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CompletedNCT03866512Updated Jun 21, 2024Results posted

Forearm Immobilization, Metabolic Health, and Muscle Loss

An interventional study of Forearm immobilization in Healthy, sponsored by University of Exeter. Completed at 1 site in United Kingdom. Open to participants aged 18 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-06-21.

Sponsored by University of Exeter · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
37
Allocation
Randomized
Ages
18 Years to 40 Years
Sex
All
01

Study summary

The present study will investigate the impact of altered substrate availability on muscle atrophy, insulin sensitivity and muscle protein synthesis following short-term forearm immobilization

Read the detailed description

Thirty-six healthy young volunteers will undergo 2 days of forearm immobilization combined with ingestion of one of two drug or placebo. Before and after immobilization, they will receive a stable isotope tracer infusion (5.5 h) combined with repeated blood and muscle sampling under insulin clamp conditions, in order to measure insulin sensitivity and muscle protein synthesis in the fasted and fed state.

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Conditions studied

  • Healthy
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In context

Lead sponsor

University of Exeter is the lead sponsor of 138 studies on the registry; 25 are open to participants now.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years to 40 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • Males and females 18-40 years of age
  • Body mass index between 18 and 27

Exclusion criteria

Exclusion Criteria:

  • Any diagnosed metabolic impairment (e.g. type 1 or 2 diabetes)
  • Any diagnosed cardiovascular disease
  • Hypertension (≥140 mmHg systolic and/or ≥90 mmHg diastolic)
  • Chronic use of any prescribed or over the counter pharmaceuticals (excluding oral contraceptives and contraceptive devices)
  • Regular use of nutritional supplements
  • Metallic implants
  • A personal or family history of thrombosis, epilepsy, seizures or schizophrenia
  • Any previous motor disorders
  • Any known disorders in lipid metabolism
  • Any known disorders in muscle metabolism
  • Known allergy for Acipimox, beta agonist, or other substances in the tablets
  • Known sensitivity for sympathomimetic drugs
  • Known hypokalaemia
  • Presence of an ulcer in the stomach or gut and/or strong history of indigestion
  • Known severe kidney problems
  • Pregnancy
  • Unable to give consent
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Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
37 participants (actual)

Study arms

  • Experimental
    Acipimox ingestion during immobilization

    Oral ingestion of Acipimox during 2 days of forearm immobilization

    Behavioral: Forearm immobilization

  • Experimental
    B-agonist during immobilization

    Oral ingestion of salbutamol during 2 days of forearm immobilization

    Behavioral: Forearm immobilization

  • Placebo comparator
    Placebo ingestion during immobilization

    Oral ingestion of a placebo 2 days of forearm immobilization

    Behavioral: Forearm immobilization

Interventions

  • BehavioralForearm immobilization

    Two days of forearm immobilization

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What researchers measure

Primary outcomes

  1. Percent Change in Forearm Glucose Uptake

    Insulin sensitivity, measured as forearm glucose uptake, during a 30-min baseline period and hyperinsulinaemic-euglycaemic conditions

    Time frame: During the steady-state phase of the insulin clamp (i.e. last 30 min)

Secondary outcomes

  1. Percent Change in Muscle Protein Synthesis

    Percent change in muscle protein synthesis, measured as using the arteriovenous-venous method, via stable isotope tracer infusion

    Time frame: In the fasted state (30 min before starting insulin clamp), and during the steady-state phase of the insulin clamp (i.e. last 30 min)

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Results

Posted Jun 21, 2024

Participant flow

Participant flow — Overall Study
MilestoneAcipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During Immobilization
Started111412
Completed10119
Not completed133
Withdrew: Lost to follow-up121
Withdrew: Cannulation issues012

Outcome measures

PrimaryPercent Change in Forearm Glucose Uptake

Insulin sensitivity, measured as forearm glucose uptake, during a 30-min baseline period and hyperinsulinaemic-euglycaemic conditions

Time frame:
During the steady-state phase of the insulin clamp (i.e. last 30 min)
Reported as:
Mean · Percent change in clamp FGU with immob
Percent Change in Forearm Glucose Uptake
Percent change in clamp FGU with immobAcipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During Immobilization
Percent Change in Forearm Glucose Uptake-73 ± 15127 ± 134-95 ± 113
SecondaryPercent Change in Muscle Protein Synthesis

Percent change in muscle protein synthesis, measured as using the arteriovenous-venous method, via stable isotope tracer infusion

Time frame:
In the fasted state (30 min before starting insulin clamp), and during the steady-state phase of the insulin clamp (i.e. last 30 min)
Reported as:
Mean · Percent change in clamp phenylalanine Rd
Percent Change in Muscle Protein Synthesis
Percent change in clamp phenylalanine RdAcipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During Immobilization
Percent Change in Muscle Protein Synthesis-93 ± 40-124 ± 29-251 ± 145

Adverse events

Collected over Adverse event data were collected throughout the entire study, up to 48h following the final study visit. Non-serious events are listed at a 0% frequency threshold.

Adverse event summary by group
GroupDeathsSeriousOther
Acipimox Ingestion During Immobilization0/10 (0%)0/10 (0%)1/10 (10%)
B-agonist During Immobilization0/11 (0%)0/11 (0%)4/11 (36.4%)
Placebo Ingestion During Immobilization0/9 (0%)0/9 (0%)1/9 (11.1%)
Most frequent other events
Most frequent other events
EventAcipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During Immobilization
Nausea and vomitingProduct Issues1/104/111/9

Baseline characteristics

All completed participants were included in the analysis population

Age, Categorical
Age, Categorical(Participants)Acipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During ImmobilizationTotal
<=18 years0000
Between 18 and 65 years1011930
>=65 years0000
Age, Continuous
Age, Continuous(years)Acipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During ImmobilizationTotal
Mean21 ± 323 ± 423 ± 722 ± 5
Sex: Female, Male
Sex: Female, Male(Participants)Acipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During ImmobilizationTotal
Female55414
Male56516
Race and Ethnicity Not Collected
Race and Ethnicity Not Collected(Participants)Acipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During ImmobilizationTotal
Count of participants———0
Region of Enrollment
Region of Enrollment(participants)Acipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During ImmobilizationTotal
United Kingdom1011930
Body mass index
Body mass index(kg^m2)Acipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During ImmobilizationTotal
Mean22.9 ± 2.724.1 ± 3.523.9 ± 2.123.7 ± 2.8
Fat mass percentage
Fat mass percentage(percentage of body fat)Acipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During ImmobilizationTotal
Mean20.9 ± 9.424.4 ± 12.125.1 ± 9.223.5 ± 10.2
Systolic blood pressure
Systolic blood pressure(mmHg)Acipimox Ingestion During ImmobilizationB-agonist During ImmobilizationPlacebo Ingestion During ImmobilizationTotal
Mean117 ± 11111 ± 9114 ± 44114 ± 10

1 further baseline measures are reported on the registry.

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Study locations

1 site
  • Royal Exeter & Devon NHS Foundation Trust
    Exeter, Devon, United Kingdom
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References and documents

Study documents

  • Protocol and statistical analysis plan · Mar 9, 2021

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jun 21, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT03866512
Lead sponsor
University of Exeter
Collaborators
Wellcome Trust
Responsible party
Sponsor
First posted
Mar 7, 2019
Start date
May 10, 2019
Primary completion
Jul 1, 2021
Completion
Jul 1, 2021
Results posted
Jun 21, 2024
Last update
Jun 21, 2024

Study contacts

Marlou Dirks, PhD
principal investigator · University of Exeter

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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