Fig. 1

Flow chart for the participant selection. A total of 1304 students underwent the baseline examination in an annual medical checkup performed during the period from 2008 to 2009. At the baseline examination, 107 students were excluded because of incomplete data collection. Of the 1197 participants, three participants were excluded because they refused to provide their medical checkup data, and three participants were excluded because they had conditions that might cause secondary hypertension. The final analysis set comprised 1129 participants