Arterial Hypertension, Hemodialysis
Conditions
Keywords
hemodialysis, hypertension, inflammation, renin angiotensin system, sympathetic nervous system, interdialysis, Interdialytic weight gain
Brief summary
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.
Detailed description
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
Interventions
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
Sponsors
Bernardo Rodríguez Iturbe
Study design
Observational model
COHORT
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Cardiac Output | 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. |
| Interdialytic Weight Change | 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. |
| Systemic Vascular Resistance | 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
| Measure | Time frame | Description |
|---|---|---|
| Angiotensin II Serum Levels | 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) |
| Monocyte+Neutrophiles/Lymphocyte Ratio (MNLR) | 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). |
| Serum Norepinephrine Levels | 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); |
| Serum Copeptin Levels | 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) |
| Hypertension Phenotypes | 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 |
Countries
Mexico
Contacts
PRINCIPAL_INVESTIGATORBernardo RODRIGUEZITURBE, MD, PhD
Department of Nephrology, Instituto Nacional de Ciencias Medicas y Nutrición "Salvador Zubirán"
Baseline characteristics
| Characteristic | — |
|---|---|
| Age, Continuous | 39 years |
| Cardiac output | 4.25 L/min STANDARD_DEVIATION 0.34 |
| Hypertension Phenotypes Dippers | 3 Participants |
| Hypertension Phenotypes Extreme Dippers | 0 Participants |
| Hypertension Phenotypes Non-dippers | 4 Participants |
| Hypertension Phenotypes Reverse-dippers | 5 Participants |
| Race and Ethnicity Not Collected | 0 Participants |
| Region of Enrollment Mexico | 7 participants |
| Sex: Female, Male Female | 5 Participants |
| Sex: Female, Male Male | 5 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk |
|---|---|---|---|
| deaths Total, all-cause mortality | 0 / 15 | 0 / 7 | 0 / 10 |
| other Total, other adverse events | 0 / 15 | 0 / 7 | 0 / 10 |
| serious Total, serious adverse events | 0 / 15 | 0 / 7 | 0 / 10 |
Outcome results
None listed