Observational Single-center Study of the Relationship Between Arterial Hypertension and Hypervolemia Defined by Self-measurement of Impedancemetry in Kidney Transplant Patients With Transplantation Less Than 6 Months Old

Monocentric Observational Study to Determine the Relationship Between Arterial Hypertension and Hypervolaemia, Defined by Self-measurement of Impedancemetry in Kidney Transplant Recipients Under 6 Months Old

The working hypothesis is that hypertension during the first post-transplant trimester is partly explained by the patient's hypervolemia. The main objective of the single-center observational study "HTA ô Connect" is to study the relationship between hypertension and extracellular hyperhydration, thanks to repeated self-measurements of blood pressure and impedancemetry between the 30th and the 90th day post-transplant, in 150 incident kidney transplant patients from our department, the ITUN (Institute of Urology-Nephrology Transplantation).

The study population involves 150 incident kidney transplant patients, presenting to the Nantes University Hospital Transplant Institute for 1 month (D30), and presenting with hypertension ≥ 140/90mmHg and not treated with a diuretic.

Data collected at the patients' homes will be used to establish a relationship between blood pressure and extracellular water volume. The data collected will not be used to follow up patients who participated in the study in this first stage of exploration.

Evaluation parameters

1. Blood pressure :

   • At inclusion and at the end of the study (in consultation at D30 and D90, respectively), blood pressure will be measured 3 times after a few minutes of rest in a sitting position Hypertension in consultation will be defined by values > 140/90 mmHg.
   • Between D30 and D90, blood pressure will be measured by self-measurement using DM-certified devices, 3 times in the morning at breakfast and in the evening before bedtime, in a sitting position after a few minutes of rest. The operation will be repeated 3 days a week (Monday to Wednesday) between the 30th and the 90th day post-transplant. Self-measurement hypertension will be defined by values > 135/85 mmHg. Self-measurement blood pressure data will be directly transmitted to the "INTEGRALIS" specialty medical record of transplant patients at the ITUN via the epatient application (https://www.idbc.fr/e-patient/).

2. Weight :

   • Weight will be measured only once at the inclusion consultation (D30) and at the end of the study (D90).
   • Between D30 and D90 the weight will be measured by self-measurement using DM certified scales. The operation will be repeated once in the morning and once in the evening at the time of blood pressure measurements, 3 days a week (Monday to Wednesday) between the 30th and the 90th day after transplantation. The data from the self-measurement of weight will be directly transmitted to the "INTEGRALIS" medical record of the transplanted patients at the ITUN

3. Impedance measurement :

   • At inclusion and at the end of the study in consultation, respectively at D 30 and D90, impedancemetry will be measured once
   • Between D30 and D90, impedancemetry measurements will be collected at the same time as blood pressure measurements at the patients' homes by self-measurement 3 times in the morning and 3 times in the evening, 3 days a week (from Monday to Wednesday) between the 30th and the 90th day after transplantation. The impedancemetry will be collected with the help of a bluetooth-connected BIODYLIFEZM self-measurement device. The impedancemetry data collected via bluetooth will be directly transmitted to the "INTEGRALIS" specialty medical record of the transplanted patients at the ITUN.

Inclusion Criteria :

• Age ≥ 18 years
• Blood pressure ≥ 140/90mmHg on 3 occasions and according to the recommendations of the French Society of Hypertension (6) at the M1 consultation
• Patients 1 to 6 months post-kidney transplant
• Isolated kidney transplant patient
• BMI between 16 and 34 kg/cm2
• Not opposed to the research

Exclusion Criteria :

• History of non-renal transplantation
• Patients treated with diuretics on the day of inclusion
• Minors, adults under guardianship and protected persons