Potential Biological and Physiological Determinants for Exercice in Patients With Polycythemia Vera

NCT07341048 | Not Yet Recruiting

• 2 other identifiers: 69HCL25_03642025-A01032-47
• Study Type: interventional
• Target: 54
• Locations: 1 country
• Sites: 1

Brief Summary

Polycythemia vera (PV) is a rare haematological disorder characterized by an excessive production of red blood cells, associated with the somatic JAK2 V617F mutation. Clinical manifestations are varied and often include exercise intolerance but the underlying mechanisms remain poorly understood. Physical activity is recommended in the management of chronic diseases, but it must be tailored to the physiological profile of the patient. A cardiopulmonary exercise test (CPET) is essential to ensure safety, detect possible contraindications, and assess maximal oxygen uptake (VO₂max), a key indicator of aerobic performance. This prospective, experimental, non-randomized study will include patients with PV followed at Lyon Sud University Hospital and for which a CPET is scheduled in their routine clinical follow-up. The primary objective is to compare VO₂max between two groups of patients: moderate (\<10%) versus marked (≥10%) extent of blood viscosity increase after the completion of the CPET. The main hypothesis is that a significant increase in blood viscosity during exercise (≥10%) is a major limiting factor in oxygen transport and leads to a reduced VO₂max, reflecting impaired exercise tolerance. Secondary analyses will focus on hemorheological parameters, tissue oxygenation, and cardiorespiratory and metabolic responses. The study aims to better understand the biological and physiological determinants of exercise intolerance in this population.

Conditions

Polycythemia; Polycythemia Vera (PV)

Keywords

Blood viscosity; polycythemia

Outcome Measures

Primary Outcomes (1)

• Blood viscosity (Centipoise) at 6 shear rates.

  Blood viscosity will be measured using a cone-plate viscometer (Brookfield, model LVDVII+ PRO, cone CPE 40) on native hematocrit blood, at 7 different shear rates: 2.25, 4.5, 11.5, 22.5, 45, 90, and 225 s-¹, using an ascending ramp shear protocol.

  Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET

Secondary Outcomes (3)

• Rheological properties of blood: deformability and aggregation of erythrocytes

  Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET.

• Viscoelasticity of blood

  Measurements will be performed at baseline (pre-test), at 3 minutes post-CPET, and at 60 minutes post-CPET

• Tissue and haemoglobin oxygenation with near-infrared spectroscopy (NIRS)

  Measurement will be performed during the CPET.

Study Arms (1)

Polycythemia vera

EXPERIMENTAL

Patients diagnosed with polycythemia vera, with confirmed presence of the JAK2 V617F mutation, who wish to resume regular daily physical activity and have been prescribed an exercise test for this purpose as part of their follow-up at Lyon Sud Hospital

Biological: Research samples blood viscosity and viscoelasticity:

Interventions

Research samples blood viscosity and viscoelasticity: BIOLOGICAL

Research samples: Blood rheology: hematocrit, blood viscosity, deformability and erythrocyte aggregation, viscoelasticity

Also known as: the level of tissue oxygenation and hemoglobin oxygenation that will be measured by near-infrared spectroscopy (NIRS).

Polycythemia vera

Eligibility Criteria

• Age: 18 Years - 70 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patient aged at least 18 years and under 70.
• Patient followed for a diagnosis of Polycytemia vera (confirmed JAK2 V617F mutation) and who were prescribed a CPET because of their wish to resume regular physical activity.
• Patient affiliated with or benefiting from a social security scheme.

You may not qualify if:

• Any known history of heart disease or chronic respiratory illness likely to affect VO₂max independently of Polycytemia vera (e.g., asthma), according to the investigator's judgment.
• Any known history of major thromboembolic complication, according to the investigator's judgment.
• Body mass index (BMI) greater than 35, according to the investigator's judgment.
• Participation in another interventional research protocol that may interfere with the present study, according to the investigator's judgment.
• Adult subject under legal protection measures (guardianship, curatorship).
• Subject currently receiving psychiatric care.
• Subject deprived of liberty by judicial or administrative decision.

Sponsors & Collaborators

• Hospices Civils de Lyon: lead

Study Sites (1)

Department of Sports Medicine and Physical Activity. Pulmonary Function Testing. Croix Rousse Hospital.

Lyon, 69001, France

Location

MeSH Terms

Conditions

Polycythemia; Polycythemia Vera

Interventions

Spectroscopy, Near-Infrared

Condition Hierarchy (Ancestors)

Hematologic Diseases; Hemic and Lymphatic Diseases; Bone Marrow Neoplasms; Hematologic Neoplasms; Neoplasms by Site; Neoplasms; Bone Marrow Diseases; Myeloproliferative Disorders

Intervention Hierarchy (Ancestors)

Diagnostic Imaging; Diagnostic Techniques and Procedures; Diagnosis; Spectrum Analysis; Chemistry Techniques, Analytical; Investigative Techniques

Central Study Contacts

Emeric Stauffer, Dr

CONTACT

+33 (0)4 72 07 18 62; emeric.stauffer@chu-lyon.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Prospective, experimental, single-center, non-randomized study.

Study Record Dates

• First Submitted: January 5, 2026
• First Posted: January 14, 2026
• Study Start: January 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027
• Last Updated: January 15, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

FR (1)