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Completed

NCT Number: NCT06764277

Mechanisms and Phenotypes of Hypertension in Patients in Chronic Hemodialysis

The goal of this study is to evaluate interdialytic blood pressure changes of the patients in chronic hemodialysis.

The main question to be answered is: What is the relative importance of weight gain, the renin angiotensin system, the sympathetic nervous system and inflammatory immune reactivity in the interdialytic hypertension of patients in chronic hemodialysis, The participants will have hemodynamic evaluation (cardiac output and peripheral vascular resistance) at the end of dialysis, ambulatory monitoring of blood pressure in the interdialytic period. Serum samples will be collected at the end of dialysis and before the start of the next dialysis, 2-3 days later.

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Key information

Conditions

Arterial Hypertension Cardiovascular Diseases Hemodialysis Hypertension Inflammation Pathologic Processes Pathological Conditions, Signs and Symptoms Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán"

Mexico City, 14080, Mexico

About this study

This is a prospective observational study that will study stable patients in the chronic hemodialysis program of the Instituto Nacional de Ciencias Médicas y Nutrición "Salvador Zubirán" (INCMNSZ) patients. There will be no modifications in the dialysis prescriptions or treatments and the patients with inclusion criteria will be studied after and before their usual hemodialysis sesion.

  • Weight changes will be studied after dialysis and before the next dialysis session (2-3 days later)
  • Serum samples will be obtained at the end of dialysis and before the next session (2-3 days later).
  • ultrasound estimation of cardiac output and peripheral vascular rersistance will be done after dialysis
  • Ambulatory blood pressure (ABP) monitoring will be done in the interdialytic period (24-40 hours) between the end of dialysis and the next dialysis session.
  • If possible there will be a predialysis study of bioimpedance.
  • Associations of interdialytic weight gain, serum angiotensin II, copeptin levels (surrogate of arginine vasopressin) and norepinephrine levels with ABP, systolic and diastolic blood pressure before and after dialysis will be explored.
  • Phenotypes of blood pressure (sustained hypertension, nocturnal and diurnal hypertension, dippers, non-dippers, extreme dippers and reverse dippers) determined by ambulatory monitoring will be studied in relation of levels of angiotensin II, inflammatory markers, copeptin and norepinephrine levels.

All serum levels will be determined by commercial ELISA kits

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Patients with more than 3 months in the chronic hemodialysis program in the INCMNSZ and assumed to remained in the program for longer than 3 months
  • Stable patients with no change in medication 1 month prior to the study
  • Unchanged drug therapy and dialysis prescription for >1 month prior to the studies
  • Informed consent to participate in the study

Exclusion criteria

  • Patients unable to give informed consent or withdrawal of informed consent to the study
  • Patients with active infection
  • Patients with prosthesis or pacemakers
  • Patients with immunosuppressive treatment of more than 10mg Prednisone daily
  • Prior nephrectomy
  • incomplete collection of data specified in the study protocol

Treatment and study plan

There will be no intervention

Other

There will be no intervention. This is an observational studies and 3 groups will be organized depending on the level of ABP in the interdialytic period

Primary outcomes

  1. Cardiac Output

    Time frame: Each participant was studied once 1-3 hours after dialysis ended

    Cardiac output (systolic volume x heart rate) was determined by 2 experienced observers using a Siemens Acuson P500 ultrasound equipment with a phased array transducer . Systolic volume was calculated with the velocity time integral of the flow of the left ventricle outflow tract of the aortic area.

  2. Interdialytic Weight Change

    Time frame: Interdialytic weight change was studied once, by the difference between the weight at the end of dialysis and the weight 2-3 days later, before the next dialysis.

    The weight was determined in 2 ocassions: first, immediately after dialysis and second, 2-3 days later, before the next dialysis. The weight change in this interval is expressed as percentage change of the second measure in relation to the first measure.

  3. Systemic Vascular Resistance

    Time frame: Systemic vascular resistance was determined once in the participants 1-3 hours after dialysis

    Systemic vascular resistance was calculated using MediCalcR using the mean arterial pressure (MAP), the central venous pressure (CVP) anf the cardiac output (CO) and the equation: SVR=[(MAP-CVP)x79.92]/CO. Cardiac output (CO= systolic volume x heart rate) and central venous pressure were determined by 2 experienced observers using a Siemens Acuson P500 ultrasound equipment with a phased array transducer. Systolic volume was calculated with the velocity time integral of the flow of the left ventricle outflow tract of the aortic area.

Secondary outcomes

  1. Angiotensin II Serum Levels

    Time frame: Each participant was studied once. Serum samples taken before dialysis

    Angiotensin serum levels (pg/ml) were determined once at the end of the interdialytic period, before dialysis, using ELISA (my BioSource Cat.# MBS703599)

  2. Monocyte+Neutrophiles/Lymphocyte Ratio (MNLR)

    Time frame: Each participant was studied once. Blood samples taken before dialysis (following the end of the interdialytic period).

    Monocyte+Neutrophile/lymphocyte ratio obtained from peripheral blood counts in samples taken before dialysis (following the end of the interdialytic period).

  3. Serum Norepinephrine Levels

    Time frame: Each participant was studied once. Serum samples taken before dialysis

    Interdialytic serum norepinephrine levels determined in blood samples obtained before dialysis (end of interdialytic period) using ELISA (ABCAM, Cat. # AB287789);

  4. Serum Copeptin Levels

    Time frame: Each participant was studied once. Serum samples taken before dialysis

    The copeptin levels (surrogate for arginine vasopressin) were measured before dialyisis (end of the interdialytic period) using ELISA (Bio-techne/NovusBiological, Cat, # NBP2-69822)

  5. Hypertension Phenotypes

    Time frame: Each participant was studied once. Ambulatory blood pressure was monitored or 24-44 hours during the interdialytic perdiod starting 1-3 hours after dialysis

    Interdialytic ambulatory blood pressure determined during 24-44 hours using Space Labs Health Care, model 90217A and Contec ABPM50 equipment. Determinations every 30 minutes during daytime and every hour during the night. We are here reporting the phenotypes in the total number of participants (n=32) instead that in each group (groups A n=15, B n=7 and C n=10) because our main interest was to determine the incidence of each phenotyte in stable patients treated with chronic dialysis, rather than in each group that, individually, had few patients

Sponsors and collaborators

Lead sponsor

Bernardo Rodríguez Iturbe

Other

Registry information

Important dates

Study start
2023
Primary completion
2024
Study completion
2025
First posted
Jan 8, 2025
Registry last updated
Feb 3, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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