OBJECTIVETo 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.

METHODSEssential 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.

RESULTSSixty-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).

CONCLUSIONSAge, 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.

Adult ; Aged ; Aldosterone ; blood ; Blood Pressure ; drug effects ; Electrolytes ; urine ; Essential Hypertension ; Female ; Humans ; Hypertension ; physiopathology ; Male ; Middle Aged ; Potassium ; urine ; Sodium Chloride, Dietary ; administration & dosage ; urine

Gitelman's syndrome is a variant of Bartter's syndrome characterized by hypocalciuria and hypomagnesemia. The administration of thiazide diuretics may induce a subnormal increase of urinary Na+ and Cl- excretion in patients with Gitelman's syndrome, consistent with the hypothesis that less Na+ and Cl- than normal is reabsorbed by the thiazide-inhibitable transporter in Gitelman's syndrome. Specific mutations of NaCl cotransporter, coupled with mutant NaCl cotransporter expression studies clearly demonstrated that many of the characteristics of individuals with Gitelman's syndrome are explained by lack of function of NaCl cotransporter. We recently diagnosed a patient with Gitelman's syndrome by performing the thiazide and furosemide tests, and it is suggested that the clearance studies by diuretic administration may be of diagnostic help in Gitelman's syndrome.
Adolescent ; Bartter Syndrome/*diagnosis/metabolism/physiopathology ; *Benzothiadiazines ; Chlorides/blood/urine ; Diuretics/diagnostic use ; Electrolytes/blood/urine ; Female ; Furosemide/diagnostic use ; Humans ; Kidney/*physiopathology ; Kidney Function Tests ; Sodium/blood/urine ; Sodium Chloride Symporter Inhibitors/*diagnostic use ; Sodium Chloride Symporters ; Symporters/metabolism ; Syndrome