Introduction Blood pressure is a well established cardiovascular risk factor. In addition to traditional blood pressure indexes such as SBP and DBP, estimation of central SBP (cSBP) has become available recently. The characteristics of cSBP have not been fully described. This study investigated the relationship between cSBP and known cardiovascular risk factors according to age group and comparing this with four traditional blood pressure indexes, SBP, DBP, PP and MBP.

Methods This study examined baseline cross-sectional data from 4375 healthy men and women aged 30–74 years old who participated in a community-based cohort study conducted from 2008 to 2009. Linear regression analyses were carried out on the five blood pressure indexes adjusting for sex, age, BMI, triglycerides, HDL-cholesterol, LDL-cholesterol, HbA1c, state of anti-hypertensive medication, smoking, alcohol Intake, exercise, past history of cardiovascular diseases, ABI and cardio-ankle vascular index. We analysed the following two models: including these risk factors without sex and age (model 1); including age groups (age<50/age≥50) (model 2). Subgroup analyses according to age group and sex were also performed.

Results In model 1 the R² for sBP was 0.356, and in model 2, 0.385. Incremental R² was 0.028 between the models. Subgroup analyses showed five blood pressure indexes were explained by the total variances of known cardiovascular risk factors, more so for the younger than the older age group which was more apparent for cSBP than for the other blood pressure indexes.

Conclusion Known cardiovascular risk factors are associated with cSBP. This association is greater in younger (age<50) than in older (age≥50) patients.