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In patients with severe hypertension, chronic heart failure or a history of stroke, the lower limit of autoregulation of cerebral blood flow (CBF) is shifted to higher levels of blood pressure (BP) than those observed in healthy subjects. The aim of pharmacotherapy for hypertensive patients with an impaired autoregulation of CBF should be to reduce BP while preserving an appropriate CBF. In the present study, 16 hypertensive patients who had had an episode of stroke more than 4 weeks previously were administered the angiotensin II (AT1) receptor antagonist losartan at daily doses of 25-100?mg for 4 weeks. Systolic and diastolic blood pressures were recorded for 24?h using an ambulatory BP monitoring system. CBF in both hemispheres of the cerebrum and cerebellum was quantified using single photon emission tomography with N-isopropyl-p-[123I]iodoamphetamine. At baseline, CBF was 29.7±6.7?ml/min/100?g in the cerebrum and 31.5±7.5?ml/min/100?g in the cerebellum. At the end of treatment, BP was lower, while CBF increased by 7.7%in the cerebrum, and remained at the baseline level in the cerebellum. Thus, CBF was preserved despite the reduction in BP. We consider the use of losartan is advantageous for hypertensive patients with a history of stroke in whom autoregulation of CBF is potentially impaired.Journal of Human Hypertension (2004) 18, 693-699. doi:10.1038/sj.jhh.1001735 Published online 6 May 2004 [ABSTRACT FROM AUTHOR]

The spot urinary sodium-to-potassium (Na/K) ratio is a simple measure of salt loading and has been shown to be associated with elevated blood pressure (BP) in middle-aged and older adults. This study aimed to evaluate the association between the spot urinary Na/K ratio and BP in 457 healthy adolescents aged 12-15 years in a school-based setting. The mean urinary Na/K ratio was 4.99 ± 2.76, and no significant difference was found between the boys and girls. When the participants were stratified based on urinary Na/K ratio quartile, age- and sex-adjusted systolic and diastolic BP gradually increased as Na/K ratio increased (systolic BP: 106.1, 106.9, 108.2, and 111.5 mmHg, P trend  < 0.001; diastolic BP: 62.0, 62.4, 63.1, 64.3 mmHg, P trend  = 0.022). The systolic and diastolic BP were more closely associated with urinary Na/K ratio than with Na and K levels, as well as estimated daily salt intake. In the multiple regression analysis, the urinary Na/K ratio was significantly associated with systolic BP (β = 0.144, P < 0.001) and diastolic BP (β = 0.114, P = 0.015) independent of potential confounding factors. An additional subgroup analysis revealed that the BP of the group with both high salt intake (≥8.5 g/day) and high Na/K ratio (≥6.60) was significantly higher than that of the group with high salt intake alone (systolic BP, 115.0 vs. 109.1 mmHg, P < 0.001; diastolic BP, 66.0 vs. 62.5 mmHg, P = 0.017). These results suggest that the urinary Na/K ratio is associated with BP levels in healthy adolescents and may be useful for assessing salt loading and its effects on BP elevation., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

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.