Does ethnicity affect blood pressure regulation?

INTERVENTION: Participants enter the study in a randomised fashion after an initial recruitment process. The order of the subject’s test entry before the very first test will be randomised by using a random sequence generator where the test entry order will be determined for each subject. All participants will complete an oral glucose tolerance test (OGTT) using a glucose drink containing 75 g of glucose dissolved in 300 ml water. This will be ingested over a 4 minute period. Changes in blood glucose levels will be monitored before the OGTT and 120 minutes following this. A normal OGTT will be classed as a 2 hour blood glucose value less than 140 mg/dL (less than 7.8 mmol/L). An impaired OGTT will be classed as a 2 hour glucose value between 140 and 199 mg/dL (7.8–11.1 mmol/L). Every test with an impaired OGTT will not enter further analysis. CONDITION: Blood pressure regulation ; Circulatory System ; Blood pressure regulation PRIMARY OUTCOME: ; 1. The following haemodynamic parameters will be assessed continuously, starting with a 30 minute baseline and continued after the oral glucose tolerance test (OGTT) for another 120 minutes using a Task Force Monitor:; 1.1. Blood pressure (systolic and diastolic); 1.2. Heart rate; 1.3. Stroke volume; 1.4. Heather index (marker for myocardial contractility); 2. The following blood parameters will be assessed at the end of the 30 minute baseline and after the OGTT every 30 minutes until the end of the OGTT (120 minutes post‐drink):; 2.1. Plasma glucose, assessed using hexokinase Glucose HK Gen 3; 2.2. Plasma insulin, assessed using ELISA; SECONDARY OUTCOME: ; 1. The following haemodynamic parameters will be assessed continuouslty during the 30 minute baseline and over the 120 minutes following the OGTT:; 1.1. Cardiac output, assessed using impedance cardiography; 1.2. Total peripheral resistance, assessed by dividing mean blood pressure by cardiac output; 1.3. Index of contractility, assessed using impedance cardiography; 1.4. Thoracic fluid contact, assessed using impedance cardiography; 1.5. Thoracic impedance, assessed using impedance cardiography; 1.6. Spectral analysis parameters, assessed using power spectral analysis; 1.7. Baroreflex sensitivity, assessed using the sequence technique; 2. Central arterial waveform analysis of the following parameters, performed using applanation tonometry prior to each blood sample:; 2.1. Central systolic blood pressure; 2.2. Central diastolic blood pressure; 2.3. Mean blood pressure; 2.4. Augmentation index (AIx75); 2.5. Ejection duration index; 2.6. Sub‐endocardial viability ratio; 3. The following anthropometric parameters, assessed using a calibrated scale and a statiometer prior to the OGTT:; 3.1. Weight; 3.2. Height; 3.3. Sitting heigh; 3.4. Leg length; 3.5. Waist circumference; 3.6. Hip circumference; 4. The following body composition parameters, assessed using body impedance measurements and the deuterium dilution technique prior to the OGTT:; 4.1. Total body fat in kg and %; 4.2. Trunk (abdominal) fat in %; 4.3. Fat free mass in kg and %; 4.4. Skeletal muscle mass in kg and %; INCLUSION CRITERIA: 1. Healthy 2. Non‐smoking 3. EITHER of South Asian ancestry (India, Pakistan, Bangladesh, Sri Lanka or Nepal) OR Caucasian 4. BMI between 18.5 and 24.9 kg/m² 5. Aged 20‐30 years 6. Male