morning, 2 in the evening), orally. Medication starts 24 hours before ascent to 3'100m until the morning after the second night at 3'100m
Primary Outcome Measures
NameTimeMethod
Change in anterio-posterior sway velocity (AP)Day 2 at 760m and 3'100m

Difference in altitude-induced change (between day 2 at 760 meters a.s.l. vs. day 2 at 3'100 meters a.s.l.) of AP sway velocity between acetazolamide and placebo group, measured by a balance platform

Secondary Outcome Measures
NameTimeMethod
Change in arterial oxygen saturationDay 2 at 760m and 3'100m

Difference in altitude-induced change (between day 2 at 760 meters a.s.l. vs. day 2 at 3'100 meters a.s.l.) of arterial oxygen saturation between acetazolamide and placebo group, measured by pulse oximetry

Acute mountain sickness, severityDay 2 at 3'100m

Difference in acute mountain sickness severity on day 2 at 3'100 meters a.s.l. between acetazolamide and placebo group.

Change in cerebral tissue oxygenationDay 2 at 760m and 3'100m

Difference in altitude-induced change (between day 2 at 760 meters a.s.l. vs. day 2 at 3'100 meters a.s.l.) of cerebral tissue oxygenation between acetazolamide and placebo group, measured by near-infrared spectroscopy.

Change in muscle tissue oxygenationDay 2 at 760m and 3'100m

Difference in altitude-induced change (between day 2 at 760 meters a.s.l. vs. day 2 at 3'100 meters a.s.l.) of muscle tissue oxygenation between acetazolamide and placebo group, measured by near-infrared spectroscopy.

AP sway velocity with and without study medicationDay 3 at 760m

Difference in AP sway velocity between acetazolamide and placebo group at 760 m.

Trial Locations

Locations (1)

National Center of Cardiology and Internal Medicine

🇰🇬

Bishkek, Kyrgyzstan

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