Study population

The study participants were members of two population-based cohorts included in the Korean Genome Epidemiology Study, an ongoing longitudinal investigation. Details of the enrollment method and study procedures are available in previous reports [21,22]. Using a 2-stage cluster sampling method, we identified 10,957 Korean male and female residents aged 40 years to 69 years for enrollment in 2 cities, Ansan and Ansung. Approximately 91% of these cohorts (9,996 participants) completed on-site health examinations between June 2001 and January 2003. The examination included BP measurement, anthropometric assessment, blood collection for biochemical and genetic assays, and a questionnairebased interview. The questionnaire covered socio-demographic information, medical history and health conditions, and lifestyle factors. Similar examinations were conducted biennially during the follow-up period.

Participants who reported the use of medications for HTN or pregnancy at baseline were excluded (n= 1,095), leaving a total of 8,901 participants who were eligible for mortality follow-up. Furthermore, 3,487 participants in a sub-study initially underwent an additional examination including ultrasonography. Approximately 80% (n= 2,780) of the sub-study participants who were < 65 years old, free of diagnosed CVD at baseline, and had completed follow-up for mortality were included in the sub-study analysis.