The population retained for the present analysis is a subgroup of the ‘Reference Values for Arterial Stiffness' Collaboration database’, described previously.19 (link) Briefly, this database contains patients and subjects having had measurements of arterial stiffness (PWV or local stiffness measures obtained from ultrasound echotracking) and/or measurements of central pressure, together with a full medical history on record. These were provided by 13 centres distributed across eight European countries (see Appendix for the list of contributing centres). Inclusion criteria also included the availability of a full set of documentation regarding the protocol and measurement techniques used for the assessment of stiffness parameters.
Subjects were excluded from the present analysis if PWV measurement was unavailable, if they had an identified genetic cause of hypertension or secondary hypertension, or had overt CVD. Diabetic patients (either treated or untreated) and patients treated for hypertension or dyslipidaemia were also excluded.
Subject data included vital parameters, BPs, and the recording of any relevant CV risk factor, CVD, or treatment at the time of measurement. Ethnicity was not reported in all data sets; however, subjects other than Caucasians were a small minority. Subjects were further categorized (Figure1 ) according to the presence of additional CV risk factors (gender, dyslipidaemia, or current smoking). Dyslipidaemia was defined as total cholesterol >5.0 mmol/L, HDL cholesterol <1.0 mmol/L for men and <1.2 mmol/L for women, LDL cholesterol >3.0 mmol/L, or triglycerides >1.7 mmol/L. Blood pressure was measured according to the procedures of each participating centre. The values of BP are those obtained during the measurement of PWV. Methods for BP measurement may vary with time and within centres. Automatic oscillometric devices were used in more than 80% of subjects. Mean BP (MBP) was calculated from systolic BP (SBP) and diastolic BP (DBP) as MBP = DBP + 0.4(SBP − DBP). Threshold values for CV risk factors were chosen according to the 2007 ESC/ESH hypertension guidelines.3 (link)![]()
Subjects were excluded from the present analysis if PWV measurement was unavailable, if they had an identified genetic cause of hypertension or secondary hypertension, or had overt CVD. Diabetic patients (either treated or untreated) and patients treated for hypertension or dyslipidaemia were also excluded.
Subject data included vital parameters, BPs, and the recording of any relevant CV risk factor, CVD, or treatment at the time of measurement. Ethnicity was not reported in all data sets; however, subjects other than Caucasians were a small minority. Subjects were further categorized (Figure
Flowchart describing the selection and categorization of subjects from the reference value database for the present analysis. PWV, pulse wave velocity; CVD, cardiovascular disease; BP, blood pressure.
