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Blood Flow and Vascular Function in Cystic Fibrosis (CF-FLOW)

23 avril 2020 mis à jour par: Ryan Harris, Augusta University

Role of Blood Flow and Vascular Function on Exercise Capacity in Cystic Fibrosis

Cystic fibrosis (CF) has many health consequences. A reduction in the ability to perform exercise in patients with CF is related to greater death rates, steeper decline in lung function, and more frequent lung infections. However, the physiological mechanisms for this reduced exercise capacity are unknown. The investigators laboratory recently published the first evidence of systemic vascular dysfunction in patients with CF. Therefore, it is reasonable to suspect that the blood vessels are involved with exercise intolerance in CF. This study will look at how 1) blood flow and 2) artery function contribute to exercise capacity in CF.

Aperçu de l'étude

Description détaillée

The most disturbing aspect of Cystic Fibrosis (CF) is the associated premature death. Low exercise capacity predicts death in patients with CF and is also associated with a steeper decline in lung function and more lung infections. A critical barrier to improving exercise tolerance in patients with CF is the investigators lack of knowledge regarding the different physiological mechanisms which contribute to their lower exercise capacity. We have compelling data to indicate that the blood vessels may contribute to the low exercise capacity in CF. The impact of this proof of concept investigation will test Phosphodiesterase Type 5 inhibitors (PDE5) inhibitors as a potential therapy in CF and will explore blood flow and endothelial function as potential mechanisms which contribute to exercise intolerance in CF. Improvements in exercise capacity will not only contribute to a better quality of live for patients with CF, it will also increase longevity in these patients.

Type d'étude

Interventionnel

Inscription (Réel)

19

Phase

  • Phase 2

Contacts et emplacements

Cette section fournit les coordonnées de ceux qui mènent l'étude et des informations sur le lieu où cette étude est menée.

Lieux d'étude

    • Georgia
      • Augusta, Georgia, États-Unis, 30912
        • Augusta University

Critères de participation

Les chercheurs recherchent des personnes qui correspondent à une certaine description, appelée critères d'éligibilité. Certains exemples de ces critères sont l'état de santé général d'une personne ou des traitements antérieurs.

Critère d'éligibilité

Âges éligibles pour étudier

18 ans et plus (Adulte, Adulte plus âgé)

Accepte les volontaires sains

Oui

Sexes éligibles pour l'étude

Tout

La description

Inclusion Criteria.

  • Diagnosis of CF and healthy controls
  • Men and women (greater than 18 yrs. old)
  • Resting oxygen saturation (room air) greater than 90%
  • Forced expiratory volume (FEV1) percent predicted greater than 30%
  • Patients with or without CF related diabetes
  • Traditional CF-treatment medications
  • Ability to perform reliable/reproducible pulmonary function tests (PFT)
  • Clinically stable for 2 weeks (no exacerbations or need for antibiotic treatment within 2 weeks of testing or major change in medical status)

Exclusion Criteria.

  • Children less than 17 years old
  • Body mass less than 20 kg
  • A diagnosis of pulmonary arterial hypertension (PAH)
  • FEV1 less than 30% of predicted
  • Resting oxygen saturation (SpO2) less than 90%
  • Self-reported to be a smoker
  • Current use of any vaso-active medications
  • History of migraine headaches
  • Pregnant or nursing at the time of the investigation
  • A clinical diagnosis of cardiovascular disease, hypertension, or CF related diabetes

Plan d'étude

Cette section fournit des détails sur le plan d'étude, y compris la façon dont l'étude est conçue et ce que l'étude mesure.

Comment l'étude est-elle conçue ?

Détails de conception

  • Objectif principal: Traitement
  • Répartition: Randomisé
  • Modèle interventionnel: Affectation croisée
  • Masquage: Double

Armes et Interventions

Groupe de participants / Bras
Intervention / Traitement
Expérimental: Acute Study: Sildenafil first, then Placebo
In randomized order, on two separate days, endothelial function and exercise capacity will be determined 1 hour following a single dose of sildenafil (50 mg) or placebo.
Vascular function will be assessed 1 hour following oral ingestion of sildenafil (50 mg)
Autres noms:
  • Viagra
  • Revatio
Sugar pill designed to mimic the sildenafil treatment
Expérimental: Acute Study: Placebo first, then Sildenafil
In randomized order, on two separate days, endothelial function and exercise capacity will be determined 1 hour following a single dose of sildenafil (50 mg) or placebo.
Vascular function will be assessed 1 hour following oral ingestion of sildenafil (50 mg)
Autres noms:
  • Viagra
  • Revatio
Sugar pill designed to mimic the sildenafil treatment
Expérimental: Sub-Chronic Study Sildenafil
Following the acute study, patients will be instructed to take 20 mg of sildenafil, three times a day, for 4 weeks. Endothelial function will be determined within 48 hours following the last dose.
Vascular function will be assessed 4 weeks following 20 mg three times per day (TID) of sildenafil for four weeks
Autres noms:
  • Viagra
  • Revatio

Que mesure l'étude ?

Principaux critères de jugement

Mesure des résultats
Description de la mesure
Délai
Acute Study: Percentage Flow-Mediated Dilation (FMD)
Délai: pre-treatment Baseline and 1 hour post-treatment
FMD determined one hour after ingestion of 50 mg Sildenafil or placebo
pre-treatment Baseline and 1 hour post-treatment
Baseline Diameter
Délai: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Brachial Artery Diameter during FMD (pre-occlusion or "baseline")
pre-treatment Baseline and following 4 weeks sub-chronic treatment
Peak Diameter
Délai: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Peak Brachial Artery Diameter during FMD (post-occlusion)
pre-treatment Baseline and following 4 weeks sub-chronic treatment
Absolute Change in Diameter
Délai: pre-treatment Baseline and following 4 weeks sub-chronic treatment
Absolute change in brachial artery diameter taken from the FMD assessment
pre-treatment Baseline and following 4 weeks sub-chronic treatment
FEV1 (% Predicted)
Délai: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
Forced Expiratory Volume in the first second expressed as a percent predicted.
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
VO2 Peak (Absolute)
Délai: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
absolute (L/min) peak oxygen consumption during maximal exercise test
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
VO2 Peak (Relative)
Délai: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
relative (mL/kg/min) peak oxygen consumption during maximal exercise test
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
VO2 Peak (Percent Predicted)
Délai: pre-treatment Baseline and 1 hour post-treatment, and 4 weeks sub-chronic treatment
Maximal Oxygen consumption expressed as percent predicted taken from maximal exercise test.
pre-treatment Baseline and 1 hour post-treatment, and 4 weeks sub-chronic treatment
VE Peak
Délai: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
peak ventilation (L/min) during maximal exercise test
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
RER Peak
Délai: pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment
peak respiratory exchange ratio during maximal exercise test
pre-treatment Baseline, 1 hour post-treatment, and following 4 weeks sub-chronic treatment

Collaborateurs et enquêteurs

C'est ici que vous trouverez les personnes et les organisations impliquées dans cette étude.

Parrainer

Les enquêteurs

  • Chercheur principal: Ryan Harris, Ph.D., Augusta University

Publications et liens utiles

La personne responsable de la saisie des informations sur l'étude fournit volontairement ces publications. Il peut s'agir de tout ce qui concerne l'étude.

Dates d'enregistrement des études

Ces dates suivent la progression des dossiers d'étude et des soumissions de résultats sommaires à ClinicalTrials.gov. Les dossiers d'étude et les résultats rapportés sont examinés par la Bibliothèque nationale de médecine (NLM) pour s'assurer qu'ils répondent à des normes de contrôle de qualité spécifiques avant d'être publiés sur le site Web public.

Dates principales de l'étude

Début de l'étude (Réel)

1 avril 2014

Achèvement primaire (Réel)

1 juillet 2018

Achèvement de l'étude (Réel)

1 juillet 2018

Dates d'inscription aux études

Première soumission

4 février 2014

Première soumission répondant aux critères de contrôle qualité

6 février 2014

Première publication (Estimation)

7 février 2014

Mises à jour des dossiers d'étude

Dernière mise à jour publiée (Réel)

24 avril 2020

Dernière mise à jour soumise répondant aux critères de contrôle qualité

23 avril 2020

Dernière vérification

1 avril 2020

Plus d'information

Ces informations ont été extraites directement du site Web clinicaltrials.gov sans aucune modification. Si vous avez des demandes de modification, de suppression ou de mise à jour des détails de votre étude, veuillez contacter register@clinicaltrials.gov. Dès qu'un changement est mis en œuvre sur clinicaltrials.gov, il sera également mis à jour automatiquement sur notre site Web .

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