Objective: To explore the influence factors of salt-sensitive hypertension and to observe changes of blood pressures and urinary sodium and potassium excretion in response to acute oral saline loading among essential hypertensive patients in China.
Methods: Essential hypertensive patients from Beijing Jinzhan second community were included in this study. Salt-sensitivity was determined via the improved Sullivan's acute oral saline loading and furosemide volume-depletion tests. Binary logistic regression analysis was applied to explore influence factors of salt-sensitive hypertension. Acute oral saline loading induced changes on blood pressures and urinary sodium and potassium excretion were observed.
Results: Sixty-three salt-sensitive hypertensive patients were classified out of a total of 342(18.4%) essential hypertensive patients. Salt-sensitive patients were elder than the non-salt-sensitive patients (P < 0.05) . Binary logistic regression analysis showed that age (OR = 1.744, 95%CI:0.922-3.300, P > 0.05) , gender (OR = 0.728, 95%CI:0.374-1.415, P > 0.05) , total cholesterol level (OR = 1.168, 95%CI:0.882-1.547, P > 0.05) and 24-hour urinary sodium (OR = 0.998, 95%CI:0.995-1.002, P > 0.05) were not influencing factors of salt-sensitivity among essential hypertensive patients. Bivariate general linear models for repeated measures showed that there were significant statistical differences on blood pressures and urinary electrolytes concentrations between the beginning of trials, 2 hours after acute saline loading and 2 hours after furosemide volume-depletion(all P < 0.01). There was a greater blood pressures change in salt-sensitive patients than in non-salt-sensitive patients(all P < 0.01) while urinary electrolytes concentrations change was similar between two groups(all P > 0.05).
Conclusions: Age, gender, total cholesterol level and 24-hour urinary sodium are not influencing factors of salt-sensitivity among essential hypertensive patients in this study. Impaired pressure natriuresis during acute oral saline loading and furosemide volume-depletion tests is presented in salt-sensitive essential hypertensive patients.