January 1, 1980
View Full PaperNorepinephrine in urine and plasma following provocative maneuvers in normal and hypertensive subjects.
Key Result
Volume expansion and contraction altered urinary and plasma norepinephrine in 373 subjects, with hypertensive women exhibiting greater norepinephrine values than normal women or hypertensive men.
Study Design
Type
Observational (n=373)
Structured PICO
Does the response of urinary and plasma norepinephrine to volume expansion and contraction differ between normotensive and essential hypertensive subjects?
P
Population
373 men and women, comprising 266 normotensive subjects and 107 subjects with essential hypertension.
I
Intervention
Provocative maneuvers consisting of volume expansion (2 liters of intravenous normal saline over 4 hours) and volume contraction (10 mEq sodium diet and 120 mg oral furosemide).
C
Comparator
Normotensive subjects compared to essential hypertensive subjects undergoing the same provocative maneuvers.
O
Outcome
Urinary norepinephrine (UNE) excretion rate and venous plasma norepinephrine (PNE) concentrations.surrogate
Hypertensive women exhibit altered sympathetic activity, characterized by elevated norepinephrine levels and a loss of normal physiological correlations between norepinephrine, blood pressure, and volume status.
Limitations
- Insufficient numbers of older subjects were available to exclude absolutely an age relationship among normals.
Abstract
Urinary norepinephrine (UNE) excretion rate and venous plasma norepinephrine (PNE) concentrations were studied in 266 normotensive and 107 essential hypertensive men and women under conditions of volume expansion with 2 liters of intravenous normal saline over 4 hours, and volume contraction with a 10 mEq sodium diet and 120 mg oral furosemide. The UNE excretion rate was correlated with age in normal women only. In men, and in hypertensives of both sexes, the relationship appeared to be biphasic. The PNE concentration was not correlated with age in the hypertensive subjects. Insufficient numbers of older subjects were available to exclude absolutely such a relationship among normals. The UNE and PNE were influenced by volume expansion and contraction in both normals and hypertensives; however, normals exhibited a correlation between UNE and blood pressure as well as consistent correlations between UNE and PNE, neither of which were observed in the hypertensives. Hypertensive women generally had greater UNE and PNE values than normal women or hypertensive men. Hypertensive women may have altered sympathetic activity.