The combination of obesity and high salt intake are associated with blood pressure elevation among healthy Japanese adolescents.

We examined the associations of obesity and high salt intake with blood pressure (BP) in a cross-sectional sample of 1679 healthy Japanese adolescents (827 females and 852 males) aged 12-18 years (mean age: 14.9 years) who had no history of treatment for hypertension, diabetes mellitus, or renal disease. Brachial arterial BP of the subject was measured at the left arm using a digital BP monitor with an appropriate cuff size. The weight status was evaluated by body mass index (BMI), and obesity was determined according to the age- and sex-specific cut-off values for adolescents. All subjects were interviewed by dietitians using a food frequency questionnaire to obtain data on their average daily salt intake. In the study subjects, obesity and high salt intake were associated with a significantly increased BP except for diastolic BP in females. In multiple regression analyses, both BMI (z-score) and salt intake were found to be major determinants of systolic BP and diastolic BP after adjustment for potential confounders, including age, sex, and serum lipid and glucose parameters. The association between salt intake and BP values was more pronounced among individuals with obesity than among those with normal weight. These results suggest that high salt intake is associated with BP elevation in healthy adolescents, and the association may become stronger by the presence or severity of obesity.