Muscle Sympathetic Nerve Activity and Cardiovascular Organ Damage in Patients with Chronic Kidney Disease and Hypertension

Sympathetic hyperactivity is often present in chronic kidney disease (CKD)
patients. Apart from the so called traditional risk factors, also risk factors
more or less specific to CKD contribute in the pathogenesis of these problems.
There is evidence that also independent of its effect on blood pressure,
sympathetic hyperactivity is important in the pathogenesis of cardiovascular
organ damage. Previously, we have shown that angiotensin converting enzyme
inhibitors (ACEi) and angiotensin II receptor blockers (ARB) reduce but not
normalize this sympathetic hyperactivity. We re-analysed the cohort of patients
who were investigated in the past and subsequently treated according to present
guidelines. Our results show that, despite of treatment, the unfavourable
relation between sympathetic hyperactivity and clinical outcome still exists.
In present project, we propose to investigate the relation between sympathetic
activity and signs of cardiovascular (CV) organ damage in the patients who had
had MSNA measurement previously.

The central hypothesis of this project is that sympathetic hyperactivity is of
critical importance in the pathogenesis of CV organ damage in CKD patients.

Our primary objective is to investigate if the previously found MSNA is related
to the presence and severity of CV organ damage quantified as left ventricular
mass, independent of other CV risk factors.

We hypothesize that despite of treatment previously assessed MSNA is still
predictive for the presence of CV organ damage.

Secondary objective is the relation of MSNA to the presence of other signs of
CV damage such as reduced left ventricular function and reduced GFR.

This is a follow-up study. We collect prospectively data on presence of CV
organ damage, in particular LV mass and kidney function and relate these
variables to MSNA data obtained in the past and with retrospectively collected
data on various treatment aspects. The participants will be invited for a
Magnetic Resonance Imaging (MRI) without contrast.


Materials:

Blood pressure measurement: Systolic and diastolic blood pressure will be
measured at the arm with an automated and calibrated blood pressure device with
the subject in supine position.

MRI-scan without contrast: Left ventricular mass and ejection fraction will be
assessed using MRI without contrast.

Renal function: Plasma Renin Activity, GFR en serum creatinine will be measured
as routin laboratory controls.

There are no risks associated with participation in this study. The magnetic
field produced by MRI without contrast agent is harmless for the participants.