PWV was determined from transcutaneous Doppler flow recordings and the foot-to-foot method triggered by the simultaneous ECG. Two simultaneous Doppler flow tracings were taken at the left common carotid and the right femoral artery in the groin with a linear array probe. The time delay (t) was measured between R wave of the ECG and the base of the flow waves recorded at these points, and averaged over 10 beats. The distance (D) traveled by the pulse wave was measured over body surface as the distance from the suprasternal notch to the carotid artery. PWV was calculated as PWV=D/t.

Cutaneous blood flow was continuously recorded by a laser Doppler flowmeter. The laser Doppler flow probe was applied on the volar part of the right forearm with a plastic holder 10 cm proximal to the wrist. All measurements were made with a pressure cuff on the arm and inflated 20 mmHg above systolic BP and maintained for 2 min then rapidly deflated. All measurements were made in a quiet room with a patient in the supine position. The maximal reactive hyperemia was measured after cuff deflation, which allows measurement of the right forearm postischemic skin reactive hyperemia (SRH).

Cutaneous blood flow was continuously recorded by a laser Doppler flowmeter. The laser Doppler flow probe was applied on the volar part of the right forearm with a plastic holder 10 cm proximal to the wrist. All measurements were made with a pressure cuff on the arm and inflated 20 mmHg above systolic BP and maintained for 2 min then rapidly deflated. All measurements were made in a quiet room with a patient in the supine position. The maximal reactive hyperemia was measured after cuff deflation, which allows measurement of the right forearm postischemic skin reactive hyperemia (SRH).

Endothelial function will be assessed using high-resolution duplex ultrasound with wall tracking to measure FMD of the brachial artery during reactive hyperemia. FMD of the brachial artery in response to reactive hyperemia in the distal forearm (and glyceryl trinitrate as a non-endothelium dependent control) will be measured from B-mode ultrasound images using a standard 7 MHz linear array transducer and HDI 5000 system with edge detection.

Endothelial function will be assessed using high-resolution duplex ultrasound with wall tracking to measure FMD of the brachial artery during reactive hyperemia. FMD of the brachial artery in response to reactive hyperemia in the distal forearm (and glyceryl trinitrate as a non-endothelium dependent control) will be measured from B-mode ultrasound images using a standard 7 MHz linear array transducer and HDI 5000 system with edge detection.

For carotid distensibility, the left and right bulbs and common carotid arteries are measured using tissue Doppler imaging with the linear array probe. Absolute diameter and diameter changes over the cardiac cycles will be recorded. Distensibility of each bulb will be calculated for three consecutive heart cycles and averaged and corrected for blood pressure.

For carotid distensibility, the left and right bulbs and common carotid arteries are measured using tissue Doppler imaging with the linear array probe. Absolute diameter and diameter changes over the cardiac cycles will be recorded. Distensibility of each bulb will be calculated for three consecutive heart cycles and averaged and corrected for blood pressure.

For carotid distensibility, the left and right bulbs and common carotid arteries are measured using tissue Doppler imaging with the linear array probe. Absolute diameter and diameter changes over the cardiac cycles will be recorded. Distensibility of each bulb will be calculated for three consecutive heart cycles and averaged and corrected for blood pressure.

For carotid distensibility, the left and right bulbs and common carotid arteries are measured using tissue Doppler imaging with the linear array probe. Absolute diameter and diameter changes over the cardiac cycles will be recorded. Distensibility of each bulb will be calculated for three consecutive heart cycles and averaged and corrected for blood pressure.

The calculation of spontaneous baroflex sensitivity was obtained by the sequence method. Baroflex sequences are defined by at least three consecutive beats in which the systolic blood pressure and the RR interval of the following beat either both increased or decreased. The slope of each individual sequence is computed and the mean slope is determined as the average of all slopes within a given period of time and taken as the gain of the cardiac baroflex (BRSs).

The calculation of spontaneous baroflex sensitivity was obtained by the sequence method. Baroflex sequences are defined by at least three consecutive beats in which the systolic blood pressure and the RR interval of the following beat either both increased or decreased. The slope of each individual sequence is computed and the mean slope is determined as the average of all slopes within a given period of time and taken as the gain of the cardiac baroflex (BRSs).

Central Blood Pressure was measured via applanation tonometry recordings of the common carotid artery and from brachial oscillometric recordings. The Simultaneously obtained carotid artery pressure and standard brachial artery blood pressure are computed to obtain the central systolic pressure.