NCT03866512

Forearm Immobilization, Metabolic Health, and Muscle Loss

Completed NA Results posted Last updated 21 June 2024

What this trial tests

NA trial testing Forearm immobilization in Healthy in 37 participants. Completed in 1 July 2021.

Timeline

10 May 2019

Primary endpoint
1 July 2021

1 July 2021

Quick facts

Lead sponsor	University of Exeter
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	double
Primary purpose	basic science
Enrollment	37
Start date	10 May 2019
Primary completion	1 July 2021
Estimated completion	1 July 2021
Sites	1 location across United Kingdom

Drugs / interventions tested

• Forearm immobilization

Conditions studied

• Healthy — all drugs for Healthy →

Sponsor

University of Exeter

Who can join

Adults 18 to 40, any sex, with Healthy. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Percent Change in Forearm Glucose Uptake Primary · During the steady-state phase of the insulin clamp (i.e. last 30 min)

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

Group	Value	95% CI
Acipimox Ingestion During Immobilization	-73	± 15
B-agonist During Immobilization	127	± 134
Placebo Ingestion During Immobilization	-95	± 113

Percent Change in Muscle Protein Synthesis Secondary · 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)

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

Group	Value	95% CI
Acipimox Ingestion During Immobilization	-93	± 40
B-agonist During Immobilization	-124	± 29
Placebo Ingestion During Immobilization	-251	± 145

Adverse events — posted to ClinicalTrials.gov

Time frame: Adverse event data were collected throughout the entire study, up to 48h following the final study visit. Reporting threshold: 0%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

Acipimox Ingestion During Immobilization

Serious: 0/10 (0%)

Deaths: 0/10

B-agonist During Immobilization

Serious: 0/11 (0%)

Deaths: 0/11

Placebo Ingestion During Immobilization

Serious: 0/9 (0%)

Deaths: 0/9

Other adverse events (1 terms — click to expand)

Reaction	System	Acipimox Ingestion During …	B-agonist During Immobiliz…	Placebo Ingestion During I…
Nausea and vomiting	Product Issues	—	—	—

Data from ClinicalTrials.gov NCT03866512 adverse events section.

Sponsor's own description

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

Publications & conference data

3 peer-reviewed publications reference this trial (live from Europe PMC):

1. The impact of forearm immobilization and acipimox administration on muscle amino acid metabolism and insulin sensitivity in healthy, young volunteers.
   Dirks ML, Jameson TSO, Andrews RC, Dunlop MV, et al · · 2024 · cited 3× · PMID 38231001 · DOI 10.1152/ajpendo.00345.2023
2. Anabolic Effects of Salbutamol Are Lost Upon Immobilization.
   de Jong JCBC, Jameson TSO, Andrews RC, Dunlop MV, et al · · 2025 · cited 1× · PMID 41194654 · DOI 10.1002/jcsm.70114
3. The impact of short-term forearm immobilization and acipimox administration on muscle amino acid metabolism and insulin sensitivity in healthy, young volunteers
   Dirks ML, Jameson TS, Andrews RC, Dunlop MV, et al · · 2023 · DOI 10.1101/2023.10.10.561668