Endothelial Dysfunction in Autosomal Dominant Polycystic Kidney Disease

Following recruitment we will record the following baseline demographics; age, gender, smoking status, body mass index, medical history.

Participants will undergo a noninvasive vascular assessment, venepuncture and will provide a urine sample.This will be done during a single visit to the CRF.

Noninvasive vascular assessment will consist of:

1. Peripheral Arterial Tonometry This will be measured using the EndoPAT system (Itamar Medical)

Endothelial shear stress flow stimulus will be provided by inflation of a blood pressure cuff around the upper non-dominant arm to suprasystolic pressure (but <300mmHg) for 5 minutes. Following release of the cuff the resulting digital microcirculation vasodilatory response to ischaemic hyperaemia, quantified as the pulse wave amplitude, will be monitored over 5 minutes. The peak pulse wave amplitude measured at 90-150s post cuff deflation relative to baseline will be indexed to the changes in the opposite arm to give the reactive hyperaemia index. This measure of endothelial function constitutes the outcome measure. 2. Blood Pressure Assessment Brachial artery blood pressure will be measured in the left arm in the supine position using an automated device (Dinamap) and in accordance with the clinical research facility SOP. 3. Blood samples and urine samples